repeat subscribe when reconnected to MQTT broker (#337)

* repeat subscribe when reconnected to MQTT broker; added comments

* Resolved pylint issues in server.py

* Resolved pylint issues in asyncio_mqtt.py

* Outcommented "keepalive" option in asyncio_mqtt.py

---------

Co-authored-by: Johannes.Hennecke <johannes.hennecke@vorwerk.com>

mqtt_io/events.py

@@ -74,6 +74,18 @@ class StreamDataSentEvent(Event):
     stream_name: str
     data: bytes
 
+@dataclass
+class StreamDataSubscribeEvent(Event):
+    """
+    Trigger MQTT subscribe
+    """
+
+@dataclass
+class DigitalSubscribeEvent(Event):
+    """
+    Trigger MQTT subscribe
+    """
+
 
 class EventBus:
     """

mqtt_io/mqtt/asyncio_mqtt.py

@@ -26,8 +26,27 @@
 
 
 def _map_exception(func: Func) -> Func:
+    """
+    Creates a decorator that wraps a function and maps any raised `MqttError`
+    exception to a `MQTTException`.
+
+    :param func: The function to be wrapped.
+    :type func: Func
+    :return: The wrapped function.
+    :rtype: Func
+    """
     @wraps(func)
     async def inner(*args: Any, **kwargs: Any) -> Any:
+        """
+        Decorator for asynchronous functions that catches `MqttError` exceptions
+        and raises `MQTTException` instead.
+
+        Parameters:
+            func (Callable): The function to be decorated.
+
+        Returns:
+            Callable: The decorated function.
+        """
         try:
             await func(*args, **kwargs)
         except MqttError as exc:
@@ -42,6 +61,15 @@ class MQTTClient(AbstractMQTTClient):
     """
 
     def __init__(self, options: MQTTClientOptions):
+        """
+        Initializes a new instance of the MQTTClient class.
+
+        Args:
+            options (MQTTClientOptions): The options for the MQTT client.
+
+        Returns:
+            None
+        """
         super().__init__(options)
         protocol_map = {
             MQTTProtocol.V31: paho.MQTTv31,
@@ -66,7 +94,7 @@ def __init__(self, options: MQTTClientOptions):
             username=options.username,
             password=options.password,
             client_id=options.client_id,
-            # keepalive=options.keepalive,  # This isn't implemented yet on 0.8.1
+            #keepalive=options.keepalive,
             tls_context=tls_context,
             protocol=protocol_map[options.protocol],
             will=will,
@@ -76,28 +104,82 @@ def __init__(self, options: MQTTClientOptions):
 
     @_map_exception
     async def connect(self, timeout: int = 10) -> None:
+        """
+        Connects to the client asynchronously.
+
+        Args:
+            timeout (int): The timeout value in seconds (default: 10).
+
+        Returns:
+            None: This function does not return anything.
+        """
         await self._client.connect(timeout=timeout)
 
     @_map_exception
     async def disconnect(self) -> None:
+        """
+        This function is an asynchronous method that handles the disconnection of the client.
+
+        Parameters:
+            self: The current instance of the class.
+
+        Returns:
+            None
+        """
         try:
             await self._client.disconnect()
         except TimeoutError:
             await self._client.force_disconnect()
 
     @_map_exception
     async def subscribe(self, topics: List[Tuple[str, int]]) -> None:
+        """
+        Subscribe to the given list of topics.
+
+        Args:
+            topics (List[Tuple[str, int]]): A list of tuples representing the topics
+                to subscribe to.
+            Each tuple should contain a string representing the topic name and
+                an integer representing the QoS level.
+
+        Returns:
+            None: This function does not return anything.
+
+        Raises:
+            Exception: If there is an error while subscribing to the topics.
+
+        """
         await self._client.subscribe(topics)
 
     @_map_exception
     async def publish(self, msg: MQTTMessageSend) -> None:
+        """
+        Publishes an MQTT message to the specified topic.
+
+        Args:
+            msg (MQTTMessageSend): The MQTT message to be published.
+
+        Returns:
+            None: This function does not return anything.
+        """
         await self._client.publish(
             topic=msg.topic, payload=msg.payload, qos=msg.qos, retain=msg.retain
         )
 
     def _on_message(
         self, client: paho.Client, userdata: Any, msg: paho.MQTTMessage
     ) -> None:
+        """
+        Callback function that is called when a message is received through MQTT.
+
+        Args:
+            client (paho.Client): The MQTT client instance.
+            userdata (Any): The user data associated with the client.
+            msg (paho.MQTTMessage): The received MQTT message.
+
+        Returns:
+            None: This function does not return anything.
+        """
         if self._message_queue is None:
             _LOG.warning("Discarding MQTT message because queue is not initialised")
             return
@@ -111,6 +193,12 @@ def _on_message(
 
     @property
     def message_queue(self) -> "asyncio.Queue[MQTTMessage]":
+        """
+        Returns the message queue for receiving MQTT messages.
+
+        :return: The message queue for receiving MQTT messages.
+        :rtype: asyncio.Queue[MQTTMessage]
+        """
         if self._message_queue is None:
             self._message_queue = asyncio.Queue(self._options.message_queue_size)
             # pylint: disable=protected-access