Change to double quotes and implement unicast messaging

DecisionSystem/CentralisedDecision/messenger.py

@@ -1,5 +1,6 @@
 import paho.mqtt.client as mqtt
 import json
+import random
 
 class Messenger:
     _connect_callbacks = []
@@ -9,93 +10,90 @@ class Messenger:
     def __init__(self):
         pass
 
-    def broadcast_message(self, topic, message):
-        '''
+    def broadcast_message(self, message):
+        """
         Broadcasts the specified message to the swarm based upon its topic(or group).
-        '''
+        """
         raise NotImplementedError
 
     def unicast_message(self, target, message):
-        '''
+        """
         Broadcasts the specified message to the single target.
-        '''
+        """
         raise NotImplementedError
 
     def connect(self):
-        '''
+        """
         Connect to the swarm.
-        '''
+        """
         raise NotImplementedError
 
     def disconnect(self):
-        '''
+        """
         Disconnect from the swarm.
-        '''
+        """
         raise NotImplementedError
 
     def add_connect(self, connect):
-        '''
+        """
         Adds a callback to do something else once we are connected.
-        '''
+        """
         self._connect_callbacks.append(connect)
 
     def on_connect(self, code = None):
-        '''
+        """
         Called once the messenger connects to the swarm.
-        '''
+        """
         for cb in self._connect_callbacks:
             cb(code)
 
     def on_disconnect(self, code = None):
-        '''
+        """
         Called when the messenger is disconnected from the swarm.
-        '''
+        """
         for cb in self._disconnect_callbacks:
             cb(code)
 
     def add_disconnect_callback(self, on_disconnect):
-        '''
+        """
         Adds a callback for when the messenger is disconnected.
-        '''
+        """
         self._disconnect_callbacks.append(on_disconnect)
 
     def add_message_callback(self, on_message):
-        '''
+        """
         Adds a callback
-        '''
+        """
         self._message_callbacks.append(on_message)
 
     def on_message(self, message):
-        '''
+        """
         Called when the messenger receives a message.
-        '''
+        """
         for cb in self._message_callbacks:
             cb(message)
 
     @property
     def id(self):
-        '''
+        """
         The id for this messenger that is being used in communication.
-        '''
+        """
         raise NotImplementedError
 
     @property
     def swarm(self):
-        '''
+        """
         Gets the name of the swarm this instance is a part of.
-        '''
+        """
         raise NotImplementedError
     
 
 class MqttMessenger(Messenger):
-    '''
-    A messenger that uses MQTT.
-    '''
+    """A messenger that uses MQTT."""
     def __init__(self):
         with open('config.json') as json_config:
             self._cfg = json.load(json_config)
-
-        self._client = mqtt.Client()
+        self._client = mqtt.Client(client_id=str(random.randint(0,500)))
         self._client.on_connect = self.on_connect
         self._client.on_message = self.on_message
         self._client.on_disconnect = self.on_disconnect
@@ -106,13 +104,19 @@ class MqttMessenger(Messenger):
     def on_connect(self, client, userdata, flags, rc):
         # Subscribe to the swarm specified in the config.
         self._client.subscribe(self._cfg['mqtt']['swarm'])
+
+        # Also subscribe to our own topic for unicast messages. 
+        self._client.subscribe(self._cfg['mqtt']['swarm'] + str(self._client._client_id))
         Messenger.on_connect(self, rc)
 
     def on_disconnect(self, client, userdata, rc):
         Messenger.on_disconnect(self, rc)
     
-    def broadcast_message(self, topic, message):
-        self._client.publish(topic, message, qos=1)
+    def broadcast_message(self, message):
+        self._client.publish(self._cfg['mqtt']['swarm'], message, qos=1)
+
+    def unicast_message(self, target, message):
+        self._client.publish(target, message, qos=1)
 
     def connect(self):
         self._client.connect(self._cfg['mqtt']['host'], \