#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <Servo.h>
#include <IRremote.h>
#include <dht.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4

#define SERVO_PIN 6
#define SERVO_LOCK_POS   20
#define SERVO_UNLOCK_POS 90
#define PIN_RECEIVER 10
#define PIN_LED 13
#define DHT22_PIN 11

dht DHT;
IRrecv receiver(PIN_RECEIVER);
Servo lockServo;
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

bool isLocked = true;
int LED = 1;

const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {5, 4, 3, 2};
byte colPins[KEYPAD_COLS] = {A3, A2, A1, A0};
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);

String correctCode = "1234";

void lock() {
  lockServo.write(SERVO_LOCK_POS);
  isLocked = true;
}

void unlock() {
  lockServo.write(SERVO_UNLOCK_POS);
  isLocked = false;
}

void setup() {
  lcd.begin(16, 2);
  receiver.enableIRIn();
  pinMode(PIN_LED, OUTPUT);
  lockServo.attach(SERVO_PIN);
  lock();
  lcd.setCursor(4, 0);
  lcd.print("Welcome!");
  delay(1000);
  lcd.clear();
}

void loop() {
  if (receiver.decode()) {
    if (receiver.decodedIRData.command == 162) {
      LED = !LED;
      digitalWrite(PIN_LED, LED);
    }
    receiver.resume();
  }

  if (isLocked) {
    int chk = DHT.read22(DHT22_PIN);
    lcd.setCursor(0, 0);
    lcd.print("Temp: ");
    lcd.print(DHT.temperature, 1);
    lcd.print("C ");
    lcd.setCursor(0, 1);
    lcd.print("Hum: ");
    lcd.print(DHT.humidity, 1);
    lcd.print("%");
    
    char key = keypad.getKey();
    if (key == 'B') {
      lcd.clear();
      lcd.print("Enter Code: ");
      String enteredCode = "";
      while (enteredCode.length() < 4) {
        key = keypad.getKey();
        if (key && key >= '0' && key <= '9') {
          lcd.print('*');
          enteredCode += key;
        }
      }

      if (enteredCode == correctCode) {
        unlock();
        lcd.clear();
        lcd.print("Unlocked!");
        delay(1000);
        lock();
        lcd.clear();
      } else {
        lcd.clear();
        lcd.print("Wrong Code!");
        delay(1000);
        lcd.clear();
      }
    }
  }

  delay(200);
}