implemented integrations and events system

api/src/services/events/eventBus.ts

@@ -0,0 +1,56 @@
+import { randomUUID } from "crypto";
+import { logger } from "../logging/logger";
+
+interface Event {
+    id: string
+    type: string
+    occurredAt: string
+    payload?: Record<string, any>
+}
+
+type EventHandler = (event: Event) => void | Promise<void>;
+
+class EventBus {
+    private handlers: Map<string, EventHandler[]> = new Map();
+
+    /**
+     * Register event listener
+     * @param type 
+     * @param handler 
+     */
+    on(type: string, handler: EventHandler) {
+        const handlers = this.handlers.get(type) ?? [];
+        handlers.push(handler);
+        this.handlers.set(type, handlers);
+    }
+
+    /**
+     * Emit event of given type
+     * @param type
+     * @param payload 
+     */
+    async emit(type: string, payload?: Record<string, any>) {
+        const event: Event = {
+            id: randomUUID(),
+            type,
+            occurredAt: new Date().toISOString(),
+            payload
+        }
+
+        const handlers = this.handlers.get(type) ?? []
+
+        for (const h of handlers) {
+            try {
+                await h(event)
+            } catch (error) {
+                logger.error('app', 'Event handler failed', {
+                    type: event.type,
+                    id: event.id,
+                    error: error instanceof Error ? error.message : String(error),
+                })
+            }
+        }
+    }
+}
+
+export const bus = new EventBus();