feat: implement mqtt ingestion, parsing, and archive pipeline

backend/app/mqtt/ingestor.py

@@ -0,0 +1,78 @@
+from __future__ import annotations
+
+import logging
+
+import paho.mqtt.client as mqtt  # type: ignore[import-not-found,import-untyped]
+from sqlmodel import Session
+
+from app.core.config import settings
+from app.core.db import engine
+from app.mqtt.repository import insert_raw_message
+from app.mqtt.topic import extract_device_id
+
+logger = logging.getLogger(__name__)
+
+
+def _on_connect(
+    client: mqtt.Client,
+    _userdata: object,
+    _flags: dict[str, int],
+    reason_code: int,
+    _properties: mqtt.Properties | None = None,
+) -> None:
+    if reason_code != 0:
+        logger.error("MQTT connect failed: rc=%s", reason_code)
+        return
+
+    logger.info(
+        "Connected to MQTT broker %s:%s", settings.MQTT_HOST, settings.MQTT_PORT
+    )
+    client.subscribe(settings.MQTT_TOPIC_PATTERN, qos=1)
+
+
+def _on_message(
+    _client: mqtt.Client,
+    _userdata: object,
+    message: mqtt.MQTTMessage,
+) -> None:
+    try:
+        device_id = extract_device_id(message.topic)
+    except ValueError:
+        logger.warning("Skipping unexpected topic: %s", message.topic)
+        return
+
+    with Session(engine) as session:
+        insert_raw_message(
+            session=session,
+            device_id=device_id,
+            topic=message.topic,
+            payload=bytes(message.payload),
+            qos=message.qos,
+            retain=message.retain,
+        )
+
+
+def create_client() -> mqtt.Client:
+    client = mqtt.Client(
+        callback_api_version=mqtt.CallbackAPIVersion.VERSION2,
+        client_id=settings.MQTT_CLIENT_ID,
+        clean_session=False,
+    )
+    if settings.MQTT_USERNAME:
+        client.username_pw_set(settings.MQTT_USERNAME, settings.MQTT_PASSWORD)
+
+    client.on_connect = _on_connect
+    client.on_message = _on_message
+    client.reconnect_delay_set(min_delay=1, max_delay=30)
+    return client
+
+
+def run() -> None:
+    logging.basicConfig(level=logging.INFO)
+    client = create_client()
+    client.connect(settings.MQTT_HOST, settings.MQTT_PORT, keepalive=60)
+    client.loop_forever()
+
+
+if __name__ == "__main__":
+    run()