//Libraries
#include <dht.h> // sensor lib from https://www.ardumotive.com/how-to-use-dht-22-sensor-en.html
#include <LiquidCrystal_I2C.h> // i2c LCD lib from  https://www.ardumotive.com/i2clcden.html
#include <Keypad.h>
#include <Servo.h>
#include <IRremote.h>

dht DHT;
Servo doorServo;

//Constants
#define SERVO_PIN 9
#define DHT22_PIN A3
#define RECV_PIN 12

LiquidCrystal_I2C lcd(0x27, 16, 2);

// Setup the 4x4 keypad
const uint8_t ROWS = 4;
const uint8_t COLS = 4;
uint8_t rowPins[ROWS] = {7, 6, 5, 4};
uint8_t colPins[COLS] = {3, 2, 1, 0};
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

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

// Variables
String enteredCode = "";
const String correctCode = "8888"; // door unlock code
IRrecv irrecv(RECV_PIN);
decode_results results;
float hum;  //Stores  humidity value
float temp; //Stores temperature value

void setup()
{
  Serial.begin(9600);
  // Setup servo
  doorServo.attach(SERVO_PIN);
  // Start with door locked
  Serial.println("Door Lock System Initialized");
  lockDoor();
  // Start IR receiver
  irrecv.enableIRIn();
  Serial.println("IR Receiver is ready and waiting for input...");
  // Start LCD
  lcd.init();
  lcd.backlight();
}

void  loop()
{
  char key = keypad.getKey();
  if (key) { // If a key is pressed
    Serial.print("Key Pressed: ");
    Serial.println(key);
    if (key == '#') { // '#' to check entered code
      if (enteredCode == correctCode) {
        Serial.println("Correct Code! Door Unlocked.");
        unlockDoor();
        delay(5000); //delay door open for 5s
        lockDoor();
      } else {
        Serial.println("Incorrect Code. Try Again.");
      }
      enteredCode = ""; // Reset the code after checking
    } else {
      enteredCode += key; // Append the pressed key to the entered code
      Serial.print("Current Code: ");
      Serial.println(enteredCode);
    }
  }
  if (irrecv.decode(&results)) { // Check if a signal is received
    Serial.print("IR Code received: ");
    Serial.println(results.value, HEX); // Print the received value in HEX
    irrecv.resume(); // Receive the next value
  }
  int chk = DHT.read22(DHT22_PIN);
  //Read data and store  it to variables hum and temp
  hum = DHT.humidity;
  temp = DHT.temperature;
  //Print temp and humidity values to LCD
  lcd.setCursor(0, 0);
  lcd.print("Humidity:  ");
  lcd.print(hum);
  lcd.print("%");
  lcd.setCursor(0, 1);
  lcd.print("Temp: ");
  lcd.print(temp);
  lcd.println("Celcius");
  delay(2000); //Delay 2s between temperature/humidity check.
}
//unlock door
void unlockDoor() {
  Serial.println("Door Unlocked");
  doorServo.write(90);
}
// lock door
void lockDoor() {
  Serial.println("Door Locked");
  doorServo.write(0);
}