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

int buzzerPin = 48; 
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}; // Rows 1 to 4
byte colPins[COLS] = {4, 3, 2, 10}; // Columns 1 to 4

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

LiquidCrystal_I2C lcd(0x27, 20, 4); // Address 0x27, 20 chars, 4 rows

char inputCode[5] = "";
char code[] = "2002"; // Password

Servo myservo;  // Servo object

// Maximum number of attempts
const int maxAttempts = 3;
int attemptCount = 0;  // Tracks incorrect code attempts
bool codeEntered = false; // Track if code is entered correctly

void clearInputCode() {
  for (int i = 0; i < sizeof(inputCode); i++) {
    inputCode[i] = '\0';
  }
}

void setup() {
  Serial.begin(9600);
  lcd.begin(20, 4);
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Enter code:");
  pinMode(buzzerPin, OUTPUT);
  myservo.attach(9); 
  myservo.write(0);  // Set servo to initial position (0 degrees)
}

void loop() {
  char key = keypad.getKey();
  if (key != NO_KEY) {
    if (!codeEntered) {
      if (attemptCount < maxAttempts) { // Only allow up to maxAttempts
        if (strlen(inputCode) < 4) {
          inputCode[strlen(inputCode)] = key;
          lcd.setCursor(strlen(inputCode), 1);
          lcd.print("*");  // Display asterisk instead of actual key
        }
        if (strlen(inputCode) == 4) {
          lcd.setCursor(0, 1);
          lcd.print(""); // Clear the line with spaces (better than multiple spaces)
          lcd.setCursor(0, 1);
          lcd.print(inputCode); // Display entered code with asterisks
          if (strcmp(inputCode, code) == 0) {
            lcd.setCursor(0, 2);
            lcd.print(""); // Clear the line with spaces
            lcd.setCursor(0, 2);
            lcd.print("Correct code!");
            delay(250); // Delay before opening the door
            myservo.write(90); // Open the door
            delay(5000); // Door open time
            myservo.write(0); // Close the door
            delay(2000);
            lcd.noBacklight();
            lcd.clear(); 
            // Wait for A press to turn off LCD and clear attempt count
            codeEntered = true; // Code entered correctly
          } else {
            attemptCount++;
            lcd.setCursor(0, 2);
            lcd.print(""); // Clear the line with spaces
            lcd.setCursor(0, 2);
            lcd.print("Wrong code!");
            delay(1000); // Delay before clearing LCD
            lcd.clear(); // Clear input code (already done in first call)
            lcd.setCursor(0, 0);
            lcd.print("Enter code:");
            clearInputCode(); // Clear input code
            // Sound alarm if maxAttempts is reached
            if (attemptCount == maxAttempts) {
              lcd.setCursor(0, 2);
              lcd.print("Max attempts reached");
              tone(buzzerPin, 1000); // Sound alarm
            }
          }
        }
      } else {
        // Max attempts reached
        while (key != 'B' && key != NO_KEY) {
          key = keypad.getKey();
          tone(buzzerPin, 1000); // Sound alarm
        }
        noTone(buzzerPin); // Stop alarm
        attemptCount = 0; // Reset attempt count
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter code:");
        clearInputCode(); // Clear input code
      }
    } else {
      // Code entered correctly
      if (key == 'A') {
        codeEntered = false; // Reset code entered flag
        lcd.clear();
        lcd.backlight(); // Turn on LCD backlight
        lcd.setCursor(0, 0);
        lcd.print("Enter code:");
        clearInputCode(); // Clear input code
      }
    }
  }
}