#
# This whole implementation is adapted from the upstream GitHub example
# https://github.com/eclipse-paho/paho.mqtt.python/blob/master/examples/loop_asyncio.py
# 

import logging
import asyncio
import socket

import paho.mqtt.client as mqtt


logger = logging.getLogger(__name__)


class AsyncLooper:
    """
    Helper class to implement loopgin with asyncio for the underlying mqtt IO  
    """

    def __init__(self, loop: asyncio.AbstractEventLoop, client: mqtt.Client):
        self.loop = loop

        self.client = client
        self.client.on_socket_open = self.on_socket_open
        self.client.on_socket_close = self.on_socket_close
        self.client.on_socket_register_write = self.on_socket_register_write
        self.client.on_socket_unregister_write = self.on_socket_unregister_write

    def on_socket_open(self, client, userdata, sock):
        logger.debug("mqtt socket opened")

        def cb():
            logger.debug("mqtt socket is readable, calling loop_read()")
            client.loop_read()

        self.loop.add_reader(sock, cb)
        self.task_misc = self.loop.create_task(self.misc_loop())

    def on_socket_close(self, client, userdata, sock):
        logger.debug("mqtt socket closed")
        self.loop.remove_reader(sock)
        self.task_misc.cancel()

    def on_socket_register_write(self, client, userdata, sock):
        logger.debug("watching mqtt socket for writability")

        def cb():
            logger.debug("mqtt socket ist writable, calling loop_write()")
            client.loop_write()

        self.loop.add_writer(sock, cb)

    def on_socket_unregister_write(self, client, userdata, sock):
        logger.debug("stopping to watch mqtt socket for writability")
        self.loop.remove_writer(sock)

    async def misc_loop(self):
        logger.debug("mqtt misc_loop() started")

        while self.client.loop_misc() == mqtt.MQTT_ERR_SUCCESS:
            try:
                await asyncio.sleep(1)
            except asyncio.CancelledError:
                break

        logger.debug("mqtt exiting misc_loop()")


class AsyncMqttClient:
    loop: asyncio.AbstractEventLoop
    
    def __init__(self):
        self.client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2, client_id="dooris")
        self.client.on_connect = self.on_connect
        self.client.on_message = self.on_message
        self.client.on_disconnect = self.on_disconnect

    def on_connect(self, client, userdata, flags, reason_code, properties):
        logger.debug("mqtt client connected")
        print("client", type(client), client)
        print("userdata", type(userdata), userdata)
        print("flags", type(flags), flags)
        print("reason_code", type(reason_code), reason_code)
        print("properties", type(properties), properties)

    def on_disconnect(self, client, userdata, flags, reason_code, properties):
        logger.debug("mqtt client disconnected")
        print("client", type(client), client)
        print("userdata", type(userdata), userdata)
        print("flags", type(flags), flags)
        print("reason_code", type(reason_code), reason_code)
        print("properties", type(properties), properties)

    def on_message(self, client, userdata, msg):
        logger.debug("mqtt client got message")
        print("client", type(client), client)
        print("userdata", type(userdata), userdata)
        print("msg", type(msg), msg)

    async def connect(self):
        looper = AsyncLooper(asyncio.get_running_loop(), self.client)
        self.client.connect("mqtt.eclipseprojects.io", 1883, 60)
        self.client.socket().setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 2048)