feat(task): add task labels and push-based task events

ts/taskbuffer.classes.task.ts

@@ -2,7 +2,7 @@ import * as plugins from './taskbuffer.plugins.js';
 import { BufferRunner } from './taskbuffer.classes.bufferrunner.js';
 import { CycleCounter } from './taskbuffer.classes.cyclecounter.js';
 import { TaskStep, type ITaskStep } from './taskbuffer.classes.taskstep.js';
-import type { ITaskMetadata } from './taskbuffer.interfaces.js';
+import type { ITaskMetadata, ITaskEvent, TTaskEventType } from './taskbuffer.interfaces.js';
 
 import { logger } from './taskbuffer.logging.js';
 
@@ -91,6 +91,7 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
     // Reset steps and error state at the beginning of task execution
     taskToRun.resetSteps();
     taskToRun.lastError = undefined;
+    taskToRun.emitEvent('started');
 
     done.promise
       .then(async () => {
@@ -98,6 +99,7 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
 
         // Complete all steps when task finishes
         taskToRun.completeAllSteps();
+        taskToRun.emitEvent(taskToRun.lastError ? 'failed' : 'completed');
 
         // When the task has finished running, resolve the finished promise
         taskToRun.resolveFinished();
@@ -109,6 +111,7 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
       })
       .catch((err) => {
         taskToRun.running = false;
+        taskToRun.emitEvent('failed', { error: err instanceof Error ? err.message : String(err) });
 
         // Resolve finished so blocking dependants don't hang
         taskToRun.resolveFinished();
@@ -218,6 +221,8 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
   public catchErrors: boolean = false;
   public lastError?: Error;
   public errorCount: number = 0;
+  public labels: Record<string, string> = {};
+  public readonly eventSubject = new plugins.smartrx.rxjs.Subject<ITaskEvent>();
 
   public get idle() {
     return !this.running;
@@ -227,6 +232,38 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
     this.lastError = undefined;
   }
 
+  public setLabel(key: string, value: string): void {
+    this.labels[key] = value;
+  }
+
+  public getLabel(key: string): string | undefined {
+    return this.labels[key];
+  }
+
+  public removeLabel(key: string): boolean {
+    if (key in this.labels) {
+      delete this.labels[key];
+      return true;
+    }
+    return false;
+  }
+
+  public hasLabel(key: string, value?: string): boolean {
+    if (value !== undefined) {
+      return this.labels[key] === value;
+    }
+    return key in this.labels;
+  }
+
+  private emitEvent(type: TTaskEventType, extra?: Partial<ITaskEvent>): void {
+    this.eventSubject.next({
+      type,
+      task: this.getMetadata(),
+      timestamp: Date.now(),
+      ...extra,
+    });
+  }
+
   public taskSetup: ITaskSetupFunction<T>;
   public setupValue: T;
 
@@ -247,6 +284,7 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
     taskSetup?: ITaskSetupFunction<T>;
     steps?: TSteps;
     catchErrors?: boolean;
+    labels?: Record<string, string>;
   }) {
     this.taskFunction = optionsArg.taskFunction;
     this.preTask = optionsArg.preTask;
@@ -257,6 +295,7 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
     this.name = optionsArg.name;
     this.taskSetup = optionsArg.taskSetup;
     this.catchErrors = optionsArg.catchErrors ?? false;
+    this.labels = optionsArg.labels ? { ...optionsArg.labels } : {};
 
     // Initialize steps if provided
     if (optionsArg.steps) {
@@ -309,8 +348,8 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
     if (step) {
       step.start();
       this.currentStepName = stepName as string;
-      
-      // Emit event for frontend updates (could be enhanced with event emitter)
+      this.emitEvent('step', { stepName: stepName as string });
+
       if (this.name) {
         logger.log('info', `Task ${this.name}: Starting step "${stepName}" - ${step.description}`);
       }
@@ -369,6 +408,7 @@ export class Task<T = undefined, TSteps extends ReadonlyArray<{ name: string; de
       cronSchedule: this.cronJob?.cronExpression,
       lastError: this.lastError?.message,
       errorCount: this.errorCount,
+      labels: { ...this.labels },
     };
   }