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

LiquidCrystal_I2C lcd(0x27, 16, 2);

const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {9, 8, 7, 6};
byte colPins[KEYPAD_COLS] = {5, 4, 3, 2};
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);
const int relay = 1;
const String correctCode = "1234";
String enteredCode;
int codeIndex = 0;
bool backlightOn = true; 

void setup() {
  pinMode(relay, OUTPUT);
  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("Enter code :");
  lcd.backlight();
}

void loop() {
  key();
  A();
}

void relayControl() {
  if (enteredCode== correctCode) {
    lcd.setCursor(6, 1);
    lcd.print("WIN");
    digitalWrite(relay, HIGH);
    resetCode();
  } else {
    lcd.setCursor(6, 1);
    lcd.print("LOSE");
    resetCode();
  }
}

void resetCode() {
  delay(2000);
  lcd.clear();
  digitalWrite(relay,LOW);
  enteredCode = "";
}

void key() {
  char key = keypad.getKey();
  if (key != NO_KEY) {
    if (key == '#') {
      relayControl();
    } else {
      lcd.print(key);
      enteredCode += key;
    }

  }
}

void A() {
  char key = keypad.getKey();
  if (key != NO_KEY) {
    if (key == 'A') {
      if (backlightOn) {
      lcd.noBacklight();
      } else {
        lcd.backlight(); 
      }
      backlightOn = !backlightOn; 
    }
  }
}