#include <Keypad.h>
#include <LiquidCrystal.h>

const byte ROWS = 4;
const byte 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}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2}; // Connect to the column pinouts of the keypad

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

LiquidCrystal lcd(12, 11, 5, 4, 3, 2); // RS, EN, D4, D5, D6, D7

const int ledPin = 13;
const int buzzerPin = 10;

const char correctPasscode[] = "1234"; // Change this to your desired initial passcode

char enteredPasscode[5]; // To store entered passcode
int passcodeIndex = 0;
bool locked = false;
int attempts = 3; // Maximum number of attempts

void setup() {
  lcd.begin(16, 2);
  lcd.print("Enter passcode:");
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
}

void loop() {
  if (!locked) {
    char key = keypad.getKey();
    
    if (key != NO_KEY && passcodeIndex < 4) {
      enteredPasscode[passcodeIndex++] = key;
      lcd.setCursor(passcodeIndex - 1, 1);
      lcd.print('*');
    }
    
    if (passcodeIndex == 4) {
      enteredPasscode[4] = '\0'; // Null-terminate the entered passcode
      delay(500); // Small delay for stability
      
      if (strcmp(enteredPasscode, correctPasscode) == 0) {
        lcd.clear();
        lcd.print("Code correct");
        digitalWrite(ledPin, HIGH);
        tone(buzzerPin, 1000, 1000); // Buzz for 1 second
        delay(3000); // Keep the door open for 3 seconds
        digitalWrite(ledPin, LOW);
        passcodeIndex = 0; // Reset passcode index for the next attempt
        attempts = 3; // Reset attempts after correct code entry
      } else {
        lcd.clear();
        lcd.print("Code incorrect");
        digitalWrite(ledPin, LOW);
        for (int i = 0; i < 3; i++) {
          tone(buzzerPin, 2000, 200); // Buzz at 2000 Hz for 0.2 second (repeated 3 times)
          delay(300);
        }
        attempts--;
        if (attempts == 0) {
          lcd.setCursor(0, 1);
          lcd.print("System locked");
          locked = true;
          delay(5000); // Lock for 5 seconds before allowing new attempts
          lcd.clear();
          lcd.print("Enter passcode:");
          attempts = 3; // Reset attempts after unlocking
        } else {
          lcd.setCursor(0, 1);
          lcd.print("Attempts left: ");
          lcd.print(attempts);
        }
      }
      
      delay(2000); // Wait for 2 seconds before resetting
      lcd.clear();
      lcd.print("Enter passcode:");
      passcodeIndex = 0;
      memset(enteredPasscode, 0, sizeof(enteredPasscode)); // Reset the entered passcode
    }
  }
}