import network
import time
import machine
from umqtt.simple import MQTTClient

# Wi-Fi and MQTT details
SSID = "Wokwi-GUEST"
PASSWORD = ""
MQTT_BROKER = "broker.hivemq.com"
TOPIC_SUB = b"esp32/print"
TOPIC_PUB = b"esp32/temp"

# Pin setup
TEMP_SENSOR = machine.ADC(machine.Pin(34))
TEMP_SENSOR.atten(machine.ADC.ATTN_11DB)  # Full range: 0-3.6V
RELAY = machine.Pin(19, machine.Pin.OUT)

def connect_wifi():
    print("Connecting to Wi-Fi...")
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(SSID, PASSWORD)
    while not wlan.isconnected():
        time.sleep(0.5)
    print("Connected:", wlan.ifconfig())

def mqtt_callback(topic, msg):
    print("Topic:", topic, "Message:", msg)
    if msg == b'on':
        RELAY.value(1)
        print("Relay turned ON")
    elif msg == b'off':
        RELAY.value(0)
        print("Relay turned OFF")

def read_temperature():
    adc_val = TEMP_SENSOR.read()
    voltage = adc_val * (3.3 / 4095)  # Convert ADC reading to voltage
    # Estimate temperature from voltage (simplified for NTC, not accurate)
    temp_c = (voltage - 0.5) * 100  # Assuming LM35 or similar
    return round(temp_c, 2)

def main():
    connect_wifi()
    client = MQTTClient("wokwi-esp32", MQTT_BROKER)
    client.set_callback(mqtt_callback)
    client.connect()
    client.subscribe(TOPIC_SUB)
    print("MQTT connected and subscribed to:", TOPIC_SUB)

    last_sent = time.ticks_ms()

    while True:
        client.check_msg()

        # Send temperature every 10 seconds
        if time.ticks_diff(time.ticks_ms(), last_sent) > 10000:
            temp = read_temperature()
            client.publish(TOPIC_PUB, str(temp))
            print("Published temperature:", temp, "°C")
            last_sent = time.ticks_ms()

        time.sleep(0.1)

main()