import re
import json
from typing import NamedTuple
from datetime import datetime

import paho.mqtt.client as mqtt

MQTT_ADDRESS = 'mqtt.nbit.ch'
MQTT_USER = 'mqtt'
MQTT_PASSWORD = 'mqtt7355@'
MQTT_TOPIC = 'shellies/events/rpc'
MQTT_CLIENT_ID = 'MQTT_Logfile_Bridge'

def on_connect(client, userdata, flags, reason_code, properties):
    """ The callback for when the client receives a CONNACK response from the server."""
    print('Connected with result code ' + reason_code)
    client.subscribe(MQTT_TOPIC)

def _parse_mqtt_message(topic, payload):
    print("_parse_mqtt_message")
    payload = json.loads(payload)
    src = payload.get('src','N/A')
    if 'params' in payload.keys():
        ts = payload['params'].get('ts',-1)
        if 'switch:0' in payload['params'].keys():
            if 'aenergy' in payload['params']['switch:0'].keys():
                if 'total' in payload['params']['switch:0']['aenergy'].keys():
                    return "E,%.0f,%s,%.3f" % (ts,src,payload['params']['switch:0']['aenergy']['total'])
            if 'apower' in payload['params']['switch:0'].keys():
                return "P,%.0f,%s,%.1f" % (ts,src,payload['params']['switch:0']['apower'])
    else:
        return None

def write2file(msg):
    now = datetime.now() # current date and time
    filename = "/data/" + now.strftime("%Y%m%d") + ".log"
    f = open(filename, "a")
    f.write(msg + "\n")
    f.close()

def on_message(client, userdata, msg):
    """The callback for when a PUBLISH message is received from the server."""
    print(msg.topic + ' ' + str(msg.payload))
    result = _parse_mqtt_message(msg.topic, msg.payload.decode('utf-8'))
    if result is None:
        print("Couldn't parse sensor data!")
        print(msg.payload.decode('utf-8'))
        return
    else:
        write2file(result)
        return

def main():
    mqtt_client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2,MQTT_CLIENT_ID)
    mqtt_client.username_pw_set(MQTT_USER, MQTT_PASSWORD)
    mqtt_client.on_connect = on_connect
    mqtt_client.on_message = on_message

    mqtt_client.connect(MQTT_ADDRESS, 1883)
    mqtt_client.loop_forever()


if __name__ == '__main__':
    print('MQTT to Logfile bridge')
    main()