#include <Keypad.h>

const uint8_t LEDS = 4;
const uint8_t ROWS = 4;
const uint8_t COLS = 4;
#define SPEAKER_PIN 8

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

// Pins connected to LED1, LED2, LED3, ...LED12
uint8_t ledPins[LEDS] = { 13,4,28,27 };
uint8_t rowPins[ROWS] = { 26, 22, 21, 20 }; // Pins connected to R1, R2, R3, R4
uint8_t colPins[COLS] = { 19, 18, 17, 16 }; // Pins connected to C1, C2, C3, C4

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
String password = "1234";    // Define the correct password
String inputPassword = "";   // Store the input password


void setup() {
  for (uint8_t l = 0; l < LEDS; l++) {
    pinMode(ledPins[l], OUTPUT);
    digitalWrite(ledPins[l], LOW);
  }
  pinMode(8, OUTPUT);
  noTone(SPEAKER_PIN);
}

void loop() {
  char key = keypad.getKey();
  if (key != NO_KEY) {
    inputPassword += key;  // Add the key to the input password
    
    // If the input password reaches the length of the correct password, check it
    if (inputPassword.length() == password.length()) {
      if (inputPassword == password) {
        // Correct password entered
        Serial.println("Password Correct!");
        turnOffLEDs();  // Turn off all LEDs
        noTone(SPEAKER_PIN);  // Stop any alarm sound
      } else {
        // Incorrect password entered
        Serial.println("Incorrect Password");
        turnOnLEDs();  // Turn on LEDs to indicate failure
        tone(SPEAKER_PIN, 1000);  // Activate alarm sound (tone 1000Hz)
        delay(1000);  // Keep alarm sound for 1 second
        turnOffLEDs();  // Turn off LEDs after alarm
        noTone(SPEAKER_PIN);  // Stop the alarm sound
      }
      
      // Reset input password for next attempt
      inputPassword = "";
    }
  }

  delay(10);  // Small delay to debounce keypad
}

// Function to turn on LEDs (to indicate incorrect password)
void turnOnLEDs() {
  for (uint8_t l = 0; l < LEDS; l++) {
    digitalWrite(ledPins[l], HIGH);  // Turn on each LED
  }
}

// Function to turn off LEDs (when password is correct or after alarm)
void turnOffLEDs() {
  for (uint8_t l = 0; l < LEDS; l++) {
    digitalWrite(ledPins[l], LOW);  // Turn off each LED
  }
}