// First Row LED Pins
const int row1[] = {2, 4, 5, 18, 19, 0};  // Added dummy pin to match row2 length
// Second Row LED Pins
const int row2[] = {21, 22, 23, 25, 26, 33};  // Added GPIO 36 as the last LED

const int numLEDs = 6; // Increased to 6 LEDs
const int delayTime = 500; // LED delay time in milliseconds
const int buzzerPin = 15;  // Buzzer pin

// Happy Birthday melody and note durations
int melody[] = {
  262, 262, 294, 262, 349, 330,
  262, 262, 294, 262, 392, 349,
  262, 262, 523, 440, 349, 330, 294,
  466, 466, 440, 349, 392, 349
};

int durations[] = {
  4, 8, 4, 4, 4, 2,
  4, 8, 4, 4, 4, 2,
  4, 8, 4, 4, 4, 4, 2,
  4, 8, 4, 4, 4, 2
};

unsigned long previousLedMillis = 0;
unsigned long previousToneMillis = 0;
int currentLed = 0;
int currentNote = 0;

void setup() {
  for (int i = 0; i < numLEDs; i++) {
    pinMode(row1[i], OUTPUT);
    pinMode(row2[i], OUTPUT);
  }
  pinMode(buzzerPin, OUTPUT);
}

void loop() {
  unsigned long currentMillis = millis();

  // LED Animation (non-blocking)
  if (currentMillis - previousLedMillis >= delayTime) {
    previousLedMillis = currentMillis;
    turnOffAll();
    digitalWrite(row1[currentLed], HIGH);
    digitalWrite(row2[currentLed], HIGH);
    currentLed = (currentLed + 1) % numLEDs;
  }

  // Buzzer Melody (non-blocking)
  static bool notePlaying = false;
  int noteDuration = 1000 / durations[currentNote];

  if (!notePlaying && currentMillis - previousToneMillis >= noteDuration * 1.3) {
    tone(buzzerPin, melody[currentNote], noteDuration);
    previousToneMillis = currentMillis;
    notePlaying = true;
  }

  if (notePlaying && currentMillis - previousToneMillis >= noteDuration) {
    noTone(buzzerPin);
    notePlaying = false;
    currentNote = (currentNote + 1) % (sizeof(melody) / sizeof(melody[0]));
  }
}

void turnOffAll() {
  for (int i = 0; i < numLEDs; i++) {
    digitalWrite(row1[i], LOW);
    digitalWrite(row2[i], LOW);
  }
}