/*
 Project    : Arduino Keypad Password Lock System
 Author     : Moamen Abouhaty
 Board      : Arduino UNO
 Year       : 2026
 Copyright  : © 2026 Moamen Abouhaty
 Description:
   - Password-based access control system
   - Uses Keypad for input
   - LCD for user feedback
   - Green LED for success
   - Red LED for failure
   - Buzzer for sound effects
*/

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

// ================= LCD Configuration =================
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C LCD address 0x27, 16 columns, 2 rows

// ================= Keypad Configuration =================
const byte ROWS = 4;
const byte COLS = 4;

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

// Arduino pins connected to keypad rows and columns
byte rowPins[ROWS] = {9, 8, 7, 6};
byte colPins[COLS] = {5, 4, 3, 2};

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

// ================= Hardware Pins =================
#define BUZZER     10
#define GREEN_LED  11
#define RED_LED    12

// ================= Password Settings =================
String password = "1234";   // Correct password
String input    = "";       // User input buffer

// ================= Function Prototypes =================
void checkPassword();
void resetInput();
void resetAll();
void playMario();
void playError();

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

  lcd.init();        // Initialize LCD
  lcd.backlight();   // Turn on LCD backlight

  lcd.setCursor(0, 0);
  lcd.print("Enter Password");
  lcd.setCursor(0, 1);
}

// ================= Main Loop =================
void loop() {
  char key = keypad.getKey(); // Read pressed key

  if (key) {
    tone(BUZZER, 1000, 50); // Beep sound on key press

    if (key == '#') {
      // Confirm password
      checkPassword();
    }
    else if (key == '*') {
      // Clear input
      resetInput();
    }
    else {
      // Add key to input and show * on LCD
      input += key;
      lcd.print("*");
    }
  }
}

// ================= Password Check =================
void checkPassword() {
  lcd.clear();

  if (input == password) {
    lcd.print("Access Granted");
    digitalWrite(GREEN_LED, HIGH);
    playMario();
  } else {
    lcd.print("Access Denied");
    digitalWrite(RED_LED, HIGH);
    playError();
  }

  delay(2000);
  resetAll();
}

// ================= Reset Functions =================
void resetInput() {
  input = "";
  lcd.clear();
  lcd.print("Enter Password");
  lcd.setCursor(0, 1);
}

void resetAll() {
  digitalWrite(GREEN_LED, LOW);
  digitalWrite(RED_LED, LOW);
  resetInput();
}

// ================= Sound Effects =================
void playError() {
  tone(BUZZER, 200, 300);
  delay(300);
  tone(BUZZER, 100, 500);
  delay(500);
  noTone(BUZZER);
}

void playMario() {
  int melody[]   = {660, 660, 0, 660, 0, 510, 660, 0, 770};
  int duration[] = {150, 150, 150, 150, 150, 150, 150, 150, 300};

  for (int i = 0; i < 9; i++) {
    if (melody[i] > 0) {
      tone(BUZZER, melody[i], duration[i]);
    }
    delay(duration[i] * 1.3);
  }
  noTone(BUZZER);
}