server-ts: Port bbranch (with some build errors)

src/services/task_context.ts

@@ -0,0 +1,79 @@
+"use strict";
+
+import ws = require('./ws.js');
+
+// taskId => TaskContext
+const taskContexts: Record<string, TaskContext> = {};
+
+class TaskContext {
+
+    private taskId: string;
+    private taskType: string | null;
+    private data: {} | null;
+    private noteDeletionHandlerTriggered: boolean;
+    private progressCount: number;
+    private lastSentCountTs: number;
+
+    constructor(taskId: string, taskType: string | null = null, data: {} | null = {}) {
+        this.taskId = taskId;
+        this.taskType = taskType;
+        this.data = data;
+        this.noteDeletionHandlerTriggered = false;
+
+        // progressCount is meant to represent just some progress - to indicate the task is not stuck
+        this.progressCount = -1; // we're incrementing immediately
+        this.lastSentCountTs = 0; // 0 will guarantee the first message will be sent
+
+        // just the fact this has been initialized is a progress which should be sent to clients
+        // this is esp. important when importing big files/images which take a long time to upload/process
+        // which means that first "real" increaseProgressCount() will be called quite late and user is without
+        // feedback until then
+        this.increaseProgressCount();
+    }
+
+    static getInstance(taskId: string, taskType: string, data: {} | null = null): TaskContext {
+        if (!taskContexts[taskId]) {
+            taskContexts[taskId] = new TaskContext(taskId, taskType, data);
+        }
+
+        return taskContexts[taskId];
+    }
+
+    increaseProgressCount() {
+        this.progressCount++;
+
+        if (Date.now() - this.lastSentCountTs >= 300 && this.taskId !== 'no-progress-reporting') {
+            this.lastSentCountTs = Date.now();
+
+            ws.sendMessageToAllClients({
+                type: 'taskProgressCount',
+                taskId: this.taskId,
+                taskType: this.taskType,
+                data: this.data || undefined,
+                progressCount: this.progressCount
+            });
+        }
+    }
+
+    reportError(message: string) {
+        ws.sendMessageToAllClients({
+            type: 'taskError',
+            taskId: this.taskId,
+            taskType: this.taskType,
+            data: this.data || undefined,
+            message: message
+        });
+    }
+
+    taskSucceeded(result: string) {
+        ws.sendMessageToAllClients({
+            type: 'taskSucceeded',
+            taskId: this.taskId,
+            taskType: this.taskType,
+            data: this.data || undefined,
+            result: result
+        });
+    }
+}
+
+export = TaskContext;