import paho.mqtt.client as mqtt
from loguru import logger
import threading
import ssl



def mqttOnConnectCallback(client, userdata, flags, rc):
    userdata.onConnect()

def mqttOnMessageCallback(client, userdata, message):
    userdata.onMessage(message.topic, message.payload)

def mqttOnDisconnectCallback(client, userdata, rc):
    userdata.onDisconnect(rc)


class AbstractMqttPublisher(threading.Thread):
    def __init__(self, config):
        super().__init__()

        self.config = config["mqtt"]

        self.client = mqtt.Client(userdata=self)

        # consider this flag in the localLoop
        self.killBill = False
        self.killEvent = threading.Event()

    def run(self):
        self.client.on_message = mqttOnMessageCallback
        self.client.on_connect = mqttOnConnectCallback
        self.client.on_disconnect = mqttOnDisconnectCallback

        if ("login" in self.config) and ("password" in self.config):
            self.client.username_pw_set(self.config["login"], self.config["password"])
        
        if ("ca" in self.config) and ("cert" in self.config) and ("key" in self.config):
            self.client.tls_set(
                ca_certs=self.config["ca"],
                certfile=self.config["cert"],
                keyfile=self.config["key"],
                cert_reqs=ssl.CERT_REQUIRED,
                tls_version=ssl.PROTOCOL_TLSv1_2, 
                ciphers=None # this does not mean "no cipher" but it means "default ciphers"
            )

        self.client.connect(self.config["broker"], int(self.config["port"]))
        self.client.loop_start()
        logger.info("mqtt loop started")

        self.localLoop()
    
    def localLoop(self):
        raise NotImplementedError()

    def stop(self):
        self.client.loop_stop()
        logger.info("mqtt loop stopped")
        
        self.killBill = True
        logger.info("kill flag set")

        self.killEvent.set()
        logger.info("kill events triggered")

    def onConnect(self):
        logger.info("mqtt connected")
    
    def onDisconnect(self, rc):
        logger.warning("mqtt disconnect, rc: {}".format(rc))

    def onMessage(self, topic, payload):
        logger.warning("mqtt unexpected message received: {} -> {}".format(topic, str(payload)))