mildly OOPify

assethandler.py

@@ -1,25 +1,47 @@
 #! /usr/bin/env python3
-
 import asyncio
 import uuid
 import aioserial
 import aiomqtt
 import pyubx2
-from datetime import datetime, timedelta
 
-SERIAL_PORT = "/tmp/ttyV0"
 BAUD = 115200
 
-SERIAL_PUBLISH_TOPIC = "serial/data"
-SERIAL_COMMAND_TOPIC = "serial/command"
 
-async def parse_serial(ser):
+class SerialMQTTHandler:
+    def __init__(
+        self,
+        handler_id: str,
+        serial_port: str,
+        mqtt_host: str = "127.0.0.1",
+        mqtt_port: int = 1883,
+    ):
+        self.handler_id = handler_id
+        self.serial_port = serial_port
+        self.mqtt_host = mqtt_host
+        self.mqtt_port = mqtt_port
+
+        # Serial
+        self.ser = aioserial.AioSerial(
+            port=serial_port,
+            baudrate=BAUD,
+            timeout=0.05,  # 50 ms
+        )
+
+        # MQTT client
+        self.client_id = f"{handler_id}-{uuid.uuid4()}"
+        self.mqtt_client = aiomqtt.Client(
+            mqtt_host, port=mqtt_port, identifier=self.client_id
+        )
+
+        # Topic base
+        self.topic_base = f"asset/{handler_id}"
+
+    async def parse_serial(self):
         buffer = bytearray()
 
-    # pyubx2 requires a file-like object, so we'll use a memoryview wrapper
         class StreamWrapper:
-        def read(self, n=1):
-            # grab at most n bytes from buffer
+            def read(inner_self, n=1):
                 if not buffer:
                     raise BlockingIOError
                 out = buffer[:n]
@@ -29,7 +51,7 @@ async def parse_serial(ser):
         ubr = pyubx2.UBXReader(StreamWrapper(), parsing=True)
 
         while True:
-        chunk = await ser.read_async(200)
+            chunk = await self.ser.read_async(200)
             if chunk:
                 buffer.extend(chunk)
 
@@ -42,60 +64,54 @@ async def parse_serial(ser):
                 except (pyubx2.UBXStreamError, BlockingIOError, Exception):
                     pass
             else:
-            await asyncio.sleep(0)  # yield control
+                await asyncio.sleep(0)
 
-
-async def serial_reader(ser, mqtt_client):
-    async for raw, parsed in parse_serial(ser):
+    async def serial_reader_task(self):
+        async for raw, parsed in self.parse_serial():
             if isinstance(parsed, pyubx2.UBXMessage):
                 for name, value in vars(parsed).items():
-                if name.startswith('_'):
+                    if name.startswith("_"):
                         continue
-                await mqtt_client.publish(f"ubx/{parsed.identity}/{name}", value, retain=True)
+                    topic = f"{self.topic_base}/{parsed.identity}/{name}"
+                    await self.mqtt_client.publish(topic, value, qos=1, retain=True)
             else:
-            print(parsed.identity, parsed)
+                print(parsed)
 
-        await mqtt_client.publish(f"ubx/raw", raw)
-        await mqtt_client.publish(f"ubx/parsed", str(parsed))
+            await self.mqtt_client.publish(f"{self.topic_base}/raw", raw)
+            await self.mqtt_client.publish(f"{self.topic_base}/parsed", str(parsed))
 
-async def mqtt_command_writer(ser, client):
-    async for message in client.messages:
+    async def mqtt_command_writer_task(self):
+        command_topic = f"{self.topic_base}/command"
+        async for message in self.mqtt_client.messages:
             topic = str(message.topic)
-        print(message.topic, message.payload)
+            if topic == command_topic:
+                await self.ser.write_async(message.payload)
 
-        if str(topic) == SERIAL_COMMAND_TOPIC:
-            await ser.write_async(message.payload)
-
-
-async def main():
-    client_id = f"jono-test-{uuid.uuid4()}"
+    async def run(self):
+        command_topic = f"{self.topic_base}/command"
         interval = 5
 
-    ser = aioserial.AioSerial(
-        port=SERIAL_PORT,
-        baudrate=BAUD,
-        timeout=0.05,  # 50 ms
-    )
-
         while True:
             try:
-            async with aiomqtt.Client(
-                "127.0.0.1",
-                port=1883,
-                identifier=client_id,
-            ) as client:
-                await client.subscribe(SERIAL_COMMAND_TOPIC)
+                async with self.mqtt_client as client:
+                    await client.subscribe(command_topic)
 
                     await asyncio.gather(
-                    serial_reader(ser, client),
-                    mqtt_command_writer(ser, client),
+                        self.serial_reader_task(),
+                        self.mqtt_command_writer_task(),
                     )
 
             except aiomqtt.MqttError as e:
-            print(e)
-            print(f"Connection lost; reconnecting in {interval} seconds...")
+                print(
+                    f"[{self.handler_id}] MQTT connection error: {e}. Reconnecting in {interval}s..."
+                )
                 await asyncio.sleep(interval)
 
 
 if __name__ == "__main__":
+
+    async def main():
+        handler = SerialMQTTHandler("example-gps", "/tmp/ttyV0")
+        await handler.run()
+
     asyncio.run(main())