---

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

const byte ROWS = 4, COLS = 4;

char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {9, 8, 7, 6};
byte colPins[COLS] = {5, 4, 3, 2};

Keypad keypad = Keypad(makeKeymap(keys),
                       rowPins, colPins, ROWS, COLS);

const int BUZZER = 10;

String password;
String entered = "";
int attempts = 5;
bool gameOver = false;

void melody() {
  tone(BUZZER, 523, 150);
  delay(180);
  tone(BUZZER, 659, 150);
  delay(180);
  tone(BUZZER, 784, 150);
  delay(180);
  tone(BUZZER, 1047, 300);
  delay(350);
  noTone(BUZZER);
}

void newGame() {
  password = String(random(1000, 10000));
  entered = "";
  attempts = 5;
  gameOver = false;

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Guess 4 digits");
  lcd.setCursor(0, 1);
  lcd.print("Left: 5 A=Check");

  melody();
}

void setup() {
  pinMode(BUZZER, OUTPUT);
  randomSeed(analogRead(A0));

  lcd.init();
  lcd.backlight();

  newGame();
}

void loop() {
  char key = keypad.getKey();
  if (!key) return;

  if (key == 'B') {
    newGame();
    return;
  }

  if (gameOver) return;

  if (key >= '0' && key <= '9' &&
      entered.length() < 4) {
    entered += key;

    tone(BUZZER, 900, 70);
    showInput();
  }

  if (key == '*') {
    entered = "";
    tone(BUZZER, 500, 100);
    showInput();
  }

  if (key == 'A') {
    if (entered.length() != 4) {
      tone(BUZZER, 250, 200);
      lcd.setCursor(0, 0);
      lcd.print("Enter 4 digits  ");
      delay(700);
      showInput();
      return;
    }

    attempts--;
    lcd.clear();

    if (entered == password) {
      lcd.setCursor(0, 0);
      lcd.print("Correct!");
      lcd.setCursor(0, 1);
      lcd.print("You won!");
      tone(BUZZER, 1200, 500);
      gameOver = true;
    } else {
      tone(BUZZER, 200, 400);
      lcd.setCursor(0, 0);
      lcd.print("Wrong password");

      if (attempts > 0) {
        lcd.setCursor(0, 1);
        lcd.print("Attempts: ");
        lcd.print(attempts);
        delay(1500);
        entered = "";
        showInput();
      } else {
        lcd.setCursor(0, 0);
        lcd.print("Game over      ");
        lcd.setCursor(0, 1);
        lcd.print("Code: ");
        lcd.print(password);
        gameOver = true;
      }
    }
  }
}

void showInput() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Code: ");
  lcd.print(entered);

  lcd.setCursor(0, 1);
  lcd.print("Left: ");
  lcd.print(attempts);
  lcd.print(" A=Check");
}