name: Build PR Plugin

on:
  pull_request:
    paths:
      - 'emhttp/**'
      - '.github/workflows/pr-plugin-build.yml'
      - '.github/scripts/**'

permissions:
  contents: read
  pull-requests: read
  actions: read

jobs:
  build-plugin:
    runs-on: ubuntu-latest
    
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      
      - name: Get changed files
        id: changed-files
        run: |
          set -euo pipefail
          
          # Get list of changed files in emhttp directory using PR SHAs
          git diff --name-only "${{ github.event.pull_request.base.sha }}...${{ github.event.pull_request.head.sha }}" | grep '^emhttp/' > changed_files.txt || true
          
          # Output for debugging
          echo "Changed files:"
          cat changed_files.txt
          
          # Check if we have any changes
          if [ ! -s "changed_files.txt" ]; then
            echo "No emhttp files changed"
            echo "has_changes=false" >> "$GITHUB_OUTPUT"
          else
            echo "has_changes=true" >> "$GITHUB_OUTPUT"
          fi
      
      - name: Generate plugin version
        if: steps.changed-files.outputs.has_changes == 'true'
        id: version
        run: |
          # Generate version with proper timestamp format: YYYY.MM.DD.HHMM
          VERSION=$(date -u +"%Y.%m.%d.%H%M")
          # Also keep PR info for reference
          PR_VERSION="pr.${{ github.event.pull_request.number }}.$(git rev-parse --short HEAD)"
          
          # Generate URLs with versioned TXZ to prevent SHA conflicts
          S3_BASE_URL="${{ secrets.CLOUDFLARE_PREVIEW_BUCKET_BASE_URL }}/pr-plugins/pr-${{ github.event.pull_request.number }}"
          
          # Define filenames
          LOCAL_TXZ_NAME="webgui-pr-${{ github.event.pull_request.number }}.tar.gz"
          REMOTE_TXZ_NAME="webgui-pr-${{ github.event.pull_request.number }}-${VERSION}.tar.gz"
          PLUGIN_NAME="webgui-pr-${{ github.event.pull_request.number }}.plg"
          
          # TXZ gets unique versioned path to prevent SHA conflicts on updates
          TXZ_URL="${S3_BASE_URL}/${REMOTE_TXZ_NAME}"
          PLUGIN_URL="${S3_BASE_URL}/${PLUGIN_NAME}"
          TXZ_KEY="pr-plugins/pr-${{ github.event.pull_request.number }}/${REMOTE_TXZ_NAME}"
          PLUGIN_KEY="pr-plugins/pr-${{ github.event.pull_request.number }}/${PLUGIN_NAME}"

          echo "version=$VERSION" >> $GITHUB_OUTPUT
          echo "pr_version=$PR_VERSION" >> $GITHUB_OUTPUT
          echo "local_txz=$LOCAL_TXZ_NAME" >> $GITHUB_OUTPUT
          echo "remote_txz=$REMOTE_TXZ_NAME" >> $GITHUB_OUTPUT
          echo "plugin_name=$PLUGIN_NAME" >> $GITHUB_OUTPUT
          echo "txz_url=$TXZ_URL" >> $GITHUB_OUTPUT
          echo "plugin_url=$PLUGIN_URL" >> $GITHUB_OUTPUT
          echo "txz_key=$TXZ_KEY" >> $GITHUB_OUTPUT
          echo "plugin_key=$PLUGIN_KEY" >> $GITHUB_OUTPUT
          echo "Generated version: $VERSION (PR: $PR_VERSION)"
      
      - name: Create plugin package
        if: steps.changed-files.outputs.has_changes == 'true'
        run: |
          # Create build directory
          mkdir -p build/usr/local
          
          # Copy changed files preserving directory structure
          while IFS= read -r file; do
            if [ -f "$file" ]; then
              # Create directory structure in build
              dir=$(dirname "$file")
              mkdir -p "build/usr/local/$dir"
              cp "$file" "build/usr/local/$dir/"
              echo "Added: $file"
            fi
          done < changed_files.txt
          
          # Create tarball - consistent filename for updates
          cd build
          echo "Creating tarball with contents:"
          find usr/ -type f
          tar -czf ../${{ steps.version.outputs.local_txz }} usr/
          cd ..
          
          # Generate file list for plugin
          find build/usr/local/emhttp -type f | sed 's|^build||' > file_list.txt
          echo "File list for plugin:"
          cat file_list.txt
          
          # Verify tarball contents
          echo "Tarball contents:"
          tar -tzf ${{ steps.version.outputs.local_txz }}
      
      - name: Generate plugin file
        if: steps.changed-files.outputs.has_changes == 'true'
        run: |
          # Generate with placeholder URLs - will be updated by upload workflow
          bash .github/scripts/generate-pr-plugin.sh \
            "${{ steps.version.outputs.version }}" \
            "${{ github.event.pull_request.number }}" \
            "$(git rev-parse --short HEAD)" \
            "${{ steps.version.outputs.local_txz }}" \
            "${{ steps.version.outputs.remote_txz }}" \
            "PENDING_UPLOAD" \
            "PENDING_UPLOAD"
      
      - name: Save metadata for upload workflow
        if: steps.changed-files.outputs.has_changes == 'true'
        run: |
          cat > pr-metadata.json << EOF
          {
            "pr_number": ${{ github.event.pull_request.number }},
            "version": "${{ steps.version.outputs.version }}",
            "pr_version": "${{ steps.version.outputs.pr_version }}",
            "local_txz": "${{ steps.version.outputs.local_txz }}",
            "remote_txz": "${{ steps.version.outputs.remote_txz }}",
            "plugin_name": "${{ steps.version.outputs.plugin_name }}",
            "changed_files": $(cat changed_files.txt | jq -R -s -c 'split("\n") | map(select(length > 0))')
          }
          EOF

          echo "Metadata saved:"
          cat pr-metadata.json

      - name: Upload artifacts to GitHub
        if: steps.changed-files.outputs.has_changes == 'true'
        uses: actions/upload-artifact@v4
        with:
          name: webgui-pr-plugin-${{ github.event.pull_request.number }}
          path: |
            webgui-pr-*.plg
            webgui-pr-*.tar.gz
            pr-metadata.json
            changed_files.txt
          retention-days: 30