Add on chat presence event

Last_seen time stamps were handled in unknown message type, this info is freely available and potentially useful

fbchat/client.py

@@ -1389,6 +1389,15 @@ class Client(object):
                 elif mtype == "deltaflow":
                     pass
                 
+                # Chat timestamp
+                elif mtype == "chatproxy-presence":
+                    buddyList = []
+                    for id in m.get("buddyList", {}).keys():
+                        payload = m["buddyList"][id]
+                        timestamp = payload["lat"]
+                        buddyList.append({id:timestamp})
+                    self.onChatTimestamp(buddylist=buddyList, msg=m)
+                    
                 # Unknown message type
                 else:
                     self.onUnknownMesssageType(msg=m)
@@ -1676,6 +1685,14 @@ class Client(object):
         """
         pass
 
+    def onChatTimestamp(self, buddylist={), msg={}):
+                                         """
+        Called when the client receives chat online presence update
+
+        :param buddylist: A list of dicts with friend id and last seen timestamp
+        :param msg: A full set of the data recieved
+        """
+        log.debug('Chat Timestamps received: {}'.format(buddylist))
         
     def onUnknownMesssageType(self, msg={}):
         """