const int buttonPins[] = {9, 8, 7, 6};
const int ledPins[] = {13, 12, 11, 10};

int sequence[100];
int level = 1;
int sequenceLength = 0;
int playerInput = 0;

const int buttonDebounce = 200;

void setup() {
  for (int i = 0; i < 4; i++) {
    pinMode(buttonPins[i], INPUT_PULLUP);
  }
  
  for (int i = 0; i < 4; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
  }
  
  randomSeed(analogRead(0));
  startGame();
}

void loop() {
  showSequence();
  waitForPlayerInput();
  level++;
  delay(1000);
}

void startGame() {
  level = 1;
  sequenceLength = 0;
  generateSequence();
  
  for (int i = 0; i < 3; i++) {
    allLedsOn();
    delay(200);
    allLedsOff();
    delay(200);
  }
}

void generateSequence() {
  for (int i = 0; i < 100; i++) {
    sequence[i] = random(0, 4);
  }
  sequenceLength = level;
}

void showSequence() {
  allLedsOff();
  delay(500);
  
  for (int i = 0; i < level; i++) {
    int ledIndex = sequence[i];
    digitalWrite(ledPins[ledIndex], HIGH);
    delay(600);
    digitalWrite(ledPins[ledIndex], LOW);
    delay(300);
  }
}

void waitForPlayerInput() {
  playerInput = 0;
  
  while (playerInput < level) {
    for (int i = 0; i < 4; i++) {
      if (digitalRead(buttonPins[i]) == LOW) {
        buttonPressed(i);
        
        if (sequence[playerInput] != i) {
          gameOver();
          return;
        }
        
        playerInput++;
        delay(buttonDebounce);
        
        if (playerInput == level) {
          allLedsOn();
          delay(2000);
          allLedsOff();
          sequenceLength = level + 1;
          return;
        }
      }
    }
    delay(10);
  }
}

void buttonPressed(int buttonIndex) {
  digitalWrite(ledPins[buttonIndex], HIGH);
  delay(300);
  digitalWrite(ledPins[buttonIndex], LOW);
}

void gameOver() {
  for (int i = 0; i < 3; i++) {
    allLedsOn();
    delay(200);
    allLedsOff();
    delay(200);
  }
  
  delay(2000);
  startGame();
}

void allLedsOn() {
  for (int i = 0; i < 4; i++) {
    digitalWrite(ledPins[i], HIGH);
  }
}

void allLedsOff() {
  for (int i = 0; i < 4; i++) {
    digitalWrite(ledPins[i], LOW);
  }
}