#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h> // Include Keypad library

// Define LCD I2C address
const int lcd_I2C_address = 0x27;

// Define LCD size
const int lcd_columns = 16;
const int lcd_rows = 2;

LiquidCrystal_I2C lcd(lcd_I2C_address, lcd_columns, lcd_rows);

// Keypad configuration (adjust rows and columns based on your keypad)
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] = {19, 18, 5, 17};
byte colPins[COLS] = {16, 4, 0, 2};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// Define door state variables
bool doorIsOpen = false;
bool doorIsLocked = true;  // Initial state

// Define your correct door unlock code (replace with your desired sequence)
const char correctCode[] = "1234";
int codeLength = sizeof(correctCode) - 1; // Calculate code length (excluding null terminator)
int enteredChars = 0;
char enteredCode[codeLength]; // Array to store entered keypad digits

void setup() {
  Serial.begin(115200);        // Initialize serial communication for debugging

  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();

  // Display initial door state
  lcd.print("Door: ");
  updateDoorStatus();
}

void loop() {
  char enteredCode[codeLength];
  char key = keypad.getKey();

  if (key) {
    // Handle keypad input
    if (isdigit(key)) { // Check if pressed key is a digit (0-9)
      if (enteredChars < codeLength) {
        enteredCode[enteredChars++] = key;
        lcd.setCursor(enteredChars, 0); // Move cursor to next digit position
        lcd.print("*"); // Display asterisk for each entered digit (optional, for visual feedback)
      }
    } else if (key == '#') { // Handle enter key (#)
      if (enteredChars == codeLength) {
        if (strncmp(enteredCode, correctCode, codeLength) == 0) {
          // Unlock door if code is correct
          doorIsLocked = false;
          lcd.clear();
          lcd.print("Door Unlocked!");
        } else {
          // Display error message on incorrect code
          lcd.clear();
          lcd.print("Incorrect Code!");
          delay(2000);
          lcd.clear();
          enteredChars = 0; // Reset entered code for next attempt
        }
      } else {
        // Display message for incomplete code entry
        lcd.clear();
        lcd.print("Enter Full Code!");
        delay(2000);
        lcd.clear();
        enteredChars = 0; // Reset entered code for next attempt
      }
    } else {
      // Handle invalid key presses (optional: display message or ignore)
    }
  }

  updateDoorStatus(); // Update LCD even without keypad input
  delay(250);           // Delay to avoid rapid key reading issues
}

void updateDoorStatus() {
  lcd.setCursor(5, 0);

  if (doorIsOpen) {
    lcd.print("Open");
  } else {
    lcd.print("Closed");
  }

  lcd.setCursor(0, 1);
  lcd.print("Lock: ");

  if (doorIsLocked) {
    lcd.print("Locked");
  } else {
    lcd.print("Unlocked");
  }
}