import json
import logging
import re
from queue import Queue

import paho.mqtt.client as mqtt

LOG = logging.getLogger('MQTTQueue')


class MQTTQueue:
    def __init__(self, config, queue):
        self.config = config
        self.client = mqtt.Client()
        self.queue = queue

        self.client.on_connect = self.on_connect
        self.client.on_disconnect = self.on_disconnect
        self.client.on_message = self.on_mqtt_message

    def start(self):
        if self.config.mqtt.user and self.config.mqtt.password:
            self.client.username_pw_set(
                self.config.mqtt.user, self.config.mqtt.password
            )

        self.client.connect(self.config.mqtt.host, 1883, 60)
        self.client.loop_start()

    def stop(self):
        self.client.loop_stop()
        self.client.disconnect()

    def on_connect(self, client, userdata, flags, rc):
        LOG.info(f'Connected to {self.config.mqtt.host} with code {rc}')

        self.client.subscribe(self.config.mqtt.topic)
        LOG.info(f'Subscribed')

    def on_disconnect(self, client, userdata, rc):
        LOG.warning(f'Disconnected from {self.config.mqtt.host} with code {rc}')

    def on_mqtt_message(self, client, userdata, msg):
        try:
            data = json.loads(msg.payload.decode('utf-8'))

            text = re.sub(r'\<[a-z\/]+\>', '', data['msg'])

            add_to_queue = True
            if self.config.alerts.filters:
                add_to_queue = False
                for f in self.config.alerts.filters:
                    if re.search(f, data['component'], re.IGNORECASE):
                        add_to_queue = True
                        break # no point in searching further

            if add_to_queue:
                self.queue.put(
                    (
                        data['level'].lower(),
                        data['component'],
                        text,
                    )
                )
                LOG.info(f'Put queue item: {data["level"].lower()} {data["component"]} : {text}')
            else:
                LOG.info(f'Ignoring message for {data["component"]} because it was filtered')
        except Exception as e:
            LOG.exception(msg.payload)