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

// Define the keypad configuration
const byte ROW_NUM    = 4; // four rows
const byte COLUMN_NUM = 4; // four columns

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

byte pin_rows[ROW_NUM] = {9,8,7,6};     // Connect the row pins to 5, 4, 3, 2
byte pin_column[COLUMN_NUM] = {5,4,3,2}; // Connect the column pins to 9, 8, 7, 6

Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM);
Servo myServo;    // Create a servo object

int buzzerPin = 11;  // Buzzer connected to pin 11
int servoPin = 10;   // Servo connected to pin 10
String inputPassword = "";   // Stores the entered password
String correctPassword = "1234"; // The correct password
bool doorUnlocked = false; // Flag to check if the door is unlocked

// Initialize LCD with I2C address 0x27 (check if this is the correct one for your LCD)
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  // Initialize the servo and buzzer
  myServo.attach(servoPin);
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(9600);
  
  // Initialize the LCD
  lcd.begin(16, 2);
  lcd.backlight();  // Turn on the backlight

  // Initially, set the servo to the locked position (0 degrees)
  myServo.write(0);

  // Display initial message on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Enter Password:");
}

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

  if (key) {
    Serial.println(key); // Display keypress for debugging
    inputPassword += key; // Add the pressed key to the input string

    // Update the LCD with the entered key
    lcd.setCursor(inputPassword.length() - 1, 1);  // Move to the next position on the second row
    lcd.print(key);  // Display the entered character

    // If the input password is correct
    if (inputPassword == correctPassword) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Correct Password");
      lcd.setCursor(0, 1);
      lcd.print("Welcome");
      buzz(1); //beep once for correct password
      
      unlockDoor(); // Call the function to unlock the door
      inputPassword = ""; // Clear input after unlocking
    }
    // If the password is incorrect, play the buzzer
    else if (inputPassword.length() == correctPassword.length()) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Incorrect Password!");
      
      buzz(4); // Call the buzzer function to beep 5 times
      inputPassword = ""; // Clear the input password
      delay(2000); // Wait for 2 seconds to show the message
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Enter Password:");
    }

    // If user enters "##", lock the door
    if (inputPassword == "##" && doorUnlocked) {
      lockDoor();
      inputPassword = ""; // Clear the input after locking
    }
  }
}

void unlockDoor() {
  // Move the servo to 90 degrees to unlock the door
  myServo.write(90);
  doorUnlocked = true; // Set door status as unlocked

  // After unlocking, show the message on the LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Door Unlocked");
  lcd.setCursor(0, 1);
  lcd.print("Press ## to Lock");
}

void lockDoor() {
  // Move the servo to 0 degrees to lock the door
  myServo.write(0);
  doorUnlocked = false; // Set door status as locked

  // After locking, show the message on the LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Door Locked");
}

void buzz(int times) {
  for (int i = 0; i < times; i++) {
    tone(buzzerPin, 1000);  // Play a tone at 1000 Hz
    delay(400);              // Beep duration: 500ms
    noTone(buzzerPin);      // Turn off the buzzer
    delay(400);              // Pause between beeps
  }
}