import network
import time
from machine import Pin, I2C
import ssd1306
from umqtt.simple import MQTTClient
import dht
import ujson

MQTT_CLIENT_ID = "esp32-variant-2-sensor"
MQTT_BROKER = "mqtt-dashboard.com"
MQTT_TOPIC = "test/tues/wokwi/variant-2"
sensor = dht.DHT22(Pin(14))

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!")

client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER)
client.connect()
print("Connected to MQTT!")

i2c = I2C(0, scl=Pin(22), sda=Pin(23))
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)

def display_message(temp):
    oled.fill(0)
    oled.text('Last Message', 0, 0)
    oled.text('{"temp":' + str(temp) + '}', 0, 10)
    oled.show()

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