lwt actually working. i hate how it works though

handler.py

@@ -2,6 +2,8 @@ import aiomqtt
 import asyncio
 import inspect
 import paho
+import signal
+from dataclasses import dataclass
 
 from command import (
     Command,
@@ -11,20 +13,43 @@ from command import (
 )
 
 
+@dataclass
+class MQTTConfig:
+    host: str
+    port: int = 1883
+    username: str | None = None
+    password: str | None = None
+    keepalive: int = 60
+
+
 class MQTTHandler:
 
     def __init__(
         self,
-        mqtt_client: aiomqtt.Client,
+        mqtt_config: MQTTConfig,
         handler_id: str,
     ):
         self.handler_id = handler_id
-        self.mqtt_client = mqtt_client
+        self.mqtt_config = mqtt_config
 
         self.topic_base = f"asset/{handler_id}"
+        self.status_topic = f"{self.topic_base}/status"
         self.command_topic = f"{self.topic_base}/command"
         self.property_topic = f"{self.topic_base}/property"
 
+        self._shutdown_event = asyncio.Event()
+        will = aiomqtt.Will(
+            topic=self.status_topic, payload="OFFLINE", qos=1, retain=True
+        )
+
+        self.mqtt_client = aiomqtt.Client(
+            self.mqtt_config.host,
+            port=self.mqtt_config.port,
+            identifier=handler_id,
+            protocol=paho.mqtt.client.MQTTv5,
+            will=will,
+        )
+
     def get_available_commands(self):
         commands = {}
         for base in self.__class__.__mro__:
@@ -93,6 +118,14 @@ class MQTTHandler:
                 command_name = topic.removeprefix(f"{self.command_topic}/")
                 await self.execute_command(command_name, payload, message.properties)
 
+    async def shutdown_watcher(self):
+        await self._shutdown_event.wait()
+        await self.mqtt_client.publish(self.status_topic, "OFFLINE", qos=1, retain=True)
+
+    def stop(self):
+        self._shutdown_event.set()
+        signal.signal(signal.SIGINT, signal.SIG_DFL)
+
     async def run(self):
         INTERVAL = 5
         while True:
@@ -101,7 +134,12 @@ class MQTTHandler:
                     await client.subscribe(f"{self.command_topic}/+")
                     await self.publish_commands()
 
-                    tasks = [self.mqtt_command_writer_task()]
+                    # announce that we are online
+                    await client.publish(
+                        self.status_topic, "ONLINE", qos=1, retain=True
+                    )
+
+                    tasks = [self.mqtt_command_writer_task(), self.shutdown_watcher()]
 
                     # Inspect instance methods
                     for attr_name in dir(self):

main.py

@@ -4,26 +4,18 @@ import aiomqtt
 import aioserial
 import asyncio
 import paho
-import uuid
 import socket
+import signal
 
 from ubxhandler import UBXHandler
+from handler import MQTTConfig
 
 BAUD = 115200
 
 
 async def main():
     handler_id = f"example-gps-{socket.gethostname()}"
-    mqtt_host = "127.0.0.1"
+    mqtt_config = MQTTConfig(host="127.0.0.1", port=1883)
-    mqtt_port = 1883
-
-    client_id = f"{handler_id}-{uuid.uuid4()}"
-    mqtt_client = aiomqtt.Client(
-        mqtt_host,
-        port=mqtt_port,
-        identifier=client_id,
-        protocol=paho.mqtt.client.MQTTv5,
-    )
 
     serial_port = aioserial.AioSerial(
         port="/tmp/ttyV0",
@@ -31,7 +23,9 @@ async def main():
         timeout=0.05,  # 50 ms
     )
 
-    handler = UBXHandler(mqtt_client, handler_id, serial_port)
+    handler = UBXHandler(mqtt_config, handler_id, serial_port)
+
+    signal.signal(signal.SIGINT, lambda signum, frame: handler.stop())
     await handler.run()