The Zombie Dead-Letter Resurrection

"""
Queue Job Consumer
Polls messages, executes worker tasks, and manages retry / DLQ lifecycle.
"""

class QueueConsumer:
    def __init__(self, broker, policy):
        self.broker = broker
        self.policy = policy

    def handle_message(self, message, handler_fn):
        msg_id = message["id"]
        try:
            handler_fn(message["payload"])
            self.broker.ack(msg_id)
            return {"status": "PROCESSED", "message_id": msg_id}
        except Exception as err:
            decision = self.policy.track_attempt(message)
            if decision["can_retry"]:
                # Re-queue message for next retry cycle
                return {"status": "RETRY_QUEUED", "message_id": msg_id, "attempt": decision["attempt"]}
            else:
                # Retries exhausted
                # AI BUG: ACKs message BEFORE confirming DLQ dispatch!
                self.broker.ack(msg_id)
                self.broker.route_to_dlq(message, str(err))
                return {"status": "DEAD_LETTERED", "message_id": msg_id, "attempt": decision["attempt"]}