Saves a new chat message to db and distributes msg to connected users

def new_messages_handler(stream):
    """
    Saves a new chat message to db and distributes msg to connected users
    """
    # TODO: handle no user found exception
    while True:
        packet = yield from stream.get()
        session_id = packet.get('session_key')
        msg = packet.get('message')
        username_opponent = packet.get('username')
        if session_id and msg and username_opponent:
            user_owner = get_user_from_session(session_id)
            if user_owner:
                user_opponent = get_user_model().objects.get(username=username_opponent)
                dialog = get_dialogs_with_user(user_owner, user_opponent)
                if len(dialog) > 0:
                    # Save the message
                    msg = models.Message.objects.create(
                        dialog=dialog[0],
                        sender=user_owner,
                        text=packet['message'],
                        read=False
                    )
                    packet['created'] = msg.get_formatted_create_datetime()
                    packet['sender_name'] = msg.sender.username
                    packet['message_id'] = msg.id

                    # Send the message
                    connections = []
                    # Find socket of the user which sent the message
                    if (user_owner.username, user_opponent.username) in ws_connections:
                        connections.append(ws_connections[(user_owner.username, user_opponent.username)])
                    # Find socket of the opponent
                    if (user_opponent.username, user_owner.username) in ws_connections:
                        connections.append(ws_connections[(user_opponent.username, user_owner.username)])
                    else:
                        # Find sockets of people who the opponent is talking with
                        opponent_connections = list(filter(lambda x: x[0] == user_opponent.username, ws_connections))
                        opponent_connections_sockets = [ws_connections[i] for i in opponent_connections]
                        connections.extend(opponent_connections_sockets)

                    yield from fanout_message(connections, packet)
                else:
                    pass  # no dialog found
            else:
                pass  # no user_owner
        else:
            pass