from machine import Pin, ADC
from time import sleep
import dht
import network
import ujson
from umqtt.simple import MQTTClient

# MQTT Server Parameters
MQTT_CLIENT_ID = "micropython-bin-prototype-demo"
MQTT_BROKER    = "broker.mqttdashboard.com"
MQTT_USER      = ""
MQTT_PASSWORD  = ""
MQTT_TOPIC     = "wokwi-bin"

# Connect to WiFi
print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('Wokwi-GUEST', '')  # Change if needed
while not sta_if.isconnected():
    print(".", end="")
    sleep(0.1)
print(" Connected!")

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

# Sensor setup
gas_sensor = ADC(Pin(36))  # GPIO36 = VP = ADC1_CH0
gas_sensor.atten(ADC.ATTN_11DB)  # 0-3.6V range

led = Pin(12, Pin.OUT)
buzzer = Pin(14, Pin.OUT)

dht_sensor = dht.DHT22(Pin(4))  # GPIO4

GAS_THRESHOLD = 900  # Adjust according to your environment

prev_data = ""

while True:
    gas_level = gas_sensor.read()
    leak_detected = gas_level > GAS_THRESHOLD

    if leak_detected:
        led.on()
        buzzer.on()
    else:
        led.off()
        buzzer.off()

    try:
        dht_sensor.measure()
        temperature = dht_sensor.temperature()
        humidity = dht_sensor.humidity()

        print("Gas level:", gas_level)
        print("Temperature: {:.1f}°C".format(temperature))
        print("Humidity: {:.1f}%".format(humidity))

        # Prepare the MQTT message
        message = ujson.dumps({
            "gas_level": gas_level,
            "temperature": temperature,
            "humidity": humidity,
            "leak_detected": leak_detected
        })
        print("Publishing to MQTT...")
        client.publish(MQTT_TOPIC, message)
        prev_data = message

        # Only send if data changed
        """if message != prev_data:
            print("Publishing to MQTT...")
            client.publish(MQTT_TOPIC, message)
            prev_data = message
        else:
            print("No change in data, not publishing.")"""

    except Exception as e:
        print("DHT22 error:", e)

    sleep(1)