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

const int servoPin = 10;  // Connect servo to digital pin 9
const int redLedPin = 11;  // Connect red LED to digital pin 10
const int greenLedPin = 12;  // Connect green LED to digital pin 11
const int buzzerPin = 13;  // Connect buzzer to digital pin 12

Servo myServo;

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] = {2, 3, 4, 5}; // connect to the row pinouts of the keypad
byte pin_column[COLUMN_NUM] = {6, 7, 8, 9}; // connect to the column pinouts of the keypad

Keypad myKeypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM);
String enteredPassword = "";
String correctPassword = "1234"; // Change this to your desired password
int wrongAttempts = 0;
const int maxWrongAttempts = 3;

LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 columns and 2 rows

void setup() {
  myServo.attach(servoPin);
  pinMode(redLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  myServo.write(90);  // Lock the servo initially
  lcd.begin(16, 2);  // Initialize the LCD
  lcd.print("Enter password:");
  Serial.begin(9600);
}

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

  if (key) {
    if (key == '#') {
      // Check the entered password when '#' is pressed
      if (enteredPassword == correctPassword) {
        lcd.clear();
        lcd.print("Password correct");
        lcd.setCursor(0, 1);
        lcd.print("Unlocking...");
        digitalWrite(greenLedPin, HIGH);  // Turn on green LED
        unlock();
      } else {
        lcd.clear();
        lcd.print("Incorrect password");
        lcd.setCursor(0, 1);
        lcd.print("Locking...");
        digitalWrite(redLedPin, HIGH);  // Turn on red LED
        lock();
        wrongAttempts++;

        // Buzz the buzzer if three wrong attempts are reached
        if (wrongAttempts >= maxWrongAttempts) {
          digitalWrite(buzzerPin, HIGH);  // Turn on the buzzer
          delay(1000);  // Buzz for 1 second
          digitalWrite(buzzerPin, LOW);  // Turn off the buzzer
          wrongAttempts = 0;  // Reset the wrong attempts counter
        }
      }

      // Clear entered password for the next attempt
      enteredPassword = "";

      // Delay to display the result on the LCD
      delay(2000);

      // Turn off LEDs and clear LCD
      digitalWrite(redLedPin, LOW);
      digitalWrite(greenLedPin, LOW);
      lcd.clear();
      lcd.print("Enter password:");
    } else {
      // Append the pressed key to the entered password
      enteredPassword += key;
      lcd.setCursor(0, 1);
      lcd.print("                "); // Clear the line
      lcd.setCursor(0, 1);
      lcd.print(enteredPassword);
    }
  }
}

void unlock() {
  myServo.write(0);  // Open the lock
  delay(8000);       // Keep the lock open for 8 seconds
  myServo.write(90);  // Close the lock
}

void lock() {
  myServo.write(90);  // Close the lock
  delay(1000);       // Keep the lock closed for 1 second
}