feat(infrastructure): use celery worker

backend/app/core/queue.py

@@ -1,35 +1,28 @@
-import json
-import os
-from typing import Any, Dict
-import asyncio
+# Route email jobs via Celery instead of raw RabbitMQ publishing
+# Ensure Celery app is initialized so producers use correct broker credentials.
+# Import has side effects (sets Celery default app), safe to keep at module level.
+import app.celery_app  # noqa: F401
 
-RABBITMQ_URL = os.getenv("RABBITMQ_URL") or (
-    f"amqp://{os.getenv('RABBITMQ_USERNAME', 'user')}:"
-    f"{os.getenv('RABBITMQ_PASSWORD', 'bitnami123')}@"
-    f"{os.getenv('RABBITMQ_HOST', 'localhost')}:"
-    f"{os.getenv('RABBITMQ_PORT', '5672')}"
-)
-QUEUE_NAME = os.getenv("MAIL_QUEUE", "mail_queue")
+# Use a lazy proxy so _send_email_task is never None, even if Celery modules
+# are not yet importable at import time (e.g., different working dir during startup).
+class _LazySendTask:
+    def delay(self, to: str, subject: str, body: str):  # type: ignore[no-untyped-def]
+        # Late import on first use
+        from app.workers.celery_tasks import send_email_fields as _send  # type: ignore
+        return _send.delay(to, subject, body)
+
+
+try:
+    # Try eager import for normal operation
+    from app.workers.celery_tasks import send_email_fields as _send_email_task  # type: ignore
+except ImportError:  # pragma: no cover - fallback lazy import proxy
+    _send_email_task = _LazySendTask()  # type: ignore
 
-async def _publish_async(message: Dict[str, Any]) -> None:
-    import aio_pika
-    connection = await aio_pika.connect_robust(RABBITMQ_URL)
-    try:
-        channel = await connection.channel()
-        await channel.declare_queue(QUEUE_NAME, durable=True)
-        body = json.dumps(message).encode("utf-8")
-        await channel.default_exchange.publish(
-            aio_pika.Message(body=body, delivery_mode=aio_pika.DeliveryMode.PERSISTENT),
-            routing_key=QUEUE_NAME,
-        )
-    finally:
-        await connection.close()
 
 def enqueue_email(to: str, subject: str, body: str) -> None:
-    message = {"type": "email", "to": to, "subject": subject, "body": body}
-    try:
-        loop = asyncio.get_running_loop()
-        loop.create_task(_publish_async(message))
-    except RuntimeError:
-        asyncio.run(_publish_async(message))
+    """Enqueue an email job using Celery.
+
+    Keeps the same public API as before.
+    """
+    _send_email_task.delay(to, subject, body)