import paho.mqtt.client as mqtt
from urllib.parse import urlparse
import time, datetime

import json
import os

import yaml
import logging

import psutil
import threading

import re

from logging.handlers import RotatingFileHandler

class ServerStats():
    def __init__(self):
        self.stop = False
        self.init_logging('Server_Metrics.log')
        self.thread = threading.Event()
        self.devices = {}
        self.devices['cpu_usage'] = {'name':'Cpu Usage', 'device_class':'sensor', 'location':'server', 'unit_of_measurement':'%', 'value_template':'{{ value_json.cpu_usage}}', 'value':0}
        self.devices['vmem_usage'] = {'name':'Virtual Memory', 'device_class':'sensor', 'location':'server', 'unit_of_measurement':'%', 'value_template':'{{ value_json.vmem_usage}}', 'value':0}
        self.devices['smem_usage'] = {'name':'Swap Memory', 'device_class':'sensor', 'location':'server', 'unit_of_measurement':'%', 'value_template':'{{ value_json.smem_usage}}', 'value':0}
        self.read_config()
        self.connect_to_mqtt()
        self.config_devices()


        self.get_stats()

    def get_stats(self):
        self.devices['cpu_usage']['value'] = psutil.cpu_percent(interval=1)
        self.devices['vmem_usage']['value'] = psutil.virtual_memory().percent
        self.devices['smem_usage']['value'] = psutil.swap_memory().percent

        state_topic = '%s/%s/%s/state' % (self.mqtt_topic, 'sensor', 'server')

        self.mqttc.publish(state_topic, json.dumps({'cpu_usage': self.devices['cpu_usage']['value'],
                                         'vmem_usage': self.devices['vmem_usage']['value'],
                                         'smem_usage': self.devices['smem_usage']['value'],}))

        if not self.thread.is_set() and not self.stop:
            threading.Timer(10, self.get_stats).start()

    def read_config(self):
        """read config, filename is config.yml"""
        cur_dir = os.path.dirname(os.path.abspath(__file__))
        config_file = os.path.join(cur_dir, 'config.yml')
        with open(config_file, "r") as f:
            config = list(yaml.load_all(f))[0]

        if 'mqtt' in config:
            self.mqtt_path = 'mqtt://%s:%s' % (config['mqtt']['server'], config['mqtt']['port'])
            self.mqtt_topic = config['mqtt']['topic']
            self.ha_state_topic = config['mqtt']['ha_state_topic']

    def connect_to_mqtt(self):
        self.mqttc = mqtt.Client()

        url = urlparse(self.mqtt_path)

        # Connect
        self.mqttc.connect(url.hostname, url.port)

        # Start subscribe, with QoS level 0
        self.mqttc.subscribe(self.mqtt_topic + '/server_stats', 0)
        self.mqttc.subscribe(self.ha_state_topic, 0)

        # Assign event callbacks
        self.mqttc.on_message = self.on_message

    def on_message(self, client, obj, msg):
        self.logger.debug(msg.topic + " " + str(msg.qos) + " " + str(msg.payload))
        #isilentllc/switch/garage/set

        if msg.topic == self.ha_state_topic:
             if msg.payload == b'online':
                self.logger.debug('Homeassistant boot event, resending Server Metrics device list.')
                #Resend device info
                self.config_devices()
    def init_logging(self, path):
        """Start Logging"""
        self.logger = logging.getLogger("Server Metrics Log")
        self.logger.setLevel(logging.DEBUG)

        handler = RotatingFileHandler(path, maxBytes=20000, backupCount=1)
        self.logger.addHandler(handler)
        self.logger.debug('Server Metrics Start Event')


    def config_devices(self):
        """Configure devices in home assistant"""

        state_topic = '%s/%s/%s/state' % (self.mqtt_topic, 'sensor', 'server')

        for dev, config in self.devices.items():
            config_topic = '%s/%s/%s/config' % (self.mqtt_topic, config['device_class'], dev)
            config_payload = {#'device_class': config['device_class'],
                              'name': config['name'],
                              'state_topic': state_topic,
                              'unit_of_measurement': config['unit_of_measurement'],
                              'value_template': config['value_template'],
                             }
            self.mqttc.publish(config_topic, json.dumps(config_payload))
if __name__ == "__main__":
    try:
        server_stats = ServerStats()
        server_stats.mqttc.loop_start()

        print('server2mqtt running')

        while 1:
            time.sleep(1)

    except KeyboardInterrupt:
        pass
    except Exception as e:
        print(e)
    finally:
        if server_stats:
            server_stats.mqttc.loop_stop()
            server_stats.stop = True