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

const int servoPin = 9;
Servo myServo;

const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {8, 7, 6, 5};
byte colPins[COLS] = {4, 3, 2, A0};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

LiquidCrystal_I2C lcd(0x27, 16, 2); // Address 0x27 for the I2C module, 16x2 display

char password[] = "1234"; // Change this to your desired password
char enteredPassword[5];
char securityAnswer[10]; // Increase size for alphanumeric input
int passwordIndex = 0;
int securityIndex = 0;
bool isAuthenticated = false; // Flag to track authentication status

void setup() {
  Wire.begin();
  lcd.init();
  lcd.backlight();
  lcd.print("Enter Password:");
  myServo.attach(servoPin);
}

void loop() {
  char key = keypad.getKey();
  if (!isAuthenticated) { // Check if not authenticated
    if (key) {
      if (key == '*' || key == '#') {
        // Ignore these keys
      } else if (key == 'D') {
        if (strcmp(enteredPassword, password) == 0) {
          lcd.clear();
          lcd.print("Password OK");
          delay(1000);
          lcd.clear();
          lcd.print("Security Question:");
          lcd.setCursor(0, 1);
          lcd.print("What is UR FAV THINGS?");
          passwordIndex = 0;
          memset(enteredPassword, 0, sizeof(enteredPassword));
          isAuthenticated = true; // Set authentication flag
        } else {
          lcd.clear();
          lcd.print("Wrong Password");
          delay(1000);
          lcd.clear();
          lcd.print("Enter Password:");
          passwordIndex = 0;
          memset(enteredPassword, 0, sizeof(enteredPassword));
        }
      } else {
        enteredPassword[passwordIndex++] = key;
        lcd.setCursor(passwordIndex - 1, 1);
        lcd.print('*');
      }
    }
  } else { // Authenticated
    if (key && isAlphaNumeric(key)) { // Check if the key is alphanumeric
      securityAnswer[securityIndex++] = key;
      lcd.setCursor(securityIndex - 1, 1);
      lcd.print('*');
    } else if (key == '#') { // End of security answer
      securityAnswer[securityIndex] = '\0'; // Null terminate the string
      if (strcmp(securityAnswer, "3A23AC") == 0) { // Change "4" to your desired answer
        lcd.clear();
        lcd.print("Security Answer:");
        lcd.setCursor(0, 1);
        lcd.print("Correct!");
        delay(1000);
        lcd.clear();
        lcd.print("Access Granted");
        delay(2000);
        lcd.clear();
        myServo.write(90); // Rotate servo to 90 degrees
        delay(2000);
        myServo.write(0); // Rotate servo back to 0 degrees
        lcd.print("Enter Password:");
        isAuthenticated = false; // Reset authentication flag
        securityIndex = 0; // Reset security answer index
      } else {
        lcd.clear();
        lcd.print("Security Answer:");
        lcd.setCursor(0, 1);
        lcd.print("Incorrect!");
        delay(1000);
        lcd.clear();
        lcd.print("Access Denied");
        delay(2000);
        lcd.clear();
        lcd.print("Enter Password:");
        isAuthenticated = false; // Reset authentication flag
        securityIndex = 0; // Reset security answer index
      }
    }
  }
}

bool isAlphaNumeric(char c) {
  return isalnum(c) || c == ' ';
}