// LDR Characteristics
const float GAMMA = 0.7;
const float RL10 = 50;

const int ledPins[] = {2, 4, 5, 18};  // Pin numbers for the LEDs

void setup() {
  Serial.begin(11200);
  for (int i = 0; i < 4; i++) {
    pinMode(ledPins[i], OUTPUT);
  }
}

float manage_led(int nb){
  digitalWrite(ledPins[nb], HIGH);  // LED ON
  for (int i = 0; i < 4; i++) {
    if (i != nb){
      digitalWrite(ledPins[i], LOW);  // LED OFF
    }
  }
  return nb;
}

void loop() {
  int analogValue = analogRead(32);
  float voltage = analogValue / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));

  if (lux < 10) {
    manage_led(0);
    Serial.print("sombre : ");
    Serial.println(lux);
  }
  if (lux > 10 && lux < 100) {
    manage_led(1);
    Serial.print("faible : ");
    Serial.println(lux);
  }
  if (lux > 100 && lux < 1000) {
    manage_led(2);
    Serial.print("lumineux : ");
    Serial.println(lux);
  }
  if (lux > 1000) {
    manage_led(3);
    Serial.print("Très lumineux : ");
    Serial.println(lux);
  }
  else {
    for (int i = 0; i < 4; i++) {
      digitalWrite(ledPins[i], LOW);  // LED OFF
    }
  }
}