UMQTT MICROPYTHON

from umqtt.robust import MQTTClient
import network
import time
import machine
import json

wlan = network.WLAN(network.STA_IF)
ID = 'ESP32'
mqtt_broker = '192.168.1.X'
my_user = 'username'
my_pass = 'password'
topic = (b'home/garden/#')
c = MQTTClient(ID, mqtt_broker, user=my_user, password=my_pass)
# c.DEBUG = True


def subscribe():
    try:
        c.connect(clean_session=False)
        c.set_callback(publish)
        c.subscribe(topic)
        print('Connected to MQTT broker, subscribed to', topic)
    except:
        print('Error, MQTT broker is not responding')


def check_json(msg):
    try:
        msg = json.loads(msg)
    except:
        print('Message was not JSON')
        return False
    return True


def check_int(time):
    try:
        time = int(time)
    except:
        print('Time field invalid')
        return False
    return True


def publish(topic, msg):
    # print((topic, msg))
    if check_json(msg):
        message = {}
        message = json.loads(msg)
        relay = message['relay']
        state = message['state']
        time = int(message['time'])
        if check_int(time):
            print("Last received:", message)
            message = json.dumps(message)
            c.publish(topic, message)
            # response = json.dumps("Relay": relay, "State": state, "Time": time)
        else:
            # response = "json.dumps("Time Invalid": type(time))"
            print("Time entered was invalid.  Type was", type(time))


# Blocking wait for message (this is for single task code)
# c.wait_msg()
# Non-blocking wait for message (this is for multi tasking projects)
# c.check_msg()


def wlan_disconnect():
    tick = 1
    while not wlan.isconnected():
        print('WLAN is reconnecting...', tick, '/5')
        time.sleep(5)
        tick += 1
        if tick == 5:
            print("Restarting...")
            machine.reset()


def main():
    if wlan.isconnected():  # Check if WiFi is connected
        if not c.connect():  # Check if MQTT broker is connected
            subscribe()
            print("Waiting for messages")
    while True:
        if wlan.isconnected():
            c.wait_msg()
        else:  # If wifi is not connected...run a tick routine to reboot ESP32, then resubscribe
            wlan_disconnect()
            subscribe()