""" Module to Publish Sensor Data to MQTT """

import paho.mqtt.client as paho
from copy import copy

class MQTT(object):
    """ Class to Represent a Client to a single MQTT Broker """

    def __init__(self, host, port=1883, base="sensor/", user=None, passwd=None, certfile=None):
        """ Initialize Class

        Arguments:
            host   :     MQTT Broker Hostname (mandatory)
            port:        MQTT Broker Port
            base:        Base MQTT Topic
            user:        Username
            pass:        Passwort (mandatory if user is set)
            certfile:    Path to CA-Cert File of the broker. TLS if used if set
        """

        self.__base = base
        self.__client = paho.Client()
        self.__client.on_connect = self.__on_connect
        if user != None and passwd != None:
            self.__client.username_pw_set(user, passwd)
        if certfile != None:
            self.__client.tls_set(certfile)

        try:
            self.__client.connect(host, port, 60)
            self.__client.loop_start()
        except:
            print("Error Setting up MQTT Client")
            raise RuntimeError

    def __del__(self):
        self.__client.loop_stop()
        self.__client.disconnect()

    def __on_connect(self, client, userdata, ret, dummy):
        """ Do Something when MQTT Connection is established """
        print("Connected with result code "+str(ret))

    def notify(self, msg):
        """ Publish Sensor data to MQTT

        Arguments:
            msg: Object Representation of the Sensor Data
        """
        tmp = copy(msg)

        sid = tmp['sid']
        tmp.pop('sid', None)

        for stype, svalue in tmp.items():
            self.__client.publish(self.__base + str(sid) + "/" + stype, str(svalue), 2, True)