#include <Keypad.h>

#define GREEN_LED D13
#define RED_LED D12
#define BUZZER D11

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

byte rowPins[ROWS] = {D7, D6, D5, D4}; // Row connections
byte colPins[COLS] = {A0, A1, A2, A3}; // Column connections

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

const String password = "1234"; // Set your password here
String input = ""; // Store user input

void setup() {
  pinMode(GREEN_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(BUZZER, OUTPUT);

  digitalWrite(GREEN_LED, LOW); // Lock is initially locked
  digitalWrite(RED_LED, LOW);

  Serial.begin(9600); // Initialize serial communication
  Serial.println("Password-Protected Lock System");
  Serial.println("Enter the password using the keypad:");
}

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

  if (key) {
    beep(); // Play a beep on key press
    Serial.print("Key Pressed: ");
    Serial.println(key);

    if (key == '#') { // Submit password
      Serial.print("Entered Password: ");
      Serial.println(input);

      if (input == password) {
        unlock();
        Serial.println("Correct Password: Door Unlocked!");
      } else {
        errorFeedback();
        Serial.println("Incorrect Password: Access Denied!");
      }
      input = ""; // Reset input after each attempt
    } else if (key == '*') { // Clear input
      input = "";
      Serial.println("Input cleared.");
    } else {
      input += key; // Append the key to the input string
      Serial.print("Current Input: ");
      Serial.println(input);
    }
  }
}

void beep() {
  digitalWrite(BUZZER, HIGH);
  delay(100);
  digitalWrite(BUZZER, LOW);
}

void unlock() {
  digitalWrite(GREEN_LED, HIGH); // Green LED ON
  delay(2000); // Keep it on for 2 seconds
  digitalWrite(GREEN_LED, LOW); // Lock again
}

void errorFeedback() {
  for (int i = 0; i < 3; i++) { // Flash the red LED 3 times
    digitalWrite(RED_LED, HIGH);
    beep(); // Error beep
    delay(300);
    digitalWrite(RED_LED, LOW);
    delay(300);
  }
}