Implement heartbeat

app/c2_main.py

@@ -54,6 +54,14 @@ def on_message(client, userdata, msg):
     if MAIN_LOOP:
         asyncio.run_coroutine_threadsafe(handle_message(msg), MAIN_LOOP)
 
+async def update_last_seen(node_id):
+    """Generic helper to update the timestamp on any contact."""
+    try:
+        doc_ref = db.collection("nodes").document(node_id)
+        await async_firestore(doc_ref.set, {"last_seen": datetime.utcnow()}, merge=True)
+    except Exception as e:
+        print(f"Failed to update heartbeat for {node_id}: {e}")
+
 async def handle_message(msg):
     topic_parts = msg.topic.split('/')
     if len(topic_parts) < 3: return
@@ -65,37 +73,46 @@ async def handle_message(msg):
         payload = json.loads(msg.payload.decode())
         timestamp = datetime.utcnow()
 
+        # 1. ALWAYS update last_seen if we hear from the node
+        await update_last_seen(node_id)
+
         if event_type == "checkin":
-            print(f"Processing checkin for {node_id}...")
+            # This now receives the periodic heartbeat
+            print(f"Heartbeat/Checkin from {node_id}")
             data = {
                 "node_id": node_id,
                 "last_seen": timestamp,
                 "status": payload.get("status", "online"),
                 "active_system": payload.get("active_system"),
                 "available_systems": payload.get("available_systems", []),
-                "config": payload,
                 "radio_state": "active" if payload.get("is_listening") else "idle"
             }
             doc_ref = db.collection("nodes").document(node_id)
-            print(f"Writing to Firestore: {doc_ref.path} in DB {FIRESTORE_DB_ID}")
             await async_firestore(doc_ref.set, data, merge=True)
-            print(f"Successfully updated checkin for {node_id}")
             ACTIVE_NODES_CACHE[node_id] = data
 
         elif event_type == "status":
-            print(f"Processing status update for {node_id}...")
+            # Handle explicit Offline messages (LWT or clean shutdown)
+            print(f"Status update for {node_id}: {payload.get('status')}")
             status = payload.get("status")
+            
+            data = {"status": status, "last_seen": timestamp}
+            
+            # If offline, maybe clear active system?
+            if status == "offline":
+                data["radio_state"] = "unknown"
+                
             doc_ref = db.collection("nodes").document(node_id)
-            print(f"Writing to Firestore: {doc_ref.path} in DB {FIRESTORE_DB_ID}")
+            await async_firestore(doc_ref.set, data, merge=True)
-            await async_firestore(doc_ref.set, {"status": status, "last_seen": timestamp}, merge=True)
+            
-            print(f"Successfully updated status for {node_id}")
             if node_id in ACTIVE_NODES_CACHE:
-                ACTIVE_NODES_CACHE[node_id]["status"] = status
+                ACTIVE_NODES_CACHE[node_id].update(data)
 
     except Exception as e:
         print(f"Error processing MQTT message from {node_id}: {e}")
         traceback.print_exc()
 
+
 # MQTT Setup
 mqtt_client = mqtt.Client(client_id=C2_ID)
 mqtt_client.on_connect = on_connect