#Import Libraries
import time
from umqtt.simple import MQTTClient
import ubinascii
import machine
import micropython
import network
import esp
import dht

#Import and use garbage collector
import gc
gc.collect()

#Disable debug output
esp.osdebug(None)

# MQTT Server Parameters
MQTT_CLIENT_ID = "micropython-weather-demo"
MQTT_BROKER    = "broker.mqttdashboard.com"
MQTT_USER      = "Wokwi-GUEST"
MQTT_PASSWORD  = ""
MQTT_TOPIC     = "wokwi-weather"
PREV_WEATHER   = ""

def sub_cb(topic, msg):
  print((topic, msg))
  if(top == b'temperature' and  msg == b'received'):
    print('Temperature received by ESP')
  if(top == b'humidity' and msg == b'received'):
    print('Temperature received by ESP')

#Connect ESP32 to Wifi
print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect("Wokwi-GUEST", "")
while not sta_if.isconnected():
  print(".", end="")
  time.sleep(0.1)
print(" Connected!")
print(sta_if.ifconfig())

#Declare sensor object and assign it PIN 15
sensor = dht.DHT22(machine.Pin(15))

def connect_and_subscribe(MQTT_CLIENT_ID, MQTT_SERVER, TOPIC_SUB, MQTT_USER, MQTT_PASSWORD,MQTT_TOPIC):
  print("Connecting to MQTT server... ", end="")
  client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
  client.set_callback(sub_cb)
  client.connect()
  client.subscribe(TOPIC_SUB)
  print('Connected to %s MQTT broker, subscribed to %s topic' % (MQTT_SERVER, TOPIC_SUB))
  return client

def restart_and_reconnect():
  print('Failed to connect to MQTT broker. Reconnecting...')
  time.sleep(10)
  machine.reset()

try:
  client = connect_and_subscribe(MQTT_CLIENT_ID, MQTT_BROKER, MQTT_TOPIC)
except OSError as e:
  restart_and_reconnect()

while True:
  print("Measuring weather conditions... ", end="")
  sensor.measure() 
  message = ujson.dumps({
    "temp": sensor.temperature(),
    "humidity": sensor.humidity(),
  if message != PREV_WEATHER:
    print("Updated!")
    print("Reporting to MQTT topic {}: {}".format(MQTT_TOPIC, message))
    client.publish(MQTT_TOPIC, message)
    prev_weather = message
  else:
    print("No change")
  time.sleep(1)
  })