feat: FastAPI app with REST API routes and WebSocket endpoint

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/mqtt_home/main.py

@@ -0,0 +1,84 @@
+import asyncio
+import logging
+from contextlib import asynccontextmanager
+
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+
+from mqtt_home.config import get_settings
+from mqtt_home.database import init_db, get_session_factory, Base
+from mqtt_home.mqtt_client import MqttClient
+from mqtt_home.emqx_api import EmqxApiClient
+from mqtt_home.discovery import handle_discovery_message
+from mqtt_home.device_registry import handle_state_update
+from mqtt_home.api import api_router
+from mqtt_home.ws import websocket_endpoint, broadcast_device_update
+
+logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(name)s: %(message)s")
+logger = logging.getLogger(__name__)
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    settings = get_settings()
+
+    await init_db()
+    logger.info("Database initialized")
+
+    emqx = EmqxApiClient(settings)
+    app.state.emqx_client = emqx
+    logger.info("EMQX API client initialized")
+
+    mqtt = MqttClient(settings)
+    app.state.mqtt_client = mqtt
+
+    session_factory = get_session_factory()
+
+    async def on_discovery(topic: str, payload: str):
+        async with session_factory() as db:
+            await handle_discovery_message(topic, payload, db, mqtt)
+
+    async def on_state(topic: str, payload: str):
+        async with session_factory() as db:
+            device = await handle_state_update(db, topic, payload)
+            if device:
+                await broadcast_device_update(device.id, {
+                    "state": device.state,
+                    "is_online": device.is_online,
+                    "last_seen": device.last_seen.isoformat() if device.last_seen else None,
+                })
+
+    mqtt.on_message("homeassistant/#", on_discovery)
+    mqtt.on_message("home/#", on_state)
+
+    await mqtt.start()
+    logger.info("MQTT client started")
+
+    yield
+
+    await mqtt.stop()
+    await emqx.close()
+    logger.info("Shutdown complete")
+
+
+app = FastAPI(title="MQTT Home", version="0.1.0", lifespan=lifespan)
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+app.include_router(api_router)
+app.websocket("/ws/devices")(websocket_endpoint)
+
+
+@app.get("/health")
+async def health():
+    mqtt = getattr(app.state, "mqtt_client", None)
+    return {
+        "status": "ok",
+        "mqtt_connected": mqtt.is_connected if mqtt else False,
+    }