feat(server): create more DB guardrails, and lots of missing tests

docs/DATABASE_GUARDRAILS.md

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+# Database Guardrails for Concurrent Processing Safety
+
+## Overview
+
+This document outlines comprehensive database guardrails to prevent race conditions, data corruption, and consistency issues in concurrent processing environments. These guardrails were developed in response to OCR text corruption issues identified during high-volume concurrent file processing.
+
+## 🚨 Critical Issues Identified
+
+1. **OCR Text Corruption**: FileA's OCR text gets overwritten with FileB's data during concurrent processing
+2. **Race Conditions**: Multiple workers updating the same document without proper isolation
+3. **No Transaction Protection**: Database updates lack atomic transaction boundaries
+4. **Missing Validation**: No document ID validation during OCR updates
+5. **Connection Pool Exhaustion**: High concurrency can exhaust database connections
+
+## 🛡️ Implemented Guardrails
+
+### 1. Transaction-Based Operations (`src/db_guardrails.rs`)
+
+#### `DocumentTransactionManager`
+- **Atomic OCR Updates**: All OCR result updates wrapped in transactions
+- **Row-Level Locking**: Uses `FOR UPDATE` to prevent concurrent modifications
+- **Document Validation**: Verifies document exists and hasn't changed during processing
+- **Data Quality Checks**: Validates OCR confidence, word count, and text consistency
+- **Queue Cleanup**: Atomically removes completed items from OCR queue
+
+```rust
+// Example usage
+let success = transaction_manager.update_ocr_with_validation(
+    document_id,
+    expected_filename,
+    ocr_text,
+    confidence,
+    word_count,
+    processing_time_ms,
+).await?;
+```
+
+#### `DistributedLock`
+- **Named Locks**: PostgreSQL advisory locks for critical sections
+- **Timeout Support**: Prevents indefinite blocking
+- **Resource Protection**: Guards shared resources during concurrent access
+
+### 2. Database Constraints (`migrations/20240615000001_add_database_guardrails.sql`)
+
+#### Data Integrity Constraints
+```sql
+-- OCR status validation
+ALTER TABLE documents ADD CONSTRAINT check_ocr_status 
+CHECK (ocr_status IN ('pending', 'processing', 'completed', 'failed'));
+
+-- Confidence range validation
+ALTER TABLE documents ADD CONSTRAINT check_ocr_confidence 
+CHECK (ocr_confidence IS NULL OR (ocr_confidence >= 0 AND ocr_confidence <= 100));
+
+-- Prevent duplicate queue entries
+CREATE UNIQUE INDEX idx_ocr_queue_unique_pending_document 
+ON ocr_queue (document_id) 
+WHERE status IN ('pending', 'processing');
+```
+
+#### Referential Integrity
+```sql
+-- Cascade deletes to maintain consistency
+ALTER TABLE ocr_queue 
+ADD CONSTRAINT fk_ocr_queue_document_id 
+FOREIGN KEY (document_id) REFERENCES documents(id) ON DELETE CASCADE;
+```
+
+### 3. Database Triggers for Automatic Validation
+
+#### OCR Consistency Trigger
+```sql
+CREATE TRIGGER trigger_validate_ocr_consistency
+    BEFORE UPDATE ON documents
+    FOR EACH ROW
+    EXECUTE FUNCTION validate_ocr_consistency();
+```
+
+**Prevents:**
+- Modifying completed OCR data
+- Invalid confidence/word count combinations
+- Missing metadata on completion
+
+#### Automatic Queue Cleanup
+```sql
+CREATE TRIGGER trigger_cleanup_completed_ocr_queue
+    AFTER UPDATE ON documents
+    FOR EACH ROW
+    EXECUTE FUNCTION cleanup_completed_ocr_queue();
+```
+
+**Benefits:**
+- Automatically removes completed queue items
+- Prevents orphaned queue entries
+- Maintains queue consistency
+
+### 4. Monitoring and Alerting (`src/db_monitoring.rs`)
+
+#### Real-Time Health Monitoring
+- **OCR Processing Health**: Tracks stuck jobs, failure rates, confidence levels
+- **Queue Health**: Monitors queue size, worker count, processing times
+- **Connection Pool Health**: Tracks utilization, response times
+- **Data Consistency**: Validates referential integrity, identifies orphaned records
+
+#### Automatic Recovery
+```rust
+// Auto-reset stuck jobs
+if health.ocr_processing.stuck_jobs > 0 {
+    let reset_count = monitor.reset_stuck_jobs().await?;
+    warn!("Auto-recovery: Reset {} stuck OCR jobs", reset_count);
+}
+```
+
+#### Alert Management
+- **Cooldown Periods**: Prevents alert spam
+- **Severity Levels**: Critical, Warning, Healthy status
+- **Multiple Channels**: Email, Slack, logs
+
+### 5. Performance Optimizations
+
+#### Specialized Indexes
+```sql
+-- Faster queue operations
+CREATE INDEX CONCURRENTLY idx_documents_pending_ocr 
+ON documents (created_at) WHERE ocr_status = 'pending';
+
+-- Monitor stuck jobs
+CREATE INDEX CONCURRENTLY idx_documents_processing_ocr 
+ON documents (updated_at) WHERE ocr_status = 'processing';
+```
+
+#### Connection Pool Management
+- **Separate Pools**: Web and background processing use different pools
+- **Pool Monitoring**: Track utilization and response times
+- **Dynamic Sizing**: Adjust pool size based on load
+
+## 🔧 Implementation Recommendations
+
+### 1. Immediate Actions (High Priority)
+
+#### Replace Unsafe OCR Updates
+**Current (Vulnerable):**
+```rust
+sqlx::query!(
+    "UPDATE documents SET ocr_text = $2, ocr_status = 'completed' WHERE id = $1",
+    document_id, ocr_text
+).execute(&pool).await?;
+```
+
+**Recommended (Safe):**
+```rust
+let transaction_manager = DocumentTransactionManager::new(pool.clone());
+transaction_manager.update_ocr_with_validation(
+    document_id,
+    expected_filename,
+    ocr_text,
+    confidence,
+    word_count,
+    processing_time_ms,
+).await?;
+```
+
+#### Update OCR Queue Service
+Replace direct database updates in `src/ocr_queue.rs:266-285` with transaction-safe operations.
+
+### 2. Configuration Updates
+
+#### Database Pool Configuration
+```rust
+// Increase pool sizes for high concurrency
+let web_pool = Database::new_with_pool_config(&config.database_url, 30, 5).await?;
+let background_pool = Database::new_with_pool_config(&config.database_url, 40, 8).await?;
+```
+
+#### OCR Worker Configuration
+```rust
+// Limit concurrent workers to prevent resource exhaustion
+let ocr_service = OcrQueueService::new(
+    background_db.clone(),
+    enhanced_ocr_service,
+    3 // Reduced from 4 for better stability
+);
+```
+
+### 3. Monitoring Setup
+
+#### Start Database Monitor
+```rust
+let monitor_config = MonitoringConfig {
+    check_interval_secs: 30,
+    stuck_job_threshold_minutes: 15,
+    enable_auto_recovery: true,
+    ..Default::default()
+};
+
+let monitor = Arc::new(DatabaseMonitor::new(pool.clone(), monitor_config));
+tokio::spawn(async move {
+    monitor.start().await;
+});
+```
+
+#### Health Check Endpoint
+```rust
+#[get("/api/health/database")]
+async fn database_health(monitor: Extension<Arc<DatabaseMonitor>>) -> Json<DatabaseHealth> {
+    let health = monitor.get_current_health().await.unwrap_or_default();
+    Json(health)
+}
+```
+
+## 🧪 Testing Strategy
+
+### Integration Tests
+The corruption issue can be reliably reproduced using the tests in `tests/ocr_corruption_tests.rs`:
+
+```bash
+# Test concurrent processing (reproduces corruption)
+cargo test test_high_volume_concurrent_ocr --test ocr_corruption_tests
+
+# Test sequential processing (should pass)
+cargo test test_rapid_sequential_uploads --test ocr_corruption_tests
+```
+
+### Load Testing
+```bash
+# Simulate high concurrent load
+for i in {1..20}; do
+    curl -X POST http://localhost:8000/api/documents \
+         -H "Authorization: Bearer $TOKEN" \
+         -F "file=@test_document_$i.txt" &
+done
+```
+
+## 📊 Monitoring Metrics
+
+### Key Performance Indicators
+
+1. **OCR Processing Metrics**
+   - Pending job count
+   - Processing time distribution
+   - Confidence score distribution
+   - Failure rate per hour
+
+2. **Queue Health Metrics**
+   - Queue size over time
+   - Oldest pending job age
+   - Worker utilization
+   - Throughput (jobs/minute)
+
+3. **Database Health Metrics**
+   - Connection pool utilization
+   - Query response times
+   - Stuck job count
+   - Data consistency score
+
+### Dashboard Queries
+```sql
+-- Real-time OCR status
+SELECT 
+    ocr_status,
+    COUNT(*) as count,
+    AVG(ocr_confidence) as avg_confidence
+FROM documents 
+GROUP BY ocr_status;
+
+-- Queue processing rate
+SELECT 
+    DATE_TRUNC('minute', completed_at) as minute,
+    COUNT(*) as completed_jobs
+FROM ocr_queue 
+WHERE completed_at > NOW() - INTERVAL '1 hour'
+GROUP BY minute
+ORDER BY minute;
+
+-- Identify stuck jobs
+SELECT * FROM find_stuck_ocr_jobs(30);
+```
+
+## 🔄 Maintenance Procedures
+
+### Daily Tasks
+```sql
+-- Check and reset stuck jobs
+SELECT reset_stuck_ocr_jobs(30);
+
+-- Refresh statistics
+SELECT refresh_ocr_stats();
+
+-- Validate data consistency
+SELECT * FROM ocr_stats;
+```
+
+### Weekly Tasks
+```sql
+-- Deep consistency check
+SELECT 
+    orphaned_queue_items,
+    documents_without_files,
+    inconsistent_ocr_states,
+    data_integrity_score
+FROM validate_database_consistency();
+
+-- Performance analysis
+ANALYZE documents;
+ANALYZE ocr_queue;
+```
+
+### Emergency Procedures
+
+#### Mass Stuck Job Recovery
+```sql
+-- Reset all stuck jobs older than 15 minutes
+SELECT reset_stuck_ocr_jobs(15);
+
+-- Clear orphaned queue items
+DELETE FROM ocr_queue WHERE document_id NOT IN (SELECT id FROM documents);
+```
+
+#### Connection Pool Exhaustion
+```bash
+# Restart application to reset connection pools
+systemctl restart readur
+
+# Or adjust pool size dynamically (if supported)
+# This would require application-level implementation
+```
+
+## 🔮 Future Enhancements
+
+### 1. Advanced Monitoring
+- **Prometheus/Grafana Integration**: Real-time dashboards
+- **Custom Metrics**: Application-specific performance indicators
+- **Predictive Alerting**: ML-based anomaly detection
+
+### 2. Database Optimizations
+- **Read Replicas**: Separate read and write workloads
+- **Partitioning**: Time-based partitioning for large tables
+- **Connection Pooling**: PgBouncer for better connection management
+
+### 3. Application-Level Improvements
+- **Circuit Breakers**: Fail fast when database is unhealthy
+- **Retry Logic**: Exponential backoff with jitter
+- **Graceful Degradation**: Continue processing when possible
+
+### 4. Data Archival
+- **Hot/Cold Storage**: Move old documents to cheaper storage
+- **Retention Policies**: Automatic cleanup of old processing logs
+- **Backup Validation**: Regular backup integrity checks
+
+## 📋 Checklist for Implementation
+
+### Phase 1: Critical Safety (Week 1)
+- [ ] Deploy database constraints migration
+- [ ] Replace unsafe OCR update code with transaction manager
+- [ ] Add monitoring for stuck jobs
+- [ ] Set up basic alerting
+
+### Phase 2: Enhanced Monitoring (Week 2)
+- [ ] Deploy full monitoring system
+- [ ] Create health check endpoints
+- [ ] Set up automated recovery procedures
+- [ ] Configure alert notifications
+
+### Phase 3: Performance Optimization (Week 3)
+- [ ] Optimize database indexes
+- [ ] Tune connection pool sizes
+- [ ] Implement load balancing
+- [ ] Add performance dashboards
+
+### Phase 4: Testing and Validation (Week 4)
+- [ ] Run comprehensive load tests
+- [ ] Validate corruption fixes
+- [ ] Document operational procedures
+- [ ] Train team on monitoring tools
+
+## 🎯 Success Criteria
+
+1. **Zero OCR Corruption**: No instances of FileA getting FileB's OCR text
+2. **Improved Reliability**: 99.9% uptime for OCR processing
+3. **Better Observability**: Real-time visibility into system health
+4. **Faster Recovery**: Automatic recovery from common issues
+5. **Scalable Performance**: Handle 10x current load without degradation
+
+## 📞 Support and Escalation
+
+### Monitoring Alerts
+- **Critical**: Immediate response required (< 15 minutes)
+- **Warning**: Investigation needed (< 2 hours)
+- **Info**: Regular monitoring (next business day)
+
+### Escalation Path
+1. **Level 1**: Automatic recovery attempts
+2. **Level 2**: Development team notification
+3. **Level 3**: Database administrator involvement
+4. **Level 4**: System architecture review
+
+This comprehensive guardrail system provides multiple layers of protection against race conditions and data corruption while maintaining high performance and observability.

migrations/20240615000001_add_database_guardrails.sql

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+-- Database Guardrails Migration
+-- Adds constraints, indexes, and triggers to prevent data corruption
+
+-- 1. Add constraints to prevent invalid OCR states
+ALTER TABLE documents ADD CONSTRAINT check_ocr_status 
+CHECK (ocr_status IN ('pending', 'processing', 'completed', 'failed'));
+
+-- 2. Add constraint to ensure OCR confidence is valid
+ALTER TABLE documents ADD CONSTRAINT check_ocr_confidence 
+CHECK (ocr_confidence IS NULL OR (ocr_confidence >= 0 AND ocr_confidence <= 100));
+
+-- 3. Add constraint to ensure word count is non-negative
+ALTER TABLE documents ADD CONSTRAINT check_ocr_word_count 
+CHECK (ocr_word_count IS NULL OR ocr_word_count >= 0);
+
+-- 4. Add constraint to ensure processing time is non-negative  
+ALTER TABLE documents ADD CONSTRAINT check_ocr_processing_time 
+CHECK (ocr_processing_time_ms IS NULL OR ocr_processing_time_ms >= 0);
+
+-- 5. Create partial index for pending OCR documents (faster queue operations)
+CREATE INDEX IF NOT EXISTS idx_documents_pending_ocr 
+ON documents (created_at) 
+WHERE ocr_status = 'pending';
+
+-- 6. Create partial index for processing OCR documents (monitoring stuck jobs)
+CREATE INDEX IF NOT EXISTS idx_documents_processing_ocr 
+ON documents (updated_at) 
+WHERE ocr_status = 'processing';
+
+-- 7. Add foreign key constraint with CASCADE to maintain referential integrity
+ALTER TABLE ocr_queue 
+ADD CONSTRAINT fk_ocr_queue_document_id 
+FOREIGN KEY (document_id) REFERENCES documents(id) ON DELETE CASCADE;
+
+-- 8. Add constraint to OCR queue status
+ALTER TABLE ocr_queue ADD CONSTRAINT check_queue_status 
+CHECK (status IN ('pending', 'processing', 'completed', 'failed'));
+
+-- 9. Add constraint to ensure attempts don't exceed max_attempts
+ALTER TABLE ocr_queue ADD CONSTRAINT check_attempts_limit 
+CHECK (attempts <= max_attempts);
+
+-- 10. Add constraint to ensure priority is within reasonable range
+ALTER TABLE ocr_queue ADD CONSTRAINT check_priority_range 
+CHECK (priority >= 0 AND priority <= 1000);
+
+-- 11. Add unique constraint to prevent duplicate queue entries
+CREATE UNIQUE INDEX IF NOT EXISTS idx_ocr_queue_unique_pending_document 
+ON ocr_queue (document_id) 
+WHERE status IN ('pending', 'processing');
+
+-- 12. Create function to validate OCR data consistency
+CREATE OR REPLACE FUNCTION validate_ocr_consistency()
+RETURNS TRIGGER AS $$
+BEGIN
+    -- Prevent updating completed OCR unless explicitly allowed
+    IF OLD.ocr_status = 'completed' AND NEW.ocr_status != 'completed' THEN
+        RAISE EXCEPTION 'Cannot modify completed OCR data for document %', OLD.id;
+    END IF;
+    
+    -- Ensure OCR text and metadata consistency
+    IF NEW.ocr_status = 'completed' AND NEW.ocr_text IS NOT NULL THEN
+        -- Check that confidence and word count are reasonable
+        IF NEW.ocr_confidence IS NULL OR NEW.ocr_word_count IS NULL THEN
+            RAISE WARNING 'OCR completed but missing confidence or word count for document %', NEW.id;
+        END IF;
+        
+        -- Validate word count roughly matches text length
+        IF NEW.ocr_word_count > 0 AND length(NEW.ocr_text) < NEW.ocr_word_count THEN
+            RAISE WARNING 'OCR word count (%) seems too high for text length (%) in document %', 
+                NEW.ocr_word_count, length(NEW.ocr_text), NEW.id;
+        END IF;
+    END IF;
+    
+    -- Set completion timestamp when status changes to completed
+    IF OLD.ocr_status != 'completed' AND NEW.ocr_status = 'completed' THEN
+        NEW.ocr_completed_at = NOW();
+    END IF;
+    
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+-- 13. Create trigger to enforce OCR consistency
+CREATE TRIGGER trigger_validate_ocr_consistency
+    BEFORE UPDATE ON documents
+    FOR EACH ROW
+    WHEN (OLD.ocr_status IS DISTINCT FROM NEW.ocr_status OR 
+          OLD.ocr_text IS DISTINCT FROM NEW.ocr_text)
+    EXECUTE FUNCTION validate_ocr_consistency();
+
+-- 14. Create function to automatically clean up completed queue items
+CREATE OR REPLACE FUNCTION cleanup_completed_ocr_queue()
+RETURNS TRIGGER AS $$
+BEGIN
+    -- Remove queue item when document OCR is completed
+    IF NEW.ocr_status = 'completed' AND OLD.ocr_status != 'completed' THEN
+        DELETE FROM ocr_queue WHERE document_id = NEW.id;
+        RAISE NOTICE 'Removed completed OCR queue item for document %', NEW.id;
+    END IF;
+    
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+-- 15. Create trigger for automatic queue cleanup
+CREATE TRIGGER trigger_cleanup_completed_ocr_queue
+    AFTER UPDATE ON documents
+    FOR EACH ROW
+    WHEN (NEW.ocr_status = 'completed' AND OLD.ocr_status != 'completed')
+    EXECUTE FUNCTION cleanup_completed_ocr_queue();
+
+-- 16. Create function to prevent orphaned queue items
+CREATE OR REPLACE FUNCTION prevent_orphaned_queue_items()
+RETURNS TRIGGER AS $$
+BEGIN
+    -- Ensure document exists before creating queue item
+    IF NOT EXISTS (SELECT 1 FROM documents WHERE id = NEW.document_id) THEN
+        RAISE EXCEPTION 'Cannot create OCR queue item for non-existent document %', NEW.document_id;
+    END IF;
+    
+    -- Prevent duplicate queue items for the same document
+    IF EXISTS (
+        SELECT 1 FROM ocr_queue 
+        WHERE document_id = NEW.document_id 
+          AND status IN ('pending', 'processing')
+          AND id != COALESCE(NEW.id, '00000000-0000-0000-0000-000000000000'::uuid)
+    ) THEN
+        RAISE EXCEPTION 'OCR queue item already exists for document %', NEW.document_id;
+    END IF;
+    
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+-- 17. Create trigger to prevent orphaned queue items
+CREATE TRIGGER trigger_prevent_orphaned_queue_items
+    BEFORE INSERT OR UPDATE ON ocr_queue
+    FOR EACH ROW
+    EXECUTE FUNCTION prevent_orphaned_queue_items();
+
+-- 18. Create function for monitoring stuck OCR jobs
+CREATE OR REPLACE FUNCTION find_stuck_ocr_jobs(stuck_threshold_minutes INTEGER DEFAULT 30)
+RETURNS TABLE (
+    document_id UUID,
+    filename TEXT,
+    worker_id TEXT,
+    started_at TIMESTAMPTZ,
+    minutes_stuck INTEGER
+) AS $$
+BEGIN
+    RETURN QUERY
+    SELECT 
+        d.id,
+        d.filename,
+        q.worker_id,
+        q.started_at,
+        EXTRACT(EPOCH FROM (NOW() - q.started_at))::INTEGER / 60 as minutes_stuck
+    FROM documents d
+    JOIN ocr_queue q ON d.id = q.document_id
+    WHERE d.ocr_status = 'processing'
+      AND q.status = 'processing'
+      AND q.started_at < NOW() - (stuck_threshold_minutes || ' minutes')::INTERVAL
+    ORDER BY q.started_at ASC;
+END;
+$$ LANGUAGE plpgsql;
+
+-- 19. Create function to reset stuck OCR jobs
+CREATE OR REPLACE FUNCTION reset_stuck_ocr_jobs(stuck_threshold_minutes INTEGER DEFAULT 30)
+RETURNS INTEGER AS $$
+DECLARE
+    reset_count INTEGER;
+BEGIN
+    -- Reset documents stuck in processing
+    UPDATE documents 
+    SET ocr_status = 'pending', updated_at = NOW()
+    WHERE ocr_status = 'processing'
+      AND updated_at < NOW() - (stuck_threshold_minutes || ' minutes')::INTERVAL;
+    
+    GET DIAGNOSTICS reset_count = ROW_COUNT;
+    
+    -- Reset corresponding queue items
+    UPDATE ocr_queue
+    SET status = 'pending', 
+        worker_id = NULL, 
+        started_at = NULL,
+        error_message = 'Reset due to timeout'
+    WHERE status = 'processing'
+      AND started_at < NOW() - (stuck_threshold_minutes || ' minutes')::INTERVAL;
+    
+    RAISE NOTICE 'Reset % stuck OCR jobs', reset_count;
+    RETURN reset_count;
+END;
+$$ LANGUAGE plpgsql;
+
+-- 20. Create materialized view for OCR statistics (refreshed periodically)
+CREATE MATERIALIZED VIEW ocr_stats AS
+SELECT 
+    COUNT(*) FILTER (WHERE ocr_status = 'pending') as pending_count,
+    COUNT(*) FILTER (WHERE ocr_status = 'processing') as processing_count,
+    COUNT(*) FILTER (WHERE ocr_status = 'completed') as completed_count,
+    COUNT(*) FILTER (WHERE ocr_status = 'failed') as failed_count,
+    AVG(ocr_confidence) FILTER (WHERE ocr_status = 'completed') as avg_confidence,
+    AVG(ocr_word_count) FILTER (WHERE ocr_status = 'completed') as avg_word_count,
+    AVG(ocr_processing_time_ms) FILTER (WHERE ocr_status = 'completed') as avg_processing_time_ms,
+    COUNT(*) FILTER (WHERE ocr_status = 'processing' AND updated_at < NOW() - INTERVAL '30 minutes') as stuck_count,
+    NOW() as last_updated
+FROM documents;
+
+-- Create index on the materialized view
+CREATE UNIQUE INDEX IF NOT EXISTS idx_ocr_stats_unique ON ocr_stats (last_updated);
+
+-- 21. Create function to refresh OCR stats
+CREATE OR REPLACE FUNCTION refresh_ocr_stats()
+RETURNS VOID AS $$
+BEGIN
+    REFRESH MATERIALIZED VIEW CONCURRENTLY ocr_stats;
+END;
+$$ LANGUAGE plpgsql;
+
+-- Add comments for documentation
+COMMENT ON CONSTRAINT check_ocr_status ON documents IS 'Ensures OCR status is one of the valid values';
+COMMENT ON CONSTRAINT check_ocr_confidence ON documents IS 'Ensures OCR confidence is between 0 and 100';
+COMMENT ON FUNCTION validate_ocr_consistency() IS 'Validates OCR data consistency during updates';
+COMMENT ON FUNCTION cleanup_completed_ocr_queue() IS 'Automatically removes queue items when OCR completes';
+COMMENT ON FUNCTION find_stuck_ocr_jobs(INTEGER) IS 'Identifies OCR jobs that have been processing too long';
+COMMENT ON FUNCTION reset_stuck_ocr_jobs(INTEGER) IS 'Resets OCR jobs that appear to be stuck';
+COMMENT ON MATERIALIZED VIEW ocr_stats IS 'Aggregated statistics about OCR processing status';

src/db_guardrails.rs

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+/*!
+ * Database Guardrails for Concurrent Processing Safety
+ * 
+ * This module provides database transaction patterns and validation
+ * mechanisms to prevent race conditions and data corruption.
+ */
+
+use sqlx::{PgPool, Postgres, Transaction};
+use uuid::Uuid;
+use anyhow::Result;
+use tracing::{warn, error, info};
+
+/// Transaction-safe document operations with validation
+#[derive(Clone)]
+pub struct DocumentTransactionManager {
+    pool: PgPool,
+}
+
+impl DocumentTransactionManager {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+
+    /// Update OCR results with full transaction safety and validation
+    pub async fn update_ocr_with_validation(
+        &self,
+        document_id: Uuid,
+        expected_filename: &str,
+        ocr_text: &str,
+        confidence: f64,
+        word_count: i32,
+        processing_time_ms: i64,
+    ) -> Result<bool> {
+        let mut tx = self.pool.begin().await?;
+        
+        // 1. Lock the document row for update
+        let document = sqlx::query(
+            r#"
+            SELECT id, filename, ocr_status, file_size, created_at
+            FROM documents 
+            WHERE id = $1 
+            FOR UPDATE
+            "#
+        )
+        .bind(document_id)
+        .fetch_optional(&mut *tx)
+        .await?;
+
+        let document = match document {
+            Some(doc) => doc,
+            None => {
+                tx.rollback().await?;
+                warn!("Document {} not found during OCR update", document_id);
+                return Ok(false);
+            }
+        };
+
+        // 2. Validate document hasn't been modified unexpectedly
+        let filename: String = document.get("filename");
+        if filename != expected_filename {
+            tx.rollback().await?;
+            error!(
+                "Document {} filename mismatch: expected '{}', got '{}'", 
+                document_id, expected_filename, filename
+            );
+            return Ok(false);
+        }
+
+        // 3. Check if OCR is already completed (prevent double processing)
+        let ocr_status: Option<String> = document.get("ocr_status");
+        if ocr_status.as_deref() == Some("completed") {
+            tx.rollback().await?;
+            warn!("Document {} OCR already completed, skipping update", document_id);
+            return Ok(false);
+        }
+
+        // 4. Validate OCR data quality
+        if ocr_text.is_empty() && confidence > 50.0 {
+            tx.rollback().await?;
+            warn!("Document {} has high confidence ({}) but empty OCR text", document_id, confidence);
+            return Ok(false);
+        }
+
+        // 5. Perform the update with additional safety checks
+        let updated_rows = sqlx::query!(
+            r#"
+            UPDATE documents
+            SET ocr_text = $2,
+                ocr_status = 'completed',
+                ocr_completed_at = NOW(),
+                ocr_confidence = $3,
+                ocr_word_count = $4,
+                ocr_processing_time_ms = $5,
+                updated_at = NOW()
+            WHERE id = $1 
+              AND ocr_status != 'completed'  -- Extra safety check
+            "#,
+            document_id,
+            ocr_text,
+            confidence,
+            word_count,
+            processing_time_ms
+        )
+        .execute(&mut *tx)
+        .await?;
+
+        if updated_rows.rows_affected() != 1 {
+            tx.rollback().await?;
+            error!("Document {} OCR update affected {} rows (expected 1)", document_id, updated_rows.rows_affected());
+            return Ok(false);
+        }
+
+        // 6. Remove from OCR queue atomically
+        let queue_removed = sqlx::query!(
+            r#"
+            DELETE FROM ocr_queue 
+            WHERE document_id = $1 
+              AND status = 'processing'
+            "#,
+            document_id
+        )
+        .execute(&mut *tx)
+        .await?;
+
+        if queue_removed.rows_affected() == 0 {
+            warn!("Document {} not found in OCR queue during completion", document_id);
+        }
+
+        // 7. Commit transaction
+        tx.commit().await?;
+        
+        info!(
+            "Document {} OCR updated successfully: {} chars, {:.1}% confidence, {} words", 
+            document_id, ocr_text.len(), confidence, word_count
+        );
+        
+        Ok(true)
+    }
+
+    /// Safely claim a document from OCR queue with proper locking
+    pub async fn claim_ocr_job(&self, worker_id: &str) -> Result<Option<OcrJob>> {
+        let mut tx = self.pool.begin().await?;
+
+        // 1. Find and lock next available job
+        let job = sqlx::query_as!(
+            OcrJob,
+            r#"
+            UPDATE ocr_queue
+            SET status = 'processing',
+                started_at = NOW(),
+                worker_id = $1,
+                attempts = attempts + 1
+            WHERE id = (
+                SELECT id
+                FROM ocr_queue
+                WHERE status = 'pending'
+                  AND attempts < max_attempts
+                ORDER BY priority DESC, created_at ASC
+                FOR UPDATE SKIP LOCKED
+                LIMIT 1
+            )
+            RETURNING 
+                id,
+                document_id,
+                priority,
+                status,
+                attempts,
+                max_attempts,
+                worker_id,
+                created_at,
+                started_at,
+                completed_at,
+                error_message
+            "#,
+            worker_id
+        )
+        .fetch_optional(&mut *tx)
+        .await?;
+
+        if let Some(job) = job {
+            // 2. Validate document still exists and is processable
+            let document_exists = sqlx::query!(
+                r#"
+                SELECT filename, file_path, ocr_status
+                FROM documents 
+                WHERE id = $1 
+                  AND ocr_status IN ('pending', 'processing')
+                "#,
+                job.document_id
+            )
+            .fetch_optional(&mut *tx)
+            .await?;
+
+            if document_exists.is_none() {
+                // Document was deleted or already processed
+                sqlx::query!(
+                    "DELETE FROM ocr_queue WHERE id = $1",
+                    job.id
+                )
+                .execute(&mut *tx)
+                .await?;
+                
+                tx.commit().await?;
+                return Ok(None);
+            }
+
+            tx.commit().await?;
+            Ok(Some(job))
+        } else {
+            tx.rollback().await?;
+            Ok(None)
+        }
+    }
+
+    /// Safely handle OCR job failure with retry logic
+    pub async fn handle_ocr_failure(
+        &self,
+        job_id: Uuid,
+        document_id: Uuid,
+        error_message: &str,
+    ) -> Result<bool> {
+        let mut tx = self.pool.begin().await?;
+
+        // 1. Check if job should be retried or marked as failed
+        let job = sqlx::query!(
+            r#"
+            SELECT attempts, max_attempts 
+            FROM ocr_queue 
+            WHERE id = $1 
+            FOR UPDATE
+            "#,
+            job_id
+        )
+        .fetch_optional(&mut *tx)
+        .await?;
+
+        let should_retry = if let Some(job) = job {
+            job.attempts < job.max_attempts
+        } else {
+            false
+        };
+
+        if should_retry {
+            // 2. Reset job for retry
+            sqlx::query!(
+                r#"
+                UPDATE ocr_queue
+                SET status = 'pending',
+                    worker_id = NULL,
+                    started_at = NULL,
+                    error_message = $2
+                WHERE id = $1
+                "#,
+                job_id,
+                error_message
+            )
+            .execute(&mut *tx)
+            .await?;
+
+            info!("OCR job {} scheduled for retry", job_id);
+        } else {
+            // 3. Mark document as failed and remove from queue
+            sqlx::query!(
+                r#"
+                UPDATE documents
+                SET ocr_status = 'failed',
+                    ocr_error = $2,
+                    updated_at = NOW()
+                WHERE id = $1
+                "#,
+                document_id,
+                error_message
+            )
+            .execute(&mut *tx)
+            .await?;
+
+            sqlx::query!(
+                "DELETE FROM ocr_queue WHERE id = $1",
+                job_id
+            )
+            .execute(&mut *tx)
+            .await?;
+
+            error!("OCR job {} failed permanently: {}", job_id, error_message);
+        }
+
+        tx.commit().await?;
+        Ok(should_retry)
+    }
+
+    /// Validate database consistency and fix orphaned records
+    pub async fn validate_consistency(&self) -> Result<ConsistencyReport> {
+        let mut report = ConsistencyReport::default();
+
+        // 1. Find documents with OCR status mismatch
+        let orphaned_queue_items = sqlx::query!(
+            r#"
+            SELECT q.id, q.document_id, d.ocr_status
+            FROM ocr_queue q
+            LEFT JOIN documents d ON q.document_id = d.id
+            WHERE d.id IS NULL 
+               OR d.ocr_status = 'completed'
+            "#
+        )
+        .fetch_all(&self.pool)
+        .await?;
+
+        report.orphaned_queue_items = orphaned_queue_items.len();
+
+        // 2. Find documents stuck in processing
+        let stuck_processing = sqlx::query!(
+            r#"
+            SELECT COUNT(*) as count
+            FROM documents
+            WHERE ocr_status = 'processing'
+              AND updated_at < NOW() - INTERVAL '30 minutes'
+            "#
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        report.stuck_processing_docs = stuck_processing.count.unwrap_or(0) as usize;
+
+        // 3. Find queue items without corresponding documents
+        let queue_without_docs = sqlx::query!(
+            r#"
+            SELECT COUNT(*) as count
+            FROM ocr_queue q
+            LEFT JOIN documents d ON q.document_id = d.id
+            WHERE d.id IS NULL
+            "#
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        report.queue_without_docs = queue_without_docs.count.unwrap_or(0) as usize;
+
+        Ok(report)
+    }
+
+    /// Clean up orphaned and inconsistent records
+    pub async fn cleanup_orphaned_records(&self) -> Result<CleanupReport> {
+        let mut report = CleanupReport::default();
+
+        // 1. Remove queue items for completed documents
+        let removed_completed = sqlx::query!(
+            r#"
+            DELETE FROM ocr_queue
+            WHERE document_id IN (
+                SELECT d.id FROM documents d 
+                WHERE d.ocr_status = 'completed'
+            )
+            "#
+        )
+        .execute(&self.pool)
+        .await?;
+
+        report.removed_completed_queue_items = removed_completed.rows_affected() as usize;
+
+        // 2. Remove queue items for non-existent documents  
+        let removed_orphaned = sqlx::query!(
+            r#"
+            DELETE FROM ocr_queue
+            WHERE document_id NOT IN (
+                SELECT id FROM documents
+            )
+            "#
+        )
+        .execute(&self.pool)
+        .await?;
+
+        report.removed_orphaned_queue_items = removed_orphaned.rows_affected() as usize;
+
+        // 3. Reset stuck processing documents
+        let reset_stuck = sqlx::query!(
+            r#"
+            UPDATE documents
+            SET ocr_status = 'pending'
+            WHERE ocr_status = 'processing'
+              AND updated_at < NOW() - INTERVAL '30 minutes'
+            "#
+        )
+        .execute(&self.pool)
+        .await?;
+
+        report.reset_stuck_documents = reset_stuck.rows_affected() as usize;
+
+        Ok(report)
+    }
+}
+
+/// OCR job structure with all necessary fields
+#[derive(Debug, Clone)]
+pub struct OcrJob {
+    pub id: Uuid,
+    pub document_id: Uuid,
+    pub priority: i32,
+    pub status: String,
+    pub attempts: i32,
+    pub max_attempts: i32,
+    pub worker_id: Option<String>,
+    pub created_at: chrono::DateTime<chrono::Utc>,
+    pub started_at: Option<chrono::DateTime<chrono::Utc>>,
+    pub completed_at: Option<chrono::DateTime<chrono::Utc>>,
+    pub error_message: Option<String>,
+}
+
+/// Database consistency validation report
+#[derive(Debug, Default)]
+pub struct ConsistencyReport {
+    pub orphaned_queue_items: usize,
+    pub stuck_processing_docs: usize,
+    pub queue_without_docs: usize,
+    pub is_consistent: bool,
+}
+
+impl ConsistencyReport {
+    pub fn is_consistent(&self) -> bool {
+        self.orphaned_queue_items == 0 
+            && self.stuck_processing_docs == 0 
+            && self.queue_without_docs == 0
+    }
+}
+
+/// Database cleanup operation report
+#[derive(Debug, Default)]
+pub struct CleanupReport {
+    pub removed_completed_queue_items: usize,
+    pub removed_orphaned_queue_items: usize,
+    pub reset_stuck_documents: usize,
+}
+
+/// Database connection health checker
+pub struct DatabaseHealthChecker {
+    pool: PgPool,
+}
+
+impl DatabaseHealthChecker {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+
+    /// Check database connection pool health
+    pub async fn check_pool_health(&self) -> Result<PoolHealthReport> {
+        let start = std::time::Instant::now();
+        
+        // Test basic connectivity
+        let test_query = sqlx::query!("SELECT 1 as test")
+            .fetch_one(&self.pool)
+            .await?;
+        
+        let response_time = start.elapsed();
+        
+        // Get pool statistics if available
+        let pool_size = self.pool.size();
+        let idle_connections = self.pool.num_idle();
+        
+        Ok(PoolHealthReport {
+            is_healthy: test_query.test == Some(1),
+            response_time_ms: response_time.as_millis() as u64,
+            pool_size,
+            idle_connections,
+            utilization_percent: if pool_size > 0 {
+                ((pool_size - idle_connections) as f64 / pool_size as f64 * 100.0) as u8
+            } else {
+                0
+            },
+        })
+    }
+}
+
+#[derive(Debug)]
+pub struct PoolHealthReport {
+    pub is_healthy: bool,
+    pub response_time_ms: u64,
+    pub pool_size: u32,
+    pub idle_connections: u32,
+    pub utilization_percent: u8,
+}
+
+/// Distributed locking for critical sections
+pub struct DistributedLock {
+    pool: PgPool,
+}
+
+impl DistributedLock {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+
+    /// Acquire a named lock with timeout
+    pub async fn acquire_lock(&self, lock_name: &str, timeout_secs: i32) -> Result<bool> {
+        let lock_id = self.hash_lock_name(lock_name);
+        
+        let result = sqlx::query!(
+            "SELECT pg_try_advisory_lock($1, $2) as acquired",
+            lock_id,
+            timeout_secs
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        Ok(result.acquired.unwrap_or(false))
+    }
+
+    /// Release a named lock
+    pub async fn release_lock(&self, lock_name: &str) -> Result<bool> {
+        let lock_id = self.hash_lock_name(lock_name);
+        
+        let result = sqlx::query!(
+            "SELECT pg_advisory_unlock($1, 0) as released",
+            lock_id
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        Ok(result.released.unwrap_or(false))
+    }
+
+    fn hash_lock_name(&self, name: &str) -> i64 {
+        use std::collections::hash_map::DefaultHasher;
+        use std::hash::{Hash, Hasher};
+        
+        let mut hasher = DefaultHasher::new();
+        name.hash(&mut hasher);
+        hasher.finish() as i64
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    
+    // Mock tests for the transaction manager
+    // These would need a test database to run properly
+}

src/db_guardrails_simple.rs

@@ -0,0 +1,288 @@
+/*!
+ * Critical Database Guardrails for OCR Corruption Prevention
+ * 
+ * Simplified transaction-safe operations to prevent the FileA/FileB
+ * OCR corruption issue during concurrent processing.
+ */
+
+use sqlx::{PgPool, Row};
+use uuid::Uuid;
+use anyhow::Result;
+use tracing::{warn, error, info};
+
+/// Simplified transaction manager focused on preventing OCR corruption
+#[derive(Clone)]
+pub struct DocumentTransactionManager {
+    pool: PgPool,
+}
+
+impl DocumentTransactionManager {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+
+    /// Update OCR results with full transaction safety and validation
+    /// This is the critical function that prevents FileA/FileB corruption
+    pub async fn update_ocr_with_validation(
+        &self,
+        document_id: Uuid,
+        expected_filename: &str,
+        ocr_text: &str,
+        confidence: f64,
+        word_count: i32,
+        processing_time_ms: i64,
+    ) -> Result<bool> {
+        let mut tx = self.pool.begin().await?;
+        
+        // 1. Lock the document row for update to prevent race conditions
+        let document = sqlx::query(
+            r#"
+            SELECT id, filename, ocr_status, file_size, created_at
+            FROM documents 
+            WHERE id = $1 
+            FOR UPDATE
+            "#
+        )
+        .bind(document_id)
+        .fetch_optional(&mut *tx)
+        .await?;
+
+        let document = match document {
+            Some(doc) => doc,
+            None => {
+                tx.rollback().await?;
+                warn!("Document {} not found during OCR update", document_id);
+                return Ok(false);
+            }
+        };
+
+        // 2. Validate document hasn't been modified unexpectedly
+        let filename: String = document.get("filename");
+        if filename != expected_filename {
+            tx.rollback().await?;
+            error!(
+                "Document {} filename mismatch: expected '{}', got '{}'", 
+                document_id, expected_filename, filename
+            );
+            return Ok(false);
+        }
+
+        // 3. Check if OCR is already completed (prevent double processing)
+        let ocr_status: Option<String> = document.get("ocr_status");
+        if ocr_status.as_deref() == Some("completed") {
+            tx.rollback().await?;
+            warn!("Document {} OCR already completed, skipping update", document_id);
+            return Ok(false);
+        }
+
+        // 4. Validate OCR data quality
+        if ocr_text.is_empty() && confidence > 50.0 {
+            tx.rollback().await?;
+            warn!("Document {} has high confidence ({}) but empty OCR text", document_id, confidence);
+            return Ok(false);
+        }
+
+        // 5. Perform the atomic update with additional safety checks
+        let updated_rows = sqlx::query(
+            r#"
+            UPDATE documents
+            SET ocr_text = $2,
+                ocr_status = 'completed',
+                ocr_completed_at = NOW(),
+                ocr_confidence = $3,
+                ocr_word_count = $4,
+                ocr_processing_time_ms = $5,
+                updated_at = NOW()
+            WHERE id = $1 
+              AND ocr_status != 'completed'  -- Extra safety check
+            "#
+        )
+        .bind(document_id)
+        .bind(ocr_text)
+        .bind(confidence)
+        .bind(word_count)
+        .bind(processing_time_ms)
+        .execute(&mut *tx)
+        .await?;
+
+        if updated_rows.rows_affected() != 1 {
+            tx.rollback().await?;
+            error!("Document {} OCR update affected {} rows (expected 1)", document_id, updated_rows.rows_affected());
+            return Ok(false);
+        }
+
+        // 6. Remove from OCR queue atomically
+        let _queue_removed = sqlx::query(
+            r#"
+            DELETE FROM ocr_queue 
+            WHERE document_id = $1 
+              AND status = 'processing'
+            "#
+        )
+        .bind(document_id)
+        .execute(&mut *tx)
+        .await?;
+
+        // Note: We don't fail if queue removal fails - it might have been cleaned up already
+
+        // 7. Commit transaction
+        tx.commit().await?;
+        
+        info!(
+            "✅ Document {} OCR updated successfully: {} chars, {:.1}% confidence, {} words", 
+            document_id, ocr_text.len(), confidence, word_count
+        );
+        
+        Ok(true)
+    }
+
+    /// Safely handle OCR job failure with proper transaction boundaries
+    pub async fn mark_ocr_failed(
+        &self,
+        document_id: Uuid,
+        error_message: &str,
+    ) -> Result<()> {
+        let mut tx = self.pool.begin().await?;
+
+        // Update document status
+        sqlx::query(
+            r#"
+            UPDATE documents
+            SET ocr_status = 'failed',
+                ocr_error = $2,
+                updated_at = NOW()
+            WHERE id = $1
+            "#
+        )
+        .bind(document_id)
+        .bind(error_message)
+        .execute(&mut *tx)
+        .await?;
+
+        // Remove from queue
+        sqlx::query(
+            r#"
+            DELETE FROM ocr_queue 
+            WHERE document_id = $1
+            "#
+        )
+        .bind(document_id)
+        .execute(&mut *tx)
+        .await?;
+
+        tx.commit().await?;
+        
+        error!("Document {} OCR marked as failed: {}", document_id, error_message);
+        Ok(())
+    }
+
+    /// Check database consistency for monitoring
+    pub async fn check_consistency(&self) -> Result<ConsistencyReport> {
+        let result = sqlx::query(
+            r#"
+            SELECT 
+                -- Orphaned queue items
+                (SELECT COUNT(*) FROM ocr_queue q 
+                 LEFT JOIN documents d ON q.document_id = d.id 
+                 WHERE d.id IS NULL) as orphaned_queue,
+                
+                -- Documents stuck in processing
+                (SELECT COUNT(*) FROM documents
+                 WHERE ocr_status = 'processing'
+                   AND updated_at < NOW() - INTERVAL '30 minutes') as stuck_processing,
+                
+                -- Inconsistent states
+                (SELECT COUNT(*) FROM documents d
+                 JOIN ocr_queue q ON d.id = q.document_id
+                 WHERE d.ocr_status = 'completed' AND q.status != 'completed') as inconsistent_states
+            "#
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        let orphaned: i64 = result.get("orphaned_queue");
+        let stuck: i64 = result.get("stuck_processing");
+        let inconsistent: i64 = result.get("inconsistent_states");
+
+        Ok(ConsistencyReport {
+            orphaned_queue_items: orphaned as i32,
+            stuck_processing_docs: stuck as i32,
+            inconsistent_ocr_states: inconsistent as i32,
+        })
+    }
+
+    /// Clean up stuck and orphaned records
+    pub async fn cleanup_stuck_records(&self) -> Result<CleanupReport> {
+        let mut tx = self.pool.begin().await?;
+
+        // Reset stuck processing documents
+        let reset_stuck = sqlx::query(
+            r#"
+            UPDATE documents
+            SET ocr_status = 'pending'
+            WHERE ocr_status = 'processing'
+              AND updated_at < NOW() - INTERVAL '30 minutes'
+            "#
+        )
+        .execute(&mut *tx)
+        .await?;
+
+        // Remove orphaned queue items
+        let removed_orphaned = sqlx::query(
+            r#"
+            DELETE FROM ocr_queue
+            WHERE document_id NOT IN (SELECT id FROM documents)
+            "#
+        )
+        .execute(&mut *tx)
+        .await?;
+
+        // Remove completed queue items
+        let removed_completed = sqlx::query(
+            r#"
+            DELETE FROM ocr_queue
+            WHERE document_id IN (
+                SELECT d.id FROM documents d 
+                WHERE d.ocr_status = 'completed'
+            )
+            "#
+        )
+        .execute(&mut *tx)
+        .await?;
+
+        tx.commit().await?;
+
+        let report = CleanupReport {
+            reset_stuck_documents: reset_stuck.rows_affected() as usize,
+            removed_orphaned_queue_items: removed_orphaned.rows_affected() as usize,
+            removed_completed_queue_items: removed_completed.rows_affected() as usize,
+        };
+
+        info!("Database cleanup completed: {:?}", report);
+        Ok(report)
+    }
+}
+
+/// Database consistency validation report
+#[derive(Debug)]
+pub struct ConsistencyReport {
+    pub orphaned_queue_items: i32,
+    pub stuck_processing_docs: i32,
+    pub inconsistent_ocr_states: i32,
+}
+
+impl ConsistencyReport {
+    pub fn is_consistent(&self) -> bool {
+        self.orphaned_queue_items == 0 
+            && self.stuck_processing_docs == 0 
+            && self.inconsistent_ocr_states == 0
+    }
+}
+
+/// Database cleanup operation report
+#[derive(Debug)]
+pub struct CleanupReport {
+    pub reset_stuck_documents: usize,
+    pub removed_orphaned_queue_items: usize,
+    pub removed_completed_queue_items: usize,
+}

src/db_monitoring.rs

@@ -0,0 +1,588 @@
+/*!
+ * Database Monitoring and Alerting System
+ * 
+ * Provides real-time monitoring of database health, OCR processing,
+ * and automatic alerting for potential issues.
+ */
+
+use sqlx::PgPool;
+use serde::{Deserialize, Serialize};
+use tokio::time::{Duration, interval};
+use tracing::{error, warn, info, debug};
+use anyhow::Result;
+use std::sync::Arc;
+
+/// Database monitoring service that runs in the background
+pub struct DatabaseMonitor {
+    pool: PgPool,
+    config: MonitoringConfig,
+}
+
+#[derive(Debug, Clone)]
+pub struct MonitoringConfig {
+    pub check_interval_secs: u64,
+    pub stuck_job_threshold_minutes: i32,
+    pub high_queue_size_threshold: i32,
+    pub low_confidence_threshold: f64,
+    pub pool_utilization_threshold: u8,
+    pub slow_query_threshold_ms: u64,
+    pub enable_auto_recovery: bool,
+}
+
+impl Default for MonitoringConfig {
+    fn default() -> Self {
+        Self {
+            check_interval_secs: 60,
+            stuck_job_threshold_minutes: 30,
+            high_queue_size_threshold: 100,
+            low_confidence_threshold: 70.0,
+            pool_utilization_threshold: 80,
+            slow_query_threshold_ms: 5000,
+            enable_auto_recovery: true,
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct DatabaseHealth {
+    pub overall_status: HealthStatus,
+    pub ocr_processing: OcrProcessingHealth,
+    pub queue_health: QueueHealth,
+    pub connection_pool: PoolHealth,
+    pub data_consistency: ConsistencyHealth,
+    pub performance_metrics: PerformanceMetrics,
+    pub timestamp: chrono::DateTime<chrono::Utc>,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub enum HealthStatus {
+    Healthy,
+    Warning,
+    Critical,
+    Unknown,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct OcrProcessingHealth {
+    pub status: HealthStatus,
+    pub pending_jobs: i32,
+    pub processing_jobs: i32,
+    pub stuck_jobs: i32,
+    pub failed_jobs_last_hour: i32,
+    pub average_confidence: Option<f64>,
+    pub average_processing_time_ms: Option<f64>,
+    pub throughput_per_minute: f64,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct QueueHealth {
+    pub status: HealthStatus,
+    pub queue_size: i32,
+    pub oldest_pending_age_minutes: Option<i32>,
+    pub worker_count: i32,
+    pub queue_growth_rate: f64,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct PoolHealth {
+    pub status: HealthStatus,
+    pub total_connections: u32,
+    pub active_connections: u32,
+    pub idle_connections: u32,
+    pub utilization_percent: u8,
+    pub average_response_time_ms: u64,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ConsistencyHealth {
+    pub status: HealthStatus,
+    pub orphaned_queue_items: i32,
+    pub documents_without_files: i32,
+    pub inconsistent_ocr_states: i32,
+    pub data_integrity_score: f64,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct PerformanceMetrics {
+    pub queries_per_second: f64,
+    pub slow_queries_count: i32,
+    pub cache_hit_ratio: Option<f64>,
+    pub index_usage_efficiency: f64,
+    pub deadlock_count: i32,
+}
+
+impl DatabaseMonitor {
+    pub fn new(pool: PgPool, config: MonitoringConfig) -> Self {
+        Self { pool, config }
+    }
+
+    /// Start the monitoring service
+    pub async fn start(self: Arc<Self>) {
+        let mut interval = interval(Duration::from_secs(self.config.check_interval_secs));
+        
+        info!("Database monitoring started with {}s intervals", self.config.check_interval_secs);
+        
+        loop {
+            interval.tick().await;
+            
+            match self.perform_health_check().await {
+                Ok(health) => {
+                    self.process_health_report(health).await;
+                }
+                Err(e) => {
+                    error!("Database health check failed: {}", e);
+                }
+            }
+        }
+    }
+
+    /// Perform comprehensive database health check
+    async fn perform_health_check(&self) -> Result<DatabaseHealth> {
+        let start_time = std::time::Instant::now();
+        
+        // Run all health checks concurrently
+        let (ocr_health, queue_health, pool_health, consistency_health, perf_metrics) = tokio::try_join!(
+            self.check_ocr_processing_health(),
+            self.check_queue_health(),
+            self.check_pool_health(),
+            self.check_data_consistency(),
+            self.check_performance_metrics()
+        )?;
+
+        let overall_status = self.determine_overall_status(&ocr_health, &queue_health, &pool_health, &consistency_health);
+        
+        let health_check_duration = start_time.elapsed();
+        debug!("Health check completed in {:?}", health_check_duration);
+
+        Ok(DatabaseHealth {
+            overall_status,
+            ocr_processing: ocr_health,
+            queue_health,
+            connection_pool: pool_health,
+            data_consistency: consistency_health,
+            performance_metrics: perf_metrics,
+            timestamp: chrono::Utc::now(),
+        })
+    }
+
+    async fn check_ocr_processing_health(&self) -> Result<OcrProcessingHealth> {
+        let stats = sqlx::query!(
+            r#"
+            SELECT 
+                COUNT(*) FILTER (WHERE ocr_status = 'pending') as pending,
+                COUNT(*) FILTER (WHERE ocr_status = 'processing') as processing,
+                COUNT(*) FILTER (WHERE ocr_status = 'processing' AND updated_at < NOW() - INTERVAL '30 minutes') as stuck,
+                COUNT(*) FILTER (WHERE ocr_status = 'failed' AND updated_at > NOW() - INTERVAL '1 hour') as failed_recent,
+                AVG(ocr_confidence) FILTER (WHERE ocr_status = 'completed' AND ocr_completed_at > NOW() - INTERVAL '1 hour') as avg_confidence,
+                AVG(ocr_processing_time_ms) FILTER (WHERE ocr_status = 'completed' AND ocr_completed_at > NOW() - INTERVAL '1 hour') as avg_time,
+                COUNT(*) FILTER (WHERE ocr_status = 'completed' AND ocr_completed_at > NOW() - INTERVAL '1 minute') as completed_last_minute
+            FROM documents
+            "#
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        let pending = stats.pending.unwrap_or(0) as i32;
+        let processing = stats.processing.unwrap_or(0) as i32;
+        let stuck = stats.stuck.unwrap_or(0) as i32;
+        let failed_recent = stats.failed_recent.unwrap_or(0) as i32;
+        let avg_confidence = stats.avg_confidence;
+        let avg_time = stats.avg_time;
+        let throughput = stats.completed_last_minute.unwrap_or(0) as f64;
+
+        let status = if stuck > 0 || failed_recent > 10 {
+            HealthStatus::Critical
+        } else if pending > self.config.high_queue_size_threshold || avg_confidence.unwrap_or(100.0) < self.config.low_confidence_threshold {
+            HealthStatus::Warning
+        } else {
+            HealthStatus::Healthy
+        };
+
+        Ok(OcrProcessingHealth {
+            status,
+            pending_jobs: pending,
+            processing_jobs: processing,
+            stuck_jobs: stuck,
+            failed_jobs_last_hour: failed_recent,
+            average_confidence: avg_confidence,
+            average_processing_time_ms: avg_time,
+            throughput_per_minute: throughput,
+        })
+    }
+
+    async fn check_queue_health(&self) -> Result<QueueHealth> {
+        let queue_stats = sqlx::query!(
+            r#"
+            SELECT 
+                COUNT(*) as total_items,
+                MIN(EXTRACT(EPOCH FROM (NOW() - created_at))/60) as oldest_pending_minutes,
+                COUNT(DISTINCT worker_id) FILTER (WHERE status = 'processing') as active_workers
+            FROM ocr_queue
+            WHERE status IN ('pending', 'processing')
+            "#
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        let queue_size = queue_stats.total_items.unwrap_or(0) as i32;
+        let oldest_pending = queue_stats.oldest_pending_minutes.map(|m| m as i32);
+        let worker_count = queue_stats.active_workers.unwrap_or(0) as i32;
+
+        // Calculate queue growth rate (simplified)
+        let growth_rate = 0.0; // Would need historical data for accurate calculation
+
+        let status = if queue_size > self.config.high_queue_size_threshold {
+            HealthStatus::Critical
+        } else if queue_size > self.config.high_queue_size_threshold / 2 {
+            HealthStatus::Warning
+        } else {
+            HealthStatus::Healthy
+        };
+
+        Ok(QueueHealth {
+            status,
+            queue_size,
+            oldest_pending_age_minutes: oldest_pending,
+            worker_count,
+            queue_growth_rate: growth_rate,
+        })
+    }
+
+    async fn check_pool_health(&self) -> Result<PoolHealth> {
+        let start = std::time::Instant::now();
+        
+        // Test pool responsiveness
+        sqlx::query!("SELECT 1")
+            .fetch_one(&self.pool)
+            .await?;
+        
+        let response_time = start.elapsed().as_millis() as u64;
+        
+        let total_connections = self.pool.size();
+        let idle_connections = self.pool.num_idle();
+        let active_connections = total_connections - idle_connections;
+        let utilization = if total_connections > 0 {
+            (active_connections as f64 / total_connections as f64 * 100.0) as u8
+        } else {
+            0
+        };
+
+        let status = if utilization > self.config.pool_utilization_threshold {
+            HealthStatus::Critical
+        } else if utilization > self.config.pool_utilization_threshold / 2 || response_time > self.config.slow_query_threshold_ms {
+            HealthStatus::Warning
+        } else {
+            HealthStatus::Healthy
+        };
+
+        Ok(PoolHealth {
+            status,
+            total_connections,
+            active_connections,
+            idle_connections,
+            utilization_percent: utilization,
+            average_response_time_ms: response_time,
+        })
+    }
+
+    async fn check_data_consistency(&self) -> Result<ConsistencyHealth> {
+        let consistency_check = sqlx::query!(
+            r#"
+            SELECT 
+                -- Orphaned queue items
+                (SELECT COUNT(*) FROM ocr_queue q 
+                 LEFT JOIN documents d ON q.document_id = d.id 
+                 WHERE d.id IS NULL) as orphaned_queue,
+                
+                -- Documents without files (would need file system check)
+                0 as missing_files,
+                
+                -- Inconsistent OCR states
+                (SELECT COUNT(*) FROM documents d
+                 JOIN ocr_queue q ON d.id = q.document_id
+                 WHERE d.ocr_status = 'completed' AND q.status != 'completed') as inconsistent_states
+            "#
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        let orphaned = consistency_check.orphaned_queue.unwrap_or(0) as i32;
+        let missing_files = consistency_check.missing_files.unwrap_or(0) as i32;
+        let inconsistent = consistency_check.inconsistent_states.unwrap_or(0) as i32;
+
+        let total_issues = orphaned + missing_files + inconsistent;
+        let integrity_score = if total_issues == 0 { 100.0 } else { 100.0 - (total_issues as f64 * 10.0).min(100.0) };
+
+        let status = if total_issues > 10 {
+            HealthStatus::Critical
+        } else if total_issues > 0 {
+            HealthStatus::Warning
+        } else {
+            HealthStatus::Healthy
+        };
+
+        Ok(ConsistencyHealth {
+            status,
+            orphaned_queue_items: orphaned,
+            documents_without_files: missing_files,
+            inconsistent_ocr_states: inconsistent,
+            data_integrity_score: integrity_score,
+        })
+    }
+
+    async fn check_performance_metrics(&self) -> Result<PerformanceMetrics> {
+        // These would need more sophisticated monitoring in production
+        // For now, return basic metrics
+        
+        Ok(PerformanceMetrics {
+            queries_per_second: 0.0,
+            slow_queries_count: 0,
+            cache_hit_ratio: None,
+            index_usage_efficiency: 95.0,
+            deadlock_count: 0,
+        })
+    }
+
+    fn determine_overall_status(
+        &self,
+        ocr: &OcrProcessingHealth,
+        queue: &QueueHealth,
+        pool: &PoolHealth,
+        consistency: &ConsistencyHealth,
+    ) -> HealthStatus {
+        let statuses = [&ocr.status, &queue.status, &pool.status, &consistency.status];
+        
+        if statuses.iter().any(|s| matches!(s, HealthStatus::Critical)) {
+            HealthStatus::Critical
+        } else if statuses.iter().any(|s| matches!(s, HealthStatus::Warning)) {
+            HealthStatus::Warning
+        } else {
+            HealthStatus::Healthy
+        }
+    }
+
+    /// Process health report and take actions
+    async fn process_health_report(&self, health: DatabaseHealth) {
+        match health.overall_status {
+            HealthStatus::Critical => {
+                error!("🚨 CRITICAL: Database health issues detected!");
+                self.handle_critical_issues(&health).await;
+            }
+            HealthStatus::Warning => {
+                warn!("⚠️ WARNING: Database health degraded");
+                self.handle_warnings(&health).await;
+            }
+            HealthStatus::Healthy => {
+                debug!("✅ Database health is good");
+            }
+            HealthStatus::Unknown => {
+                warn!("❓ Database health status unknown");
+            }
+        }
+
+        // Log key metrics
+        info!(
+            "DB Health: OCR pending={}, processing={}, stuck={}, pool={}%",
+            health.ocr_processing.pending_jobs,
+            health.ocr_processing.processing_jobs,
+            health.ocr_processing.stuck_jobs,
+            health.connection_pool.utilization_percent
+        );
+    }
+
+    async fn handle_critical_issues(&self, health: &DatabaseHealth) {
+        if self.config.enable_auto_recovery {
+            // Reset stuck OCR jobs
+            if health.ocr_processing.stuck_jobs > 0 {
+                match self.reset_stuck_jobs().await {
+                    Ok(reset_count) => {
+                        warn!("Auto-recovery: Reset {} stuck OCR jobs", reset_count);
+                    }
+                    Err(e) => {
+                        error!("Failed to reset stuck OCR jobs: {}", e);
+                    }
+                }
+            }
+
+            // Clean up orphaned queue items
+            if health.data_consistency.orphaned_queue_items > 0 {
+                match self.cleanup_orphaned_items().await {
+                    Ok(cleanup_count) => {
+                        warn!("Auto-recovery: Cleaned up {} orphaned queue items", cleanup_count);
+                    }
+                    Err(e) => {
+                        error!("Failed to cleanup orphaned items: {}", e);
+                    }
+                }
+            }
+        }
+    }
+
+    async fn handle_warnings(&self, health: &DatabaseHealth) {
+        // Log detailed warning information
+        if health.ocr_processing.pending_jobs > self.config.high_queue_size_threshold / 2 {
+            warn!("High OCR queue size: {} pending jobs", health.ocr_processing.pending_jobs);
+        }
+
+        if health.connection_pool.utilization_percent > self.config.pool_utilization_threshold / 2 {
+            warn!("High connection pool utilization: {}%", health.connection_pool.utilization_percent);
+        }
+    }
+
+    async fn reset_stuck_jobs(&self) -> Result<i32> {
+        let result = sqlx::query!(
+            "SELECT reset_stuck_ocr_jobs($1) as reset_count",
+            self.config.stuck_job_threshold_minutes
+        )
+        .fetch_one(&self.pool)
+        .await?;
+
+        Ok(result.reset_count.unwrap_or(0))
+    }
+
+    async fn cleanup_orphaned_items(&self) -> Result<i32> {
+        let result = sqlx::query!(
+            r#"
+            DELETE FROM ocr_queue
+            WHERE document_id NOT IN (SELECT id FROM documents)
+            "#
+        )
+        .execute(&self.pool)
+        .await?;
+
+        Ok(result.rows_affected() as i32)
+    }
+
+    /// Get current health status (for API endpoints)
+    pub async fn get_current_health(&self) -> Result<DatabaseHealth> {
+        self.perform_health_check().await
+    }
+
+    /// Force a consistency check and cleanup
+    pub async fn force_cleanup(&self) -> Result<String> {
+        let reset_count = self.reset_stuck_jobs().await?;
+        let cleanup_count = self.cleanup_orphaned_items().await?;
+        
+        // Refresh OCR stats
+        sqlx::query!("SELECT refresh_ocr_stats()")
+            .execute(&self.pool)
+            .await?;
+
+        Ok(format!(
+            "Cleanup completed: {} stuck jobs reset, {} orphaned items removed",
+            reset_count, cleanup_count
+        ))
+    }
+}
+
+/// Alert configuration for different severity levels
+#[derive(Debug, Clone)]
+pub struct AlertConfig {
+    pub email_notifications: bool,
+    pub slack_webhook: Option<String>,
+    pub critical_alert_cooldown_minutes: u64,
+    pub warning_alert_cooldown_minutes: u64,
+}
+
+/// Alert manager for sending notifications
+pub struct AlertManager {
+    config: AlertConfig,
+    last_critical_alert: std::sync::Mutex<Option<chrono::DateTime<chrono::Utc>>>,
+    last_warning_alert: std::sync::Mutex<Option<chrono::DateTime<chrono::Utc>>>,
+}
+
+impl AlertManager {
+    pub fn new(config: AlertConfig) -> Self {
+        Self {
+            config,
+            last_critical_alert: std::sync::Mutex::new(None),
+            last_warning_alert: std::sync::Mutex::new(None),
+        }
+    }
+
+    pub async fn send_alert(&self, health: &DatabaseHealth) -> Result<()> {
+        match health.overall_status {
+            HealthStatus::Critical => {
+                if self.should_send_critical_alert() {
+                    self.send_critical_alert(health).await?;
+                    self.update_last_critical_alert();
+                }
+            }
+            HealthStatus::Warning => {
+                if self.should_send_warning_alert() {
+                    self.send_warning_alert(health).await?;
+                    self.update_last_warning_alert();
+                }
+            }
+            _ => {}
+        }
+        Ok(())
+    }
+
+    fn should_send_critical_alert(&self) -> bool {
+        let last_alert = self.last_critical_alert.lock().unwrap();
+        match *last_alert {
+            Some(last) => {
+                let cooldown = chrono::Duration::minutes(self.config.critical_alert_cooldown_minutes as i64);
+                chrono::Utc::now() - last > cooldown
+            }
+            None => true,
+        }
+    }
+
+    fn should_send_warning_alert(&self) -> bool {
+        let last_alert = self.last_warning_alert.lock().unwrap();
+        match *last_alert {
+            Some(last) => {
+                let cooldown = chrono::Duration::minutes(self.config.warning_alert_cooldown_minutes as i64);
+                chrono::Utc::now() - last > cooldown
+            }
+            None => true,
+        }
+    }
+
+    async fn send_critical_alert(&self, health: &DatabaseHealth) -> Result<()> {
+        let message = format!(
+            "🚨 CRITICAL DATABASE ALERT 🚨\n\
+            Stuck OCR jobs: {}\n\
+            Pool utilization: {}%\n\
+            Orphaned queue items: {}\n\
+            Timestamp: {}",
+            health.ocr_processing.stuck_jobs,
+            health.connection_pool.utilization_percent,
+            health.data_consistency.orphaned_queue_items,
+            health.timestamp
+        );
+
+        error!("{}", message);
+        // Add actual notification sending logic here (email, Slack, etc.)
+        Ok(())
+    }
+
+    async fn send_warning_alert(&self, health: &DatabaseHealth) -> Result<()> {
+        let message = format!(
+            "⚠️ Database Warning\n\
+            Pending OCR jobs: {}\n\
+            Pool utilization: {}%\n\
+            Average confidence: {:.1}%\n\
+            Timestamp: {}",
+            health.ocr_processing.pending_jobs,
+            health.connection_pool.utilization_percent,
+            health.ocr_processing.average_confidence.unwrap_or(0.0),
+            health.timestamp
+        );
+
+        warn!("{}", message);
+        Ok(())
+    }
+
+    fn update_last_critical_alert(&self) {
+        let mut last_alert = self.last_critical_alert.lock().unwrap();
+        *last_alert = Some(chrono::Utc::now());
+    }
+
+    fn update_last_warning_alert(&self) {
+        let mut last_alert = self.last_warning_alert.lock().unwrap();
+        *last_alert = Some(chrono::Utc::now());
+    }
+}

src/lib.rs

@@ -2,6 +2,7 @@ pub mod auth;
 pub mod batch_ingest;
 pub mod config;
 pub mod db;
+pub mod db_guardrails_simple;
 pub mod enhanced_ocr;
 pub mod file_service;
 pub mod local_folder_service;

src/ocr_queue.rs

@@ -8,7 +8,7 @@ use tokio::time::{sleep, Duration};
 use tracing::{error, info, warn};
 use uuid::Uuid;
 
-use crate::{db::Database, enhanced_ocr::EnhancedOcrService};
+use crate::{db::Database, enhanced_ocr::EnhancedOcrService, db_guardrails_simple::DocumentTransactionManager};
 
 #[derive(Debug, Clone, Serialize, Deserialize, FromRow)]
 pub struct OcrQueueItem {
@@ -43,16 +43,19 @@ pub struct OcrQueueService {
     pool: PgPool,
     max_concurrent_jobs: usize,
     worker_id: String,
+    transaction_manager: DocumentTransactionManager,
 }
 
 impl OcrQueueService {
     pub fn new(db: Database, pool: PgPool, max_concurrent_jobs: usize) -> Self {
         let worker_id = format!("worker-{}-{}", hostname::get().unwrap_or_default().to_string_lossy(), Uuid::new_v4());
+        let transaction_manager = DocumentTransactionManager::new(pool.clone());
         Self {
             db,
             pool,
             max_concurrent_jobs,
             worker_id,
+            transaction_manager,
         }
     }
 
@@ -108,51 +111,104 @@ impl OcrQueueService {
         Ok(ids)
     }
 
-    /// Get the next item from the queue
-    async fn dequeue(&self) -> Result<Option<OcrQueueItem>> {
-        let row = sqlx::query(
+    /// Get the next item from the queue with atomic job claiming and retry logic
+    pub async fn dequeue(&self) -> Result<Option<OcrQueueItem>> {
+        // Retry up to 3 times for race condition scenarios
+        for attempt in 1..=3 {
+            // Use a transaction to ensure atomic job claiming
+            let mut tx = self.pool.begin().await?;
+        
+        // Step 1: Find and lock the next available job atomically
+        let job_row = sqlx::query(
+            r#"
+            SELECT id, document_id, priority, status, attempts, max_attempts, 
+                   created_at, started_at, completed_at, error_message, 
+                   worker_id, processing_time_ms, file_size
+            FROM ocr_queue
+            WHERE status = 'pending'
+              AND attempts < max_attempts
+            ORDER BY priority DESC, created_at ASC
+            FOR UPDATE SKIP LOCKED
+            LIMIT 1
+            "#
+        )
+        .fetch_optional(&mut *tx)
+        .await?;
+
+        let job_id = match job_row {
+            Some(ref row) => row.get::<Uuid, _>("id"),
+            None => {
+                // No jobs available
+                tx.rollback().await?;
+                return Ok(None);
+            }
+        };
+
+        // Step 2: Atomically update the job to processing state
+        let updated_rows = sqlx::query(
             r#"
             UPDATE ocr_queue
             SET status = 'processing',
                 started_at = NOW(),
                 worker_id = $1,
                 attempts = attempts + 1
-            WHERE id = (
-                SELECT id
-                FROM ocr_queue
-                WHERE status = 'pending'
-                  AND attempts < max_attempts
-                ORDER BY priority DESC, created_at ASC
-                FOR UPDATE SKIP LOCKED
-                LIMIT 1
-            )
-            RETURNING *
+            WHERE id = $2
+              AND status = 'pending'  -- Extra safety check
             "#
         )
         .bind(&self.worker_id)
-        .fetch_optional(&self.pool)
+        .bind(job_id)
+        .execute(&mut *tx)
         .await?;
 
-        let item = match row {
-            Some(row) => Some(OcrQueueItem {
-                id: row.get("id"),
-                document_id: row.get("document_id"),
-                status: row.get("status"),
-                priority: row.get("priority"),
-                attempts: row.get("attempts"),
-                max_attempts: row.get("max_attempts"),
-                created_at: row.get("created_at"),
-                started_at: row.get("started_at"),
-                completed_at: row.get("completed_at"),
-                error_message: row.get("error_message"),
-                worker_id: row.get("worker_id"),
-                processing_time_ms: row.get("processing_time_ms"),
-                file_size: row.get("file_size"),
-            }),
-            None => None,
+        if updated_rows.rows_affected() != 1 {
+            // Job was claimed by another worker between SELECT and UPDATE
+            tx.rollback().await?;
+            warn!("Job {} was claimed by another worker, retrying", job_id);
+            return Ok(None);
+        }
+
+        // Step 3: Get the updated job details
+        let row = sqlx::query(
+            r#"
+            SELECT id, document_id, priority, status, attempts, max_attempts, 
+                   created_at, started_at, completed_at, error_message, 
+                   worker_id, processing_time_ms, file_size
+            FROM ocr_queue
+            WHERE id = $1
+            "#
+        )
+        .bind(job_id)
+        .fetch_one(&mut *tx)
+        .await?;
+
+        tx.commit().await?;
+
+        // Return the successfully claimed job
+        let item = OcrQueueItem {
+            id: row.get("id"),
+            document_id: row.get("document_id"),
+            status: row.get("status"),
+            priority: row.get("priority"),
+            attempts: row.get("attempts"),
+            max_attempts: row.get("max_attempts"),
+            created_at: row.get("created_at"),
+            started_at: row.get("started_at"),
+            completed_at: row.get("completed_at"),
+            error_message: row.get("error_message"),
+            worker_id: row.get("worker_id"),
+            processing_time_ms: row.get("processing_time_ms"),
+            file_size: row.get("file_size"),
         };
 
-        Ok(item)
+        info!("✅ Worker {} successfully claimed job {} for document {}", 
+              self.worker_id, item.id, item.document_id);
+        
+        return Ok(Some(item));
+        }
+        
+        // If all retry attempts failed, return None
+        Ok(None)
     }
 
     /// Mark an item as completed
@@ -209,10 +265,10 @@ impl OcrQueueService {
         
         info!("Processing OCR job {} for document {}", item.id, item.document_id);
         
-        // Get document details
+        // Get document details including filename for validation
         let document = sqlx::query(
             r#"
-            SELECT file_path, mime_type, user_id
+            SELECT file_path, mime_type, user_id, filename
             FROM documents
             WHERE id = $1
             "#
@@ -226,6 +282,7 @@ impl OcrQueueService {
                 let file_path: String = row.get("file_path");
                 let mime_type: String = row.get("mime_type");
                 let user_id: Option<Uuid> = row.get("user_id");
+                let filename: String = row.get("filename");
                 // Get user's OCR settings or use defaults
                 let settings = if let Some(user_id) = user_id {
                     self.db.get_user_settings(user_id).await.ok().flatten()
@@ -263,27 +320,33 @@ impl OcrQueueService {
                         }
                         
                         if !ocr_result.text.is_empty() {
-                            // Update document with enhanced OCR text and metadata
-                            sqlx::query(
-                                r#"
-                                UPDATE documents
-                                SET ocr_text = $2,
-                                    ocr_status = 'completed',
-                                    ocr_completed_at = NOW(),
-                                    ocr_confidence = $3,
-                                    ocr_word_count = $4,
-                                    ocr_processing_time_ms = $5,
-                                    updated_at = NOW()
-                                WHERE id = $1
-                                "#
-                            )
-                            .bind(item.document_id)
-                            .bind(&ocr_result.text)
-                            .bind(ocr_result.confidence)
-                            .bind(ocr_result.word_count as i32)
-                            .bind(ocr_result.processing_time_ms as i32)
-                            .execute(&self.pool)
-                            .await?;
+                            // Use transaction-safe OCR update to prevent corruption
+                            let processing_time_ms = start_time.elapsed().as_millis() as i64;
+                            
+                            match self.transaction_manager.update_ocr_with_validation(
+                                item.document_id,
+                                &filename,
+                                &ocr_result.text,
+                                ocr_result.confidence as f64,
+                                ocr_result.word_count as i32,
+                                processing_time_ms,
+                            ).await {
+                                Ok(true) => {
+                                    info!("✅ Transaction-safe OCR update successful for document {}", item.document_id);
+                                }
+                                Ok(false) => {
+                                    let error_msg = "OCR update failed validation (document may have been modified)";
+                                    warn!("{} for document {}", error_msg, item.document_id);
+                                    self.mark_failed(item.id, error_msg).await?;
+                                    return Ok(());
+                                }
+                                Err(e) => {
+                                    let error_msg = format!("Transaction-safe OCR update failed: {}", e);
+                                    error!("{}", error_msg);
+                                    self.mark_failed(item.id, &error_msg).await?;
+                                    return Ok(());
+                                }
+                            }
                         }
 
                         let processing_time_ms = start_time.elapsed().as_millis() as i32;
@@ -354,8 +417,9 @@ impl OcrQueueService {
                     });
                 }
                 Ok(None) => {
-                    // No items in queue, sleep briefly
-                    sleep(Duration::from_secs(1)).await;
+                    // No items in queue or all jobs were claimed by other workers
+                    // Use shorter sleep for high-concurrency scenarios
+                    sleep(Duration::from_millis(100)).await;
                 }
                 Err(e) => {
                     error!("Error dequeuing item: {}", e);

src/tests/helpers.rs

@@ -2,19 +2,18 @@ use crate::{AppState, models::UserResponse};
 use axum::Router;
 use serde_json::json;
 use std::sync::Arc;
-use testcontainers::{clients::Cli, RunnableImage};
+use testcontainers::{core::WaitFor, runners::AsyncRunner, ContainerAsync, GenericImage};
 use testcontainers_modules::postgres::Postgres;
 use tower::util::ServiceExt;
 
-pub async fn create_test_app() -> (Router, testcontainers::Container<'static, Postgres>) {
-    let docker = Box::leak(Box::new(Cli::default()));
-    let postgres_image = RunnableImage::from(Postgres::default())
+pub async fn create_test_app() -> (Router, ContainerAsync<Postgres>) {
+    let postgres_image = Postgres::default()
         .with_env_var(("POSTGRES_USER", "test"))
         .with_env_var(("POSTGRES_PASSWORD", "test"))
         .with_env_var(("POSTGRES_DB", "test"));
     
-    let container = docker.run(postgres_image);
-    let port = container.get_host_port_ipv4(5432);
+    let container = postgres_image.start().await.expect("Failed to start postgres container");
+    let port = container.get_host_port_ipv4(5432).await.expect("Failed to get postgres port");
     
     let database_url = format!("postgresql://test:test@localhost:{}/test", port);
     let db = crate::db::Database::new(&database_url).await.unwrap();
@@ -42,7 +41,12 @@ pub async fn create_test_app() -> (Router, testcontainers::Container<'static, Po
         cpu_priority: "normal".to_string(),
     };
     
-    let state = Arc::new(AppState { db, config });
+    let state = Arc::new(AppState { 
+        db, 
+        config,
+        webdav_scheduler: None,
+        source_scheduler: None,
+    });
     
     let app = Router::new()
         .nest("/api/auth", crate::routes::auth::router())

src/tests/settings_tests.rs

@@ -66,6 +66,22 @@ mod tests {
             ocr_detect_orientation: None,
             ocr_whitelist_chars: None,
             ocr_blacklist_chars: None,
+            ocr_brightness_boost: None,
+            ocr_contrast_multiplier: None,
+            ocr_noise_reduction_level: None,
+            ocr_sharpening_strength: None,
+            ocr_morphological_operations: None,
+            ocr_adaptive_threshold_window_size: None,
+            ocr_histogram_equalization: None,
+            ocr_upscale_factor: None,
+            ocr_max_image_width: None,
+            ocr_max_image_height: None,
+            save_processed_images: None,
+            ocr_quality_threshold_brightness: None,
+            ocr_quality_threshold_contrast: None,
+            ocr_quality_threshold_noise: None,
+            ocr_quality_threshold_sharpness: None,
+            ocr_skip_enhancement: None,
             webdav_enabled: None,
             webdav_server_url: None,
             webdav_username: None,
@@ -170,6 +186,22 @@ mod tests {
             ocr_detect_orientation: None,
             ocr_whitelist_chars: None,
             ocr_blacklist_chars: None,
+            ocr_brightness_boost: None,
+            ocr_contrast_multiplier: None,
+            ocr_noise_reduction_level: None,
+            ocr_sharpening_strength: None,
+            ocr_morphological_operations: None,
+            ocr_adaptive_threshold_window_size: None,
+            ocr_histogram_equalization: None,
+            ocr_upscale_factor: None,
+            ocr_max_image_width: None,
+            ocr_max_image_height: None,
+            save_processed_images: None,
+            ocr_quality_threshold_brightness: None,
+            ocr_quality_threshold_contrast: None,
+            ocr_quality_threshold_noise: None,
+            ocr_quality_threshold_sharpness: None,
+            ocr_skip_enhancement: None,
             webdav_enabled: None,
             webdav_server_url: None,
             webdav_username: None,

tests/admin_functionality_tests.rs

@@ -0,0 +1,692 @@
+/*!
+ * Admin Functionality Integration Tests
+ * 
+ * Tests administrative operations including:
+ * - User management (CRUD operations)
+ * - System metrics access
+ * - Admin-only endpoints
+ * - Role-based access control
+ * - System monitoring capabilities
+ */
+
+use reqwest::Client;
+use serde_json::{json, Value};
+use std::time::Duration;
+use uuid::Uuid;
+
+use readur::models::{CreateUser, LoginRequest, LoginResponse, UserRole};
+
+const BASE_URL: &str = "http://localhost:8000";
+
+/// Test client with admin capabilities
+struct AdminTestClient {
+    client: Client,
+    admin_token: Option<String>,
+    user_token: Option<String>,
+    admin_user_id: Option<String>,
+    regular_user_id: Option<String>,
+}
+
+impl AdminTestClient {
+    fn new() -> Self {
+        Self {
+            client: Client::new(),
+            admin_token: None,
+            user_token: None,
+            admin_user_id: None,
+            regular_user_id: None,
+        }
+    }
+    
+    /// Register and login as admin user
+    async fn setup_admin(&mut self) -> Result<String, Box<dyn std::error::Error>> {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let username = format!("admin_test_{}", timestamp);
+        let email = format!("admin_test_{}@example.com", timestamp);
+        let password = "adminpassword123";
+        
+        // Register admin user
+        let admin_data = CreateUser {
+            username: username.clone(),
+            email: email.clone(),
+            password: password.to_string(),
+            role: Some(UserRole::Admin),
+        };
+        
+        let register_response = self.client
+            .post(&format!("{}/api/auth/register", BASE_URL))
+            .json(&admin_data)
+            .send()
+            .await?;
+        
+        if !register_response.status().is_success() {
+            return Err(format!("Admin registration failed: {}", register_response.text().await?).into());
+        }
+        
+        // Login admin
+        let login_data = LoginRequest {
+            username: username.clone(),
+            password: password.to_string(),
+        };
+        
+        let login_response = self.client
+            .post(&format!("{}/api/auth/login", BASE_URL))
+            .json(&login_data)
+            .send()
+            .await?;
+        
+        if !login_response.status().is_success() {
+            return Err(format!("Admin login failed: {}", login_response.text().await?).into());
+        }
+        
+        let login_result: LoginResponse = login_response.json().await?;
+        self.admin_token = Some(login_result.token.clone());
+        
+        // Get admin user info
+        let me_response = self.client
+            .get(&format!("{}/api/auth/me", BASE_URL))
+            .header("Authorization", format!("Bearer {}", login_result.token))
+            .send()
+            .await?;
+        
+        if me_response.status().is_success() {
+            let user_info: Value = me_response.json().await?;
+            self.admin_user_id = user_info["id"].as_str().map(|s| s.to_string());
+        }
+        
+        Ok(login_result.token)
+    }
+    
+    /// Register and login as regular user
+    async fn setup_regular_user(&mut self) -> Result<String, Box<dyn std::error::Error>> {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let username = format!("user_test_{}", timestamp);
+        let email = format!("user_test_{}@example.com", timestamp);
+        let password = "userpassword123";
+        
+        // Register regular user
+        let user_data = CreateUser {
+            username: username.clone(),
+            email: email.clone(),
+            password: password.to_string(),
+            role: Some(UserRole::User),
+        };
+        
+        let register_response = self.client
+            .post(&format!("{}/api/auth/register", BASE_URL))
+            .json(&user_data)
+            .send()
+            .await?;
+        
+        if !register_response.status().is_success() {
+            return Err(format!("User registration failed: {}", register_response.text().await?).into());
+        }
+        
+        // Login user
+        let login_data = LoginRequest {
+            username: username.clone(),
+            password: password.to_string(),
+        };
+        
+        let login_response = self.client
+            .post(&format!("{}/api/auth/login", BASE_URL))
+            .json(&login_data)
+            .send()
+            .await?;
+        
+        if !login_response.status().is_success() {
+            return Err(format!("User login failed: {}", login_response.text().await?).into());
+        }
+        
+        let login_result: LoginResponse = login_response.json().await?;
+        self.user_token = Some(login_result.token.clone());
+        
+        // Get user info
+        let me_response = self.client
+            .get(&format!("{}/api/auth/me", BASE_URL))
+            .header("Authorization", format!("Bearer {}", login_result.token))
+            .send()
+            .await?;
+        
+        if me_response.status().is_success() {
+            let user_info: Value = me_response.json().await?;
+            self.regular_user_id = user_info["id"].as_str().map(|s| s.to_string());
+        }
+        
+        Ok(login_result.token)
+    }
+    
+    /// Get all users (admin only)
+    async fn get_all_users(&self, as_admin: bool) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = if as_admin {
+            self.admin_token.as_ref().ok_or("Admin not logged in")?
+        } else {
+            self.user_token.as_ref().ok_or("User not logged in")?
+        };
+        
+        let response = self.client
+            .get(&format!("{}/api/users", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get users failed: {} - {}", response.status(), response.text().await?).into());
+        }
+        
+        let users: Value = response.json().await?;
+        Ok(users)
+    }
+    
+    /// Create a new user (admin only)
+    async fn create_user(&self, username: &str, email: &str, role: UserRole) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.admin_token.as_ref().ok_or("Admin not logged in")?;
+        
+        let user_data = json!({
+            "username": username,
+            "email": email,
+            "password": "temporarypassword123",
+            "role": role.to_string()
+        });
+        
+        let response = self.client
+            .post(&format!("{}/api/users", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .json(&user_data)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Create user failed: {} - {}", response.status(), response.text().await?).into());
+        }
+        
+        let user: Value = response.json().await?;
+        Ok(user)
+    }
+    
+    /// Get specific user (admin only)
+    async fn get_user(&self, user_id: &str, as_admin: bool) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = if as_admin {
+            self.admin_token.as_ref().ok_or("Admin not logged in")?
+        } else {
+            self.user_token.as_ref().ok_or("User not logged in")?
+        };
+        
+        let response = self.client
+            .get(&format!("{}/api/users/{}", BASE_URL, user_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get user failed: {} - {}", response.status(), response.text().await?).into());
+        }
+        
+        let user: Value = response.json().await?;
+        Ok(user)
+    }
+    
+    /// Update user (admin only)
+    async fn update_user(&self, user_id: &str, updates: Value) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.admin_token.as_ref().ok_or("Admin not logged in")?;
+        
+        let response = self.client
+            .put(&format!("{}/api/users/{}", BASE_URL, user_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .json(&updates)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Update user failed: {} - {}", response.status(), response.text().await?).into());
+        }
+        
+        let user: Value = response.json().await?;
+        Ok(user)
+    }
+    
+    /// Delete user (admin only)
+    async fn delete_user(&self, user_id: &str) -> Result<(), Box<dyn std::error::Error>> {
+        let token = self.admin_token.as_ref().ok_or("Admin not logged in")?;
+        
+        let response = self.client
+            .delete(&format!("{}/api/users/{}", BASE_URL, user_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Delete user failed: {} - {}", response.status(), response.text().await?).into());
+        }
+        
+        Ok(())
+    }
+    
+    /// Get system metrics
+    async fn get_metrics(&self, as_admin: bool) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = if as_admin {
+            self.admin_token.as_ref().ok_or("Admin not logged in")?
+        } else {
+            self.user_token.as_ref().ok_or("User not logged in")?
+        };
+        
+        let response = self.client
+            .get(&format!("{}/api/metrics", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get metrics failed: {} - {}", response.status(), response.text().await?).into());
+        }
+        
+        let metrics: Value = response.json().await?;
+        Ok(metrics)
+    }
+    
+    /// Get Prometheus metrics (usually public)
+    async fn get_prometheus_metrics(&self) -> Result<String, Box<dyn std::error::Error>> {
+        let response = self.client
+            .get(&format!("{}/metrics", BASE_URL))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get Prometheus metrics failed: {}", response.status()).into());
+        }
+        
+        let metrics_text = response.text().await?;
+        Ok(metrics_text)
+    }
+}
+
+#[tokio::test]
+async fn test_admin_user_management_crud() {
+    let mut client = AdminTestClient::new();
+    
+    // Setup admin user
+    client.setup_admin().await
+        .expect("Failed to setup admin user");
+    
+    println!("✅ Admin user setup complete");
+    
+    // Test getting all users
+    let all_users = client.get_all_users(true).await
+        .expect("Failed to get all users as admin");
+    
+    // Should at least contain the admin user
+    assert!(all_users.as_array().unwrap().len() >= 1);
+    
+    let admin_found = all_users.as_array().unwrap().iter()
+        .any(|u| u["role"] == "admin");
+    assert!(admin_found);
+    
+    println!("✅ Admin can list all users");
+    
+    // Create a new user via admin API
+    let created_user = client.create_user("test_managed_user", "managed@example.com", UserRole::User).await
+        .expect("Failed to create user as admin");
+    
+    let created_user_id = created_user["id"].as_str().expect("User should have ID");
+    assert_eq!(created_user["username"], "test_managed_user");
+    assert_eq!(created_user["email"], "managed@example.com");
+    assert_eq!(created_user["role"], "user");
+    
+    println!("✅ Admin can create new users");
+    
+    // Get the created user details
+    let user_details = client.get_user(created_user_id, true).await
+        .expect("Failed to get user details as admin");
+    
+    assert_eq!(user_details["id"], created_user["id"]);
+    assert_eq!(user_details["username"], "test_managed_user");
+    
+    println!("✅ Admin can get user details");
+    
+    // Update the user
+    let updates = json!({
+        "username": "updated_managed_user",
+        "email": "updated_managed@example.com",
+        "role": "user"
+    });
+    
+    let updated_user = client.update_user(created_user_id, updates).await
+        .expect("Failed to update user as admin");
+    
+    assert_eq!(updated_user["username"], "updated_managed_user");
+    assert_eq!(updated_user["email"], "updated_managed@example.com");
+    
+    println!("✅ Admin can update users");
+    
+    // Verify the update persisted
+    let updated_user_details = client.get_user(created_user_id, true).await
+        .expect("Failed to get updated user details");
+    
+    assert_eq!(updated_user_details["username"], "updated_managed_user");
+    
+    // Delete the user
+    client.delete_user(created_user_id).await
+        .expect("Failed to delete user as admin");
+    
+    println!("✅ Admin can delete users");
+    
+    // Verify deletion
+    let delete_verification = client.get_user(created_user_id, true).await;
+    assert!(delete_verification.is_err());
+    
+    println!("🎉 Admin user management CRUD test passed!");
+}
+
+#[tokio::test]
+async fn test_role_based_access_control() {
+    let mut client = AdminTestClient::new();
+    
+    // Setup both admin and regular user
+    client.setup_admin().await
+        .expect("Failed to setup admin user");
+    
+    client.setup_regular_user().await
+        .expect("Failed to setup regular user");
+    
+    println!("✅ Both admin and regular user setup complete");
+    
+    // Test that regular user CANNOT access user management endpoints
+    
+    // Regular user should not be able to list all users
+    let user_list_attempt = client.get_all_users(false).await;
+    assert!(user_list_attempt.is_err());
+    println!("✅ Regular user cannot list all users");
+    
+    // Regular user should not be able to get specific user details
+    let admin_user_id = client.admin_user_id.as_ref().unwrap();
+    let user_details_attempt = client.get_user(admin_user_id, false).await;
+    assert!(user_details_attempt.is_err());
+    println!("✅ Regular user cannot access other user details");
+    
+    // Regular user should not be able to create users
+    let token = client.user_token.as_ref().unwrap();
+    let create_user_data = json!({
+        "username": "unauthorized_user",
+        "email": "unauthorized@example.com",
+        "password": "password123",
+        "role": "user"
+    });
+    
+    let create_response = client.client
+        .post(&format!("{}/api/users", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .json(&create_user_data)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!create_response.status().is_success());
+    println!("✅ Regular user cannot create users");
+    
+    // Test that admin CAN access all user management endpoints
+    let admin_users_list = client.get_all_users(true).await
+        .expect("Admin should be able to list users");
+    
+    assert!(admin_users_list.as_array().unwrap().len() >= 2); // At least admin and regular user
+    println!("✅ Admin can list all users");
+    
+    // Admin should be able to get regular user details
+    let regular_user_id = client.regular_user_id.as_ref().unwrap();
+    let regular_user_details = client.get_user(regular_user_id, true).await
+        .expect("Admin should be able to get user details");
+    
+    assert_eq!(regular_user_details["role"], "user");
+    println!("✅ Admin can access other user details");
+    
+    println!("🎉 Role-based access control test passed!");
+}
+
+#[tokio::test]
+async fn test_system_metrics_access() {
+    let mut client = AdminTestClient::new();
+    
+    // Setup admin and regular user
+    client.setup_admin().await
+        .expect("Failed to setup admin user");
+    
+    client.setup_regular_user().await
+        .expect("Failed to setup regular user");
+    
+    println!("✅ Users setup for metrics testing");
+    
+    // Test Prometheus metrics endpoint (usually public)
+    let prometheus_metrics = client.get_prometheus_metrics().await
+        .expect("Failed to get Prometheus metrics");
+    
+    // Should contain some basic metrics
+    assert!(prometheus_metrics.contains("# TYPE"));
+    assert!(prometheus_metrics.len() > 0);
+    println!("✅ Prometheus metrics accessible");
+    
+    // Test JSON metrics endpoint access
+    
+    // Admin should be able to access metrics
+    let admin_metrics = client.get_metrics(true).await;
+    if admin_metrics.is_ok() {
+        let metrics = admin_metrics.unwrap();
+        // Should have some system information
+        assert!(metrics.is_object());
+        println!("✅ Admin can access JSON metrics");
+    } else {
+        println!("⚠️  JSON metrics endpoint may not be implemented or accessible");
+    }
+    
+    // Regular user may or may not have access depending on implementation
+    let user_metrics = client.get_metrics(false).await;
+    match user_metrics {
+        Ok(_) => println!("ℹ️  Regular user can access JSON metrics"),
+        Err(_) => println!("ℹ️  Regular user cannot access JSON metrics (expected)"),
+    }
+    
+    println!("🎉 System metrics access test passed!");
+}
+
+#[tokio::test]
+async fn test_admin_user_role_management() {
+    let mut client = AdminTestClient::new();
+    
+    client.setup_admin().await
+        .expect("Failed to setup admin user");
+    
+    println!("✅ Admin user setup complete");
+    
+    // Create a regular user
+    let regular_user = client.create_user("role_test_user", "roletest@example.com", UserRole::User).await
+        .expect("Failed to create regular user");
+    
+    let user_id = regular_user["id"].as_str().unwrap();
+    assert_eq!(regular_user["role"], "user");
+    
+    println!("✅ Regular user created");
+    
+    // Promote user to admin
+    let promotion_updates = json!({
+        "username": "role_test_user",
+        "email": "roletest@example.com", 
+        "role": "admin"
+    });
+    
+    let promoted_user = client.update_user(user_id, promotion_updates).await
+        .expect("Failed to promote user to admin");
+    
+    assert_eq!(promoted_user["role"], "admin");
+    println!("✅ User promoted to admin");
+    
+    // Demote back to regular user
+    let demotion_updates = json!({
+        "username": "role_test_user",
+        "email": "roletest@example.com",
+        "role": "user"
+    });
+    
+    let demoted_user = client.update_user(user_id, demotion_updates).await
+        .expect("Failed to demote user back to regular user");
+    
+    assert_eq!(demoted_user["role"], "user");
+    println!("✅ User demoted back to regular user");
+    
+    // Clean up
+    client.delete_user(user_id).await
+        .expect("Failed to delete test user");
+    
+    println!("🎉 Admin user role management test passed!");
+}
+
+#[tokio::test]
+async fn test_admin_bulk_operations() {
+    let mut client = AdminTestClient::new();
+    
+    client.setup_admin().await
+        .expect("Failed to setup admin user");
+    
+    println!("✅ Admin user setup complete");
+    
+    // Create multiple users
+    let mut created_user_ids = Vec::new();
+    
+    for i in 1..=5 {
+        let user = client.create_user(
+            &format!("bulk_user_{}", i),
+            &format!("bulk_user_{}@example.com", i),
+            UserRole::User
+        ).await.expect("Failed to create bulk user");
+        
+        created_user_ids.push(user["id"].as_str().unwrap().to_string());
+    }
+    
+    println!("✅ Created 5 test users");
+    
+    // Verify all users exist in the list
+    let all_users = client.get_all_users(true).await
+        .expect("Failed to get all users");
+    
+    let users_array = all_users.as_array().unwrap();
+    assert!(users_array.len() >= 6); // At least admin + 5 created users
+    
+    // Verify each created user exists
+    for user_id in &created_user_ids {
+        let user_exists = users_array.iter()
+            .any(|u| u["id"].as_str() == Some(user_id));
+        assert!(user_exists);
+    }
+    
+    println!("✅ All created users found in list");
+    
+    // Update all users
+    for (i, user_id) in created_user_ids.iter().enumerate() {
+        let updates = json!({
+            "username": format!("updated_bulk_user_{}", i + 1),
+            "email": format!("updated_bulk_user_{}@example.com", i + 1),
+            "role": "user"
+        });
+        
+        client.update_user(user_id, updates).await
+            .expect("Failed to update bulk user");
+    }
+    
+    println!("✅ All users updated");
+    
+    // Verify updates
+    let updated_users = client.get_all_users(true).await
+        .expect("Failed to get updated users");
+    
+    let updated_count = updated_users.as_array().unwrap().iter()
+        .filter(|u| u["username"].as_str().unwrap_or("").starts_with("updated_bulk_user_"))
+        .count();
+    
+    assert_eq!(updated_count, 5);
+    println!("✅ All user updates verified");
+    
+    // Delete all created users
+    for user_id in &created_user_ids {
+        client.delete_user(user_id).await
+            .expect("Failed to delete bulk user");
+    }
+    
+    println!("✅ All test users deleted");
+    
+    // Verify deletions
+    let final_users = client.get_all_users(true).await
+        .expect("Failed to get final user list");
+    
+    for user_id in &created_user_ids {
+        let user_still_exists = final_users.as_array().unwrap().iter()
+            .any(|u| u["id"].as_str() == Some(user_id));
+        assert!(!user_still_exists);
+    }
+    
+    println!("🎉 Admin bulk operations test passed!");
+}
+
+#[tokio::test]
+async fn test_admin_error_handling() {
+    let mut client = AdminTestClient::new();
+    
+    client.setup_admin().await
+        .expect("Failed to setup admin user");
+    
+    println!("✅ Admin user setup complete");
+    
+    // Test creating user with invalid data
+    let invalid_user_data = json!({
+        "username": "", // Empty username
+        "email": "invalid-email", // Invalid email format
+        "password": "123", // Too short password
+        "role": "invalid_role" // Invalid role
+    });
+    
+    let token = client.admin_token.as_ref().unwrap();
+    let invalid_create_response = client.client
+        .post(&format!("{}/api/users", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .json(&invalid_user_data)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!invalid_create_response.status().is_success());
+    println!("✅ Invalid user creation properly rejected");
+    
+    // Test accessing non-existent user
+    let fake_user_id = Uuid::new_v4().to_string();
+    let non_existent_user_result = client.get_user(&fake_user_id, true).await;
+    assert!(non_existent_user_result.is_err());
+    println!("✅ Non-existent user access properly handled");
+    
+    // Test updating non-existent user
+    let update_non_existent = client.update_user(&fake_user_id, json!({"username": "test"})).await;
+    assert!(update_non_existent.is_err());
+    println!("✅ Non-existent user update properly handled");
+    
+    // Test deleting non-existent user
+    let delete_non_existent = client.delete_user(&fake_user_id).await;
+    assert!(delete_non_existent.is_err());
+    println!("✅ Non-existent user deletion properly handled");
+    
+    // Test creating duplicate username
+    let user1 = client.create_user("duplicate_test", "test1@example.com", UserRole::User).await
+        .expect("Failed to create first user");
+    
+    let duplicate_result = client.create_user("duplicate_test", "test2@example.com", UserRole::User).await;
+    // Should fail due to duplicate username
+    assert!(duplicate_result.is_err());
+    println!("✅ Duplicate username creation properly rejected");
+    
+    // Clean up
+    let user1_id = user1["id"].as_str().unwrap();
+    client.delete_user(user1_id).await
+        .expect("Failed to cleanup user");
+    
+    println!("🎉 Admin error handling test passed!");
+}

tests/comprehensive_source_management_tests.rs

@@ -0,0 +1,758 @@
+/*!
+ * Comprehensive Source Management Integration Tests
+ * 
+ * Tests complete CRUD operations and workflows for all source types:
+ * - WebDAV sources
+ * - S3 sources  
+ * - Local Folder sources
+ * 
+ * Covers:
+ * - Source creation, update, deletion
+ * - Connection testing and validation
+ * - Sync operations and status monitoring
+ * - Error handling and edge cases
+ * - Multi-user source isolation
+ */
+
+use reqwest::Client;
+use serde_json::{json, Value};
+use std::time::{Duration, Instant};
+use tokio::time::sleep;
+use uuid::Uuid;
+
+use readur::models::{CreateUser, LoginRequest, LoginResponse, UserRole, SourceType};
+
+const BASE_URL: &str = "http://localhost:8000";
+const TIMEOUT: Duration = Duration::from_secs(30);
+
+/// Test client for source management operations
+struct SourceTestClient {
+    client: Client,
+    token: Option<String>,
+    user_id: Option<String>,
+}
+
+impl SourceTestClient {
+    fn new() -> Self {
+        Self {
+            client: Client::new(),
+            token: None,
+            user_id: None,
+        }
+    }
+    
+    /// Register and login a test user
+    async fn register_and_login(&mut self, role: UserRole) -> Result<String, Box<dyn std::error::Error>> {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let username = format!("source_test_{}_{}", role.to_string(), timestamp);
+        let email = format!("source_test_{}@example.com", timestamp);
+        let password = "testpassword123";
+        
+        // Register user
+        let user_data = CreateUser {
+            username: username.clone(),
+            email: email.clone(),
+            password: password.to_string(),
+            role: Some(role),
+        };
+        
+        let register_response = self.client
+            .post(&format!("{}/api/auth/register", BASE_URL))
+            .json(&user_data)
+            .send()
+            .await?;
+        
+        if !register_response.status().is_success() {
+            return Err(format!("Registration failed: {}", register_response.text().await?).into());
+        }
+        
+        // Login to get token
+        let login_data = LoginRequest {
+            username: username.clone(),
+            password: password.to_string(),
+        };
+        
+        let login_response = self.client
+            .post(&format!("{}/api/auth/login", BASE_URL))
+            .json(&login_data)
+            .send()
+            .await?;
+        
+        if !login_response.status().is_success() {
+            return Err(format!("Login failed: {}", login_response.text().await?).into());
+        }
+        
+        let login_result: LoginResponse = login_response.json().await?;
+        self.token = Some(login_result.token.clone());
+        
+        // Get user info to store user_id
+        let me_response = self.client
+            .get(&format!("{}/api/auth/me", BASE_URL))
+            .header("Authorization", format!("Bearer {}", login_result.token))
+            .send()
+            .await?;
+        
+        if me_response.status().is_success() {
+            let user_info: Value = me_response.json().await?;
+            self.user_id = user_info["id"].as_str().map(|s| s.to_string());
+        }
+        
+        Ok(login_result.token)
+    }
+    
+    /// Create a WebDAV source
+    async fn create_webdav_source(&self, name: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let source_data = json!({
+            "name": name,
+            "source_type": "webdav",
+            "config": {
+                "server_url": "https://cloud.example.com",
+                "username": "testuser",
+                "password": "testpass",
+                "watch_folders": ["/Documents", "/Pictures"],
+                "file_extensions": [".pdf", ".txt", ".docx", ".jpg", ".png"],
+                "auto_sync": true,
+                "sync_interval_minutes": 60,
+                "server_type": "nextcloud"
+            }
+        });
+        
+        let response = self.client
+            .post(&format!("{}/api/sources", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .json(&source_data)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Source creation failed: {}", response.text().await?).into());
+        }
+        
+        let source: Value = response.json().await?;
+        Ok(source)
+    }
+    
+    /// Create an S3 source
+    async fn create_s3_source(&self, name: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let source_data = json!({
+            "name": name,
+            "source_type": "s3",
+            "config": {
+                "bucket": "test-documents-bucket",
+                "region": "us-east-1",
+                "access_key_id": "AKIAIOSFODNN7EXAMPLE",
+                "secret_access_key": "wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY",
+                "prefix": "documents/",
+                "endpoint_url": null,
+                "auto_sync": true,
+                "sync_interval_minutes": 120,
+                "file_extensions": [".pdf", ".txt", ".docx"]
+            }
+        });
+        
+        let response = self.client
+            .post(&format!("{}/api/sources", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .json(&source_data)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("S3 source creation failed: {}", response.text().await?).into());
+        }
+        
+        let source: Value = response.json().await?;
+        Ok(source)
+    }
+    
+    /// Create a Local Folder source
+    async fn create_local_folder_source(&self, name: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let source_data = json!({
+            "name": name,
+            "source_type": "local_folder",
+            "config": {
+                "folder_path": "/tmp/test_documents",
+                "watch_subdirectories": true,
+                "file_extensions": [".pdf", ".txt", ".jpg"],
+                "auto_sync": true,
+                "sync_interval_minutes": 30
+            }
+        });
+        
+        let response = self.client
+            .post(&format!("{}/api/sources", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .json(&source_data)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Local folder source creation failed: {}", response.text().await?).into());
+        }
+        
+        let source: Value = response.json().await?;
+        Ok(source)
+    }
+    
+    /// Get all sources for the authenticated user
+    async fn get_sources(&self) -> Result<Vec<Value>, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/sources", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get sources failed: {}", response.text().await?).into());
+        }
+        
+        let sources: Vec<Value> = response.json().await?;
+        Ok(sources)
+    }
+    
+    /// Get a specific source by ID
+    async fn get_source(&self, source_id: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/sources/{}", BASE_URL, source_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get source failed: {}", response.text().await?).into());
+        }
+        
+        let source: Value = response.json().await?;
+        Ok(source)
+    }
+    
+    /// Update a source
+    async fn update_source(&self, source_id: &str, updates: Value) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .put(&format!("{}/api/sources/{}", BASE_URL, source_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .json(&updates)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Update source failed: {}", response.text().await?).into());
+        }
+        
+        let source: Value = response.json().await?;
+        Ok(source)
+    }
+    
+    /// Delete a source
+    async fn delete_source(&self, source_id: &str) -> Result<(), Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .delete(&format!("{}/api/sources/{}", BASE_URL, source_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Delete source failed: {}", response.text().await?).into());
+        }
+        
+        Ok(())
+    }
+    
+    /// Test source connection
+    async fn test_source_connection(&self, source_id: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .post(&format!("{}/api/sources/{}/test", BASE_URL, source_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Test connection failed: {}", response.text().await?).into());
+        }
+        
+        let result: Value = response.json().await?;
+        Ok(result)
+    }
+    
+    /// Start source sync
+    async fn start_source_sync(&self, source_id: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .post(&format!("{}/api/sources/{}/sync", BASE_URL, source_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Start sync failed: {}", response.text().await?).into());
+        }
+        
+        let result: Value = response.json().await?;
+        Ok(result)
+    }
+    
+    /// Stop source sync
+    async fn stop_source_sync(&self, source_id: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .post(&format!("{}/api/sources/{}/sync/stop", BASE_URL, source_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Stop sync failed: {}", response.text().await?).into());
+        }
+        
+        let result: Value = response.json().await?;
+        Ok(result)
+    }
+    
+    /// Estimate source crawl
+    async fn estimate_source_crawl(&self, source_id: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .post(&format!("{}/api/sources/{}/estimate", BASE_URL, source_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Estimate crawl failed: {}", response.text().await?).into());
+        }
+        
+        let result: Value = response.json().await?;
+        Ok(result)
+    }
+}
+
+#[tokio::test]
+async fn test_webdav_source_crud_operations() {
+    let mut client = SourceTestClient::new();
+    
+    // Register and login as regular user
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    println!("✅ User registered and logged in");
+    
+    // Create WebDAV source
+    let source = client.create_webdav_source("Test WebDAV Source").await
+        .expect("Failed to create WebDAV source");
+    
+    let source_id = source["id"].as_str().expect("Source should have ID");
+    println!("✅ WebDAV source created: {}", source_id);
+    
+    // Validate source structure
+    assert_eq!(source["name"], "Test WebDAV Source");
+    assert_eq!(source["source_type"], "webdav");
+    assert_eq!(source["status"], "idle");
+    assert!(source["config"]["server_url"].as_str().unwrap().contains("cloud.example.com"));
+    assert_eq!(source["config"]["auto_sync"], true);
+    assert_eq!(source["config"]["sync_interval_minutes"], 60);
+    
+    // Get source by ID
+    let retrieved_source = client.get_source(source_id).await
+        .expect("Failed to get source by ID");
+    
+    assert_eq!(retrieved_source["id"], source["id"]);
+    assert_eq!(retrieved_source["name"], source["name"]);
+    println!("✅ Source retrieved by ID");
+    
+    // Update source
+    let updates = json!({
+        "name": "Updated WebDAV Source",
+        "config": {
+            "server_url": "https://cloud.example.com",
+            "username": "testuser",
+            "password": "testpass",
+            "watch_folders": ["/Documents", "/Pictures", "/Videos"],
+            "file_extensions": [".pdf", ".txt", ".docx", ".jpg", ".png", ".mp4"],
+            "auto_sync": false,
+            "sync_interval_minutes": 120,
+            "server_type": "nextcloud"
+        }
+    });
+    
+    let updated_source = client.update_source(source_id, updates).await
+        .expect("Failed to update source");
+    
+    assert_eq!(updated_source["name"], "Updated WebDAV Source");
+    assert_eq!(updated_source["config"]["auto_sync"], false);
+    assert_eq!(updated_source["config"]["sync_interval_minutes"], 120);
+    assert_eq!(updated_source["config"]["watch_folders"].as_array().unwrap().len(), 3);
+    println!("✅ Source updated successfully");
+    
+    // List sources
+    let sources = client.get_sources().await
+        .expect("Failed to get sources list");
+    
+    assert!(sources.len() >= 1);
+    let found_source = sources.iter().find(|s| s["id"] == source["id"])
+        .expect("Created source should be in list");
+    assert_eq!(found_source["name"], "Updated WebDAV Source");
+    println!("✅ Source found in list");
+    
+    // Delete source
+    client.delete_source(source_id).await
+        .expect("Failed to delete source");
+    
+    // Verify deletion
+    let sources_after_delete = client.get_sources().await
+        .expect("Failed to get sources after delete");
+    
+    let deleted_source = sources_after_delete.iter().find(|s| s["id"] == source["id"]);
+    assert!(deleted_source.is_none());
+    println!("✅ Source deleted successfully");
+    
+    println!("🎉 WebDAV source CRUD operations test passed!");
+}
+
+#[tokio::test]
+async fn test_s3_source_operations() {
+    let mut client = SourceTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    // Create S3 source
+    let source = client.create_s3_source("Test S3 Source").await
+        .expect("Failed to create S3 source");
+    
+    let source_id = source["id"].as_str().expect("Source should have ID");
+    println!("✅ S3 source created: {}", source_id);
+    
+    // Validate S3-specific configuration
+    assert_eq!(source["source_type"], "s3");
+    assert_eq!(source["config"]["bucket"], "test-documents-bucket");
+    assert_eq!(source["config"]["region"], "us-east-1");
+    assert_eq!(source["config"]["prefix"], "documents/");
+    assert!(source["config"]["endpoint_url"].is_null());
+    
+    // Test with MinIO configuration update
+    let minio_updates = json!({
+        "name": "MinIO S3 Source",
+        "config": {
+            "bucket": "minio-test-bucket",
+            "region": "us-east-1",
+            "access_key_id": "minioadmin",
+            "secret_access_key": "minioadmin",
+            "prefix": "",
+            "endpoint_url": "https://minio.example.com",
+            "auto_sync": true,
+            "sync_interval_minutes": 60,
+            "file_extensions": [".pdf", ".jpg"]
+        }
+    });
+    
+    let updated_source = client.update_source(source_id, minio_updates).await
+        .expect("Failed to update S3 source to MinIO");
+    
+    assert_eq!(updated_source["name"], "MinIO S3 Source");
+    assert_eq!(updated_source["config"]["endpoint_url"], "https://minio.example.com");
+    assert_eq!(updated_source["config"]["prefix"], "");
+    println!("✅ S3 source updated to MinIO configuration");
+    
+    // Clean up
+    client.delete_source(source_id).await
+        .expect("Failed to delete S3 source");
+    
+    println!("🎉 S3 source operations test passed!");
+}
+
+#[tokio::test]
+async fn test_local_folder_source_operations() {
+    let mut client = SourceTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    // Create Local Folder source
+    let source = client.create_local_folder_source("Test Local Folder").await
+        .expect("Failed to create local folder source");
+    
+    let source_id = source["id"].as_str().expect("Source should have ID");
+    println!("✅ Local folder source created: {}", source_id);
+    
+    // Validate Local Folder-specific configuration
+    assert_eq!(source["source_type"], "local_folder");
+    assert_eq!(source["config"]["folder_path"], "/tmp/test_documents");
+    assert_eq!(source["config"]["watch_subdirectories"], true);
+    assert_eq!(source["config"]["sync_interval_minutes"], 30);
+    
+    // Update with different path and settings
+    let updates = json!({
+        "name": "Updated Local Folder",
+        "config": {
+            "folder_path": "/home/user/documents",
+            "watch_subdirectories": false,
+            "file_extensions": [".pdf", ".txt", ".docx", ".xlsx"],
+            "auto_sync": false,
+            "sync_interval_minutes": 15
+        }
+    });
+    
+    let updated_source = client.update_source(source_id, updates).await
+        .expect("Failed to update local folder source");
+    
+    assert_eq!(updated_source["config"]["folder_path"], "/home/user/documents");
+    assert_eq!(updated_source["config"]["watch_subdirectories"], false);
+    assert_eq!(updated_source["config"]["auto_sync"], false);
+    println!("✅ Local folder source updated");
+    
+    // Clean up
+    client.delete_source(source_id).await
+        .expect("Failed to delete local folder source");
+    
+    println!("🎉 Local folder source operations test passed!");
+}
+
+#[tokio::test]
+async fn test_source_isolation_between_users() {
+    let mut user1_client = SourceTestClient::new();
+    let mut user2_client = SourceTestClient::new();
+    
+    // Register two different users
+    user1_client.register_and_login(UserRole::User).await
+        .expect("Failed to register user1");
+    user2_client.register_and_login(UserRole::User).await
+        .expect("Failed to register user2");
+    
+    println!("✅ Two users registered");
+    
+    // User 1 creates a source
+    let user1_source = user1_client.create_webdav_source("User1 WebDAV").await
+        .expect("Failed to create source for user1");
+    
+    let user1_source_id = user1_source["id"].as_str().unwrap();
+    
+    // User 2 creates a source
+    let user2_source = user2_client.create_s3_source("User2 S3").await
+        .expect("Failed to create source for user2");
+    
+    let user2_source_id = user2_source["id"].as_str().unwrap();
+    
+    println!("✅ Both users created sources");
+    
+    // User 1 should only see their own source
+    let user1_sources = user1_client.get_sources().await
+        .expect("Failed to get user1 sources");
+    
+    assert_eq!(user1_sources.len(), 1);
+    assert_eq!(user1_sources[0]["id"], user1_source["id"]);
+    assert_eq!(user1_sources[0]["name"], "User1 WebDAV");
+    
+    // User 2 should only see their own source
+    let user2_sources = user2_client.get_sources().await
+        .expect("Failed to get user2 sources");
+    
+    assert_eq!(user2_sources.len(), 1);
+    assert_eq!(user2_sources[0]["id"], user2_source["id"]);
+    assert_eq!(user2_sources[0]["name"], "User2 S3");
+    
+    println!("✅ Source isolation verified");
+    
+    // User 1 should not be able to access User 2's source
+    let user1_access_user2_result = user1_client.get_source(user2_source_id).await;
+    assert!(user1_access_user2_result.is_err());
+    
+    // User 2 should not be able to access User 1's source
+    let user2_access_user1_result = user2_client.get_source(user1_source_id).await;
+    assert!(user2_access_user1_result.is_err());
+    
+    println!("✅ Cross-user access prevention verified");
+    
+    // Clean up
+    user1_client.delete_source(user1_source_id).await
+        .expect("Failed to delete user1 source");
+    user2_client.delete_source(user2_source_id).await
+        .expect("Failed to delete user2 source");
+    
+    println!("🎉 Source isolation test passed!");
+}
+
+#[tokio::test]
+async fn test_source_sync_operations() {
+    let mut client = SourceTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    // Create a WebDAV source for sync testing
+    let source = client.create_webdav_source("Sync Test Source").await
+        .expect("Failed to create source");
+    
+    let source_id = source["id"].as_str().unwrap();
+    println!("✅ Source created for sync testing");
+    
+    // Test connection (this will likely fail due to fake server, but should return structured response)
+    let test_result = client.test_source_connection(source_id).await;
+    // Don't assert success since we're using fake credentials, just verify it returns a result
+    println!("✅ Connection test attempted: {:?}", test_result.is_ok());
+    
+    // Try to start sync
+    let sync_result = client.start_source_sync(source_id).await;
+    println!("✅ Sync start attempted: {:?}", sync_result.is_ok());
+    
+    // Try to get estimate
+    let estimate_result = client.estimate_source_crawl(source_id).await;
+    println!("✅ Crawl estimate attempted: {:?}", estimate_result.is_ok());
+    
+    // Try to stop sync
+    let stop_result = client.stop_source_sync(source_id).await;
+    println!("✅ Sync stop attempted: {:?}", stop_result.is_ok());
+    
+    // Get updated source to check if status changed
+    let updated_source = client.get_source(source_id).await
+        .expect("Failed to get updated source");
+    
+    // Source should still exist with some status
+    assert!(updated_source["status"].as_str().is_some());
+    println!("✅ Source status after operations: {}", updated_source["status"]);
+    
+    // Clean up
+    client.delete_source(source_id).await
+        .expect("Failed to delete source");
+    
+    println!("🎉 Source sync operations test passed!");
+}
+
+#[tokio::test]
+async fn test_source_error_handling() {
+    let mut client = SourceTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    // Test creating source with invalid configuration
+    let invalid_source_data = json!({
+        "name": "",  // Empty name should fail
+        "source_type": "webdav",
+        "config": {
+            "server_url": "invalid-url",  // Invalid URL
+            "username": "",  // Empty username
+            "password": "",  // Empty password
+        }
+    });
+    
+    let token = client.token.as_ref().unwrap();
+    let invalid_response = client.client
+        .post(&format!("{}/api/sources", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .json(&invalid_source_data)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    // Should return error for invalid data
+    assert!(!invalid_response.status().is_success());
+    println!("✅ Invalid source creation properly rejected");
+    
+    // Test accessing non-existent source
+    let fake_id = Uuid::new_v4().to_string();
+    let non_existent_result = client.get_source(&fake_id).await;
+    assert!(non_existent_result.is_err());
+    println!("✅ Non-existent source access properly handled");
+    
+    // Test operations without authentication
+    let unauth_client = Client::new();
+    let unauth_response = unauth_client
+        .get(&format!("{}/api/sources", BASE_URL))
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert_eq!(unauth_response.status(), 401);
+    println!("✅ Unauthenticated access properly rejected");
+    
+    println!("🎉 Source error handling test passed!");
+}
+
+#[tokio::test]
+async fn test_all_source_types_comprehensive() {
+    let mut client = SourceTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    // Create all three source types
+    let webdav_source = client.create_webdav_source("Comprehensive WebDAV").await
+        .expect("Failed to create WebDAV source");
+    
+    let s3_source = client.create_s3_source("Comprehensive S3").await
+        .expect("Failed to create S3 source");
+    
+    let local_source = client.create_local_folder_source("Comprehensive Local").await
+        .expect("Failed to create local folder source");
+    
+    println!("✅ All three source types created");
+    
+    // Verify all sources are in the list
+    let all_sources = client.get_sources().await
+        .expect("Failed to get all sources");
+    
+    assert_eq!(all_sources.len(), 3);
+    
+    let webdav_found = all_sources.iter().any(|s| s["source_type"] == "webdav");
+    let s3_found = all_sources.iter().any(|s| s["source_type"] == "s3");
+    let local_found = all_sources.iter().any(|s| s["source_type"] == "local_folder");
+    
+    assert!(webdav_found && s3_found && local_found);
+    println!("✅ All source types found in list");
+    
+    // Test operations on each source type
+    for source in &all_sources {
+        let source_id = source["id"].as_str().unwrap();
+        let source_type = source["source_type"].as_str().unwrap();
+        
+        // Get individual source details
+        let detailed_source = client.get_source(source_id).await
+            .expect(&format!("Failed to get {} source details", source_type));
+        
+        assert_eq!(detailed_source["id"], source["id"]);
+        assert_eq!(detailed_source["source_type"], source_type);
+        
+        // Test connection for each source
+        let _test_result = client.test_source_connection(source_id).await;
+        // Don't assert success since we're using test credentials
+        
+        println!("✅ {} source operations tested", source_type);
+    }
+    
+    // Clean up all sources
+    for source in &all_sources {
+        let source_id = source["id"].as_str().unwrap();
+        client.delete_source(source_id).await
+            .expect("Failed to delete source during cleanup");
+    }
+    
+    // Verify all sources deleted
+    let sources_after_cleanup = client.get_sources().await
+        .expect("Failed to get sources after cleanup");
+    
+    assert_eq!(sources_after_cleanup.len(), 0);
+    
+    println!("🎉 Comprehensive source types test passed!");
+}

tests/debug_ocr_test.rs

@@ -0,0 +1,244 @@
+/*!
+ * Debug OCR Test - Check what's actually happening with OCR text
+ */
+
+use reqwest::Client;
+use serde_json::Value;
+use std::time::{Duration, Instant};
+use tokio::time::sleep;
+use uuid::Uuid;
+
+use readur::models::{DocumentResponse, CreateUser, LoginRequest, LoginResponse};
+
+const BASE_URL: &str = "http://localhost:8000";
+const TIMEOUT: Duration = Duration::from_secs(60);
+
+#[tokio::test]
+async fn debug_ocr_content() {
+    println!("🔍 Debugging OCR content to see what's actually stored");
+    
+    let client = Client::new();
+    
+    // Check server health
+    let response = client
+        .get(&format!("{}/api/health", BASE_URL))
+        .timeout(Duration::from_secs(5))
+        .send()
+        .await
+        .expect("Server should be running");
+    
+    if !response.status().is_success() {
+        panic!("Server not healthy");
+    }
+    
+    // Create test user
+    let timestamp = std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .unwrap()
+        .as_millis();
+    let username = format!("debug_test_{}", timestamp);
+    let email = format!("debug_{}@test.com", timestamp);
+    
+    // Register user
+    let user_data = CreateUser {
+        username: username.clone(),
+        email: email.clone(),
+        password: "testpass123".to_string(),
+        role: Some(readur::models::UserRole::User),
+    };
+    
+    let register_response = client
+        .post(&format!("{}/api/auth/register", BASE_URL))
+        .json(&user_data)
+        .send()
+        .await
+        .expect("Registration should work");
+    
+    if !register_response.status().is_success() {
+        panic!("Registration failed: {}", register_response.text().await.unwrap_or_default());
+    }
+    
+    // Login
+    let login_data = LoginRequest {
+        username: username.clone(),
+        password: "testpass123".to_string(),
+    };
+    
+    let login_response = client
+        .post(&format!("{}/api/auth/login", BASE_URL))
+        .json(&login_data)
+        .send()
+        .await
+        .expect("Login should work");
+    
+    if !login_response.status().is_success() {
+        panic!("Login failed: {}", login_response.text().await.unwrap_or_default());
+    }
+    
+    let login_result: LoginResponse = login_response.json().await.expect("Login should return JSON");
+    let token = login_result.token;
+    
+    println!("✅ User logged in successfully");
+    
+    // Upload 2 documents with very distinctive content
+    let doc1_content = "DOCUMENT-ONE-UNIQUE-SIGNATURE-12345-ALPHA";
+    let doc2_content = "DOCUMENT-TWO-UNIQUE-SIGNATURE-67890-BETA";
+    
+    let part1 = reqwest::multipart::Part::text(doc1_content.to_string())
+        .file_name("debug_doc1.txt".to_string())
+        .mime_str("text/plain")
+        .expect("Valid mime type");
+    let form1 = reqwest::multipart::Form::new().part("file", part1);
+    
+    let part2 = reqwest::multipart::Part::text(doc2_content.to_string())
+        .file_name("debug_doc2.txt".to_string())
+        .mime_str("text/plain")
+        .expect("Valid mime type");
+    let form2 = reqwest::multipart::Form::new().part("file", part2);
+    
+    println!("📤 Uploading debug documents...");
+    
+    // Upload documents
+    let doc1_response = client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .multipart(form1)
+        .send()
+        .await
+        .expect("Upload should work");
+    
+    let doc2_response = client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .multipart(form2)
+        .send()
+        .await
+        .expect("Upload should work");
+    
+    let doc1: DocumentResponse = doc1_response.json().await.expect("Valid JSON");
+    let doc2: DocumentResponse = doc2_response.json().await.expect("Valid JSON");
+    
+    println!("📄 Document 1: {}", doc1.id);
+    println!("📄 Document 2: {}", doc2.id);
+    
+    // Wait for OCR to complete
+    let start = Instant::now();
+    let mut doc1_completed = false;
+    let mut doc2_completed = false;
+    
+    while start.elapsed() < TIMEOUT && (!doc1_completed || !doc2_completed) {
+        // Check document 1
+        if !doc1_completed {
+            let response = client
+                .get(&format!("{}/api/documents/{}/ocr", BASE_URL, doc1.id))
+                .header("Authorization", format!("Bearer {}", token))
+                .send()
+                .await
+                .expect("OCR endpoint should work");
+            
+            if response.status().is_success() {
+                let ocr_data: Value = response.json().await.expect("Valid JSON");
+                if ocr_data["ocr_status"].as_str() == Some("completed") {
+                    doc1_completed = true;
+                    println!("✅ Document 1 OCR completed");
+                }
+            }
+        }
+        
+        // Check document 2
+        if !doc2_completed {
+            let response = client
+                .get(&format!("{}/api/documents/{}/ocr", BASE_URL, doc2.id))
+                .header("Authorization", format!("Bearer {}", token))
+                .send()
+                .await
+                .expect("OCR endpoint should work");
+            
+            if response.status().is_success() {
+                let ocr_data: Value = response.json().await.expect("Valid JSON");
+                if ocr_data["ocr_status"].as_str() == Some("completed") {
+                    doc2_completed = true;
+                    println!("✅ Document 2 OCR completed");
+                }
+            }
+        }
+        
+        sleep(Duration::from_millis(100)).await;
+    }
+    
+    if !doc1_completed || !doc2_completed {
+        panic!("OCR did not complete within timeout");
+    }
+    
+    // Now get the actual OCR content and analyze it
+    let doc1_ocr_response = client
+        .get(&format!("{}/api/documents/{}/ocr", BASE_URL, doc1.id))
+        .header("Authorization", format!("Bearer {}", token))
+        .send()
+        .await
+        .expect("OCR endpoint should work");
+    
+    let doc2_ocr_response = client
+        .get(&format!("{}/api/documents/{}/ocr", BASE_URL, doc2.id))
+        .header("Authorization", format!("Bearer {}", token))
+        .send()
+        .await
+        .expect("OCR endpoint should work");
+    
+    let doc1_ocr: Value = doc1_ocr_response.json().await.expect("Valid JSON");
+    let doc2_ocr: Value = doc2_ocr_response.json().await.expect("Valid JSON");
+    
+    println!("\n🔍 DETAILED OCR ANALYSIS:");
+    println!("=====================================");
+    
+    println!("\n📋 Document 1 Analysis:");
+    println!("  - Expected content: {}", doc1_content);
+    println!("  - OCR status: {}", doc1_ocr["ocr_status"].as_str().unwrap_or("unknown"));
+    println!("  - OCR text: {:?}", doc1_ocr["ocr_text"]);
+    println!("  - OCR text length: {}", doc1_ocr["ocr_text"].as_str().unwrap_or("").len());
+    println!("  - OCR confidence: {:?}", doc1_ocr["ocr_confidence"]);
+    println!("  - OCR word count: {:?}", doc1_ocr["ocr_word_count"]);
+    
+    println!("\n📋 Document 2 Analysis:");
+    println!("  - Expected content: {}", doc2_content);
+    println!("  - OCR status: {}", doc2_ocr["ocr_status"].as_str().unwrap_or("unknown"));
+    println!("  - OCR text: {:?}", doc2_ocr["ocr_text"]);
+    println!("  - OCR text length: {}", doc2_ocr["ocr_text"].as_str().unwrap_or("").len());
+    println!("  - OCR confidence: {:?}", doc2_ocr["ocr_confidence"]);
+    println!("  - OCR word count: {:?}", doc2_ocr["ocr_word_count"]);
+    
+    // Check for corruption
+    let doc1_text = doc1_ocr["ocr_text"].as_str().unwrap_or("");
+    let doc2_text = doc2_ocr["ocr_text"].as_str().unwrap_or("");
+    
+    let doc1_has_own_signature = doc1_text.contains("DOCUMENT-ONE-UNIQUE-SIGNATURE-12345-ALPHA");
+    let doc1_has_other_signature = doc1_text.contains("DOCUMENT-TWO-UNIQUE-SIGNATURE-67890-BETA");
+    let doc2_has_own_signature = doc2_text.contains("DOCUMENT-TWO-UNIQUE-SIGNATURE-67890-BETA");
+    let doc2_has_other_signature = doc2_text.contains("DOCUMENT-ONE-UNIQUE-SIGNATURE-12345-ALPHA");
+    
+    println!("\n🚨 CORRUPTION ANALYSIS:");
+    println!("  Doc1 has own signature: {}", doc1_has_own_signature);
+    println!("  Doc1 has Doc2's signature: {}", doc1_has_other_signature);
+    println!("  Doc2 has own signature: {}", doc2_has_own_signature);
+    println!("  Doc2 has Doc1's signature: {}", doc2_has_other_signature);
+    
+    if doc1_text == doc2_text && !doc1_text.is_empty() {
+        println!("❌ IDENTICAL OCR TEXT DETECTED - Documents have the same content!");
+    }
+    
+    if doc1_text.is_empty() && doc2_text.is_empty() {
+        println!("❌ EMPTY OCR TEXT - Both documents have no OCR content!");
+    }
+    
+    if !doc1_has_own_signature || !doc2_has_own_signature {
+        println!("❌ MISSING SIGNATURES - Documents don't contain their expected content!");
+    }
+    
+    if doc1_has_other_signature || doc2_has_other_signature {
+        println!("❌ CROSS-CONTAMINATION - Documents contain each other's content!");
+    }
+    
+    if doc1_has_own_signature && doc2_has_own_signature && !doc1_has_other_signature && !doc2_has_other_signature {
+        println!("✅ NO CORRUPTION DETECTED - All documents have correct content!");
+    }
+}

tests/debug_pipeline_test.rs

@@ -0,0 +1,565 @@
+/*!
+ * Debug OCR Pipeline Test - Trace every step to find corruption source
+ */
+
+use reqwest::Client;
+use serde_json::Value;
+use std::time::{Duration, Instant};
+use tokio::time::sleep;
+use uuid::Uuid;
+use futures;
+
+use readur::models::{DocumentResponse, CreateUser, LoginRequest, LoginResponse};
+
+const BASE_URL: &str = "http://localhost:8000";
+const TIMEOUT: Duration = Duration::from_secs(120);
+
+struct PipelineDebugger {
+    client: Client,
+    token: String,
+}
+
+impl PipelineDebugger {
+    async fn new() -> Self {
+        let client = Client::new();
+        
+        // Check server health
+        let response = client
+            .get(&format!("{}/api/health", BASE_URL))
+            .timeout(Duration::from_secs(5))
+            .send()
+            .await
+            .expect("Server should be running");
+        
+        if !response.status().is_success() {
+            panic!("Server not healthy");
+        }
+        
+        // Create test user
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let username = format!("pipeline_debug_{}", timestamp);
+        let email = format!("pipeline_debug_{}@test.com", timestamp);
+        
+        // Register user
+        let user_data = CreateUser {
+            username: username.clone(),
+            email: email.clone(),
+            password: "testpass123".to_string(),
+            role: Some(readur::models::UserRole::User),
+        };
+        
+        let register_response = client
+            .post(&format!("{}/api/auth/register", BASE_URL))
+            .json(&user_data)
+            .send()
+            .await
+            .expect("Registration should work");
+        
+        if !register_response.status().is_success() {
+            panic!("Registration failed: {}", register_response.text().await.unwrap_or_default());
+        }
+        
+        // Login
+        let login_data = LoginRequest {
+            username: username.clone(),
+            password: "testpass123".to_string(),
+        };
+        
+        let login_response = client
+            .post(&format!("{}/api/auth/login", BASE_URL))
+            .json(&login_data)
+            .send()
+            .await
+            .expect("Login should work");
+        
+        if !login_response.status().is_success() {
+            panic!("Login failed: {}", login_response.text().await.unwrap_or_default());
+        }
+        
+        let login_result: LoginResponse = login_response.json().await.expect("Login should return JSON");
+        let token = login_result.token;
+        
+        println!("✅ Pipeline debugger initialized for user: {}", username);
+        
+        Self { client, token }
+    }
+    
+    async fn upload_document_with_debug(&self, content: &str, filename: &str) -> DocumentResponse {
+        println!("\n📤 UPLOAD PHASE - Starting upload for: {}", filename);
+        println!("  Content: {}", content);
+        println!("  Content Length: {} bytes", content.len());
+        
+        let part = reqwest::multipart::Part::text(content.to_string())
+            .file_name(filename.to_string())
+            .mime_str("text/plain")
+            .expect("Valid mime type");
+        let form = reqwest::multipart::Form::new().part("file", part);
+        
+        let upload_start = Instant::now();
+        let response = self.client
+            .post(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", self.token))
+            .multipart(form)
+            .send()
+            .await
+            .expect("Upload should work");
+        
+        let upload_duration = upload_start.elapsed();
+        
+        if !response.status().is_success() {
+            panic!("Upload failed: {}", response.text().await.unwrap_or_default());
+        }
+        
+        let document: DocumentResponse = response.json().await.expect("Valid JSON");
+        
+        println!("  ✅ Upload completed in {:?}", upload_duration);
+        println!("  📄 Document ID: {}", document.id);
+        println!("  📂 Filename: {}", document.filename);
+        println!("  📏 File Size: {} bytes", document.file_size);
+        println!("  🏷️  MIME Type: {}", document.mime_type);
+        println!("  🔄 Initial OCR Status: {:?}", document.ocr_status);
+        
+        document
+    }
+    
+    async fn trace_ocr_processing(&self, document_id: Uuid, expected_content: &str) -> Value {
+        println!("\n🔍 OCR PROCESSING PHASE - Tracing for document: {}", document_id);
+        
+        let start = Instant::now();
+        let mut last_status = String::new();
+        let mut status_changes = Vec::new();
+        let mut poll_count = 0;
+        
+        while start.elapsed() < TIMEOUT {
+            poll_count += 1;
+            
+            let response = self.client
+                .get(&format!("{}/api/documents/{}/ocr", BASE_URL, document_id))
+                .header("Authorization", format!("Bearer {}", self.token))
+                .send()
+                .await
+                .expect("OCR endpoint should work");
+            
+            if !response.status().is_success() {
+                println!("  ❌ OCR endpoint error: {}", response.status());
+                sleep(Duration::from_millis(100)).await;
+                continue;
+            }
+            
+            let ocr_data: Value = response.json().await.expect("Valid JSON");
+            let current_status = ocr_data["ocr_status"].as_str().unwrap_or("unknown").to_string();
+            
+            // Track status changes
+            if current_status != last_status {
+                let elapsed = start.elapsed();
+                status_changes.push((elapsed, current_status.clone()));
+                println!("  📋 Status Change #{}: {} -> {} (after {:?})", 
+                        status_changes.len(), last_status, current_status, elapsed);
+                last_status = current_status.clone();
+            }
+            
+            // Detailed logging every 10 polls or on status change
+            if poll_count % 10 == 0 || status_changes.len() > 0 {
+                println!("  🔄 Poll #{}: Status={}, HasText={}, TextLen={}", 
+                        poll_count, 
+                        current_status,
+                        ocr_data["has_ocr_text"].as_bool().unwrap_or(false),
+                        ocr_data["ocr_text"].as_str().unwrap_or("").len()
+                );
+                
+                if let Some(confidence) = ocr_data["ocr_confidence"].as_f64() {
+                    println!("    📊 Confidence: {:.1}%", confidence);
+                }
+                if let Some(word_count) = ocr_data["ocr_word_count"].as_i64() {
+                    println!("    📝 Word Count: {}", word_count);
+                }
+                if let Some(error) = ocr_data["ocr_error"].as_str() {
+                    println!("    ❌ Error: {}", error);
+                }
+            }
+            
+            // Check if processing is complete
+            match current_status.as_str() {
+                "completed" => {
+                    println!("  ✅ OCR Processing completed after {:?} and {} polls", start.elapsed(), poll_count);
+                    
+                    // Detailed final analysis
+                    let ocr_text = ocr_data["ocr_text"].as_str().unwrap_or("");
+                    println!("\n  🔬 FINAL CONTENT ANALYSIS:");
+                    println!("    Expected: {}", expected_content);
+                    println!("    Actual:   {}", ocr_text);
+                    println!("    Match: {}", ocr_text == expected_content);
+                    println!("    Expected Length: {} chars", expected_content.len());
+                    println!("    Actual Length:   {} chars", ocr_text.len());
+                    
+                    if ocr_text != expected_content {
+                        println!("    ⚠️  CONTENT MISMATCH DETECTED!");
+                        
+                        // Character-by-character comparison
+                        let expected_chars: Vec<char> = expected_content.chars().collect();
+                        let actual_chars: Vec<char> = ocr_text.chars().collect();
+                        
+                        for (i, (e, a)) in expected_chars.iter().zip(actual_chars.iter()).enumerate() {
+                            if e != a {
+                                println!("      Diff at position {}: expected '{}' got '{}'", i, e, a);
+                                break;
+                            }
+                        }
+                    }
+                    
+                    return ocr_data;
+                }
+                "failed" => {
+                    println!("  ❌ OCR Processing failed after {:?} and {} polls", start.elapsed(), poll_count);
+                    return ocr_data;
+                }
+                _ => {
+                    // Continue polling
+                }
+            }
+            
+            sleep(Duration::from_millis(50)).await;
+        }
+        
+        panic!("OCR processing did not complete within {:?}", TIMEOUT);
+    }
+    
+    async fn get_all_documents(&self) -> Vec<Value> {
+        let response = self.client
+            .get(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", self.token))
+            .send()
+            .await
+            .expect("Documents endpoint should work");
+        
+        if !response.status().is_success() {
+            panic!("Failed to get documents: {}", response.status());
+        }
+        
+        let data: Value = response.json().await.expect("Valid JSON");
+        
+        // Handle both paginated and non-paginated response formats
+        match data {
+            Value::Object(obj) if obj.contains_key("documents") => {
+                obj["documents"].as_array().unwrap_or(&vec![]).clone()
+            }
+            Value::Array(arr) => arr,
+            _ => vec![]
+        }
+    }
+}
+
+#[tokio::test]
+async fn debug_high_concurrency_pipeline() {
+    println!("🚀 STARTING HIGH-CONCURRENCY PIPELINE DEBUG");
+    println!("============================================");
+    
+    let debugger = PipelineDebugger::new().await;
+    
+    // Create 5 documents with unique, easily identifiable content
+    let documents = vec![
+        ("DOC-ALPHA-001-UNIQUE-SIGNATURE-ALPHA", "debug_alpha.txt"),
+        ("DOC-BRAVO-002-UNIQUE-SIGNATURE-BRAVO", "debug_bravo.txt"),
+        ("DOC-CHARLIE-003-UNIQUE-SIGNATURE-CHARLIE", "debug_charlie.txt"),
+        ("DOC-DELTA-004-UNIQUE-SIGNATURE-DELTA", "debug_delta.txt"),
+        ("DOC-ECHO-005-UNIQUE-SIGNATURE-ECHO", "debug_echo.txt"),
+    ];
+    
+    println!("\n📝 TEST DOCUMENTS:");
+    for (i, (content, filename)) in documents.iter().enumerate() {
+        println!("  {}: {} -> {}", i+1, filename, content);
+    }
+    
+    // Phase 1: Upload all documents simultaneously
+    println!("\n🏁 PHASE 1: SIMULTANEOUS UPLOAD");
+    println!("================================");
+    
+    let upload_start = Instant::now();
+    
+    // Execute all uploads concurrently
+    let uploaded_docs = futures::future::join_all(
+        documents.iter().map(|(content, filename)| {
+            debugger.upload_document_with_debug(content, filename)
+        }).collect::<Vec<_>>()
+    ).await;
+    let upload_duration = upload_start.elapsed();
+    
+    println!("\n✅ ALL UPLOADS COMPLETED in {:?}", upload_duration);
+    
+    // Phase 2: Trace OCR processing for each document
+    println!("\n🔬 PHASE 2: OCR PROCESSING TRACE");
+    println!("================================");
+    
+    let mut ocr_tasks = Vec::new();
+    
+    for (i, doc) in uploaded_docs.iter().enumerate() {
+        let doc_id = doc.id;
+        let expected_content = documents[i].0.to_string();
+        let debugger_ref = &debugger;
+        
+        let task = async move {
+            let result = debugger_ref.trace_ocr_processing(doc_id, &expected_content).await;
+            (doc_id, expected_content, result)
+        };
+        
+        ocr_tasks.push(task);
+    }
+    
+    // Process all OCR traces concurrently  
+    let ocr_results = futures::future::join_all(ocr_tasks).await;
+    
+    // Phase 3: Comprehensive analysis
+    println!("\n📊 PHASE 3: COMPREHENSIVE ANALYSIS");
+    println!("===================================");
+    
+    let mut corrupted_docs = Vec::new();
+    let mut successful_docs = Vec::new();
+    
+    for (doc_id, expected_content, ocr_result) in ocr_results {
+        let actual_text = ocr_result["ocr_text"].as_str().unwrap_or("");
+        let status = ocr_result["ocr_status"].as_str().unwrap_or("unknown");
+        
+        println!("\n📄 Document Analysis: {}", doc_id);
+        println!("  Status: {}", status);
+        println!("  Expected: {}", expected_content);
+        println!("  Actual:   {}", actual_text);
+        
+        if status == "completed" {
+            if actual_text == expected_content {
+                println!("  ✅ CONTENT CORRECT");
+                successful_docs.push(doc_id);
+            } else {
+                println!("  ❌ CONTENT CORRUPTED");
+                corrupted_docs.push((doc_id, expected_content.clone(), actual_text.to_string()));
+                
+                // Check if it contains any other document's content
+                for (other_expected, _) in &documents {
+                    if other_expected != &expected_content && actual_text.contains(other_expected) {
+                        println!("    🔄 Contains content from: {}", other_expected);
+                    }
+                }
+            }
+        } else {
+            println!("  ⚠️  NON-COMPLETED STATUS: {}", status);
+        }
+    }
+    
+    // Phase 4: System state analysis
+    println!("\n🏗️  PHASE 4: SYSTEM STATE ANALYSIS");
+    println!("===================================");
+    
+    let all_docs = debugger.get_all_documents().await;
+    println!("📋 Total documents in system: {}", all_docs.len());
+    
+    for doc in &all_docs {
+        if let (Some(id), Some(filename), Some(status)) = (
+            doc["id"].as_str(),
+            doc["filename"].as_str(), 
+            doc["ocr_status"].as_str()
+        ) {
+            println!("  📄 {}: {} -> {}", id, filename, status);
+        }
+    }
+    
+    // Final verdict
+    println!("\n🏆 FINAL VERDICT");
+    println!("================");
+    println!("✅ Successful: {}", successful_docs.len());
+    println!("❌ Corrupted:  {}", corrupted_docs.len());
+    
+    if corrupted_docs.is_empty() {
+        println!("🎉 NO CORRUPTION DETECTED!");
+    } else {
+        println!("🚨 CORRUPTION DETECTED IN {} DOCUMENTS:", corrupted_docs.len());
+        for (doc_id, expected, actual) in &corrupted_docs {
+            println!("  📄 {}: expected '{}' got '{}'", doc_id, expected, actual);
+        }
+        
+        // Try to identify patterns
+        if corrupted_docs.iter().all(|(_, _, actual)| actual.is_empty()) {
+            println!("🔍 PATTERN: All corrupted documents have EMPTY content");
+        } else if corrupted_docs.iter().all(|(_, _, actual)| actual == &corrupted_docs[0].2) {
+            println!("🔍 PATTERN: All corrupted documents have IDENTICAL content: '{}'", corrupted_docs[0].2);
+        } else {
+            println!("🔍 PATTERN: Mixed corruption types detected");
+        }
+        
+        panic!("CORRUPTION DETECTED - see analysis above");
+    }
+}
+
+#[tokio::test]
+async fn debug_extreme_high_concurrency_pipeline() {
+    println!("🚀 STARTING EXTREME HIGH-CONCURRENCY PIPELINE STRESS TEST");
+    println!("========================================================");
+    
+    let debugger = PipelineDebugger::new().await;
+    
+    // Create 50+ documents with unique, easily identifiable content
+    let mut documents = Vec::new();
+    for i in 1..=55 {
+        let content = format!("STRESS-TEST-DOCUMENT-{:03}-UNIQUE-SIGNATURE-{:03}", i, i);
+        let filename = format!("stress_test_{:03}.txt", i);
+        documents.push((content, filename));
+    }
+    
+    println!("\n📝 STRESS TEST SETUP:");
+    println!("  📊 Total Documents: {}", documents.len());
+    println!("  🔄 Concurrent Processing: All {} documents simultaneously", documents.len());
+    println!("  🎯 Goal: Zero corruption across all documents");
+    
+    // Phase 1: Upload all documents simultaneously
+    println!("\n🏁 PHASE 1: SIMULTANEOUS UPLOAD");
+    println!("================================");
+    
+    let upload_start = Instant::now();
+    
+    // Execute all uploads concurrently
+    let uploaded_docs = futures::future::join_all(
+        documents.iter().map(|(content, filename)| {
+            debugger.upload_document_with_debug(content, filename)
+        }).collect::<Vec<_>>()
+    ).await;
+    let upload_duration = upload_start.elapsed();
+    
+    println!("\n✅ ALL UPLOADS COMPLETED in {:?}", upload_duration);
+    
+    // Phase 2: Trace OCR processing for each document
+    println!("\n🔬 PHASE 2: OCR PROCESSING TRACE");
+    println!("================================");
+    
+    let mut ocr_tasks = Vec::new();
+    
+    for (i, doc) in uploaded_docs.iter().enumerate() {
+        let doc_id = doc.id;
+        let expected_content = documents[i].0.to_string();
+        let debugger_ref = &debugger;
+        
+        let task = async move {
+            let result = debugger_ref.trace_ocr_processing(doc_id, &expected_content).await;
+            (doc_id, expected_content, result)
+        };
+        
+        ocr_tasks.push(task);
+    }
+    
+    // Process all OCR traces concurrently  
+    let ocr_results = futures::future::join_all(ocr_tasks).await;
+    
+    // Phase 3: Comprehensive analysis
+    println!("\n📊 PHASE 3: COMPREHENSIVE ANALYSIS");
+    println!("===================================");
+    
+    let mut corrupted_docs = Vec::new();
+    let mut successful_docs = Vec::new();
+    
+    for (doc_id, expected_content, ocr_result) in ocr_results {
+        let actual_text = ocr_result["ocr_text"].as_str().unwrap_or("");
+        let status = ocr_result["ocr_status"].as_str().unwrap_or("unknown");
+        
+        println!("\n📄 Document Analysis: {}", doc_id);
+        println!("  Status: {}", status);
+        println!("  Expected: {}", expected_content);
+        println!("  Actual:   {}", actual_text);
+        
+        if status == "completed" {
+            if actual_text == expected_content {
+                println!("  ✅ CONTENT CORRECT");
+                successful_docs.push(doc_id);
+            } else {
+                println!("  ❌ CONTENT CORRUPTED");
+                corrupted_docs.push((doc_id, expected_content.clone(), actual_text.to_string()));
+                
+                // Check if it contains any other document's content
+                for (other_expected, _) in &documents {
+                    if other_expected != &expected_content && actual_text.contains(other_expected) {
+                        println!("    🔄 Contains content from: {}", other_expected);
+                    }
+                }
+            }
+        } else {
+            println!("  ⚠️  NON-COMPLETED STATUS: {}", status);
+        }
+    }
+    
+    // Phase 4: System state analysis
+    println!("\n🏗️  PHASE 4: SYSTEM STATE ANALYSIS");
+    println!("===================================");
+    
+    let all_docs = debugger.get_all_documents().await;
+    println!("📋 Total documents in system: {}", all_docs.len());
+    
+    for doc in &all_docs {
+        if let (Some(id), Some(filename), Some(status)) = (
+            doc["id"].as_str(),
+            doc["filename"].as_str(), 
+            doc["ocr_status"].as_str()
+        ) {
+            println!("  📄 {}: {} -> {}", id, filename, status);
+        }
+    }
+    
+    // Final verdict
+    println!("\n🏆 FINAL VERDICT");
+    println!("================");
+    println!("✅ Successful: {}", successful_docs.len());
+    println!("❌ Corrupted:  {}", corrupted_docs.len());
+    
+    if corrupted_docs.is_empty() {
+        println!("🎉 NO CORRUPTION DETECTED!");
+    } else {
+        println!("🚨 CORRUPTION DETECTED IN {} DOCUMENTS:", corrupted_docs.len());
+        for (doc_id, expected, actual) in &corrupted_docs {
+            println!("  📄 {}: expected '{}' got '{}'", doc_id, expected, actual);
+        }
+        
+        // Try to identify patterns
+        if corrupted_docs.iter().all(|(_, _, actual)| actual.is_empty()) {
+            println!("🔍 PATTERN: All corrupted documents have EMPTY content");
+        } else if corrupted_docs.iter().all(|(_, _, actual)| actual == &corrupted_docs[0].2) {
+            println!("🔍 PATTERN: All corrupted documents have IDENTICAL content: '{}'", corrupted_docs[0].2);
+        } else {
+            println!("🔍 PATTERN: Mixed corruption types detected");
+        }
+        
+        panic!("CORRUPTION DETECTED - see analysis above");
+    }
+}
+
+#[tokio::test] 
+async fn debug_document_upload_race_conditions() {
+    println!("🔍 DEBUGGING DOCUMENT UPLOAD PROCESS");
+    println!("====================================");
+    
+    let debugger = PipelineDebugger::new().await;
+    
+    // Upload same content with different filenames to test upload race conditions
+    let same_content = "IDENTICAL-CONTENT-FOR-RACE-CONDITION-TEST";
+    let task1 = debugger.upload_document_with_debug(same_content, "race1.txt");
+    let task2 = debugger.upload_document_with_debug(same_content, "race2.txt");
+    let task3 = debugger.upload_document_with_debug(same_content, "race3.txt");
+    
+    let (doc1, doc2, doc3) = futures::future::join3(task1, task2, task3).await;
+    let docs = vec![doc1, doc2, doc3];
+    
+    println!("\n📊 UPLOAD RACE CONDITION ANALYSIS:");
+    for (i, doc) in docs.iter().enumerate() {
+        println!("  Doc {}: ID={}, Filename={}, Size={}", 
+                i+1, doc.id, doc.filename, doc.file_size);
+    }
+    
+    // Check if all documents have unique IDs
+    let mut ids: Vec<_> = docs.iter().map(|d| d.id).collect();
+    ids.sort();
+    ids.dedup();
+    
+    if ids.len() == docs.len() {
+        println!("✅ All documents have unique IDs");
+    } else {
+        println!("❌ DUPLICATE DOCUMENT IDs DETECTED!");
+        panic!("Document upload race condition detected");
+    }
+}

tests/error_handling_edge_cases_tests.rs

@@ -0,0 +1,850 @@
+/*!
+ * Error Handling and Edge Cases Integration Tests
+ * 
+ * Tests comprehensive error scenarios and edge cases including:
+ * - Network failure recovery
+ * - Invalid input handling
+ * - Resource exhaustion scenarios
+ * - Authentication edge cases
+ * - File upload edge cases
+ * - Database constraint violations
+ * - Malformed request handling
+ * - Rate limiting and throttling
+ * - Concurrent operation conflicts
+ */
+
+use reqwest::Client;
+use serde_json::{json, Value};
+use std::time::{Duration, Instant};
+use tokio::time::sleep;
+use uuid::Uuid;
+
+use readur::models::{CreateUser, LoginRequest, LoginResponse, UserRole};
+
+const BASE_URL: &str = "http://localhost:8000";
+
+/// Test client for error handling scenarios
+struct ErrorHandlingTestClient {
+    client: Client,
+    token: Option<String>,
+}
+
+impl ErrorHandlingTestClient {
+    fn new() -> Self {
+        Self {
+            client: Client::new(),
+            token: None,
+        }
+    }
+    
+    fn new_with_timeout(timeout: Duration) -> Self {
+        let client = Client::builder()
+            .timeout(timeout)
+            .build()
+            .expect("Failed to create client with timeout");
+        
+        Self {
+            client,
+            token: None,
+        }
+    }
+    
+    /// Register and login with potential error handling
+    async fn safe_register_and_login(&mut self, role: UserRole) -> Result<String, Box<dyn std::error::Error>> {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let username = format!("error_test_{}_{}", role.to_string(), timestamp);
+        let email = format!("error_test_{}@example.com", timestamp);
+        let password = "testpassword123";
+        
+        // Register user with retry logic
+        let mut attempts = 0;
+        let max_attempts = 3;
+        
+        while attempts < max_attempts {
+            let user_data = CreateUser {
+                username: username.clone(),
+                email: email.clone(),
+                password: password.to_string(),
+                role: Some(role.clone()),
+            };
+            
+            match self.client
+                .post(&format!("{}/api/auth/register", BASE_URL))
+                .json(&user_data)
+                .send()
+                .await
+            {
+                Ok(response) => {
+                    if response.status().is_success() {
+                        break;
+                    } else {
+                        attempts += 1;
+                        if attempts >= max_attempts {
+                            return Err(format!("Registration failed after {} attempts: {}", max_attempts, response.text().await?).into());
+                        }
+                        sleep(Duration::from_millis(100 * attempts as u64)).await;
+                    }
+                }
+                Err(e) => {
+                    attempts += 1;
+                    if attempts >= max_attempts {
+                        return Err(format!("Registration network error after {} attempts: {}", max_attempts, e).into());
+                    }
+                    sleep(Duration::from_millis(100 * attempts as u64)).await;
+                }
+            }
+        }
+        
+        // Login with retry logic
+        let login_data = LoginRequest {
+            username: username.clone(),
+            password: password.to_string(),
+        };
+        
+        attempts = 0;
+        while attempts < max_attempts {
+            match self.client
+                .post(&format!("{}/api/auth/login", BASE_URL))
+                .json(&login_data)
+                .send()
+                .await
+            {
+                Ok(response) => {
+                    if response.status().is_success() {
+                        let login_result: LoginResponse = response.json().await?;
+                        self.token = Some(login_result.token.clone());
+                        return Ok(login_result.token);
+                    } else {
+                        attempts += 1;
+                        if attempts >= max_attempts {
+                            return Err(format!("Login failed after {} attempts: {}", max_attempts, response.text().await?).into());
+                        }
+                        sleep(Duration::from_millis(100 * attempts as u64)).await;
+                    }
+                }
+                Err(e) => {
+                    attempts += 1;
+                    if attempts >= max_attempts {
+                        return Err(format!("Login network error after {} attempts: {}", max_attempts, e).into());
+                    }
+                    sleep(Duration::from_millis(100 * attempts as u64)).await;
+                }
+            }
+        }
+        
+        Err("Failed to login after retries".into())
+    }
+}
+
+#[tokio::test]
+async fn test_invalid_authentication_scenarios() {
+    let client = Client::new();
+    
+    println!("🔐 Testing invalid authentication scenarios...");
+    
+    // Test 1: Empty credentials
+    let empty_login = json!({
+        "username": "",
+        "password": ""
+    });
+    
+    let response = client
+        .post(&format!("{}/api/auth/login", BASE_URL))
+        .json(&empty_login)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert_eq!(response.status(), 400);
+    println!("✅ Empty credentials properly rejected");
+    
+    // Test 2: Invalid username format
+    let invalid_username = json!({
+        "username": "user@with@multiple@ats",
+        "password": "validpassword123"
+    });
+    
+    let response = client
+        .post(&format!("{}/api/auth/login", BASE_URL))
+        .json(&invalid_username)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!response.status().is_success());
+    println!("✅ Invalid username format properly rejected");
+    
+    // Test 3: SQL injection attempt in login
+    let sql_injection = json!({
+        "username": "admin'; DROP TABLE users; --",
+        "password": "password"
+    });
+    
+    let response = client
+        .post(&format!("{}/api/auth/login", BASE_URL))
+        .json(&sql_injection)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!response.status().is_success());
+    println!("✅ SQL injection attempt in login properly rejected");
+    
+    // Test 4: Extremely long credentials
+    let long_username = "a".repeat(10000);
+    let long_password = "b".repeat(10000);
+    let long_creds = json!({
+        "username": long_username,
+        "password": long_password
+    });
+    
+    let response = client
+        .post(&format!("{}/api/auth/login", BASE_URL))
+        .json(&long_creds)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!response.status().is_success());
+    println!("✅ Extremely long credentials properly rejected");
+    
+    // Test 5: Invalid JWT token format
+    let invalid_token_response = client
+        .get(&format!("{}/api/auth/me", BASE_URL))
+        .header("Authorization", "Bearer invalid-jwt-token-format")
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert_eq!(invalid_token_response.status(), 401);
+    println!("✅ Invalid JWT token properly rejected");
+    
+    // Test 6: Malformed Authorization header
+    let malformed_auth_response = client
+        .get(&format!("{}/api/auth/me", BASE_URL))
+        .header("Authorization", "InvalidFormat token")
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert_eq!(malformed_auth_response.status(), 401);
+    println!("✅ Malformed Authorization header properly rejected");
+    
+    println!("🎉 Invalid authentication scenarios test passed!");
+}
+
+#[tokio::test]
+async fn test_malformed_request_handling() {
+    let mut client = ErrorHandlingTestClient::new();
+    
+    // Setup a valid user for testing authenticated endpoints
+    client.safe_register_and_login(UserRole::User).await
+        .expect("Failed to setup test user");
+    
+    let token = client.token.as_ref().unwrap();
+    
+    println!("🔧 Testing malformed request handling...");
+    
+    // Test 1: Invalid JSON in request body
+    let invalid_json_response = client.client
+        .post(&format!("{}/api/sources", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .header("Content-Type", "application/json")
+        .body("{invalid json syntax")
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert_eq!(invalid_json_response.status(), 400);
+    println!("✅ Invalid JSON properly rejected");
+    
+    // Test 2: Missing required fields
+    let missing_fields = json!({
+        "name": "Test Source"
+        // Missing source_type and config
+    });
+    
+    let response = client.client
+        .post(&format!("{}/api/sources", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .json(&missing_fields)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!response.status().is_success());
+    println!("✅ Missing required fields properly rejected");
+    
+    // Test 3: Invalid enum values
+    let invalid_enum = json!({
+        "name": "Test Source",
+        "source_type": "invalid_source_type",
+        "config": {}
+    });
+    
+    let response = client.client
+        .post(&format!("{}/api/sources", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .json(&invalid_enum)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!response.status().is_success());
+    println!("✅ Invalid enum values properly rejected");
+    
+    // Test 4: Nested object validation
+    let invalid_nested = json!({
+        "name": "Test Source",
+        "source_type": "webdav",
+        "config": {
+            "server_url": "not-a-valid-url",
+            "username": "",
+            "password": "",
+            "sync_interval_minutes": -1 // Invalid negative value
+        }
+    });
+    
+    let response = client.client
+        .post(&format!("{}/api/sources", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .json(&invalid_nested)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!response.status().is_success());
+    println!("✅ Invalid nested object validation working");
+    
+    // Test 5: Extra unexpected fields (should be ignored gracefully)
+    let extra_fields = json!({
+        "name": "Test Source",
+        "source_type": "webdav",
+        "config": {
+            "server_url": "https://valid-url.com",
+            "username": "testuser",
+            "password": "testpass",
+            "auto_sync": true,
+            "sync_interval_minutes": 60,
+            "watch_folders": ["/Documents"],
+            "file_extensions": [".pdf"]
+        },
+        "unexpected_field": "should be ignored",
+        "another_extra": 12345
+    });
+    
+    let response = client.client
+        .post(&format!("{}/api/sources", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .json(&extra_fields)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    // This might succeed if the API gracefully ignores extra fields
+    println!("✅ Extra fields handling: status {}", response.status());
+    
+    println!("🎉 Malformed request handling test passed!");
+}
+
+#[tokio::test]
+async fn test_file_upload_edge_cases() {
+    let mut client = ErrorHandlingTestClient::new();
+    
+    client.safe_register_and_login(UserRole::User).await
+        .expect("Failed to setup test user");
+    
+    let token = client.token.as_ref().unwrap();
+    
+    println!("📁 Testing file upload edge cases...");
+    
+    // Test 1: Empty file upload
+    let empty_part = reqwest::multipart::Part::text("")
+        .file_name("empty.txt")
+        .mime_str("text/plain")
+        .expect("Failed to create empty part");
+    let empty_form = reqwest::multipart::Form::new()
+        .part("file", empty_part);
+    
+    let response = client.client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .multipart(empty_form)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    // Empty files might be rejected or accepted depending on implementation
+    println!("✅ Empty file upload: status {}", response.status());
+    
+    // Test 2: Extremely large filename
+    let long_filename = format!("{}.txt", "a".repeat(1000));
+    let long_filename_part = reqwest::multipart::Part::text("content")
+        .file_name(long_filename)
+        .mime_str("text/plain")
+        .expect("Failed to create long filename part");
+    let long_filename_form = reqwest::multipart::Form::new()
+        .part("file", long_filename_part);
+    
+    let response = client.client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .multipart(long_filename_form)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    println!("✅ Long filename upload: status {}", response.status());
+    
+    // Test 3: Filename with special characters
+    let special_filename = "test<>:\"|?*.txt";
+    let special_filename_part = reqwest::multipart::Part::text("content")
+        .file_name(special_filename.to_string())
+        .mime_str("text/plain")
+        .expect("Failed to create special filename part");
+    let special_filename_form = reqwest::multipart::Form::new()
+        .part("file", special_filename_part);
+    
+    let response = client.client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .multipart(special_filename_form)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    println!("✅ Special characters filename: status {}", response.status());
+    
+    // Test 4: Missing file part
+    let no_file_form = reqwest::multipart::Form::new()
+        .text("not_file", "some text");
+    
+    let response = client.client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .multipart(no_file_form)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert!(!response.status().is_success());
+    println!("✅ Missing file part properly rejected");
+    
+    // Test 5: Multiple files (if not supported)
+    let file1 = reqwest::multipart::Part::text("content1")
+        .file_name("file1.txt")
+        .mime_str("text/plain")
+        .expect("Failed to create file1 part");
+    let file2 = reqwest::multipart::Part::text("content2")
+        .file_name("file2.txt")
+        .mime_str("text/plain")
+        .expect("Failed to create file2 part");
+    let multi_file_form = reqwest::multipart::Form::new()
+        .part("file", file1)
+        .part("file2", file2);
+    
+    let response = client.client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .multipart(multi_file_form)
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    println!("✅ Multiple files upload: status {}", response.status());
+    
+    // Test 6: Invalid MIME type
+    let invalid_mime_part = reqwest::multipart::Part::text("content")
+        .file_name("test.txt")
+        .mime_str("invalid/mime-type");
+    
+    if let Ok(part) = invalid_mime_part {
+        let invalid_mime_form = reqwest::multipart::Form::new()
+            .part("file", part);
+        
+        let response = client.client
+            .post(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .multipart(invalid_mime_form)
+            .send()
+            .await
+            .expect("Request should complete");
+        
+        println!("✅ Invalid MIME type: status {}", response.status());
+    } else {
+        println!("✅ Invalid MIME type rejected at client level");
+    }
+    
+    println!("🎉 File upload edge cases test passed!");
+}
+
+#[tokio::test]
+async fn test_concurrent_operation_conflicts() {
+    println!("🔄 Testing concurrent operation conflicts...");
+    
+    // Create multiple clients for concurrent operations
+    let mut clients = Vec::new();
+    for i in 0..3 {
+        let mut client = ErrorHandlingTestClient::new();
+        client.safe_register_and_login(UserRole::User).await
+            .expect(&format!("Failed to setup client {}", i));
+        clients.push(client);
+    }
+    
+    println!("✅ Setup {} concurrent clients", clients.len());
+    
+    // Test 1: Concurrent source creation with same name
+    let mut handles = Vec::new();
+    
+    for (i, client) in clients.iter().enumerate() {
+        let token = client.token.clone().unwrap();
+        let client_ref = &client.client;
+        let client_clone = client_ref.clone();
+        
+        let handle = tokio::spawn(async move {
+            let source_data = json!({
+                "name": "Concurrent Test Source", // Same name for all
+                "source_type": "webdav",
+                "config": {
+                    "server_url": format!("https://server{}.example.com", i),
+                    "username": "testuser",
+                    "password": "testpass",
+                    "auto_sync": false,
+                    "sync_interval_minutes": 60,
+                    "watch_folders": ["/Documents"],
+                    "file_extensions": [".pdf"]
+                }
+            });
+            
+            let response = client_clone
+                .post(&format!("{}/api/sources", BASE_URL))
+                .header("Authorization", format!("Bearer {}", token))
+                .json(&source_data)
+                .send()
+                .await
+                .expect("Request should complete");
+            
+            (i, response.status(), response.text().await.unwrap_or_default())
+        });
+        
+        handles.push(handle);
+    }
+    
+    // Wait for all concurrent operations
+    let mut results = Vec::new();
+    for handle in handles {
+        let result = handle.await.expect("Task should complete");
+        results.push(result);
+    }
+    
+    // Analyze results
+    let successful_count = results.iter()
+        .filter(|(_, status, _)| status.is_success())
+        .count();
+    
+    println!("✅ Concurrent source creation: {}/{} succeeded", successful_count, results.len());
+    
+    for (i, status, response) in results {
+        println!("  Client {}: {} - {}", i, status, response.chars().take(100).collect::<String>());
+    }
+    
+    // Test 2: Concurrent document uploads
+    let upload_content = "Concurrent upload test content";
+    let mut upload_handles = Vec::new();
+    
+    for (i, client) in clients.iter().enumerate() {
+        let token = client.token.clone().unwrap();
+        let client_ref = &client.client;
+        let client_clone = client_ref.clone();
+        let content = format!("{} - Client {}", upload_content, i);
+        
+        let handle = tokio::spawn(async move {
+            let part = reqwest::multipart::Part::text(content)
+                .file_name(format!("concurrent_test_{}.txt", i))
+                .mime_str("text/plain")
+                .expect("Failed to create part");
+            let form = reqwest::multipart::Form::new()
+                .part("file", part);
+            
+            let response = client_clone
+                .post(&format!("{}/api/documents", BASE_URL))
+                .header("Authorization", format!("Bearer {}", token))
+                .multipart(form)
+                .send()
+                .await
+                .expect("Request should complete");
+            
+            (i, response.status())
+        });
+        
+        upload_handles.push(handle);
+    }
+    
+    let mut upload_results = Vec::new();
+    for handle in upload_handles {
+        let result = handle.await.expect("Upload task should complete");
+        upload_results.push(result);
+    }
+    
+    let successful_uploads = upload_results.iter()
+        .filter(|(_, status)| status.is_success())
+        .count();
+    
+    println!("✅ Concurrent document uploads: {}/{} succeeded", successful_uploads, upload_results.len());
+    
+    println!("🎉 Concurrent operation conflicts test passed!");
+}
+
+#[tokio::test]
+async fn test_network_timeout_scenarios() {
+    println!("⏱️ Testing network timeout scenarios...");
+    
+    // Create client with very short timeout
+    let short_timeout_client = ErrorHandlingTestClient::new_with_timeout(Duration::from_millis(1));
+    
+    // Test 1: Registration with timeout
+    let timeout_result = short_timeout_client.client
+        .post(&format!("{}/api/auth/register", BASE_URL))
+        .json(&json!({
+            "username": "timeout_test",
+            "email": "timeout@example.com",
+            "password": "password123",
+            "role": "user"
+        }))
+        .send()
+        .await;
+    
+    // Should timeout or succeed very quickly
+    match timeout_result {
+        Ok(response) => println!("✅ Short timeout request completed: {}", response.status()),
+        Err(e) => {
+            if e.is_timeout() {
+                println!("✅ Short timeout properly triggered");
+            } else {
+                println!("✅ Request failed with error: {}", e);
+            }
+        }
+    }
+    
+    // Test 2: Normal timeout client
+    let normal_client = ErrorHandlingTestClient::new_with_timeout(Duration::from_secs(30));
+    
+    // Test long-running operation (document upload with processing)
+    let start_time = Instant::now();
+    
+    let large_content = "Large document content. ".repeat(1000);
+    let part = reqwest::multipart::Part::text(large_content)
+        .file_name("large_timeout_test.txt")
+        .mime_str("text/plain")
+        .expect("Failed to create large part");
+    let form = reqwest::multipart::Form::new()
+        .part("file", part);
+    
+    // This should complete within normal timeout
+    let upload_result = normal_client.client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .multipart(form)
+        .send()
+        .await;
+    
+    let elapsed = start_time.elapsed();
+    
+    match upload_result {
+        Ok(response) => {
+            println!("✅ Large upload completed in {:?}: {}", elapsed, response.status());
+        }
+        Err(e) => {
+            if e.is_timeout() {
+                println!("✅ Large upload timed out after {:?}", elapsed);
+            } else {
+                println!("✅ Large upload failed: {} after {:?}", e, elapsed);
+            }
+        }
+    }
+    
+    println!("🎉 Network timeout scenarios test passed!");
+}
+
+#[tokio::test]
+async fn test_resource_exhaustion_simulation() {
+    println!("💾 Testing resource exhaustion simulation...");
+    
+    let mut client = ErrorHandlingTestClient::new();
+    client.safe_register_and_login(UserRole::User).await
+        .expect("Failed to setup test user");
+    
+    let token = client.token.as_ref().unwrap();
+    
+    // Test 1: Rapid successive requests (stress test)
+    let rapid_request_count = 20;
+    let mut rapid_handles = Vec::new();
+    
+    println!("🚀 Sending {} rapid requests...", rapid_request_count);
+    
+    for i in 0..rapid_request_count {
+        let token_clone = token.clone();
+        let client_clone = client.client.clone();
+        
+        let handle = tokio::spawn(async move {
+            let start = Instant::now();
+            let response = client_clone
+                .get(&format!("{}/api/documents", BASE_URL))
+                .header("Authorization", format!("Bearer {}", token_clone))
+                .send()
+                .await;
+            
+            let elapsed = start.elapsed();
+            
+            match response {
+                Ok(resp) => (i, resp.status(), elapsed, None),
+                Err(e) => (i, reqwest::StatusCode::from_u16(500).unwrap(), elapsed, Some(e.to_string())),
+            }
+        });
+        
+        rapid_handles.push(handle);
+    }
+    
+    let mut rapid_results = Vec::new();
+    for handle in rapid_handles {
+        let result = handle.await.expect("Rapid request task should complete");
+        rapid_results.push(result);
+    }
+    
+    // Analyze rapid request results
+    let successful_rapid = rapid_results.iter()
+        .filter(|(_, status, _, _)| status.is_success())
+        .count();
+    
+    let avg_response_time = rapid_results.iter()
+        .map(|(_, _, elapsed, _)| *elapsed)
+        .sum::<Duration>() / rapid_results.len() as u32;
+    
+    println!("✅ Rapid requests: {}/{} succeeded, avg response time: {:?}", 
+             successful_rapid, rapid_request_count, avg_response_time);
+    
+    // Test 2: Large payload stress test
+    println!("📦 Testing large payload handling...");
+    
+    let very_large_content = "Very large document content for stress testing. ".repeat(10000);
+    let large_part = reqwest::multipart::Part::text(very_large_content)
+        .file_name("stress_test_large.txt")
+        .mime_str("text/plain")
+        .expect("Failed to create large stress part");
+    let large_form = reqwest::multipart::Form::new()
+        .part("file", large_part);
+    
+    let large_upload_start = Instant::now();
+    let large_upload_result = client.client
+        .post(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .multipart(large_form)
+        .send()
+        .await;
+    
+    let large_upload_elapsed = large_upload_start.elapsed();
+    
+    match large_upload_result {
+        Ok(response) => {
+            println!("✅ Large payload upload: {} in {:?}", response.status(), large_upload_elapsed);
+        }
+        Err(e) => {
+            println!("✅ Large payload upload failed: {} in {:?}", e, large_upload_elapsed);
+        }
+    }
+    
+    println!("🎉 Resource exhaustion simulation test passed!");
+}
+
+#[tokio::test]
+async fn test_database_constraint_violations() {
+    println!("🗄️ Testing database constraint violations...");
+    
+    let mut client = ErrorHandlingTestClient::new();
+    client.safe_register_and_login(UserRole::User).await
+        .expect("Failed to setup test user");
+    
+    let token = client.token.as_ref().unwrap();
+    
+    // Test 1: Duplicate email registration attempt
+    let original_user = json!({
+        "username": "original_user",
+        "email": "unique@example.com",
+        "password": "password123",
+        "role": "user"
+    });
+    
+    let register_response = client.client
+        .post(&format!("{}/api/auth/register", BASE_URL))
+        .json(&original_user)
+        .send()
+        .await
+        .expect("First registration should complete");
+    
+    println!("✅ First user registration: {}", register_response.status());
+    
+    // Try to register another user with the same email
+    let duplicate_email_user = json!({
+        "username": "different_username",
+        "email": "unique@example.com", // Same email
+        "password": "different_password",
+        "role": "user"
+    });
+    
+    let duplicate_response = client.client
+        .post(&format!("{}/api/auth/register", BASE_URL))
+        .json(&duplicate_email_user)
+        .send()
+        .await
+        .expect("Duplicate email registration should complete");
+    
+    // Should be rejected due to unique constraint
+    assert!(!duplicate_response.status().is_success());
+    println!("✅ Duplicate email registration properly rejected: {}", duplicate_response.status());
+    
+    // Test 2: Creating source with extremely long name
+    let long_name = "a".repeat(500);
+    let long_name_source = json!({
+        "name": long_name,
+        "source_type": "webdav",
+        "config": {
+            "server_url": "https://example.com",
+            "username": "user",
+            "password": "pass",
+            "auto_sync": false,
+            "sync_interval_minutes": 60,
+            "watch_folders": ["/Documents"],
+            "file_extensions": [".pdf"]
+        }
+    });
+    
+    let long_name_response = client.client
+        .post(&format!("{}/api/sources", BASE_URL))
+        .header("Authorization", format!("Bearer {}", token))
+        .json(&long_name_source)
+        .send()
+        .await
+        .expect("Long name source creation should complete");
+    
+    println!("✅ Long source name: {}", long_name_response.status());
+    
+    // Test 3: Invalid foreign key reference (if applicable)
+    let fake_user_id = Uuid::new_v4().to_string();
+    
+    // This test depends on the API structure, but we can test accessing resources
+    // that don't exist or belong to other users
+    let fake_source_id = Uuid::new_v4().to_string();
+    let fake_source_response = client.client
+        .get(&format!("{}/api/sources/{}", BASE_URL, fake_source_id))
+        .header("Authorization", format!("Bearer {}", token))
+        .send()
+        .await
+        .expect("Fake source access should complete");
+    
+    assert_eq!(fake_source_response.status(), 404);
+    println!("✅ Non-existent resource access properly rejected: {}", fake_source_response.status());
+    
+    println!("🎉 Database constraint violations test passed!");
+}

tests/file_processing_pipeline_tests.rs

@@ -0,0 +1,983 @@
+/*!
+ * File Processing Pipeline Integration Tests
+ * 
+ * Tests the complete file processing pipeline including:
+ * - File upload and validation
+ * - Thumbnail generation
+ * - Image preprocessing
+ * - OCR processing stages
+ * - Text extraction and indexing
+ * - File format support
+ * - Error recovery in processing
+ * - Pipeline performance monitoring
+ * - Resource cleanup
+ */
+
+use reqwest::Client;
+use serde_json::{json, Value};
+use std::time::{Duration, Instant};
+use tokio::time::sleep;
+use uuid::Uuid;
+
+use readur::models::{CreateUser, LoginRequest, LoginResponse, UserRole, DocumentResponse};
+
+const BASE_URL: &str = "http://localhost:8000";
+const PROCESSING_TIMEOUT: Duration = Duration::from_secs(120);
+
+/// Test client for file processing pipeline tests
+struct FileProcessingTestClient {
+    client: Client,
+    token: Option<String>,
+    user_id: Option<String>,
+}
+
+impl FileProcessingTestClient {
+    fn new() -> Self {
+        Self {
+            client: Client::new(),
+            token: None,
+            user_id: None,
+        }
+    }
+    
+    /// Setup test user
+    async fn setup_user(&mut self) -> Result<String, Box<dyn std::error::Error>> {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let username = format!("file_proc_test_{}", timestamp);
+        let email = format!("file_proc_test_{}@example.com", timestamp);
+        let password = "fileprocessingpassword123";
+        
+        // Register user
+        let user_data = CreateUser {
+            username: username.clone(),
+            email: email.clone(),
+            password: password.to_string(),
+            role: Some(UserRole::User),
+        };
+        
+        let register_response = self.client
+            .post(&format!("{}/api/auth/register", BASE_URL))
+            .json(&user_data)
+            .send()
+            .await?;
+        
+        if !register_response.status().is_success() {
+            return Err(format!("Registration failed: {}", register_response.text().await?).into());
+        }
+        
+        // Login to get token
+        let login_data = LoginRequest {
+            username: username.clone(),
+            password: password.to_string(),
+        };
+        
+        let login_response = self.client
+            .post(&format!("{}/api/auth/login", BASE_URL))
+            .json(&login_data)
+            .send()
+            .await?;
+        
+        if !login_response.status().is_success() {
+            return Err(format!("Login failed: {}", login_response.text().await?).into());
+        }
+        
+        let login_result: LoginResponse = login_response.json().await?;
+        self.token = Some(login_result.token.clone());
+        
+        // Get user info
+        let me_response = self.client
+            .get(&format!("{}/api/auth/me", BASE_URL))
+            .header("Authorization", format!("Bearer {}", login_result.token))
+            .send()
+            .await?;
+        
+        if me_response.status().is_success() {
+            let user_info: Value = me_response.json().await?;
+            self.user_id = user_info["id"].as_str().map(|s| s.to_string());
+        }
+        
+        Ok(login_result.token)
+    }
+    
+    /// Upload a file with specific content and MIME type
+    async fn upload_file(&self, content: &str, filename: &str, mime_type: &str) -> Result<DocumentResponse, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let part = reqwest::multipart::Part::text(content.to_string())
+            .file_name(filename.to_string())
+            .mime_str(mime_type)?;
+        let form = reqwest::multipart::Form::new()
+            .part("file", part);
+        
+        let response = self.client
+            .post(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .multipart(form)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Upload failed: {}", response.text().await?).into());
+        }
+        
+        let document: DocumentResponse = response.json().await?;
+        Ok(document)
+    }
+    
+    /// Upload binary file content
+    async fn upload_binary_file(&self, content: Vec<u8>, filename: &str, mime_type: &str) -> Result<DocumentResponse, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let part = reqwest::multipart::Part::bytes(content)
+            .file_name(filename.to_string())
+            .mime_str(mime_type)?;
+        let form = reqwest::multipart::Form::new()
+            .part("file", part);
+        
+        let response = self.client
+            .post(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .multipart(form)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Binary upload failed: {}", response.text().await?).into());
+        }
+        
+        let document: DocumentResponse = response.json().await?;
+        Ok(document)
+    }
+    
+    /// Wait for document processing to complete
+    async fn wait_for_processing(&self, document_id: &str) -> Result<DocumentResponse, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        let start = Instant::now();
+        
+        while start.elapsed() < PROCESSING_TIMEOUT {
+            let response = self.client
+                .get(&format!("{}/api/documents", BASE_URL))
+                .header("Authorization", format!("Bearer {}", token))
+                .send()
+                .await?;
+            
+            if response.status().is_success() {
+                let documents: Vec<DocumentResponse> = response.json().await?;
+                
+                if let Some(doc) = documents.iter().find(|d| d.id.to_string() == document_id) {
+                    match doc.ocr_status.as_deref() {
+                        Some("completed") => {
+                            // Create a copy of the document since we can't clone it
+                            let doc_copy = DocumentResponse {
+                                id: doc.id,
+                                filename: doc.filename.clone(),
+                                original_filename: doc.original_filename.clone(),
+                                file_size: doc.file_size,
+                                mime_type: doc.mime_type.clone(),
+                                ocr_status: doc.ocr_status.clone(),
+                                upload_date: doc.upload_date,
+                            };
+                            return Ok(doc_copy);
+                        }
+                        Some("failed") => return Err("Processing failed".into()),
+                        _ => {
+                            sleep(Duration::from_millis(500)).await;
+                            continue;
+                        }
+                    }
+                }
+            }
+            
+            sleep(Duration::from_millis(500)).await;
+        }
+        
+        Err("Processing timeout".into())
+    }
+    
+    /// Get document thumbnail
+    async fn get_thumbnail(&self, document_id: &str) -> Result<(reqwest::StatusCode, Vec<u8>), Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents/{}/thumbnail", BASE_URL, document_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        let status = response.status();
+        let bytes = response.bytes().await?.to_vec();
+        
+        Ok((status, bytes))
+    }
+    
+    /// Get processed image
+    async fn get_processed_image(&self, document_id: &str) -> Result<(reqwest::StatusCode, Vec<u8>), Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents/{}/processed-image", BASE_URL, document_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        let status = response.status();
+        let bytes = response.bytes().await?.to_vec();
+        
+        Ok((status, bytes))
+    }
+    
+    /// Get OCR results
+    async fn get_ocr_results(&self, document_id: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents/{}/ocr", BASE_URL, document_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("OCR retrieval failed: {}", response.text().await?).into());
+        }
+        
+        let ocr_data: Value = response.json().await?;
+        Ok(ocr_data)
+    }
+    
+    /// Download original file
+    async fn download_file(&self, document_id: &str) -> Result<(reqwest::StatusCode, Vec<u8>), Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents/{}/download", BASE_URL, document_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        let status = response.status();
+        let bytes = response.bytes().await?.to_vec();
+        
+        Ok((status, bytes))
+    }
+    
+    /// View file in browser
+    async fn view_file(&self, document_id: &str) -> Result<reqwest::StatusCode, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents/{}/view", BASE_URL, document_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        Ok(response.status())
+    }
+}
+
+#[tokio::test]
+async fn test_text_file_processing_pipeline() {
+    println!("📄 Testing text file processing pipeline...");
+    
+    let mut client = FileProcessingTestClient::new();
+    client.setup_user().await
+        .expect("Failed to setup test user");
+    
+    println!("✅ User setup complete");
+    
+    // Upload a text file
+    let text_content = r#"This is a test document for the file processing pipeline.
+It contains multiple lines of text that should be processed correctly.
+
+Key features to test:
+1. Text extraction
+2. OCR processing (even for text files)
+3. Thumbnail generation
+4. File storage and retrieval
+
+The document should be indexed and searchable.
+Processing time should be tracked.
+All pipeline stages should complete successfully.
+
+End of test document."#;
+    
+    let document = client.upload_file(text_content, "test_pipeline.txt", "text/plain").await
+        .expect("Failed to upload text file");
+    
+    let document_id = document.id.to_string();
+    println!("✅ Text file uploaded: {}", document_id);
+    
+    // Validate initial document properties
+    assert_eq!(document.mime_type, "text/plain");
+    assert!(document.file_size > 0);
+    assert_eq!(document.original_filename, "test_pipeline.txt");
+    assert!(document.ocr_status.is_some());
+    
+    // Wait for processing to complete
+    let processed_doc = client.wait_for_processing(&document_id).await
+        .expect("Failed to wait for processing");
+    
+    assert_eq!(processed_doc.ocr_status.as_deref(), Some("completed"));
+    println!("✅ Text file processing completed");
+    
+    // Test file download
+    let (download_status, downloaded_content) = client.download_file(&document_id).await
+        .expect("Failed to download file");
+    
+    assert!(download_status.is_success());
+    assert!(!downloaded_content.is_empty());
+    let downloaded_text = String::from_utf8_lossy(&downloaded_content);
+    assert!(downloaded_text.contains("test document for the file processing pipeline"));
+    println!("✅ File download successful");
+    
+    // Test file view
+    let view_status = client.view_file(&document_id).await
+        .expect("Failed to view file");
+    
+    println!("✅ File view status: {}", view_status);
+    
+    // Test OCR results
+    let ocr_results = client.get_ocr_results(&document_id).await
+        .expect("Failed to get OCR results");
+    
+    assert_eq!(ocr_results["document_id"], document_id);
+    assert_eq!(ocr_results["has_ocr_text"], true);
+    
+    if let Some(ocr_text) = ocr_results["ocr_text"].as_str() {
+        assert!(!ocr_text.is_empty());
+        assert!(ocr_text.contains("test document"));
+        println!("✅ OCR text extracted: {} characters", ocr_text.len());
+    }
+    
+    // Validate OCR metadata
+    if ocr_results["ocr_confidence"].is_number() {
+        let confidence = ocr_results["ocr_confidence"].as_f64().unwrap();
+        assert!((0.0..=100.0).contains(&confidence));
+        println!("✅ OCR confidence: {:.1}%", confidence);
+    }
+    
+    if ocr_results["ocr_word_count"].is_number() {
+        let word_count = ocr_results["ocr_word_count"].as_i64().unwrap();
+        assert!(word_count > 0);
+        println!("✅ OCR word count: {}", word_count);
+    }
+    
+    if ocr_results["ocr_processing_time_ms"].is_number() {
+        let processing_time = ocr_results["ocr_processing_time_ms"].as_i64().unwrap();
+        assert!(processing_time >= 0);
+        println!("✅ OCR processing time: {}ms", processing_time);
+    }
+    
+    // Test thumbnail generation
+    let (thumbnail_status, thumbnail_data) = client.get_thumbnail(&document_id).await
+        .expect("Failed to get thumbnail");
+    
+    if thumbnail_status.is_success() {
+        assert!(!thumbnail_data.is_empty());
+        println!("✅ Thumbnail generated: {} bytes", thumbnail_data.len());
+    } else {
+        println!("ℹ️  Thumbnail not available for text file: {}", thumbnail_status);
+    }
+    
+    println!("🎉 Text file processing pipeline test passed!");
+}
+
+#[tokio::test]
+async fn test_multiple_file_format_support() {
+    println!("📁 Testing multiple file format support...");
+    
+    let mut client = FileProcessingTestClient::new();
+    client.setup_user().await
+        .expect("Failed to setup test user");
+    
+    println!("✅ User setup complete");
+    
+    // Test different file formats
+    let test_files = vec![
+        ("text/plain", "test.txt", "Plain text file for format testing."),
+        ("text/csv", "test.csv", "name,age,city\nJohn,30,NYC\nJane,25,LA"),
+        ("application/json", "test.json", r#"{"test": "data", "format": "json"}"#),
+        ("text/xml", "test.xml", "<?xml version=\"1.0\"?><root><test>data</test></root>"),
+        ("text/markdown", "test.md", "# Test Markdown\n\nThis is **bold** text."),
+    ];
+    
+    let mut uploaded_documents = Vec::new();
+    
+    // Upload all test files
+    for (mime_type, filename, content) in &test_files {
+        println!("📤 Uploading {} file...", mime_type);
+        
+        match client.upload_file(content, filename, mime_type).await {
+            Ok(document) => {
+                println!("✅ Uploaded {}: {}", filename, document.id);
+                uploaded_documents.push((document, mime_type, filename, content));
+            }
+            Err(e) => {
+                println!("⚠️  Failed to upload {}: {}", filename, e);
+            }
+        }
+    }
+    
+    assert!(!uploaded_documents.is_empty(), "At least some files should upload successfully");
+    println!("✅ Uploaded {} files", uploaded_documents.len());
+    
+    // Test processing for each uploaded file
+    for (document, mime_type, filename, original_content) in &uploaded_documents {
+        println!("🔄 Processing {} ({})...", filename, mime_type);
+        
+        let document_id = document.id.to_string();
+        
+        // Wait for processing (with shorter timeout for multiple files)
+        match client.wait_for_processing(&document_id).await {
+            Ok(processed_doc) => {
+                println!("✅ {} processed successfully", filename);
+                
+                // Test OCR results
+                if let Ok(ocr_results) = client.get_ocr_results(&document_id).await {
+                    assert_eq!(ocr_results["document_id"], document_id);
+                    
+                    if ocr_results["has_ocr_text"] == true {
+                        if let Some(ocr_text) = ocr_results["ocr_text"].as_str() {
+                            assert!(!ocr_text.is_empty());
+                            
+                            // Verify OCR text contains some original content
+                            let content_words: Vec<&str> = original_content.split_whitespace().collect();
+                            if !content_words.is_empty() {
+                                let first_word = content_words[0];
+                                if first_word.len() > 2 { // Only check meaningful words
+                                    println!("✅ {} OCR text contains expected content", filename);
+                                }
+                            }
+                        }
+                    }
+                }
+                
+                // Test file download
+                if let Ok((download_status, _)) = client.download_file(&document_id).await {
+                    if download_status.is_success() {
+                        println!("✅ {} download successful", filename);
+                    }
+                }
+            }
+            Err(e) => {
+                println!("⚠️  {} processing failed: {}", filename, e);
+            }
+        }
+    }
+    
+    println!("🎉 Multiple file format support test completed!");
+}
+
+#[tokio::test]
+async fn test_image_processing_pipeline() {
+    println!("🖼️ Testing image processing pipeline...");
+    
+    let mut client = FileProcessingTestClient::new();
+    client.setup_user().await
+        .expect("Failed to setup test user");
+    
+    println!("✅ User setup complete");
+    
+    // Create a simple test image (minimal PNG)
+    // This is a 1x1 pixel transparent PNG
+    let png_data = vec![
+        0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, 0x00, 0x00, 0x00, 0x0D,
+        0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
+        0x08, 0x06, 0x00, 0x00, 0x00, 0x1F, 0x15, 0xC4, 0x89, 0x00, 0x00, 0x00,
+        0x0B, 0x49, 0x44, 0x41, 0x54, 0x78, 0x9C, 0x63, 0x00, 0x01, 0x00, 0x00,
+        0x05, 0x00, 0x01, 0x0D, 0x0A, 0x2D, 0xB4, 0x00, 0x00, 0x00, 0x00, 0x49,
+        0x45, 0x4E, 0x44, 0xAE, 0x42, 0x60, 0x82
+    ];
+    
+    let document = client.upload_binary_file(png_data.clone(), "test_image.png", "image/png").await
+        .expect("Failed to upload PNG image");
+    
+    let document_id = document.id.to_string();
+    println!("✅ PNG image uploaded: {}", document_id);
+    
+    // Validate image document properties
+    assert_eq!(document.mime_type, "image/png");
+    assert!(document.file_size > 0);
+    assert_eq!(document.original_filename, "test_image.png");
+    
+    // Wait for processing
+    let processed_doc = client.wait_for_processing(&document_id).await
+        .expect("Failed to wait for image processing");
+    
+    println!("✅ Image processing completed with status: {:?}", processed_doc.ocr_status);
+    
+    // Test thumbnail generation
+    let (thumbnail_status, thumbnail_data) = client.get_thumbnail(&document_id).await
+        .expect("Failed to get thumbnail");
+    
+    if thumbnail_status.is_success() {
+        assert!(!thumbnail_data.is_empty());
+        println!("✅ Image thumbnail generated: {} bytes", thumbnail_data.len());
+        
+        // Validate thumbnail is different from original (usually smaller or different format)
+        if thumbnail_data != png_data {
+            println!("✅ Thumbnail is processed (different from original)");
+        }
+    } else {
+        println!("ℹ️  Thumbnail generation failed: {}", thumbnail_status);
+    }
+    
+    // Test processed image
+    let (processed_status, processed_data) = client.get_processed_image(&document_id).await
+        .expect("Failed to get processed image");
+    
+    if processed_status.is_success() {
+        assert!(!processed_data.is_empty());
+        println!("✅ Processed image available: {} bytes", processed_data.len());
+    } else {
+        println!("ℹ️  Processed image not available: {}", processed_status);
+    }
+    
+    // Test OCR on image
+    let ocr_results = client.get_ocr_results(&document_id).await
+        .expect("Failed to get OCR results for image");
+    
+    assert_eq!(ocr_results["document_id"], document_id);
+    
+    // Image might not have text, so OCR could be empty
+    if ocr_results["has_ocr_text"] == true {
+        println!("✅ Image OCR completed with text");
+    } else {
+        println!("ℹ️  Image OCR completed but no text found (expected for test image)");
+    }
+    
+    // Test image download
+    let (download_status, downloaded_data) = client.download_file(&document_id).await
+        .expect("Failed to download image");
+    
+    assert!(download_status.is_success());
+    assert_eq!(downloaded_data, png_data);
+    println!("✅ Image download matches original");
+    
+    println!("🎉 Image processing pipeline test passed!");
+}
+
+#[tokio::test]
+async fn test_processing_error_recovery() {
+    println!("🔧 Testing processing error recovery...");
+    
+    let mut client = FileProcessingTestClient::new();
+    client.setup_user().await
+        .expect("Failed to setup test user");
+    
+    println!("✅ User setup complete");
+    
+    // Test 1: Empty file
+    println!("🔍 Testing empty file processing...");
+    
+    let empty_result = client.upload_file("", "empty.txt", "text/plain").await;
+    match empty_result {
+        Ok(document) => {
+            println!("✅ Empty file uploaded: {}", document.id);
+            
+            // Try to process empty file
+            match client.wait_for_processing(&document.id.to_string()).await {
+                Ok(processed) => {
+                    println!("✅ Empty file processing completed: {:?}", processed.ocr_status);
+                }
+                Err(e) => {
+                    println!("ℹ️  Empty file processing failed as expected: {}", e);
+                }
+            }
+        }
+        Err(e) => {
+            println!("ℹ️  Empty file upload rejected as expected: {}", e);
+        }
+    }
+    
+    // Test 2: Very large text content
+    println!("🔍 Testing large file processing...");
+    
+    let large_content = "Large file test content. ".repeat(10000);
+    let large_result = client.upload_file(&large_content, "large.txt", "text/plain").await;
+    
+    match large_result {
+        Ok(document) => {
+            println!("✅ Large file uploaded: {} (size: {} bytes)", document.id, document.file_size);
+            
+            // Give more time for large file processing
+            let start = Instant::now();
+            let extended_timeout = Duration::from_secs(180);
+            
+            while start.elapsed() < extended_timeout {
+                let response = client.client
+                    .get(&format!("{}/api/documents", BASE_URL))
+                    .header("Authorization", format!("Bearer {}", client.token.as_ref().unwrap()))
+                    .send()
+                    .await;
+                    
+                if let Ok(resp) = response {
+                    if let Ok(docs) = resp.json::<Vec<DocumentResponse>>().await {
+                    if let Some(doc) = docs.iter().find(|d| d.id == document.id) {
+                        match doc.ocr_status.as_deref() {
+                            Some("completed") => {
+                                println!("✅ Large file processing completed");
+                                break;
+                            }
+                            Some("failed") => {
+                                println!("ℹ️  Large file processing failed (may be expected for very large files)");
+                                break;
+                            }
+                            _ => {
+                                sleep(Duration::from_secs(2)).await;
+                                continue;
+                            }
+                        }
+                    }
+                    }
+                }
+                
+                sleep(Duration::from_secs(2)).await;
+            }
+        }
+        Err(e) => {
+            println!("ℹ️  Large file upload failed (may be expected): {}", e);
+        }
+    }
+    
+    // Test 3: Invalid file content but valid MIME type
+    println!("🔍 Testing corrupted file processing...");
+    
+    let corrupted_content = "This is not actually a PDF file content";
+    let corrupted_result = client.upload_file(corrupted_content, "fake.pdf", "application/pdf").await;
+    
+    match corrupted_result {
+        Ok(document) => {
+            println!("✅ Corrupted file uploaded: {}", document.id);
+            
+            // Processing should handle the mismatch gracefully
+            match client.wait_for_processing(&document.id.to_string()).await {
+                Ok(processed) => {
+                    println!("✅ Corrupted file processed: {:?}", processed.ocr_status);
+                }
+                Err(e) => {
+                    println!("ℹ️  Corrupted file processing failed as expected: {}", e);
+                }
+            }
+        }
+        Err(e) => {
+            println!("ℹ️  Corrupted file upload handled: {}", e);
+        }
+    }
+    
+    // Test 4: Special characters in filename
+    println!("🔍 Testing special characters in filename...");
+    
+    let special_filename = "test file with spaces & special chars!@#$%^&*()_+.txt";
+    let special_result = client.upload_file("Content with special filename", special_filename, "text/plain").await;
+    
+    match special_result {
+        Ok(document) => {
+            println!("✅ File with special characters uploaded: {}", document.id);
+            println!("✅ Original filename preserved: {}", document.original_filename);
+            
+            match client.wait_for_processing(&document.id.to_string()).await {
+                Ok(_) => println!("✅ Special filename file processed successfully"),
+                Err(e) => println!("⚠️  Special filename file processing failed: {}", e),
+            }
+        }
+        Err(e) => {
+            println!("ℹ️  Special filename upload handled: {}", e);
+        }
+    }
+    
+    println!("🎉 Processing error recovery test completed!");
+}
+
+#[tokio::test]
+async fn test_pipeline_performance_monitoring() {
+    println!("📊 Testing pipeline performance monitoring...");
+    
+    let mut client = FileProcessingTestClient::new();
+    client.setup_user().await
+        .expect("Failed to setup test user");
+    
+    println!("✅ User setup complete");
+    
+    // Upload multiple files to test pipeline performance
+    let test_files = vec![
+        ("Short text".to_string(), "short.txt"),
+        ("Medium length text content for performance testing. ".repeat(50), "medium.txt"),
+        ("Long text content for performance testing. ".repeat(500), "long.txt"),
+    ];
+    
+    let mut performance_results = Vec::new();
+    
+    for (content, filename) in &test_files {
+        println!("📤 Testing performance for {}...", filename);
+        
+        let upload_start = Instant::now();
+        
+        let document = client.upload_file(content, filename, "text/plain").await
+            .expect("Failed to upload file for performance test");
+        
+        let upload_time = upload_start.elapsed();
+        let processing_start = Instant::now();
+        
+        println!("✅ {} uploaded in {:?}", filename, upload_time);
+        
+        // Wait for processing and measure time
+        match client.wait_for_processing(&document.id.to_string()).await {
+            Ok(processed_doc) => {
+                let total_processing_time = processing_start.elapsed();
+                
+                // Get OCR results to check reported processing time
+                if let Ok(ocr_results) = client.get_ocr_results(&document.id.to_string()).await {
+                    let reported_time = ocr_results["ocr_processing_time_ms"]
+                        .as_i64()
+                        .map(|ms| Duration::from_millis(ms as u64));
+                    
+                    performance_results.push((
+                        filename.to_string(),
+                        content.len(),
+                        upload_time,
+                        total_processing_time,
+                        reported_time,
+                        processed_doc.ocr_status.clone(),
+                    ));
+                    
+                    println!("✅ {} processed in {:?} (reported: {:?})", 
+                             filename, total_processing_time, reported_time);
+                } else {
+                    performance_results.push((
+                        filename.to_string(),
+                        content.len(),
+                        upload_time,
+                        total_processing_time,
+                        None,
+                        processed_doc.ocr_status.clone(),
+                    ));
+                }
+            }
+            Err(e) => {
+                println!("⚠️  {} processing failed: {}", filename, e);
+                performance_results.push((
+                    filename.to_string(),
+                    content.len(),
+                    upload_time,
+                    Duration::ZERO,
+                    None,
+                    Some("failed".to_string()),
+                ));
+            }
+        }
+    }
+    
+    // Analyze performance results
+    println!("📊 Performance Analysis:");
+    println!("  {'File':<12} {'Size':<8} {'Upload':<10} {'Processing':<12} {'Reported':<10} {'Status'}");
+    println!("  {}", "-".repeat(70));
+    
+    for (filename, size, upload_time, processing_time, reported_time, status) in &performance_results {
+        let reported_str = reported_time
+            .map(|d| format!("{:?}", d))
+            .unwrap_or_else(|| "N/A".to_string());
+        
+        let status_str = status.as_deref().unwrap_or("unknown");
+        
+        println!("  {:<12} {:<8} {:?:<10} {:?:<12} {:<10} {}", 
+                 filename, size, upload_time, processing_time, reported_str, status_str);
+    }
+    
+    // Performance assertions
+    let successful_results: Vec<_> = performance_results.iter()
+        .filter(|(_, _, _, _, _, status)| status.as_deref() == Some("completed"))
+        .collect();
+    
+    assert!(!successful_results.is_empty(), "At least some files should process successfully");
+    
+    // Check that processing time generally correlates with file size
+    if successful_results.len() > 1 {
+        let avg_processing_time: Duration = successful_results.iter()
+            .map(|(_, _, _, processing_time, _, _)| *processing_time)
+            .sum::<Duration>() / successful_results.len() as u32;
+        
+        println!("✅ Average processing time: {:?}", avg_processing_time);
+        
+        // Processing should be reasonable (under 30 seconds for test files)
+        assert!(avg_processing_time < Duration::from_secs(30), "Average processing time should be reasonable");
+    }
+    
+    println!("🎉 Pipeline performance monitoring test passed!");
+}
+
+#[tokio::test]
+async fn test_concurrent_file_processing() {
+    println!("🔄 Testing concurrent file processing...");
+    
+    let mut client = FileProcessingTestClient::new();
+    client.setup_user().await
+        .expect("Failed to setup test user");
+    
+    println!("✅ User setup complete");
+    
+    // Upload multiple files concurrently
+    let concurrent_count = 5;
+    let mut upload_handles = Vec::new();
+    
+    for i in 0..concurrent_count {
+        let content = format!("Concurrent processing test document {}.\n\
+                              This document is being processed alongside {} other documents.\n\
+                              The system should handle multiple files efficiently.\n\
+                              Document UUID: {}", 
+                              i + 1, concurrent_count - 1, Uuid::new_v4());
+        let filename = format!("concurrent_{}.txt", i + 1);
+        
+        // Create a client for this upload
+        let token = client.token.clone().unwrap();
+        let client_clone = client.client.clone();
+        
+        let handle = tokio::spawn(async move {
+            let part = reqwest::multipart::Part::text(content)
+                .file_name(filename.clone())
+                .mime_str("text/plain")
+                .expect("Failed to create multipart");
+            let form = reqwest::multipart::Form::new()
+                .part("file", part);
+            
+            let start = Instant::now();
+            let response = client_clone
+                .post(&format!("{}/api/documents", BASE_URL))
+                .header("Authorization", format!("Bearer {}", token))
+                .multipart(form)
+                .send()
+                .await
+                .expect("Upload should complete");
+            
+            let upload_time = start.elapsed();
+            
+            if response.status().is_success() {
+                let document: DocumentResponse = response.json().await
+                    .expect("Should parse document response");
+                Ok((i, document, upload_time))
+            } else {
+                Err((i, response.text().await.unwrap_or_default()))
+            }
+        });
+        
+        upload_handles.push(handle);
+    }
+    
+    // Wait for all uploads to complete
+    let mut uploaded_documents = Vec::new();
+    for handle in upload_handles {
+        match handle.await.expect("Upload task should complete") {
+            Ok((index, document, upload_time)) => {
+                println!("✅ Document {} uploaded in {:?}: {}", index + 1, upload_time, document.id);
+                uploaded_documents.push(document);
+            }
+            Err((index, error)) => {
+                println!("⚠️  Document {} upload failed: {}", index + 1, error);
+            }
+        }
+    }
+    
+    assert!(!uploaded_documents.is_empty(), "At least some uploads should succeed");
+    println!("✅ {} files uploaded concurrently", uploaded_documents.len());
+    
+    // Now wait for all processing to complete
+    let mut processing_handles: Vec<tokio::task::JoinHandle<Result<(String, Duration, &str), Box<dyn std::error::Error + Send + Sync>>>> = Vec::new();
+    
+    for document in uploaded_documents {
+        let token = client.token.clone().unwrap();
+        let client_clone = client.client.clone();
+        let document_id = document.id.to_string();
+        
+        let handle = tokio::spawn(async move {
+            let start = Instant::now();
+            
+            // Wait for processing with timeout
+            while start.elapsed() < PROCESSING_TIMEOUT {
+                let response = client_clone
+                    .get(&format!("{}/api/documents", BASE_URL))
+                    .header("Authorization", format!("Bearer {}", token))
+                    .send()
+                    .await
+                    .expect("Should get documents");
+                
+                if response.status().is_success() {
+                    let documents: Vec<DocumentResponse> = response.json().await
+                        .expect("Should parse documents");
+                    
+                    if let Some(doc) = documents.iter().find(|d| d.id.to_string() == document_id) {
+                        match doc.ocr_status.as_deref() {
+                            Some("completed") => {
+                                return Ok((document_id, start.elapsed(), "completed"));
+                            }
+                            Some("failed") => {
+                                return Ok((document_id, start.elapsed(), "failed"));
+                            }
+                            _ => {
+                                sleep(Duration::from_millis(1000)).await;
+                                continue;
+                            }
+                        }
+                    }
+                }
+                
+                sleep(Duration::from_millis(1000)).await;
+            }
+            
+            Ok((document_id, start.elapsed(), "timeout"))
+        });
+        
+        processing_handles.push(handle);
+    }
+    
+    // Collect processing results
+    let mut processing_results = Vec::new();
+    for handle in processing_handles {
+        match handle.await.expect("Processing task should complete") {
+            Ok((doc_id, duration, status)) => {
+                println!("✅ Document {} processing {}: {:?}", doc_id, status, duration);
+                processing_results.push((doc_id, duration, status));
+            }
+            Err(e) => {
+                println!("⚠️  Processing task failed: {:?}", e);
+            }
+        }
+    }
+    
+    // Analyze concurrent processing results
+    let completed_count = processing_results.iter()
+        .filter(|(_, _, status)| *status == "completed")
+        .count();
+    
+    let failed_count = processing_results.iter()
+        .filter(|(_, _, status)| *status == "failed")
+        .count();
+    
+    let timeout_count = processing_results.iter()
+        .filter(|(_, _, status)| *status == "timeout")
+        .count();
+    
+    println!("📊 Concurrent Processing Results:");
+    println!("  Completed: {}", completed_count);
+    println!("  Failed: {}", failed_count);
+    println!("  Timeout: {}", timeout_count);
+    
+    if completed_count > 0 {
+        let avg_processing_time: Duration = processing_results.iter()
+            .filter(|(_, _, status)| *status == "completed")
+            .map(|(_, duration, _)| *duration)
+            .sum::<Duration>() / completed_count as u32;
+        
+        println!("  Average processing time: {:?}", avg_processing_time);
+    }
+    
+    // At least some files should process successfully
+    assert!(completed_count > 0, "At least some files should process successfully under concurrent load");
+    
+    // Most files should not timeout (indicates system responsiveness)
+    let success_rate = (completed_count + failed_count) as f64 / processing_results.len() as f64;
+    assert!(success_rate >= 0.8, "At least 80% of files should complete processing (not timeout)");
+    
+    println!("🎉 Concurrent file processing test passed!");
+}

tests/ocr_pipeline_integration_test.rs

@@ -0,0 +1,670 @@
+/*!
+ * OCR Pipeline Integration Test - Run the full pipeline internally
+ * 
+ * This test runs the OCR pipeline components directly instead of through HTTP,
+ * giving us complete visibility into the corruption process.
+ */
+
+use anyhow::Result;
+use sqlx::{PgPool, Row};
+use std::sync::Arc;
+use tokio::time::{sleep, Duration};
+use tracing::{info, warn, error};
+use uuid::Uuid;
+
+use readur::{
+    config::Config,
+    db::Database,
+    models::Document,
+    file_service::FileService,
+    enhanced_ocr::EnhancedOcrService,
+    ocr_queue::{OcrQueueService, OcrQueueItem},
+    db_guardrails_simple::DocumentTransactionManager,
+};
+
+const TEST_DB_URL: &str = "postgresql://readur_user:readur_password@localhost:5432/readur";
+
+struct OCRPipelineTestHarness {
+    db: Database,
+    pool: PgPool,
+    file_service: FileService,
+    ocr_service: EnhancedOcrService,
+    queue_service: OcrQueueService,
+    transaction_manager: DocumentTransactionManager,
+}
+
+impl OCRPipelineTestHarness {
+    async fn new() -> Result<Self> {
+        // Initialize database connection
+        let pool = sqlx::postgres::PgPoolOptions::new()
+            .max_connections(10)
+            .connect(TEST_DB_URL)
+            .await?;
+        
+        let db = Database::new(TEST_DB_URL).await?;
+        
+        // Initialize services
+        let file_service = FileService::new("./test_uploads".to_string());
+        let ocr_service = EnhancedOcrService::new("/tmp".to_string());
+        let queue_service = OcrQueueService::new(db.clone(), pool.clone(), 4);
+        let transaction_manager = DocumentTransactionManager::new(pool.clone());
+        
+        // Ensure test upload directory exists
+        std::fs::create_dir_all("./test_uploads").unwrap_or_default();
+        
+        Ok(Self {
+            db,
+            pool,
+            file_service,
+            ocr_service,
+            queue_service,
+            transaction_manager,
+        })
+    }
+    
+    async fn create_test_user(&self) -> Result<Uuid> {
+        let user_id = Uuid::new_v4();
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        
+        sqlx::query(
+            r#"
+            INSERT INTO users (id, username, email, password_hash, role)
+            VALUES ($1, $2, $3, $4, 'user')
+            "#
+        )
+        .bind(user_id)
+        .bind(format!("test_user_{}", timestamp))
+        .bind(format!("test_{}@example.com", timestamp))
+        .bind("dummy_hash") // We're not testing authentication
+        .execute(&self.pool)
+        .await?;
+        
+        info!("✅ Created test user: {}", user_id);
+        Ok(user_id)
+    }
+    
+    async fn create_test_document(&self, user_id: Uuid, content: &str, filename: &str) -> Result<(Uuid, String)> {
+        let doc_id = Uuid::new_v4();
+        let file_path = format!("./test_uploads/{}.txt", doc_id);
+        
+        // Write content to file
+        tokio::fs::write(&file_path, content).await?;
+        
+        // Create document record
+        sqlx::query(
+            r#"
+            INSERT INTO documents (
+                id, filename, original_filename, file_path, file_size, 
+                mime_type, content, user_id, ocr_status, created_at, updated_at
+            )
+            VALUES ($1, $2, $3, $4, $5, $6, $7, $8, 'pending', NOW(), NOW())
+            "#
+        )
+        .bind(doc_id)
+        .bind(filename)
+        .bind(filename)
+        .bind(&file_path)
+        .bind(content.len() as i64)
+        .bind("text/plain")
+        .bind(content) // Store original content for comparison
+        .bind(user_id)
+        .execute(&self.pool)
+        .await?;
+        
+        info!("✅ Created document: {} -> {} ({} bytes)", doc_id, filename, content.len());
+        Ok((doc_id, file_path))
+    }
+    
+    async fn enqueue_document_for_ocr(&self, doc_id: Uuid, priority: i32, file_size: i64) -> Result<Uuid> {
+        let queue_ids = self.queue_service.enqueue_document(doc_id, priority, file_size).await?;
+        info!("✅ Enqueued document {} for OCR processing", doc_id);
+        Ok(queue_ids)
+    }
+    
+    async fn get_document_details(&self, doc_id: Uuid) -> Result<DocumentDetails> {
+        let row = sqlx::query(
+            r#"
+            SELECT id, filename, file_path, ocr_status, ocr_text, ocr_confidence, 
+                   ocr_word_count, ocr_processing_time_ms, ocr_error, content
+            FROM documents 
+            WHERE id = $1
+            "#
+        )
+        .bind(doc_id)
+        .fetch_one(&self.pool)
+        .await?;
+        
+        Ok(DocumentDetails {
+            id: row.get("id"),
+            filename: row.get("filename"),
+            file_path: row.get("file_path"),
+            ocr_status: row.get("ocr_status"),
+            ocr_text: row.get("ocr_text"),
+            ocr_confidence: row.get("ocr_confidence"),
+            ocr_word_count: row.get("ocr_word_count"),
+            ocr_processing_time_ms: row.get("ocr_processing_time_ms"),
+            ocr_error: row.get("ocr_error"),
+            original_content: row.get("content"),
+        })
+    }
+    
+    async fn get_queue_item(&self, doc_id: Uuid) -> Result<Option<QueueItemDetails>> {
+        let row = sqlx::query(
+            r#"
+            SELECT id, document_id, status, priority, attempts, max_attempts,
+                   worker_id, created_at, started_at, completed_at, error_message
+            FROM ocr_queue 
+            WHERE document_id = $1
+            "#
+        )
+        .bind(doc_id)
+        .fetch_optional(&self.pool)
+        .await?;
+        
+        match row {
+            Some(r) => Ok(Some(QueueItemDetails {
+                id: r.get("id"),
+                document_id: r.get("document_id"),
+                status: r.get("status"),
+                priority: r.get("priority"),
+                attempts: r.get("attempts"),
+                max_attempts: r.get("max_attempts"),
+                worker_id: r.get("worker_id"),
+                error_message: r.get("error_message"),
+            })),
+            None => Ok(None),
+        }
+    }
+    
+    async fn process_single_ocr_job(&self, worker_id: &str) -> Result<Option<ProcessingResult>> {
+        info!("🔄 Worker {} attempting to dequeue job", worker_id);
+        
+        // Step 1: Dequeue a job
+        let item = match self.queue_service.dequeue().await? {
+            Some(item) => {
+                info!("✅ Worker {} claimed job {} for document {}", 
+                      worker_id, item.id, item.document_id);
+                item
+            }
+            None => {
+                info!("📭 No jobs available for worker {}", worker_id);
+                return Ok(None);
+            }
+        };
+        
+        let doc_id = item.document_id;
+        let job_id = item.id;
+        
+        // Step 2: Get document details
+        let doc_details = self.get_document_details(doc_id).await?;
+        info!("📄 Processing document: {} ({})", doc_details.filename, doc_details.file_path);
+        
+        // Step 3: Read file content to verify it matches expected
+        let file_content = match tokio::fs::read_to_string(&doc_details.file_path).await {
+            Ok(content) => {
+                info!("📖 Read file content: {} chars", content.len());
+                content
+            }
+            Err(e) => {
+                error!("❌ Failed to read file {}: {}", doc_details.file_path, e);
+                return Ok(Some(ProcessingResult {
+                    doc_id,
+                    job_id,
+                    success: false,
+                    error: Some(format!("File read error: {}", e)),
+                    ocr_text: None,
+                    original_content: doc_details.original_content,
+                    file_content: None,
+                }));
+            }
+        };
+        
+        // Step 4: Verify file content matches database content
+        if let Some(ref original) = doc_details.original_content {
+            if file_content != *original {
+                warn!("⚠️  File content mismatch for document {}!", doc_id);
+                warn!("   Expected: {}", original);
+                warn!("   File contains: {}", file_content);
+            } else {
+                info!("✅ File content matches database content");
+            }
+        }
+        
+        // Step 5: Run OCR processing
+        info!("🔍 Starting OCR processing for document {}", doc_id);
+        let settings = readur::models::Settings::default();
+        
+        let ocr_result = match self.ocr_service.extract_text(&doc_details.file_path, "text/plain", &settings).await {
+            Ok(result) => {
+                info!("✅ OCR extraction successful: {:.1}% confidence, {} words", 
+                      result.confidence, result.word_count);
+                info!("📝 OCR Text: {}", result.text);
+                result
+            }
+            Err(e) => {
+                error!("❌ OCR extraction failed: {}", e);
+                return Ok(Some(ProcessingResult {
+                    doc_id,
+                    job_id,
+                    success: false,
+                    error: Some(format!("OCR error: {}", e)),
+                    ocr_text: None,
+                    original_content: doc_details.original_content,
+                    file_content: Some(file_content),
+                }));
+            }
+        };
+        
+        // Step 6: Update document with OCR results using transaction manager
+        info!("💾 Saving OCR results to database");
+        let update_result = self.transaction_manager.update_ocr_with_validation(
+            doc_id,
+            &doc_details.filename,
+            &ocr_result.text,
+            ocr_result.confidence as f64,
+            ocr_result.word_count as i32,
+            ocr_result.processing_time_ms as i64,
+        ).await;
+        
+        match update_result {
+            Ok(true) => {
+                info!("✅ OCR results saved successfully for document {}", doc_id);
+                Ok(Some(ProcessingResult {
+                    doc_id,
+                    job_id,
+                    success: true,
+                    error: None,
+                    ocr_text: Some(ocr_result.text),
+                    original_content: doc_details.original_content,
+                    file_content: Some(file_content),
+                }))
+            }
+            Ok(false) => {
+                warn!("⚠️  OCR update validation failed for document {}", doc_id);
+                Ok(Some(ProcessingResult {
+                    doc_id,
+                    job_id,
+                    success: false,
+                    error: Some("OCR update validation failed".to_string()),
+                    ocr_text: Some(ocr_result.text),
+                    original_content: doc_details.original_content,
+                    file_content: Some(file_content),
+                }))
+            }
+            Err(e) => {
+                error!("❌ Failed to save OCR results: {}", e);
+                Ok(Some(ProcessingResult {
+                    doc_id,
+                    job_id,
+                    success: false,
+                    error: Some(format!("Database error: {}", e)),
+                    ocr_text: Some(ocr_result.text),
+                    original_content: doc_details.original_content,
+                    file_content: Some(file_content),
+                }))
+            }
+        }
+    }
+    
+    async fn simulate_concurrent_workers(&self, num_workers: usize, max_iterations: usize) -> Result<Vec<ProcessingResult>> {
+        info!("🏭 Starting {} concurrent OCR workers", num_workers);
+        
+        let mut handles = Vec::new();
+        
+        for worker_num in 1..=num_workers {
+            let worker_id = format!("test-worker-{}", worker_num);
+            // Clone the components we need rather than the whole harness
+            let queue_service = self.queue_service.clone();
+            let transaction_manager = self.transaction_manager.clone();
+            let ocr_service = EnhancedOcrService::new("/tmp".to_string());
+            let pool = self.pool.clone();
+            
+            let handle = tokio::spawn(async move {
+                let mut results = Vec::new();
+                
+                for iteration in 1..=max_iterations {
+                    info!("Worker {} iteration {}", worker_id, iteration);
+                    
+                    // Simulate the OCR processing within this spawned task
+                    let item = match queue_service.dequeue().await {
+                        Ok(Some(item)) => {
+                            info!("✅ Worker {} claimed job {} for document {}", 
+                                  worker_id, item.id, item.document_id);
+                            item
+                        }
+                        Ok(None) => {
+                            info!("📭 No jobs available for worker {}", worker_id);
+                            sleep(Duration::from_millis(10)).await;
+                            continue;
+                        }
+                        Err(e) => {
+                            error!("Worker {} error: {}", worker_id, e);
+                            break;
+                        }
+                    };
+                    
+                    let doc_id = item.document_id;
+                    let job_id = item.id;
+                    
+                    // Get document details 
+                    let doc_details = match sqlx::query(
+                        r#"
+                        SELECT id, filename, original_filename, file_path, file_size, 
+                               mime_type, content, user_id, ocr_status, created_at, updated_at
+                        FROM documents 
+                        WHERE id = $1
+                        "#
+                    )
+                    .bind(doc_id)
+                    .fetch_one(&pool)
+                    .await {
+                        Ok(row) => row,
+                        Err(e) => {
+                            error!("❌ Failed to get document details: {}", e);
+                            continue;
+                        }
+                    };
+                    
+                    let filename: String = doc_details.get("filename");
+                    let file_path: String = doc_details.get("file_path");
+                    let original_content: Option<String> = doc_details.get("content");
+                    
+                    // Read file content 
+                    let file_content = match tokio::fs::read_to_string(&file_path).await {
+                        Ok(content) => {
+                            info!("📖 Read file content: {} chars", content.len());
+                            content
+                        }
+                        Err(e) => {
+                            error!("❌ Failed to read file {}: {}", file_path, e);
+                            results.push(ProcessingResult {
+                                doc_id,
+                                job_id,
+                                success: false,
+                                error: Some(format!("File read error: {}", e)),
+                                ocr_text: None,
+                                original_content,
+                                file_content: None,
+                            });
+                            continue;
+                        }
+                    };
+                    
+                    // Verify file content matches database
+                    if let Some(ref original) = original_content {
+                        if file_content != *original {
+                            warn!("⚠️  File content mismatch for document {}!", doc_id);
+                            warn!("   Expected: {}", original);
+                            warn!("   File contains: {}", file_content);
+                        } else {
+                            info!("✅ File content matches database content");
+                        }
+                    }
+                    
+                    // Run OCR processing
+                    info!("🔍 Starting OCR processing for document {}", doc_id);
+                    let settings = readur::models::Settings::default();
+                    
+                    let ocr_result = match ocr_service.extract_text(&file_path, "text/plain", &settings).await {
+                        Ok(result) => {
+                            info!("✅ OCR extraction successful: {:.1}% confidence, {} words", 
+                                  result.confidence, result.word_count);
+                            info!("📝 OCR Text: {}", result.text);
+                            result
+                        }
+                        Err(e) => {
+                            error!("❌ OCR extraction failed: {}", e);
+                            results.push(ProcessingResult {
+                                doc_id,
+                                job_id,
+                                success: false,
+                                error: Some(format!("OCR error: {}", e)),
+                                ocr_text: None,
+                                original_content,
+                                file_content: Some(file_content),
+                            });
+                            continue;
+                        }
+                    };
+                    
+                    // Update document with OCR results using transaction manager
+                    info!("💾 Saving OCR results to database");
+                    let update_result = transaction_manager.update_ocr_with_validation(
+                        doc_id,
+                        &filename,
+                        &ocr_result.text,
+                        ocr_result.confidence as f64,
+                        ocr_result.word_count as i32,
+                        ocr_result.processing_time_ms as i64,
+                    ).await;
+                    
+                    match update_result {
+                        Ok(true) => {
+                            info!("✅ OCR results saved successfully for document {}", doc_id);
+                            results.push(ProcessingResult {
+                                doc_id,
+                                job_id,
+                                success: true,
+                                error: None,
+                                ocr_text: Some(ocr_result.text),
+                                original_content,
+                                file_content: Some(file_content),
+                            });
+                        }
+                        Ok(false) => {
+                            warn!("⚠️  OCR update validation failed for document {}", doc_id);
+                            results.push(ProcessingResult {
+                                doc_id,
+                                job_id,
+                                success: false,
+                                error: Some("OCR update validation failed".to_string()),
+                                ocr_text: Some(ocr_result.text),
+                                original_content,
+                                file_content: Some(file_content),
+                            });
+                        }
+                        Err(e) => {
+                            error!("❌ Failed to save OCR results: {}", e);
+                            results.push(ProcessingResult {
+                                doc_id,
+                                job_id,
+                                success: false,
+                                error: Some(format!("Database error: {}", e)),
+                                ocr_text: Some(ocr_result.text),
+                                original_content,
+                                file_content: Some(file_content),
+                            });
+                        }
+                    }
+                    
+                    // Small delay between iterations
+                    sleep(Duration::from_millis(1)).await;
+                }
+                
+                results
+            });
+            
+            handles.push(handle);
+        }
+        
+        // Wait for all workers to complete
+        let mut all_results = Vec::new();
+        for handle in handles {
+            let worker_results = handle.await?;
+            all_results.extend(worker_results);
+        }
+        
+        info!("🏁 All workers completed. Total jobs processed: {}", all_results.len());
+        Ok(all_results)
+    }
+    
+    async fn cleanup(&self) -> Result<()> {
+        // Clean up test files
+        let _ = tokio::fs::remove_dir_all("./test_uploads").await;
+        Ok(())
+    }
+}
+
+#[derive(Debug)]
+struct DocumentDetails {
+    id: Uuid,
+    filename: String,
+    file_path: String,
+    ocr_status: Option<String>,
+    ocr_text: Option<String>,
+    ocr_confidence: Option<f64>,
+    ocr_word_count: Option<i32>,
+    ocr_processing_time_ms: Option<i64>,
+    ocr_error: Option<String>,
+    original_content: Option<String>,
+}
+
+#[derive(Debug)]
+struct QueueItemDetails {
+    id: Uuid,
+    document_id: Uuid,
+    status: String,
+    priority: i32,
+    attempts: i32,
+    max_attempts: i32,
+    worker_id: Option<String>,
+    error_message: Option<String>,
+}
+
+#[derive(Debug)]
+struct ProcessingResult {
+    doc_id: Uuid,
+    job_id: Uuid,
+    success: bool,
+    error: Option<String>,
+    ocr_text: Option<String>,
+    original_content: Option<String>,
+    file_content: Option<String>,
+}
+
+#[tokio::test]
+async fn test_high_concurrency_ocr_pipeline_internal() {
+    println!("🚀 HIGH CONCURRENCY OCR PIPELINE INTERNAL TEST");
+    println!("===============================================");
+    
+    let harness = OCRPipelineTestHarness::new().await
+        .expect("Failed to initialize test harness");
+    
+    // Create test user
+    let user_id = harness.create_test_user().await
+        .expect("Failed to create test user");
+    
+    // Create 5 test documents with unique content
+    let test_documents = vec![
+        ("DOC-ALPHA-SIGNATURE-001", "test_alpha.txt"),
+        ("DOC-BRAVO-SIGNATURE-002", "test_bravo.txt"), 
+        ("DOC-CHARLIE-SIGNATURE-003", "test_charlie.txt"),
+        ("DOC-DELTA-SIGNATURE-004", "test_delta.txt"),
+        ("DOC-ECHO-SIGNATURE-005", "test_echo.txt"),
+    ];
+    
+    println!("\n📝 Creating test documents:");
+    let mut doc_ids = Vec::new();
+    
+    for (i, (content, filename)) in test_documents.iter().enumerate() {
+        let (doc_id, _) = harness.create_test_document(user_id, content, filename).await
+            .expect("Failed to create document");
+        
+        // Enqueue for OCR processing
+        harness.enqueue_document_for_ocr(doc_id, 100 - i as i32, content.len() as i64).await
+            .expect("Failed to enqueue document");
+        
+        doc_ids.push((doc_id, content.to_string()));
+        println!("  ✅ {}: {} -> {}", i+1, filename, content);
+    }
+    
+    // Simulate high concurrency with 5 workers processing simultaneously
+    println!("\n🏭 Starting concurrent OCR processing:");
+    let processing_results = harness.simulate_concurrent_workers(5, 10).await
+        .expect("Failed to run concurrent workers");
+    
+    // Analyze results
+    println!("\n📊 PROCESSING RESULTS ANALYSIS:");
+    println!("===============================");
+    
+    let mut successful_count = 0;
+    let mut failed_count = 0;
+    let mut corruption_detected = false;
+    
+    for result in &processing_results {
+        println!("\nDocument {}: {}", result.doc_id, if result.success { "✅ SUCCESS" } else { "❌ FAILED" });
+        
+        if result.success {
+            successful_count += 1;
+            
+            // Find the expected content for this document
+            if let Some((_, expected_content)) = doc_ids.iter().find(|(id, _)| *id == result.doc_id) {
+                let actual_ocr = result.ocr_text.as_deref().unwrap_or("");
+                
+                if actual_ocr == expected_content {
+                    println!("  ✅ Content matches expected");
+                } else {
+                    println!("  ❌ CORRUPTION DETECTED!");
+                    println!("    Expected: {}", expected_content);
+                    println!("    OCR Result: {}", actual_ocr);
+                    corruption_detected = true;
+                    
+                    // Check if file content was correct
+                    if let Some(ref file_content) = result.file_content {
+                        if file_content == expected_content {
+                            println!("    📁 File content was correct - corruption in OCR pipeline");
+                        } else {
+                            println!("    📁 File content was also wrong - corruption in file system");
+                        }
+                    }
+                }
+            }
+        } else {
+            failed_count += 1;
+            println!("  Error: {}", result.error.as_deref().unwrap_or("Unknown"));
+        }
+    }
+    
+    // Final verification - check database state
+    println!("\n🔍 FINAL DATABASE STATE VERIFICATION:");
+    println!("=====================================");
+    
+    for (doc_id, expected_content) in &doc_ids {
+        let details = harness.get_document_details(*doc_id).await
+            .expect("Failed to get document details");
+        
+        println!("\nDocument {}:", doc_id);
+        println!("  Status: {}", details.ocr_status.as_deref().unwrap_or("unknown"));
+        println!("  Expected: {}", expected_content);
+        println!("  OCR Text: {}", details.ocr_text.as_deref().unwrap_or("(none)"));
+        
+        if details.ocr_status == Some("completed".to_string()) {
+            let actual_text = details.ocr_text.as_deref().unwrap_or("");
+            if actual_text != expected_content {
+                println!("  ❌ DATABASE CORRUPTION CONFIRMED");
+                corruption_detected = true;
+            } else {
+                println!("  ✅ Database content correct");
+            }
+        }
+    }
+    
+    // Cleanup
+    harness.cleanup().await.expect("Failed to cleanup");
+    
+    // Final results
+    println!("\n🏆 FINAL RESULTS:");
+    println!("=================");
+    println!("✅ Successful: {}", successful_count);
+    println!("❌ Failed: {}", failed_count);
+    println!("🔬 Total processed: {}", processing_results.len());
+    
+    if corruption_detected {
+        panic!("🚨 OCR CORRUPTION DETECTED in internal pipeline test!");
+    } else {
+        println!("🎉 No corruption detected in high-concurrency test!");
+    }
+}

tests/ocr_queue_management_tests.rs

@@ -0,0 +1,637 @@
+/*!
+ * OCR Queue Management Integration Tests
+ * 
+ * Tests OCR queue operations including:
+ * - Queue statistics and monitoring
+ * - Failed job recovery and requeuing
+ * - Queue status tracking
+ * - Performance monitoring
+ * - Concurrent OCR processing
+ * - Priority handling
+ */
+
+use reqwest::Client;
+use serde_json::{json, Value};
+use std::time::{Duration, Instant};
+use tokio::time::sleep;
+use uuid::Uuid;
+
+use readur::models::{CreateUser, LoginRequest, LoginResponse, UserRole, DocumentResponse};
+
+const BASE_URL: &str = "http://localhost:8000";
+const TIMEOUT: Duration = Duration::from_secs(60);
+
+/// Test client for OCR queue operations
+struct OCRQueueTestClient {
+    client: Client,
+    token: Option<String>,
+    user_id: Option<String>,
+}
+
+impl OCRQueueTestClient {
+    fn new() -> Self {
+        Self {
+            client: Client::new(),
+            token: None,
+            user_id: None,
+        }
+    }
+    
+    /// Register and login a test user
+    async fn register_and_login(&mut self, role: UserRole) -> Result<String, Box<dyn std::error::Error>> {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let username = format!("ocr_queue_test_{}_{}", role.to_string(), timestamp);
+        let email = format!("ocr_queue_test_{}@example.com", timestamp);
+        let password = "testpassword123";
+        
+        // Register user
+        let user_data = CreateUser {
+            username: username.clone(),
+            email: email.clone(),
+            password: password.to_string(),
+            role: Some(role),
+        };
+        
+        let register_response = self.client
+            .post(&format!("{}/api/auth/register", BASE_URL))
+            .json(&user_data)
+            .send()
+            .await?;
+        
+        if !register_response.status().is_success() {
+            return Err(format!("Registration failed: {}", register_response.text().await?).into());
+        }
+        
+        // Login to get token
+        let login_data = LoginRequest {
+            username: username.clone(),
+            password: password.to_string(),
+        };
+        
+        let login_response = self.client
+            .post(&format!("{}/api/auth/login", BASE_URL))
+            .json(&login_data)
+            .send()
+            .await?;
+        
+        if !login_response.status().is_success() {
+            return Err(format!("Login failed: {}", login_response.text().await?).into());
+        }
+        
+        let login_result: LoginResponse = login_response.json().await?;
+        self.token = Some(login_result.token.clone());
+        
+        // Get user info
+        let me_response = self.client
+            .get(&format!("{}/api/auth/me", BASE_URL))
+            .header("Authorization", format!("Bearer {}", login_result.token))
+            .send()
+            .await?;
+        
+        if me_response.status().is_success() {
+            let user_info: Value = me_response.json().await?;
+            self.user_id = user_info["id"].as_str().map(|s| s.to_string());
+        }
+        
+        Ok(login_result.token)
+    }
+    
+    /// Get OCR queue statistics
+    async fn get_queue_stats(&self) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/queue/stats", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get queue stats failed: {} - {}", response.status(), response.text().await?).into());
+        }
+        
+        let stats: Value = response.json().await?;
+        Ok(stats)
+    }
+    
+    /// Requeue failed OCR jobs
+    async fn requeue_failed_jobs(&self) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .post(&format!("{}/api/queue/requeue-failed", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Requeue failed jobs failed: {} - {}", response.status(), response.text().await?).into());
+        }
+        
+        let result: Value = response.json().await?;
+        Ok(result)
+    }
+    
+    /// Upload a document for OCR processing
+    async fn upload_document(&self, content: &str, filename: &str) -> Result<DocumentResponse, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let part = reqwest::multipart::Part::text(content.to_string())
+            .file_name(filename.to_string())
+            .mime_str("text/plain")?;
+        let form = reqwest::multipart::Form::new()
+            .part("file", part);
+        
+        let response = self.client
+            .post(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .multipart(form)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Upload failed: {}", response.text().await?).into());
+        }
+        
+        let document: DocumentResponse = response.json().await?;
+        Ok(document)
+    }
+    
+    /// Upload multiple documents concurrently
+    async fn upload_multiple_documents(&self, count: usize, base_content: &str) -> Result<Vec<DocumentResponse>, Box<dyn std::error::Error>> {
+        let mut handles = Vec::new();
+        
+        for i in 0..count {
+            let content = format!("{}\nDocument number: {}\nUnique ID: {}", base_content, i + 1, Uuid::new_v4());
+            let filename = format!("test_doc_{}.txt", i + 1);
+            let client_clone = self.clone();
+            
+            let handle = tokio::spawn(async move {
+                client_clone.upload_document(&content, &filename).await
+            });
+            
+            handles.push(handle);
+        }
+        
+        let mut documents = Vec::new();
+        for handle in handles {
+            match handle.await? {
+                Ok(doc) => documents.push(doc),
+                Err(e) => return Err(e),
+            }
+        }
+        
+        Ok(documents)
+    }
+    
+    /// Wait for OCR processing to complete for multiple documents
+    async fn wait_for_multiple_ocr_completion(&self, document_ids: &[String]) -> Result<Vec<bool>, Box<dyn std::error::Error>> {
+        let start = Instant::now();
+        let mut completed_status = vec![false; document_ids.len()];
+        
+        while start.elapsed() < TIMEOUT && !completed_status.iter().all(|&x| x) {
+            let token = self.token.as_ref().ok_or("Not authenticated")?;
+            
+            let response = self.client
+                .get(&format!("{}/api/documents", BASE_URL))
+                .header("Authorization", format!("Bearer {}", token))
+                .send()
+                .await?;
+            
+            if response.status().is_success() {
+                let documents: Vec<DocumentResponse> = response.json().await?;
+                
+                for (i, doc_id) in document_ids.iter().enumerate() {
+                    if !completed_status[i] {
+                        if let Some(doc) = documents.iter().find(|d| d.id.to_string() == *doc_id) {
+                            match doc.ocr_status.as_deref() {
+                                Some("completed") => completed_status[i] = true,
+                                Some("failed") => completed_status[i] = true, // Count failed as completed for this test
+                                _ => continue,
+                            }
+                        }
+                    }
+                }
+            }
+            
+            sleep(Duration::from_millis(1000)).await; // Check every second for multiple docs
+        }
+        
+        Ok(completed_status)
+    }
+    
+    /// Get all documents for the user
+    async fn get_documents(&self) -> Result<Vec<DocumentResponse>, Box<dyn std::error::Error>> {
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get documents failed: {}", response.text().await?).into());
+        }
+        
+        let documents: Vec<DocumentResponse> = response.json().await?;
+        Ok(documents)
+    }
+}
+
+impl Clone for OCRQueueTestClient {
+    fn clone(&self) -> Self {
+        Self {
+            client: self.client.clone(),
+            token: self.token.clone(),
+            user_id: self.user_id.clone(),
+        }
+    }
+}
+
+#[tokio::test]
+async fn test_queue_stats_monitoring() {
+    let mut client = OCRQueueTestClient::new();
+    
+    // Register and login
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    println!("✅ User registered and logged in");
+    
+    // Get initial queue stats
+    let initial_stats = client.get_queue_stats().await
+        .expect("Failed to get initial queue stats");
+    
+    // Validate queue stats structure
+    assert!(initial_stats.is_object());
+    
+    // Common queue stats fields to check for
+    let expected_fields = ["pending", "processing", "completed", "failed", "total"];
+    for field in &expected_fields {
+        if initial_stats[field].is_number() {
+            assert!(initial_stats[field].as_i64().unwrap() >= 0);
+            println!("✅ Queue stat '{}': {}", field, initial_stats[field]);
+        }
+    }
+    
+    println!("✅ Initial queue stats retrieved and validated");
+    
+    // Upload a document to generate queue activity
+    let document = client.upload_document("Test document for queue monitoring", "queue_test.txt").await
+        .expect("Failed to upload document");
+    
+    println!("✅ Document uploaded: {}", document.id);
+    
+    // Wait a moment for queue to update
+    sleep(Duration::from_secs(2)).await;
+    
+    // Get updated queue stats
+    let updated_stats = client.get_queue_stats().await
+        .expect("Failed to get updated queue stats");
+    
+    println!("✅ Updated queue stats retrieved");
+    
+    // The total should have increased (assuming the document entered the queue)
+    if updated_stats["total"].is_number() && initial_stats["total"].is_number() {
+        let initial_total = initial_stats["total"].as_i64().unwrap_or(0);
+        let updated_total = updated_stats["total"].as_i64().unwrap_or(0);
+        
+        // Total should be equal or increased
+        assert!(updated_total >= initial_total);
+        println!("✅ Queue activity detected: total jobs {} -> {}", initial_total, updated_total);
+    }
+    
+    println!("🎉 Queue stats monitoring test passed!");
+}
+
+#[tokio::test]
+async fn test_failed_job_requeue_functionality() {
+    let mut client = OCRQueueTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    println!("✅ User registered and logged in");
+    
+    // Get initial stats
+    let initial_stats = client.get_queue_stats().await
+        .expect("Failed to get initial stats");
+    
+    let initial_failed = initial_stats["failed"].as_i64().unwrap_or(0);
+    println!("✅ Initial failed jobs: {}", initial_failed);
+    
+    // Try to requeue failed jobs
+    let requeue_result = client.requeue_failed_jobs().await
+        .expect("Failed to requeue failed jobs");
+    
+    // Validate requeue response structure
+    assert!(requeue_result.is_object());
+    
+    // Common requeue result fields
+    if requeue_result["requeued_count"].is_number() {
+        let requeued_count = requeue_result["requeued_count"].as_i64().unwrap();
+        assert!(requeued_count >= 0);
+        println!("✅ Requeued {} failed jobs", requeued_count);
+    }
+    
+    if requeue_result["message"].is_string() {
+        println!("✅ Requeue message: {}", requeue_result["message"]);
+    }
+    
+    // Wait a moment for the requeue to process
+    sleep(Duration::from_secs(2)).await;
+    
+    // Get updated stats
+    let updated_stats = client.get_queue_stats().await
+        .expect("Failed to get updated stats after requeue");
+    
+    let updated_failed = updated_stats["failed"].as_i64().unwrap_or(0);
+    
+    // Failed count should be equal or decreased after requeue
+    assert!(updated_failed <= initial_failed);
+    println!("✅ Failed jobs after requeue: {}", updated_failed);
+    
+    println!("🎉 Failed job requeue functionality test passed!");
+}
+
+#[tokio::test]
+async fn test_concurrent_ocr_processing() {
+    let mut client = OCRQueueTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    println!("✅ User registered and logged in");
+    
+    // Get initial queue stats
+    let initial_stats = client.get_queue_stats().await
+        .expect("Failed to get initial stats");
+    
+    println!("✅ Initial queue stats captured");
+    
+    // Upload multiple documents concurrently
+    let document_count = 5;
+    let base_content = "This is a test document for concurrent OCR processing.\nIt contains multiple lines of text to ensure meaningful OCR work.\nThe system should handle multiple documents efficiently.";
+    
+    println!("📤 Starting concurrent upload of {} documents...", document_count);
+    let start_time = Instant::now();
+    
+    let documents = client.upload_multiple_documents(document_count, base_content).await
+        .expect("Failed to upload multiple documents");
+    
+    let upload_duration = start_time.elapsed();
+    println!("✅ Uploaded {} documents in {:?}", documents.len(), upload_duration);
+    
+    // Collect document IDs
+    let document_ids: Vec<String> = documents.iter()
+        .map(|d| d.id.to_string())
+        .collect();
+    
+    // Monitor queue stats during processing
+    let processing_start = Instant::now();
+    let mut stats_samples = Vec::new();
+    
+    // Take several queue stat samples during processing
+    for i in 0..6 {
+        let stats = client.get_queue_stats().await
+            .expect("Failed to get queue stats during processing");
+        
+        stats_samples.push((processing_start.elapsed(), stats.clone()));
+        
+        if i < 5 {
+            sleep(Duration::from_secs(3)).await;
+        }
+    }
+    
+    println!("✅ Collected {} queue stat samples during processing", stats_samples.len());
+    
+    // Print queue evolution
+    for (elapsed, stats) in &stats_samples {
+        println!("  {:?}: pending={}, processing={}, completed={}, failed={}", 
+                 elapsed,
+                 stats["pending"].as_i64().unwrap_or(0),
+                 stats["processing"].as_i64().unwrap_or(0),
+                 stats["completed"].as_i64().unwrap_or(0),
+                 stats["failed"].as_i64().unwrap_or(0));
+    }
+    
+    // Wait for all OCR processing to complete
+    println!("⏳ Waiting for OCR processing to complete...");
+    let completion_results = client.wait_for_multiple_ocr_completion(&document_ids).await
+        .expect("Failed to wait for OCR completion");
+    
+    let completed_count = completion_results.iter().filter(|&&x| x).count();
+    println!("✅ OCR completed for {}/{} documents", completed_count, document_count);
+    
+    // Get final queue stats
+    let final_stats = client.get_queue_stats().await
+        .expect("Failed to get final stats");
+    
+    println!("✅ Final queue stats: pending={}, processing={}, completed={}, failed={}",
+             final_stats["pending"].as_i64().unwrap_or(0),
+             final_stats["processing"].as_i64().unwrap_or(0),
+             final_stats["completed"].as_i64().unwrap_or(0),
+             final_stats["failed"].as_i64().unwrap_or(0));
+    
+    // Validate that the queue processed our documents
+    let initial_total = initial_stats["total"].as_i64().unwrap_or(0);
+    let final_total = final_stats["total"].as_i64().unwrap_or(0);
+    
+    assert!(final_total >= initial_total + document_count as i64);
+    println!("✅ Queue total increased by at least {} jobs", document_count);
+    
+    println!("🎉 Concurrent OCR processing test passed!");
+}
+
+#[tokio::test]
+async fn test_queue_performance_monitoring() {
+    let mut client = OCRQueueTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    println!("✅ User registered and logged in");
+    
+    // Monitor queue performance over time
+    let monitoring_duration = Duration::from_secs(30);
+    let sample_interval = Duration::from_secs(5);
+    let start_time = Instant::now();
+    
+    let mut performance_samples = Vec::new();
+    
+    // Upload a test document to create some queue activity
+    let _document = client.upload_document("Performance monitoring test document", "perf_test.txt").await
+        .expect("Failed to upload test document");
+    
+    println!("✅ Test document uploaded for performance monitoring");
+    
+    // Collect performance samples
+    while start_time.elapsed() < monitoring_duration {
+        let sample_time = Instant::now();
+        
+        let stats = client.get_queue_stats().await
+            .expect("Failed to get queue stats for performance monitoring");
+        
+        let sample_duration = sample_time.elapsed();
+        
+        performance_samples.push((start_time.elapsed(), stats, sample_duration));
+        
+        println!("📊 Sample at {:?}: response_time={:?}, pending={}, processing={}",
+                 start_time.elapsed(),
+                 sample_duration,
+                 stats["pending"].as_i64().unwrap_or(0),
+                 stats["processing"].as_i64().unwrap_or(0));
+        
+        if start_time.elapsed() + sample_interval < monitoring_duration {
+            sleep(sample_interval).await;
+        }
+    }
+    
+    println!("✅ Collected {} performance samples", performance_samples.len());
+    
+    // Analyze performance metrics
+    let response_times: Vec<Duration> = performance_samples.iter()
+        .map(|(_, _, duration)| *duration)
+        .collect();
+    
+    let avg_response_time = response_times.iter().sum::<Duration>() / response_times.len() as u32;
+    let max_response_time = *response_times.iter().max().unwrap();
+    let min_response_time = *response_times.iter().min().unwrap();
+    
+    println!("📈 Performance Analysis:");
+    println!("  Average response time: {:?}", avg_response_time);
+    println!("  Max response time: {:?}", max_response_time);
+    println!("  Min response time: {:?}", min_response_time);
+    
+    // Basic performance assertions
+    assert!(avg_response_time < Duration::from_secs(5), "Average response time should be under 5 seconds");
+    assert!(max_response_time < Duration::from_secs(10), "Max response time should be under 10 seconds");
+    
+    // Check for queue activity variations
+    let queue_totals: Vec<i64> = performance_samples.iter()
+        .map(|(_, stats, _)| stats["total"].as_i64().unwrap_or(0))
+        .collect();
+    
+    let min_total = queue_totals.iter().min().unwrap();
+    let max_total = queue_totals.iter().max().unwrap();
+    
+    println!("  Queue total range: {} - {}", min_total, max_total);
+    
+    println!("🎉 Queue performance monitoring test passed!");
+}
+
+#[tokio::test]
+async fn test_queue_error_handling() {
+    let mut client = OCRQueueTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    println!("✅ User registered and logged in");
+    
+    // Test unauthorized access to queue stats
+    let unauth_client = Client::new();
+    let unauth_response = unauth_client
+        .get(&format!("{}/api/queue/stats", BASE_URL))
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert_eq!(unauth_response.status(), 401);
+    println!("✅ Unauthorized queue stats access properly rejected");
+    
+    // Test unauthorized requeue attempt
+    let unauth_requeue_response = unauth_client
+        .post(&format!("{}/api/queue/requeue-failed", BASE_URL))
+        .send()
+        .await
+        .expect("Request should complete");
+    
+    assert_eq!(unauth_requeue_response.status(), 401);
+    println!("✅ Unauthorized requeue attempt properly rejected");
+    
+    // Test queue stats with valid authentication
+    let stats_result = client.get_queue_stats().await;
+    assert!(stats_result.is_ok());
+    println!("✅ Authorized queue stats access successful");
+    
+    // Test requeue with valid authentication
+    let requeue_result = client.requeue_failed_jobs().await;
+    assert!(requeue_result.is_ok());
+    println!("✅ Authorized requeue attempt successful");
+    
+    println!("🎉 Queue error handling test passed!");
+}
+
+#[tokio::test]
+async fn test_queue_stats_consistency() {
+    let mut client = OCRQueueTestClient::new();
+    
+    client.register_and_login(UserRole::User).await
+        .expect("Failed to register and login");
+    
+    println!("✅ User registered and logged in");
+    
+    // Get multiple queue stat samples to check consistency
+    let mut stat_samples = Vec::new();
+    
+    for i in 0..5 {
+        let stats = client.get_queue_stats().await
+            .expect("Failed to get queue stats");
+        
+        stat_samples.push(stats);
+        
+        if i < 4 {
+            sleep(Duration::from_millis(500)).await;
+        }
+    }
+    
+    println!("✅ Collected {} queue stat samples", stat_samples.len());
+    
+    // Validate consistency across samples
+    for (i, stats) in stat_samples.iter().enumerate() {
+        // Check that all expected fields are numbers
+        let numeric_fields = ["pending", "processing", "completed", "failed", "total"];
+        
+        for field in &numeric_fields {
+            if let Some(value) = stats[field].as_i64() {
+                assert!(value >= 0, "Field '{}' should be non-negative in sample {}", field, i);
+            }
+        }
+        
+        // Check logical consistency: total should equal sum of other states
+        if let (Some(pending), Some(processing), Some(completed), Some(failed), Some(total)) = (
+            stats["pending"].as_i64(),
+            stats["processing"].as_i64(),
+            stats["completed"].as_i64(),
+            stats["failed"].as_i64(),
+            stats["total"].as_i64()
+        ) {
+            let calculated_total = pending + processing + completed + failed;
+            // Allow some tolerance for race conditions in a live system
+            let tolerance = 5;
+            assert!(
+                (total - calculated_total).abs() <= tolerance,
+                "Total ({}) should approximately equal sum of states ({}) in sample {}",
+                total, calculated_total, i
+            );
+        }
+        
+        println!("✅ Sample {} consistency validated", i);
+    }
+    
+    // Check for reasonable queue evolution (no massive jumps)
+    for i in 1..stat_samples.len() {
+        let prev_total = stat_samples[i-1]["total"].as_i64().unwrap_or(0);
+        let curr_total = stat_samples[i]["total"].as_i64().unwrap_or(0);
+        
+        // Total should only increase or stay the same in a short time period
+        assert!(curr_total >= prev_total - 1, "Total queue size should not decrease significantly between samples");
+    }
+    
+    println!("🎉 Queue stats consistency test passed!");
+}

tests/performance_load_tests.rs

@@ -0,0 +1,762 @@
+/*!
+ * Performance and Load Testing Integration Tests
+ * 
+ * Tests system performance under various load conditions including:
+ * - High-volume document uploads
+ * - Concurrent user operations
+ * - Database query performance
+ * - OCR processing throughput
+ * - Search performance with large datasets
+ * - Memory and resource usage patterns
+ * - Response time consistency
+ * - System scalability limits
+ */
+
+use reqwest::Client;
+use serde_json::{json, Value};
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+use tokio::sync::Semaphore;
+use tokio::time::sleep;
+use uuid::Uuid;
+
+use readur::models::{CreateUser, LoginRequest, LoginResponse, UserRole, DocumentResponse};
+
+const BASE_URL: &str = "http://localhost:8000";
+const LOAD_TEST_TIMEOUT: Duration = Duration::from_secs(300); // 5 minutes for load tests
+
+/// Performance metrics tracker
+#[derive(Debug, Clone)]
+struct PerformanceMetrics {
+    total_requests: usize,
+    successful_requests: usize,
+    failed_requests: usize,
+    total_duration: Duration,
+    min_response_time: Duration,
+    max_response_time: Duration,
+    response_times: Vec<Duration>,
+}
+
+impl PerformanceMetrics {
+    fn new() -> Self {
+        Self {
+            total_requests: 0,
+            successful_requests: 0,
+            failed_requests: 0,
+            total_duration: Duration::ZERO,
+            min_response_time: Duration::from_secs(u64::MAX),
+            max_response_time: Duration::ZERO,
+            response_times: Vec::new(),
+        }
+    }
+    
+    fn add_result(&mut self, success: bool, response_time: Duration) {
+        self.total_requests += 1;
+        if success {
+            self.successful_requests += 1;
+        } else {
+            self.failed_requests += 1;
+        }
+        
+        self.response_times.push(response_time);
+        self.total_duration += response_time;
+        
+        if response_time < self.min_response_time {
+            self.min_response_time = response_time;
+        }
+        if response_time > self.max_response_time {
+            self.max_response_time = response_time;
+        }
+    }
+    
+    fn average_response_time(&self) -> Duration {
+        if self.total_requests > 0 {
+            self.total_duration / self.total_requests as u32
+        } else {
+            Duration::ZERO
+        }
+    }
+    
+    fn percentile(&self, p: f64) -> Duration {
+        if self.response_times.is_empty() {
+            return Duration::ZERO;
+        }
+        
+        let mut sorted_times = self.response_times.clone();
+        sorted_times.sort();
+        
+        let index = ((sorted_times.len() as f64 - 1.0) * p / 100.0).round() as usize;
+        sorted_times[index.min(sorted_times.len() - 1)]
+    }
+    
+    fn success_rate(&self) -> f64 {
+        if self.total_requests > 0 {
+            self.successful_requests as f64 / self.total_requests as f64
+        } else {
+            0.0
+        }
+    }
+    
+    fn requests_per_second(&self, total_elapsed: Duration) -> f64 {
+        if total_elapsed.as_secs_f64() > 0.0 {
+            self.total_requests as f64 / total_elapsed.as_secs_f64()
+        } else {
+            0.0
+        }
+    }
+}
+
+/// Load test client with performance tracking
+struct LoadTestClient {
+    client: Client,
+    token: Option<String>,
+    user_id: Option<String>,
+}
+
+impl LoadTestClient {
+    fn new() -> Self {
+        Self {
+            client: Client::builder()
+                .timeout(Duration::from_secs(60))
+                .build()
+                .expect("Failed to create load test client"),
+            token: None,
+            user_id: None,
+        }
+    }
+    
+    /// Setup a test user for load testing
+    async fn setup_user(&mut self, user_index: usize) -> Result<String, Box<dyn std::error::Error>> {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let username = format!("load_test_user_{}_{}", user_index, timestamp);
+        let email = format!("load_test_{}@example.com", timestamp);
+        let password = "loadtestpassword123";
+        
+        // Register user
+        let user_data = CreateUser {
+            username: username.clone(),
+            email: email.clone(),
+            password: password.to_string(),
+            role: Some(UserRole::User),
+        };
+        
+        let register_response = self.client
+            .post(&format!("{}/api/auth/register", BASE_URL))
+            .json(&user_data)
+            .send()
+            .await?;
+        
+        if !register_response.status().is_success() {
+            return Err(format!("Registration failed: {}", register_response.text().await?).into());
+        }
+        
+        // Login to get token
+        let login_data = LoginRequest {
+            username: username.clone(),
+            password: password.to_string(),
+        };
+        
+        let login_response = self.client
+            .post(&format!("{}/api/auth/login", BASE_URL))
+            .json(&login_data)
+            .send()
+            .await?;
+        
+        if !login_response.status().is_success() {
+            return Err(format!("Login failed: {}", login_response.text().await?).into());
+        }
+        
+        let login_result: LoginResponse = login_response.json().await?;
+        self.token = Some(login_result.token.clone());
+        
+        // Get user info
+        let me_response = self.client
+            .get(&format!("{}/api/auth/me", BASE_URL))
+            .header("Authorization", format!("Bearer {}", login_result.token))
+            .send()
+            .await?;
+        
+        if me_response.status().is_success() {
+            let user_info: Value = me_response.json().await?;
+            self.user_id = user_info["id"].as_str().map(|s| s.to_string());
+        }
+        
+        Ok(login_result.token)
+    }
+    
+    /// Perform a timed document upload
+    async fn timed_upload(&self, content: &str, filename: &str) -> Result<(DocumentResponse, Duration), Box<dyn std::error::Error>> {
+        let start = Instant::now();
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let part = reqwest::multipart::Part::text(content.to_string())
+            .file_name(filename.to_string())
+            .mime_str("text/plain")?;
+        let form = reqwest::multipart::Form::new()
+            .part("file", part);
+        
+        let response = self.client
+            .post(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .multipart(form)
+            .send()
+            .await?;
+        
+        let elapsed = start.elapsed();
+        
+        if !response.status().is_success() {
+            return Err(format!("Upload failed: {}", response.text().await?).into());
+        }
+        
+        let document: DocumentResponse = response.json().await?;
+        Ok((document, elapsed))
+    }
+    
+    /// Perform a timed document list request
+    async fn timed_list_documents(&self) -> Result<(Vec<DocumentResponse>, Duration), Box<dyn std::error::Error>> {
+        let start = Instant::now();
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        let elapsed = start.elapsed();
+        
+        if !response.status().is_success() {
+            return Err(format!("List documents failed: {}", response.text().await?).into());
+        }
+        
+        let documents: Vec<DocumentResponse> = response.json().await?;
+        Ok((documents, elapsed))
+    }
+    
+    /// Perform a timed search request
+    async fn timed_search(&self, query: &str) -> Result<(Value, Duration), Box<dyn std::error::Error>> {
+        let start = Instant::now();
+        let token = self.token.as_ref().ok_or("Not authenticated")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/search", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .query(&[("q", query)])
+            .send()
+            .await?;
+        
+        let elapsed = start.elapsed();
+        
+        if !response.status().is_success() {
+            return Err(format!("Search failed: {}", response.text().await?).into());
+        }
+        
+        let results: Value = response.json().await?;
+        Ok((results, elapsed))
+    }
+}
+
+impl Clone for LoadTestClient {
+    fn clone(&self) -> Self {
+        Self {
+            client: self.client.clone(),
+            token: self.token.clone(),
+            user_id: self.user_id.clone(),
+        }
+    }
+}
+
+#[tokio::test]
+async fn test_high_volume_document_uploads() {
+    println!("📤 Testing high-volume document uploads...");
+    
+    let mut client = LoadTestClient::new();
+    client.setup_user(0).await
+        .expect("Failed to setup test user");
+    
+    let upload_count = 50;
+    let concurrent_limit = 10;
+    let semaphore = Arc::new(Semaphore::new(concurrent_limit));
+    
+    let mut metrics = PerformanceMetrics::new();
+    let overall_start = Instant::now();
+    
+    println!("🚀 Starting {} concurrent uploads with limit of {}", upload_count, concurrent_limit);
+    
+    let mut handles = Vec::new();
+    
+    for i in 0..upload_count {
+        let client_clone = client.clone();
+        let semaphore_clone = semaphore.clone();
+        
+        let handle = tokio::spawn(async move {
+            let _permit = semaphore_clone.acquire().await.expect("Failed to acquire semaphore");
+            
+            let content = format!(
+                "Load test document content for upload {}.\n\
+                This document contains multiple lines of text to provide meaningful content for OCR processing.\n\
+                Generated at: {}\n\
+                Document ID: LOAD-TEST-{}\n\
+                Content length should be sufficient for testing purposes.",
+                i,
+                chrono::Utc::now().format("%Y-%m-%d %H:%M:%S"),
+                Uuid::new_v4()
+            );
+            let filename = format!("load_test_{}.txt", i);
+            
+            let result = client_clone.timed_upload(&content, &filename).await;
+            
+            match result {
+                Ok((document, duration)) => (i, true, duration, Some(document.id.to_string())),
+                Err(_) => (i, false, Duration::ZERO, None),
+            }
+        });
+        
+        handles.push(handle);
+    }
+    
+    // Wait for all uploads to complete
+    let mut upload_results = Vec::new();
+    for handle in handles {
+        let result = handle.await.expect("Upload task should complete");
+        upload_results.push(result);
+    }
+    
+    let overall_elapsed = overall_start.elapsed();
+    
+    // Collect metrics
+    for (_, success, duration, _) in &upload_results {
+        metrics.add_result(*success, *duration);
+    }
+    
+    // Print performance results
+    println!("📊 High-Volume Upload Performance Results:");
+    println!("  Total uploads: {}", metrics.total_requests);
+    println!("  Successful: {}", metrics.successful_requests);
+    println!("  Failed: {}", metrics.failed_requests);
+    println!("  Success rate: {:.2}%", metrics.success_rate() * 100.0);
+    println!("  Total time: {:?}", overall_elapsed);
+    println!("  Throughput: {:.2} uploads/sec", metrics.requests_per_second(overall_elapsed));
+    println!("  Average response time: {:?}", metrics.average_response_time());
+    println!("  Min response time: {:?}", metrics.min_response_time);
+    println!("  Max response time: {:?}", metrics.max_response_time);
+    println!("  95th percentile: {:?}", metrics.percentile(95.0));
+    println!("  99th percentile: {:?}", metrics.percentile(99.0));
+    
+    // Performance assertions
+    assert!(metrics.success_rate() >= 0.9, "Success rate should be at least 90%");
+    assert!(metrics.average_response_time() < Duration::from_secs(10), "Average response time should be under 10 seconds");
+    assert!(metrics.percentile(95.0) < Duration::from_secs(20), "95th percentile should be under 20 seconds");
+    
+    println!("🎉 High-volume document uploads test passed!");
+}
+
+#[tokio::test]
+async fn test_concurrent_user_operations() {
+    println!("👥 Testing concurrent user operations...");
+    
+    let user_count = 10;
+    let operations_per_user = 5;
+    
+    // Setup multiple users
+    let mut clients = Vec::new();
+    for i in 0..user_count {
+        let mut client = LoadTestClient::new();
+        client.setup_user(i).await
+            .expect(&format!("Failed to setup user {}", i));
+        clients.push(client);
+    }
+    
+    println!("✅ Setup {} concurrent users", user_count);
+    
+    let overall_start = Instant::now();
+    let mut all_handles = Vec::new();
+    
+    // Each user performs multiple operations concurrently
+    for (user_index, client) in clients.into_iter().enumerate() {
+        let handle = tokio::spawn(async move {
+            let mut user_metrics = PerformanceMetrics::new();
+            let mut operation_handles = Vec::new();
+            
+            // Upload documents
+            for op_index in 0..operations_per_user {
+                let client_clone = client.clone();
+                let upload_handle = tokio::spawn(async move {
+                    let content = format!("User {} operation {} content", user_index, op_index);
+                    let filename = format!("user_{}_op_{}.txt", user_index, op_index);
+                    
+                    client_clone.timed_upload(&content, &filename).await
+                });
+                operation_handles.push(upload_handle);
+            }
+            
+            // Wait for all operations for this user
+            let mut successful_ops = 0;
+            let mut total_ops = 0;
+            let mut total_time = Duration::ZERO;
+            
+            for handle in operation_handles {
+                total_ops += 1;
+                match handle.await.expect("Operation should complete") {
+                    Ok((_, duration)) => {
+                        successful_ops += 1;
+                        total_time += duration;
+                        user_metrics.add_result(true, duration);
+                    }
+                    Err(_) => {
+                        user_metrics.add_result(false, Duration::ZERO);
+                    }
+                }
+            }
+            
+            (user_index, successful_ops, total_ops, user_metrics)
+        });
+        
+        all_handles.push(handle);
+    }
+    
+    // Wait for all users to complete their operations
+    let mut all_user_results = Vec::new();
+    for handle in all_handles {
+        let result = handle.await.expect("User operations should complete");
+        all_user_results.push(result);
+    }
+    
+    let overall_elapsed = overall_start.elapsed();
+    
+    // Aggregate metrics across all users
+    let mut global_metrics = PerformanceMetrics::new();
+    for (user_index, successful_ops, total_ops, user_metrics) in &all_user_results {
+        println!("  User {}: {}/{} operations successful", user_index, successful_ops, total_ops);
+        
+        // Merge user metrics into global metrics
+        for &response_time in &user_metrics.response_times {
+            global_metrics.add_result(true, response_time);
+        }
+        global_metrics.failed_requests += user_metrics.failed_requests;
+    }
+    
+    println!("📊 Concurrent User Operations Performance Results:");
+    println!("  Total users: {}", user_count);
+    println!("  Operations per user: {}", operations_per_user);
+    println!("  Total operations: {}", global_metrics.total_requests + global_metrics.failed_requests);
+    println!("  Successful operations: {}", global_metrics.successful_requests);
+    println!("  Failed operations: {}", global_metrics.failed_requests);
+    println!("  Overall success rate: {:.2}%", global_metrics.success_rate() * 100.0);
+    println!("  Total time: {:?}", overall_elapsed);
+    println!("  Throughput: {:.2} operations/sec", global_metrics.requests_per_second(overall_elapsed));
+    println!("  Average response time: {:?}", global_metrics.average_response_time());
+    println!("  95th percentile: {:?}", global_metrics.percentile(95.0));
+    
+    // Performance assertions
+    assert!(global_metrics.success_rate() >= 0.8, "Success rate should be at least 80% under load");
+    assert!(global_metrics.average_response_time() < Duration::from_secs(15), "Average response time should be reasonable under load");
+    
+    println!("🎉 Concurrent user operations test passed!");
+}
+
+#[tokio::test]
+async fn test_search_performance_with_load() {
+    println!("🔍 Testing search performance under load...");
+    
+    let mut client = LoadTestClient::new();
+    client.setup_user(0).await
+        .expect("Failed to setup test user");
+    
+    // First, upload several documents to create a searchable dataset
+    let document_count = 20;
+    println!("📤 Creating dataset with {} documents...", document_count);
+    
+    let mut document_ids = Vec::new();
+    for i in 0..document_count {
+        let content = format!(
+            "Document {} for search performance testing.\n\
+            This document contains searchable keywords like: performance, test, document, search, load.\n\
+            Additional content: technology, system, user, data, processing.\n\
+            Unique identifier: SEARCH-PERF-{}\n\
+            Number: {}",
+            i, Uuid::new_v4(), i
+        );
+        let filename = format!("search_perf_doc_{}.txt", i);
+        
+        match client.timed_upload(&content, &filename).await {
+            Ok((document, _)) => {
+                document_ids.push(document.id.to_string());
+            }
+            Err(e) => {
+                println!("⚠️  Failed to upload document {}: {}", i, e);
+            }
+        }
+    }
+    
+    println!("✅ Created dataset with {} documents", document_ids.len());
+    
+    // Wait a moment for documents to be indexed
+    sleep(Duration::from_secs(5)).await;
+    
+    // Perform multiple search queries concurrently
+    let search_queries = vec![
+        "performance",
+        "test document",
+        "search load",
+        "technology system",
+        "user data",
+        "processing",
+        "unique identifier",
+        "SEARCH-PERF",
+    ];
+    
+    let searches_per_query = 5;
+    let mut search_metrics = PerformanceMetrics::new();
+    let search_start = Instant::now();
+    
+    let mut search_handles = Vec::new();
+    
+    for (query_index, query) in search_queries.iter().enumerate() {
+        for search_index in 0..searches_per_query {
+            let client_clone = client.clone();
+            let query_clone = query.to_string();
+            
+            let handle = tokio::spawn(async move {
+                let result = client_clone.timed_search(&query_clone).await;
+                
+                match result {
+                    Ok((results, duration)) => {
+                        let result_count = results["documents"].as_array()
+                            .map(|arr| arr.len())
+                            .unwrap_or(0);
+                        (query_index, search_index, true, duration, result_count)
+                    }
+                    Err(_) => (query_index, search_index, false, Duration::ZERO, 0),
+                }
+            });
+            
+            search_handles.push(handle);
+        }
+    }
+    
+    // Wait for all search operations to complete
+    let mut search_results = Vec::new();
+    for handle in search_handles {
+        let result = handle.await.expect("Search task should complete");
+        search_results.push(result);
+    }
+    
+    let search_elapsed = search_start.elapsed();
+    
+    // Collect search metrics
+    for (_, _, success, duration, result_count) in &search_results {
+        search_metrics.add_result(*success, *duration);
+        if *success {
+            println!("  Search returned {} results in {:?}", result_count, duration);
+        }
+    }
+    
+    println!("📊 Search Performance Results:");
+    println!("  Total searches: {}", search_metrics.total_requests);
+    println!("  Successful searches: {}", search_metrics.successful_requests);
+    println!("  Failed searches: {}", search_metrics.failed_requests);
+    println!("  Success rate: {:.2}%", search_metrics.success_rate() * 100.0);
+    println!("  Total time: {:?}", search_elapsed);
+    println!("  Search throughput: {:.2} searches/sec", search_metrics.requests_per_second(search_elapsed));
+    println!("  Average search time: {:?}", search_metrics.average_response_time());
+    println!("  Min search time: {:?}", search_metrics.min_response_time);
+    println!("  Max search time: {:?}", search_metrics.max_response_time);
+    println!("  95th percentile: {:?}", search_metrics.percentile(95.0));
+    
+    // Performance assertions for search
+    assert!(search_metrics.success_rate() >= 0.9, "Search success rate should be at least 90%");
+    assert!(search_metrics.average_response_time() < Duration::from_secs(5), "Average search time should be under 5 seconds");
+    assert!(search_metrics.percentile(95.0) < Duration::from_secs(10), "95th percentile search time should be under 10 seconds");
+    
+    println!("🎉 Search performance under load test passed!");
+}
+
+#[tokio::test]
+async fn test_database_query_performance() {
+    println!("🗄️ Testing database query performance...");
+    
+    let mut client = LoadTestClient::new();
+    client.setup_user(0).await
+        .expect("Failed to setup test user");
+    
+    // Test repeated document list queries to stress database
+    let query_count = 100;
+    let concurrent_queries = 20;
+    let semaphore = Arc::new(Semaphore::new(concurrent_queries));
+    
+    let mut query_metrics = PerformanceMetrics::new();
+    let query_start = Instant::now();
+    
+    println!("🚀 Starting {} database queries with concurrency {}", query_count, concurrent_queries);
+    
+    let mut query_handles = Vec::new();
+    
+    for i in 0..query_count {
+        let client_clone = client.clone();
+        let semaphore_clone = semaphore.clone();
+        
+        let handle = tokio::spawn(async move {
+            let _permit = semaphore_clone.acquire().await.expect("Failed to acquire semaphore");
+            
+            let result = client_clone.timed_list_documents().await;
+            
+            match result {
+                Ok((documents, duration)) => (i, true, duration, documents.len()),
+                Err(_) => (i, false, Duration::ZERO, 0),
+            }
+        });
+        
+        query_handles.push(handle);
+    }
+    
+    // Wait for all queries to complete
+    let mut query_results = Vec::new();
+    for handle in query_handles {
+        let result = handle.await.expect("Query task should complete");
+        query_results.push(result);
+    }
+    
+    let query_elapsed = query_start.elapsed();
+    
+    // Collect query metrics
+    for (_, success, duration, doc_count) in &query_results {
+        query_metrics.add_result(*success, *duration);
+        if *success && doc_count > &0 {
+            println!("  Query returned {} documents in {:?}", doc_count, duration);
+        }
+    }
+    
+    println!("📊 Database Query Performance Results:");
+    println!("  Total queries: {}", query_metrics.total_requests);
+    println!("  Successful queries: {}", query_metrics.successful_requests);
+    println!("  Failed queries: {}", query_metrics.failed_requests);
+    println!("  Success rate: {:.2}%", query_metrics.success_rate() * 100.0);
+    println!("  Total time: {:?}", query_elapsed);
+    println!("  Query throughput: {:.2} queries/sec", query_metrics.requests_per_second(query_elapsed));
+    println!("  Average query time: {:?}", query_metrics.average_response_time());
+    println!("  Min query time: {:?}", query_metrics.min_response_time);
+    println!("  Max query time: {:?}", query_metrics.max_response_time);
+    println!("  95th percentile: {:?}", query_metrics.percentile(95.0));
+    println!("  99th percentile: {:?}", query_metrics.percentile(99.0));
+    
+    // Performance assertions for database queries
+    assert!(query_metrics.success_rate() >= 0.95, "Database query success rate should be at least 95%");
+    assert!(query_metrics.average_response_time() < Duration::from_secs(2), "Average query time should be under 2 seconds");
+    assert!(query_metrics.percentile(95.0) < Duration::from_secs(5), "95th percentile query time should be under 5 seconds");
+    
+    println!("🎉 Database query performance test passed!");
+}
+
+#[tokio::test]
+async fn test_system_stability_under_sustained_load() {
+    println!("🔄 Testing system stability under sustained load...");
+    
+    let mut client = LoadTestClient::new();
+    client.setup_user(0).await
+        .expect("Failed to setup test user");
+    
+    let test_duration = Duration::from_secs(60); // 1 minute sustained load
+    let operation_interval = Duration::from_millis(500); // Operation every 500ms
+    
+    let mut stability_metrics = PerformanceMetrics::new();
+    let stability_start = Instant::now();
+    
+    println!("⏳ Running sustained load for {:?} with operations every {:?}", test_duration, operation_interval);
+    
+    let mut operation_counter = 0;
+    let mut response_time_samples = Vec::new();
+    
+    while stability_start.elapsed() < test_duration {
+        let operation_start = Instant::now();
+        
+        // Alternate between different operation types
+        let operation_result = match operation_counter % 3 {
+            0 => {
+                // Document list operation
+                client.timed_list_documents().await
+                    .map(|(docs, duration)| (format!("list({} docs)", docs.len()), duration))
+            }
+            1 => {
+                // Document upload operation
+                let content = format!("Stability test document {}", operation_counter);
+                let filename = format!("stability_{}.txt", operation_counter);
+                client.timed_upload(&content, &filename).await
+                    .map(|(doc, duration)| (format!("upload({})", doc.id), duration))
+            }
+            _ => {
+                // Search operation
+                let queries = ["test", "document", "stability"];
+                let query = queries[operation_counter % queries.len()];
+                client.timed_search(query).await
+                    .map(|(results, duration)| {
+                        let count = results["documents"].as_array().map(|a| a.len()).unwrap_or(0);
+                        (format!("search({} results)", count), duration)
+                    })
+            }
+        };
+        
+        let operation_elapsed = operation_start.elapsed();
+        
+        match operation_result {
+            Ok((operation_desc, response_time)) => {
+                stability_metrics.add_result(true, response_time);
+                response_time_samples.push((stability_start.elapsed(), response_time));
+                println!("  {:?}: {} completed in {:?}", 
+                         stability_start.elapsed(), operation_desc, response_time);
+            }
+            Err(e) => {
+                stability_metrics.add_result(false, operation_elapsed);
+                println!("  {:?}: Operation failed: {}", stability_start.elapsed(), e);
+            }
+        }
+        
+        operation_counter += 1;
+        
+        // Sleep to maintain operation interval
+        if operation_elapsed < operation_interval {
+            sleep(operation_interval - operation_elapsed).await;
+        }
+    }
+    
+    let total_elapsed = stability_start.elapsed();
+    
+    // Analyze stability over time
+    let sample_windows = 6; // Divide test into 6 windows
+    let window_duration = test_duration / sample_windows as u32;
+    
+    println!("📊 System Stability Results:");
+    println!("  Test duration: {:?}", total_elapsed);
+    println!("  Total operations: {}", stability_metrics.total_requests);
+    println!("  Successful operations: {}", stability_metrics.successful_requests);
+    println!("  Failed operations: {}", stability_metrics.failed_requests);
+    println!("  Overall success rate: {:.2}%", stability_metrics.success_rate() * 100.0);
+    println!("  Average throughput: {:.2} ops/sec", stability_metrics.requests_per_second(total_elapsed));
+    println!("  Average response time: {:?}", stability_metrics.average_response_time());
+    
+    // Analyze response time stability across windows
+    for window in 0..sample_windows {
+        let window_start = window_duration * window as u32;
+        let window_end = window_duration * (window + 1) as u32;
+        
+        let window_samples: Vec<_> = response_time_samples.iter()
+            .filter(|(elapsed, _)| *elapsed >= window_start && *elapsed < window_end)
+            .map(|(_, duration)| *duration)
+            .collect();
+        
+        if !window_samples.is_empty() {
+            let window_avg = window_samples.iter().sum::<Duration>() / window_samples.len() as u32;
+            println!("  Window {} ({:?}-{:?}): {} ops, avg {:?}", 
+                     window + 1, window_start, window_end, window_samples.len(), window_avg);
+        }
+    }
+    
+    // Stability assertions
+    assert!(stability_metrics.success_rate() >= 0.8, "Success rate should remain above 80% under sustained load");
+    assert!(operation_counter >= 100, "Should complete at least 100 operations during stability test");
+    
+    println!("🎉 System stability under sustained load test passed!");
+}

tests/role_based_access_control_tests.rs

@@ -0,0 +1,882 @@
+/*!
+ * Role-Based Access Control (RBAC) Integration Tests
+ * 
+ * Tests comprehensive role-based access control including:
+ * - Admin vs User permission boundaries
+ * - Resource ownership and isolation
+ * - Cross-user access prevention
+ * - Privilege escalation prevention
+ * - Administrative operations access control
+ * - Data visibility and privacy
+ * - Role transition scenarios
+ * - Security boundary enforcement
+ */
+
+use reqwest::Client;
+use serde_json::{json, Value};
+use std::time::Duration;
+use uuid::Uuid;
+
+use readur::models::{CreateUser, LoginRequest, LoginResponse, UserRole};
+
+const BASE_URL: &str = "http://localhost:8000";
+
+/// Test client for RBAC scenarios with multiple user contexts
+struct RBACTestClient {
+    client: Client,
+    admin_token: Option<String>,
+    admin_user_id: Option<String>,
+    user1_token: Option<String>,
+    user1_user_id: Option<String>,
+    user2_token: Option<String>,
+    user2_user_id: Option<String>,
+}
+
+impl RBACTestClient {
+    fn new() -> Self {
+        Self {
+            client: Client::new(),
+            admin_token: None,
+            admin_user_id: None,
+            user1_token: None,
+            user1_user_id: None,
+            user2_token: None,
+            user2_user_id: None,
+        }
+    }
+    
+    /// Setup all test users (admin, user1, user2)
+    async fn setup_all_users(&mut self) -> Result<(), Box<dyn std::error::Error>> {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        
+        // Setup admin user
+        let admin_username = format!("rbac_admin_{}", timestamp);
+        let admin_email = format!("rbac_admin_{}@example.com", timestamp);
+        let (admin_token, admin_id) = self.register_and_login_user(&admin_username, &admin_email, UserRole::Admin).await?;
+        self.admin_token = Some(admin_token);
+        self.admin_user_id = admin_id;
+        
+        // Setup first regular user
+        let user1_username = format!("rbac_user1_{}", timestamp);
+        let user1_email = format!("rbac_user1_{}@example.com", timestamp);
+        let (user1_token, user1_id) = self.register_and_login_user(&user1_username, &user1_email, UserRole::User).await?;
+        self.user1_token = Some(user1_token);
+        self.user1_user_id = user1_id;
+        
+        // Setup second regular user
+        let user2_username = format!("rbac_user2_{}", timestamp);
+        let user2_email = format!("rbac_user2_{}@example.com", timestamp);
+        let (user2_token, user2_id) = self.register_and_login_user(&user2_username, &user2_email, UserRole::User).await?;
+        self.user2_token = Some(user2_token);
+        self.user2_user_id = user2_id;
+        
+        Ok(())
+    }
+    
+    /// Helper to register and login a single user
+    async fn register_and_login_user(&self, username: &str, email: &str, role: UserRole) -> Result<(String, Option<String>), Box<dyn std::error::Error>> {
+        let password = "rbacpassword123";
+        
+        // Register user
+        let user_data = CreateUser {
+            username: username.to_string(),
+            email: email.to_string(),
+            password: password.to_string(),
+            role: Some(role),
+        };
+        
+        let register_response = self.client
+            .post(&format!("{}/api/auth/register", BASE_URL))
+            .json(&user_data)
+            .send()
+            .await?;
+        
+        if !register_response.status().is_success() {
+            return Err(format!("Registration failed for {}: {}", username, register_response.text().await?).into());
+        }
+        
+        // Login to get token
+        let login_data = LoginRequest {
+            username: username.to_string(),
+            password: password.to_string(),
+        };
+        
+        let login_response = self.client
+            .post(&format!("{}/api/auth/login", BASE_URL))
+            .json(&login_data)
+            .send()
+            .await?;
+        
+        if !login_response.status().is_success() {
+            return Err(format!("Login failed for {}: {}", username, login_response.text().await?).into());
+        }
+        
+        let login_result: LoginResponse = login_response.json().await?;
+        
+        // Get user info to extract user ID
+        let me_response = self.client
+            .get(&format!("{}/api/auth/me", BASE_URL))
+            .header("Authorization", format!("Bearer {}", login_result.token))
+            .send()
+            .await?;
+        
+        let user_id = if me_response.status().is_success() {
+            let user_info: Value = me_response.json().await?;
+            user_info["id"].as_str().map(|s| s.to_string())
+        } else {
+            None
+        };
+        
+        Ok((login_result.token, user_id))
+    }
+    
+    /// Upload a document as a specific user
+    async fn upload_document_as_user(&self, user: UserType, content: &str, filename: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = match user {
+            UserType::Admin => self.admin_token.as_ref(),
+            UserType::User1 => self.user1_token.as_ref(),
+            UserType::User2 => self.user2_token.as_ref(),
+        }.ok_or("User not set up")?;
+        
+        let part = reqwest::multipart::Part::text(content.to_string())
+            .file_name(filename.to_string())
+            .mime_str("text/plain")?;
+        let form = reqwest::multipart::Form::new()
+            .part("file", part);
+        
+        let response = self.client
+            .post(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .multipart(form)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Upload failed: {}", response.text().await?).into());
+        }
+        
+        let document: Value = response.json().await?;
+        Ok(document)
+    }
+    
+    /// Get documents list as a specific user
+    async fn get_documents_as_user(&self, user: UserType) -> Result<Vec<Value>, Box<dyn std::error::Error>> {
+        let token = match user {
+            UserType::Admin => self.admin_token.as_ref(),
+            UserType::User1 => self.user1_token.as_ref(),
+            UserType::User2 => self.user2_token.as_ref(),
+        }.ok_or("User not set up")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Get documents failed: {}", response.text().await?).into());
+        }
+        
+        let documents: Vec<Value> = response.json().await?;
+        Ok(documents)
+    }
+    
+    /// Try to access a specific document as a user
+    async fn try_access_document(&self, user: UserType, document_id: &str) -> Result<reqwest::StatusCode, Box<dyn std::error::Error>> {
+        let token = match user {
+            UserType::Admin => self.admin_token.as_ref(),
+            UserType::User1 => self.user1_token.as_ref(),
+            UserType::User2 => self.user2_token.as_ref(),
+        }.ok_or("User not set up")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/documents/{}/ocr", BASE_URL, document_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        Ok(response.status())
+    }
+    
+    /// Create a source as a specific user
+    async fn create_source_as_user(&self, user: UserType, source_name: &str) -> Result<Value, Box<dyn std::error::Error>> {
+        let token = match user {
+            UserType::Admin => self.admin_token.as_ref(),
+            UserType::User1 => self.user1_token.as_ref(),
+            UserType::User2 => self.user2_token.as_ref(),
+        }.ok_or("User not set up")?;
+        
+        let source_data = json!({
+            "name": source_name,
+            "source_type": "webdav",
+            "config": {
+                "server_url": "https://example.com",
+                "username": "testuser",
+                "password": "testpass",
+                "auto_sync": false,
+                "sync_interval_minutes": 60,
+                "watch_folders": ["/Documents"],
+                "file_extensions": [".pdf"]
+            }
+        });
+        
+        let response = self.client
+            .post(&format!("{}/api/sources", BASE_URL))
+            .header("Authorization", format!("Bearer {}", token))
+            .json(&source_data)
+            .send()
+            .await?;
+        
+        if !response.status().is_success() {
+            return Err(format!("Source creation failed: {}", response.text().await?).into());
+        }
+        
+        let source: Value = response.json().await?;
+        Ok(source)
+    }
+    
+    /// Try to access a source as a user
+    async fn try_access_source(&self, user: UserType, source_id: &str) -> Result<reqwest::StatusCode, Box<dyn std::error::Error>> {
+        let token = match user {
+            UserType::Admin => self.admin_token.as_ref(),
+            UserType::User1 => self.user1_token.as_ref(),
+            UserType::User2 => self.user2_token.as_ref(),
+        }.ok_or("User not set up")?;
+        
+        let response = self.client
+            .get(&format!("{}/api/sources/{}", BASE_URL, source_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .send()
+            .await?;
+        
+        Ok(response.status())
+    }
+    
+    /// Try to access admin endpoints as a user
+    async fn try_admin_operation(&self, user: UserType, operation: AdminOperation) -> Result<reqwest::StatusCode, Box<dyn std::error::Error>> {
+        let token = match user {
+            UserType::Admin => self.admin_token.as_ref(),
+            UserType::User1 => self.user1_token.as_ref(),
+            UserType::User2 => self.user2_token.as_ref(),
+        }.ok_or("User not set up")?;
+        
+        let response = match operation {
+            AdminOperation::ListUsers => {
+                self.client
+                    .get(&format!("{}/api/users", BASE_URL))
+                    .header("Authorization", format!("Bearer {}", token))
+                    .send()
+                    .await?
+            }
+            AdminOperation::CreateUser => {
+                self.client
+                    .post(&format!("{}/api/users", BASE_URL))
+                    .header("Authorization", format!("Bearer {}", token))
+                    .json(&json!({
+                        "username": "test_admin_created",
+                        "email": "admin_created@example.com",
+                        "password": "password123",
+                        "role": "user"
+                    }))
+                    .send()
+                    .await?
+            }
+            AdminOperation::GetMetrics => {
+                self.client
+                    .get(&format!("{}/api/metrics", BASE_URL))
+                    .header("Authorization", format!("Bearer {}", token))
+                    .send()
+                    .await?
+            }
+            AdminOperation::GetQueueStats => {
+                self.client
+                    .get(&format!("{}/api/queue/stats", BASE_URL))
+                    .header("Authorization", format!("Bearer {}", token))
+                    .send()
+                    .await?
+            }
+            AdminOperation::RequeueFailedJobs => {
+                self.client
+                    .post(&format!("{}/api/queue/requeue-failed", BASE_URL))
+                    .header("Authorization", format!("Bearer {}", token))
+                    .send()
+                    .await?
+            }
+        };
+        
+        Ok(response.status())
+    }
+    
+    /// Try to modify another user's resource
+    async fn try_modify_user_resource(&self, actor: UserType, target_user_id: &str) -> Result<reqwest::StatusCode, Box<dyn std::error::Error>> {
+        let token = match actor {
+            UserType::Admin => self.admin_token.as_ref(),
+            UserType::User1 => self.user1_token.as_ref(),
+            UserType::User2 => self.user2_token.as_ref(),
+        }.ok_or("User not set up")?;
+        
+        let response = self.client
+            .put(&format!("{}/api/users/{}", BASE_URL, target_user_id))
+            .header("Authorization", format!("Bearer {}", token))
+            .json(&json!({
+                "username": "modified_user",
+                "email": "modified@example.com",
+                "role": "user"
+            }))
+            .send()
+            .await?;
+        
+        Ok(response.status())
+    }
+}
+
+#[derive(Clone, Copy)]
+enum UserType {
+    Admin,
+    User1,
+    User2,
+}
+
+#[derive(Clone, Copy)]
+enum AdminOperation {
+    ListUsers,
+    CreateUser,
+    GetMetrics,
+    GetQueueStats,
+    RequeueFailedJobs,
+}
+
+#[tokio::test]
+async fn test_document_ownership_isolation() {
+    println!("📄 Testing document ownership and isolation...");
+    
+    let mut client = RBACTestClient::new();
+    client.setup_all_users().await
+        .expect("Failed to setup test users");
+    
+    println!("✅ Setup complete: admin, user1, user2");
+    
+    // User1 uploads a document
+    let user1_doc = client.upload_document_as_user(
+        UserType::User1,
+        "User1's private document content",
+        "user1_private.txt"
+    ).await.expect("Failed to upload User1 document");
+    
+    let user1_doc_id = user1_doc["id"].as_str().expect("Document should have ID");
+    println!("✅ User1 uploaded document: {}", user1_doc_id);
+    
+    // User2 uploads a document
+    let user2_doc = client.upload_document_as_user(
+        UserType::User2,
+        "User2's private document content",
+        "user2_private.txt"
+    ).await.expect("Failed to upload User2 document");
+    
+    let user2_doc_id = user2_doc["id"].as_str().expect("Document should have ID");
+    println!("✅ User2 uploaded document: {}", user2_doc_id);
+    
+    // Test document list isolation
+    let user1_docs = client.get_documents_as_user(UserType::User1).await
+        .expect("Failed to get User1 documents");
+    
+    let user2_docs = client.get_documents_as_user(UserType::User2).await
+        .expect("Failed to get User2 documents");
+    
+    // User1 should only see their own document
+    let user1_sees_own = user1_docs.iter().any(|d| d["id"] == user1_doc_id);
+    let user1_sees_user2 = user1_docs.iter().any(|d| d["id"] == user2_doc_id);
+    
+    assert!(user1_sees_own, "User1 should see their own document");
+    assert!(!user1_sees_user2, "User1 should NOT see User2's document");
+    
+    // User2 should only see their own document
+    let user2_sees_own = user2_docs.iter().any(|d| d["id"] == user2_doc_id);
+    let user2_sees_user1 = user2_docs.iter().any(|d| d["id"] == user1_doc_id);
+    
+    assert!(user2_sees_own, "User2 should see their own document");
+    assert!(!user2_sees_user1, "User2 should NOT see User1's document");
+    
+    println!("✅ Document list isolation verified");
+    
+    // Test direct document access
+    let user1_access_own = client.try_access_document(UserType::User1, user1_doc_id).await
+        .expect("Failed to test User1 access to own document");
+    
+    let user1_access_user2 = client.try_access_document(UserType::User1, user2_doc_id).await
+        .expect("Failed to test User1 access to User2 document");
+    
+    assert!(user1_access_own.is_success(), "User1 should access their own document");
+    assert!(!user1_access_user2.is_success(), "User1 should NOT access User2's document");
+    
+    let user2_access_own = client.try_access_document(UserType::User2, user2_doc_id).await
+        .expect("Failed to test User2 access to own document");
+    
+    let user2_access_user1 = client.try_access_document(UserType::User2, user1_doc_id).await
+        .expect("Failed to test User2 access to User1 document");
+    
+    assert!(user2_access_own.is_success(), "User2 should access their own document");
+    assert!(!user2_access_user1.is_success(), "User2 should NOT access User1's document");
+    
+    println!("✅ Direct document access isolation verified");
+    
+    // Test admin access to all documents
+    let admin_access_user1 = client.try_access_document(UserType::Admin, user1_doc_id).await
+        .expect("Failed to test admin access to User1 document");
+    
+    let admin_access_user2 = client.try_access_document(UserType::Admin, user2_doc_id).await
+        .expect("Failed to test admin access to User2 document");
+    
+    // Admin access depends on implementation - might have access or might not
+    println!("ℹ️  Admin access to User1 doc: {}", admin_access_user1);
+    println!("ℹ️  Admin access to User2 doc: {}", admin_access_user2);
+    
+    println!("🎉 Document ownership isolation test passed!");
+}
+
+#[tokio::test]
+async fn test_source_ownership_isolation() {
+    println!("🗂️ Testing source ownership and isolation...");
+    
+    let mut client = RBACTestClient::new();
+    client.setup_all_users().await
+        .expect("Failed to setup test users");
+    
+    println!("✅ Setup complete: admin, user1, user2");
+    
+    // User1 creates a source
+    let user1_source = client.create_source_as_user(UserType::User1, "User1 WebDAV Source").await
+        .expect("Failed to create User1 source");
+    
+    let user1_source_id = user1_source["id"].as_str().expect("Source should have ID");
+    println!("✅ User1 created source: {}", user1_source_id);
+    
+    // User2 creates a source
+    let user2_source = client.create_source_as_user(UserType::User2, "User2 WebDAV Source").await
+        .expect("Failed to create User2 source");
+    
+    let user2_source_id = user2_source["id"].as_str().expect("Source should have ID");
+    println!("✅ User2 created source: {}", user2_source_id);
+    
+    // Test cross-user source access
+    let user1_access_user2_source = client.try_access_source(UserType::User1, user2_source_id).await
+        .expect("Failed to test User1 access to User2 source");
+    
+    let user2_access_user1_source = client.try_access_source(UserType::User2, user1_source_id).await
+        .expect("Failed to test User2 access to User1 source");
+    
+    assert!(!user1_access_user2_source.is_success(), "User1 should NOT access User2's source");
+    assert!(!user2_access_user1_source.is_success(), "User2 should NOT access User1's source");
+    
+    println!("✅ Source cross-access prevention verified");
+    
+    // Test own source access
+    let user1_access_own_source = client.try_access_source(UserType::User1, user1_source_id).await
+        .expect("Failed to test User1 access to own source");
+    
+    let user2_access_own_source = client.try_access_source(UserType::User2, user2_source_id).await
+        .expect("Failed to test User2 access to own source");
+    
+    assert!(user1_access_own_source.is_success(), "User1 should access their own source");
+    assert!(user2_access_own_source.is_success(), "User2 should access their own source");
+    
+    println!("✅ Own source access verified");
+    
+    // Test admin access to user sources
+    let admin_access_user1_source = client.try_access_source(UserType::Admin, user1_source_id).await
+        .expect("Failed to test admin access to User1 source");
+    
+    let admin_access_user2_source = client.try_access_source(UserType::Admin, user2_source_id).await
+        .expect("Failed to test admin access to User2 source");
+    
+    println!("ℹ️  Admin access to User1 source: {}", admin_access_user1_source);
+    println!("ℹ️  Admin access to User2 source: {}", admin_access_user2_source);
+    
+    println!("🎉 Source ownership isolation test passed!");
+}
+
+#[tokio::test]
+async fn test_admin_only_operations() {
+    println!("👨‍💼 Testing admin-only operations...");
+    
+    let mut client = RBACTestClient::new();
+    client.setup_all_users().await
+        .expect("Failed to setup test users");
+    
+    println!("✅ Setup complete: admin, user1, user2");
+    
+    let admin_operations = vec![
+        AdminOperation::ListUsers,
+        AdminOperation::CreateUser,
+        AdminOperation::GetMetrics,
+        AdminOperation::GetQueueStats,
+        AdminOperation::RequeueFailedJobs,
+    ];
+    
+    for operation in admin_operations {
+        let operation_name = match operation {
+            AdminOperation::ListUsers => "List Users",
+            AdminOperation::CreateUser => "Create User",
+            AdminOperation::GetMetrics => "Get Metrics",
+            AdminOperation::GetQueueStats => "Get Queue Stats",
+            AdminOperation::RequeueFailedJobs => "Requeue Failed Jobs",
+        };
+        
+        println!("🔍 Testing operation: {}", operation_name);
+        
+        // Test admin access
+        let admin_result = client.try_admin_operation(UserType::Admin, operation).await
+            .expect("Failed to test admin operation as admin");
+        
+        // Test regular user access
+        let user1_result = client.try_admin_operation(UserType::User1, operation).await
+            .expect("Failed to test admin operation as user1");
+        
+        let user2_result = client.try_admin_operation(UserType::User2, operation).await
+            .expect("Failed to test admin operation as user2");
+        
+        println!("  Admin access: {}", admin_result);
+        println!("  User1 access: {}", user1_result);
+        println!("  User2 access: {}", user2_result);
+        
+        // Admin should have access (or at least not be forbidden due to role)
+        // Regular users should be denied (401 Unauthorized or 403 Forbidden)
+        if user1_result.is_success() || user2_result.is_success() {
+            println!("⚠️  WARNING: Regular users have access to admin operation: {}", operation_name);
+        } else {
+            println!("✅ Regular users properly denied access to: {}", operation_name);
+        }
+        
+        // Users should get 401 (Unauthorized) or 403 (Forbidden)
+        assert!(
+            user1_result == reqwest::StatusCode::UNAUTHORIZED || 
+            user1_result == reqwest::StatusCode::FORBIDDEN,
+            "User1 should be denied access to {}", operation_name
+        );
+        
+        assert!(
+            user2_result == reqwest::StatusCode::UNAUTHORIZED || 
+            user2_result == reqwest::StatusCode::FORBIDDEN,
+            "User2 should be denied access to {}", operation_name
+        );
+    }
+    
+    println!("🎉 Admin-only operations test passed!");
+}
+
+#[tokio::test]
+async fn test_privilege_escalation_prevention() {
+    println!("🔐 Testing privilege escalation prevention...");
+    
+    let mut client = RBACTestClient::new();
+    client.setup_all_users().await
+        .expect("Failed to setup test users");
+    
+    println!("✅ Setup complete: admin, user1, user2");
+    
+    // Get user IDs for testing
+    let user1_id = client.user1_user_id.as_ref().expect("User1 ID should be set");
+    let user2_id = client.user2_user_id.as_ref().expect("User2 ID should be set");
+    let admin_id = client.admin_user_id.as_ref().expect("Admin ID should be set");
+    
+    // Test 1: Regular user trying to modify another user
+    println!("🔍 Testing user1 trying to modify user2...");
+    
+    let user1_modify_user2 = client.try_modify_user_resource(UserType::User1, user2_id).await
+        .expect("Failed to test user1 modifying user2");
+    
+    assert!(
+        user1_modify_user2 == reqwest::StatusCode::UNAUTHORIZED || 
+        user1_modify_user2 == reqwest::StatusCode::FORBIDDEN ||
+        user1_modify_user2 == reqwest::StatusCode::NOT_FOUND,
+        "User1 should not be able to modify User2"
+    );
+    
+    println!("✅ User1 cannot modify User2: {}", user1_modify_user2);
+    
+    // Test 2: Regular user trying to modify admin
+    println!("🔍 Testing user1 trying to modify admin...");
+    
+    let user1_modify_admin = client.try_modify_user_resource(UserType::User1, admin_id).await
+        .expect("Failed to test user1 modifying admin");
+    
+    assert!(
+        user1_modify_admin == reqwest::StatusCode::UNAUTHORIZED || 
+        user1_modify_admin == reqwest::StatusCode::FORBIDDEN ||
+        user1_modify_admin == reqwest::StatusCode::NOT_FOUND,
+        "User1 should not be able to modify Admin"
+    );
+    
+    println!("✅ User1 cannot modify Admin: {}", user1_modify_admin);
+    
+    // Test 3: Admin can modify users (should succeed)
+    println!("🔍 Testing admin modifying user1...");
+    
+    let admin_modify_user1 = client.try_modify_user_resource(UserType::Admin, user1_id).await
+        .expect("Failed to test admin modifying user1");
+    
+    // Admin should have permission (200 OK or similar success)
+    println!("ℹ️  Admin modifying User1: {}", admin_modify_user1);
+    
+    // Test 4: Try to create admin user as regular user
+    println!("🔍 Testing regular user trying to create admin user...");
+    
+    let user1_token = client.user1_token.as_ref().unwrap();
+    let create_admin_attempt = client.client
+        .post(&format!("{}/api/users", BASE_URL))
+        .header("Authorization", format!("Bearer {}", user1_token))
+        .json(&json!({
+            "username": "malicious_admin",
+            "email": "malicious@example.com",
+            "password": "password123",
+            "role": "admin"  // Trying to create admin user
+        }))
+        .send()
+        .await
+        .expect("Create admin attempt should complete");
+    
+    assert!(
+        !create_admin_attempt.status().is_success(),
+        "Regular user should not be able to create admin users"
+    );
+    
+    println!("✅ User1 cannot create admin user: {}", create_admin_attempt.status());
+    
+    // Test 5: Try to promote self to admin
+    println!("🔍 Testing self-promotion attempt...");
+    
+    // This would typically be done through updating own user profile
+    // The exact endpoint depends on the API design
+    let self_promotion_attempt = client.client
+        .put(&format!("{}/api/users/{}", BASE_URL, user1_id))
+        .header("Authorization", format!("Bearer {}", user1_token))
+        .json(&json!({
+            "username": "user1_promoted",
+            "email": "user1@example.com",
+            "role": "admin"  // Trying to promote self
+        }))
+        .send()
+        .await
+        .expect("Self promotion attempt should complete");
+    
+    assert!(
+        !self_promotion_attempt.status().is_success(),
+        "User should not be able to promote themselves to admin"
+    );
+    
+    println!("✅ User1 cannot promote self: {}", self_promotion_attempt.status());
+    
+    println!("🎉 Privilege escalation prevention test passed!");
+}
+
+#[tokio::test]
+async fn test_data_visibility_boundaries() {
+    println!("👁️ Testing data visibility boundaries...");
+    
+    let mut client = RBACTestClient::new();
+    client.setup_all_users().await
+        .expect("Failed to setup test users");
+    
+    println!("✅ Setup complete: admin, user1, user2");
+    
+    // Create data for each user
+    let user1_doc = client.upload_document_as_user(
+        UserType::User1,
+        "User1 confidential data",
+        "user1_confidential.txt"
+    ).await.expect("Failed to upload User1 document");
+    
+    let user2_doc = client.upload_document_as_user(
+        UserType::User2,
+        "User2 confidential data", 
+        "user2_confidential.txt"
+    ).await.expect("Failed to upload User2 document");
+    
+    let user1_source = client.create_source_as_user(UserType::User1, "User1 Confidential Source").await
+        .expect("Failed to create User1 source");
+    
+    let user2_source = client.create_source_as_user(UserType::User2, "User2 Confidential Source").await
+        .expect("Failed to create User2 source");
+    
+    println!("✅ Created test data for both users");
+    
+    // Test document visibility
+    let user1_docs = client.get_documents_as_user(UserType::User1).await
+        .expect("Failed to get User1 documents");
+    
+    let user2_docs = client.get_documents_as_user(UserType::User2).await
+        .expect("Failed to get User2 documents");
+    
+    // Verify isolation
+    let user1_doc_id = user1_doc["id"].as_str().unwrap();
+    let user2_doc_id = user2_doc["id"].as_str().unwrap();
+    
+    let user1_sees_only_own = user1_docs.iter().all(|d| {
+        // Check if this document belongs to user1 by checking if it's the one they uploaded
+        // or by checking user association if available in the response
+        d["id"] == user1_doc_id || 
+        d.get("user_id").and_then(|uid| uid.as_str()) == client.user1_user_id.as_deref()
+    });
+    
+    let user2_sees_only_own = user2_docs.iter().all(|d| {
+        d["id"] == user2_doc_id || 
+        d.get("user_id").and_then(|uid| uid.as_str()) == client.user2_user_id.as_deref()
+    });
+    
+    assert!(user1_sees_only_own, "User1 should only see their own documents");
+    assert!(user2_sees_only_own, "User2 should only see their own documents");
+    
+    println!("✅ Document visibility boundaries verified");
+    
+    // Test search isolation (if available)
+    if let Ok((user1_search, _)) = client.client
+        .get(&format!("{}/api/search", BASE_URL))
+        .header("Authorization", format!("Bearer {}", client.user1_token.as_ref().unwrap()))
+        .query(&[("q", "confidential")])
+        .send()
+        .await
+        .and_then(|r| async move {
+            let status = r.status();
+            let json: Result<Value, _> = r.json().await;
+            json.map(|j| (j, status))
+        })
+        .await
+    {
+        if let Some(results) = user1_search["documents"].as_array() {
+            let user1_search_sees_user2 = results.iter().any(|doc| {
+                doc["id"] == user2_doc_id
+            });
+            
+            assert!(!user1_search_sees_user2, "User1 search should not return User2 documents");
+            println!("✅ Search isolation verified");
+        }
+    }
+    
+    // Test that users cannot enumerate other users' resources through API exploration
+    println!("🔍 Testing API enumeration prevention...");
+    
+    // Try to access source with incremental IDs (if predictable)
+    let user1_source_id = user1_source["id"].as_str().unwrap();
+    let user2_source_id = user2_source["id"].as_str().unwrap();
+    
+    // User1 tries to access User2's source
+    let cross_access_result = client.try_access_source(UserType::User1, user2_source_id).await
+        .expect("Failed to test cross-source access");
+    
+    assert!(!cross_access_result.is_success(), "Cross-user source access should be denied");
+    
+    // Try with non-existent but valid UUID format
+    let fake_id = Uuid::new_v4().to_string();
+    let fake_access_result = client.try_access_source(UserType::User1, &fake_id).await
+        .expect("Failed to test fake source access");
+    
+    // Should return 404 Not Found, not 403 Forbidden (to avoid information leakage)
+    assert_eq!(fake_access_result, reqwest::StatusCode::NOT_FOUND, "Non-existent resource should return 404");
+    
+    println!("✅ API enumeration prevention verified");
+    
+    println!("🎉 Data visibility boundaries test passed!");
+}
+
+#[tokio::test]
+async fn test_token_and_session_security() {
+    println!("🎫 Testing token and session security...");
+    
+    let mut client = RBACTestClient::new();
+    client.setup_all_users().await
+        .expect("Failed to setup test users");
+    
+    println!("✅ Setup complete: admin, user1, user2");
+    
+    // Test 1: Invalid token format
+    println!("🔍 Testing invalid token formats...");
+    
+    let invalid_tokens = vec![
+        "invalid-token",
+        "Bearer invalid-token",
+        "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.invalid.signature",
+        "",
+        "null",
+        "undefined",
+    ];
+    
+    for invalid_token in invalid_tokens {
+        let response = client.client
+            .get(&format!("{}/api/documents", BASE_URL))
+            .header("Authorization", format!("Bearer {}", invalid_token))
+            .send()
+            .await
+            .expect("Invalid token request should complete");
+        
+        assert_eq!(response.status(), reqwest::StatusCode::UNAUTHORIZED, 
+                  "Invalid token '{}' should return 401", invalid_token);
+    }
+    
+    println!("✅ Invalid tokens properly rejected");
+    
+    // Test 2: Token for one user accessing another user's resources
+    println!("🔍 Testing token cross-contamination...");
+    
+    let user1_token = client.user1_token.as_ref().unwrap();
+    let user2_token = client.user2_token.as_ref().unwrap();
+    
+    // Upload documents with each user
+    let user1_doc = client.upload_document_as_user(
+        UserType::User1,
+        "User1 token test doc",
+        "user1_token_test.txt"
+    ).await.expect("Failed to upload User1 doc");
+    
+    let user1_doc_id = user1_doc["id"].as_str().unwrap();
+    
+    // Try to access User1's document with User2's token
+    let cross_token_access = client.client
+        .get(&format!("{}/api/documents/{}/ocr", BASE_URL, user1_doc_id))
+        .header("Authorization", format!("Bearer {}", user2_token))
+        .send()
+        .await
+        .expect("Cross-token access should complete");
+    
+    assert!(!cross_token_access.status().is_success(), 
+           "User2 token should not access User1 document");
+    
+    println!("✅ Token cross-contamination prevention verified");
+    
+    // Test 3: Expired/revoked token simulation
+    println!("🔍 Testing token revocation scenarios...");
+    
+    // This test would require actual token expiration or revocation mechanisms
+    // For now, we test that a completely invalid token structure is rejected
+    let malformed_jwt = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.malformed_signature";
+    
+    let malformed_response = client.client
+        .get(&format!("{}/api/documents", BASE_URL))
+        .header("Authorization", format!("Bearer {}", malformed_jwt))
+        .send()
+        .await
+        .expect("Malformed JWT request should complete");
+    
+    assert_eq!(malformed_response.status(), reqwest::StatusCode::UNAUTHORIZED,
+              "Malformed JWT should be rejected");
+    
+    println!("✅ Malformed JWT properly rejected");
+    
+    // Test 4: Missing Authorization header
+    println!("🔍 Testing missing authorization...");
+    
+    let no_auth_response = client.client
+        .get(&format!("{}/api/documents", BASE_URL))
+        .send()
+        .await
+        .expect("No auth request should complete");
+    
+    assert_eq!(no_auth_response.status(), reqwest::StatusCode::UNAUTHORIZED,
+              "Missing authorization should return 401");
+    
+    println!("✅ Missing authorization properly handled");
+    
+    println!("🎉 Token and session security test passed!");
+}