void setup() {
  pinMode(2, INPUT_PULLUP);
  pinMode(13, OUTPUT);
}
 
int minLight = 1023;
int maxLight = 0;
bool calibrating = false;
int calibrationStep = 0;
unsigned long buttonPressTime = 0;

void loop() {
  int ph = analogRead(A0);
  int button = digitalRead(2);

  if (button == LOW) {
    if (buttonPressTime == 0) {
      buttonPressTime = millis();
    }
    if (millis() - buttonPressTime > 2000 && !calibrating) {
      calibrating = true;
      calibrationStep = 1;
      minLight = 1023;
      maxLight = 0;
    }
  } else {

    if (buttonPressTime > 0 && millis() - buttonPressTime < 2000) {
      if (calibrating) {
        handleCalibrationStep();
      }
    }
    buttonPressTime = 0;
  }
  
  if (calibrating) {
    handleCalibration(ph);
  } else {

    int normalizedLight = map(ph, minLight, maxLight, 0, 100);
    if (normalizedLight < 30) {
      digitalWrite(13, HIGH);
    } else {
      digitalWrite(13, LOW);
    }
  }
}

void handleCalibration(int ph) {
  switch (calibrationStep) {
    case 1: 
      digitalWrite(13, (millis() / 200) % 2);
      maxLight = max(maxLight, ph);
      break;
    case 2: // Затемните датчик
      digitalWrite(13, (millis() / 800) % 2);
      minLight = min(minLight, ph);
      break;
  }
}

void handleCalibrationStep() {
  calibrationStep++;
  if (calibrationStep > 2) {
    calibrating = false;
  }
}