feat(infrastructure): use celery worker

backend/app/celery_app.py

@@ -1,8 +1,6 @@
 import os
 from celery import Celery
 
-# Reuse existing RabbitMQ configuration env vars with vhost and optional TLS support
-# If RABBITMQ_URL is provided, it takes precedence. Otherwise compose from parts.
 if os.getenv("RABBITMQ_URL"):
     RABBITMQ_URL = os.getenv("RABBITMQ_URL")  # type: ignore
 else:
@@ -27,26 +25,19 @@ else:
     if vhost in ("/", "") and not RABBITMQ_URL.endswith("//"):
         RABBITMQ_URL += "/"
 
-# Default queue name to keep parity with the previous worker
 DEFAULT_QUEUE = os.getenv("MAIL_QUEUE", "mail_queue")
 
-# Use RPC backend by default to avoid coupling to Redis
 CELERY_BACKEND = os.getenv("CELERY_BACKEND", "rpc://")
 
 celery_app = Celery(
     "app",
     broker=RABBITMQ_URL,
-    backend=CELERY_BACKEND,
-    include=[
-        "app.workers.celery_tasks",
-    ],
+    # backend=CELERY_BACKEND,
 )
+celery_app.autodiscover_tasks(["app.workers"], related_name="celery_tasks")  # discover app.workers.celery_tasks
 
-# Ensure this Celery app becomes the default for producers (e.g., FastAPI process)
-# so that @shared_task.delay(...) uses the same broker/credentials as the worker.
 celery_app.set_default()
 
-# Basic, safe defaults – single prefetch helps fairness similarly to the old worker
 celery_app.conf.update(
     task_default_queue=DEFAULT_QUEUE,
     task_acks_late=True,
@@ -54,8 +45,6 @@ celery_app.conf.update(
     task_serializer="json",
     result_serializer="json",
     accept_content=["json"],
-    broker_heartbeat=0,  # let kombu handle heartbeats robustly in some envs
 )
 
-# Expose a shortcut for Celery CLI discovery: `celery -A app.celery_app worker ...`
 __all__ = ["celery_app"]

backend/app/core/queue.py

@@ -1,28 +1,6 @@
-# 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
-
-# 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
+from app.workers.celery_tasks import send_email
 
 
 def enqueue_email(to: str, subject: str, body: str) -> None:
-    """Enqueue an email job using Celery.
-
-    Keeps the same public API as before.
-    """
-    _send_email_task.delay(to, subject, body)
-
+    send_email.delay(to, subject, body)

backend/app/workers/celery_tasks.py

@@ -1,5 +1,4 @@
 import logging
-from typing import Any, Dict
 
 from celery import shared_task
 
@@ -11,34 +10,10 @@ logger.setLevel(logging.INFO)
 
 
 @shared_task(name="workers.send_email")
-def send_email(payload: Dict[str, Any]) -> None:
-    """Celery task to send an email.
-
-    Expected payload schema:
-    {
-        "type": "email",
-        "to": "recipient@example.com",
-        "subject": "Subject text",
-        "body": "Email body text"
-    }
-
-    This mirrors the previous queue worker contract to minimize changes upstream.
-    """
-    to = payload.get("to")
-    subject = payload.get("subject")
-    body = payload.get("body")
+def send_email(to: str, subject: str, body: str) -> None:
     if not (to and subject and body):
-        logger.error("Email task missing fields. Payload: %s", payload)
+        logger.error("Email task missing fields. to=%r subject=%r body_len=%r", to, subject, len(body) if body else 0)
         return
 
     # Placeholder for real email sending logic
-    # Implement SMTP provider call here
     logger.info("[Celery] Email sent | to=%s | subject=%s | body_len=%d", to, subject, len(body))
-
-
-@shared_task(name="workers.send_email_fields")
-def send_email_fields(to: str, subject: str, body: str) -> None:
-    """Alternate signature for convenience when calling from app code.
-    Routes to the same implementation as send_email.
-    """
-    send_email({"type": "email", "to": to, "subject": subject, "body": body})