import time
from time import sleep
from machine import I2C, Pin, ADC
from i2c_lcd import I2cLcd
import dht
import math
from umqtt.simple import MQTTClient
import ujson
import network

# MQTT Server Parameters
MQTT_CLIENT_ID = "Wokwi-GUEST"
MQTT_BROKER    = "broker.emqx.io"     
MQTT_USER      = "Wokwi-GUEST"     
MQTT_PASSWORD  = ""  
MQTT_TOPIC     = "exams/Asoukidis/temp/"

# WiFi  connection 
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!")

# MQTT server connection 
print("Connecting to MQTT server... ", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.connect()
print("Connected!")

# Settings of display
AddressOfLcd = 0x27
i2c = I2C(scl=Pin(22), sda=Pin(21), freq=400000)
lcd = I2cLcd(i2c, AddressOfLcd, 2, 16)
print("display is ready")

# Settings of sensor
sensor = dht.DHT22(Pin(2))
print("sensor is ready")
time.sleep(0.5)
    
print("PROGRAM START")

last_temp = ""

while True:
    sensor.measure()
    temp = sensor.temperature()
    #hmd = sensor.humidity()
    if temp != last_temp :
        print("Temperature: {}°C".format(temp))
        #print("Temperature: {}°C  Humidity: {}%".format(temp,hmd))
        lcd.move_to(0,0)
        lcd.putstr("Temperature:")
        lcd.move_to(7,1)
        lcd.putstr(str(temp))
        message = ujson.dumps({
            "Asoukidis/temperature": temp,
        })
        print("Reporting to MQTT topic {}: {}".format(MQTT_TOPIC, message))
        client.publish(MQTT_TOPIC, message)
        last_temp = temp