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

# consts
RELAY_PIN_NUMBER = 22
LDR_PIN_NUMBER = 32
LUX_THRESHOLD = 500

GAMMA = 0.7
RL10 = 33

SSID, PASS = "Wokwi-GUEST", ""
BROKER = "broker.emqx.io"
TOPIC = b"pucpr/iot"

# setup
relay = Pin(RELAY_PIN_NUMBER, Pin.OUT)
photoresistor = ADC(Pin(LDR_PIN_NUMBER))

w = network.WLAN(network.STA_IF); w.active(True)
w.connect(SSID, PASS)
while not w.isconnected():
    time.sleep(0.1)

cid = b"esp32-" + str(int(time.time()*1000)).encode()
c = MQTTClient(cid, BROKER)
c.connect()


def ldr_to_lux():
    analog_value = photoresistor.read()
    voltage = analog_value / 4096. * 3.3;
    resistance = 2000 * voltage / (1 - voltage / 3.3);
    lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));
    return lux

def main():
    print("Starting the Lighting Automation Circuit...")

    while True:
        try:
            luminosity = ldr_to_lux()

            if luminosity <= LUX_THRESHOLD:
                relay.value(1)
                led_status = "ON"
            else:
                relay.value(0)
                led_status = "OFF"

                            
            payload = {
                "luminosity_lux": round(luminosity, 2),
                "light_status": led_status
            }
            c.publish(TOPIC, json.dumps(payload))
            
            print(f"PUB -> {payload}")

        except OSError as e:
            print("Hardware or network operation failure:", e)
        time.sleep(2)


if __name__ == "__main__":
    main()