#include <LiquidCrystal.h>
#include <Servo.h>
#include <DHT.h> 

// --- PIN DEFINITIONS ---
#define PIN_DHT A1        // TUKAR: Guna label A1 terus
#define DHTTYPE DHT22     
#define PIN_BUZZER 6      
#define PIN_HEATER 9      
#define PIN_SERVO 8       

// LED Status Pins
#define LED_RED 13      
#define LED_GREEN 10    
#define LED_BLUE 7      

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
Servo ventServo;
DHT dht(PIN_DHT, DHTTYPE); 

void setup() {
  pinMode(PIN_HEATER, OUTPUT);
  pinMode(PIN_BUZZER, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_BLUE, OUTPUT);
  
  lcd.begin(16, 2);
  lcd.print("System Loading..");
  
  dht.begin(); 
  
  ventServo.attach(PIN_SERVO);
  ventServo.write(0); 
  
  // DHT22 perlukan masa untuk "ready"
  delay(2000); 
  lcd.clear();
}

void loop() {
  // Baca Suhu & Humidity
  float temp = dht.readTemperature();
  float humidity = dht.readHumidity();

  // Jika masih error, papar mesej Checking supaya tak "stuck"
  if (isnan(temp) || isnan(humidity)) {
    lcd.setCursor(0, 0);
    lcd.print("Checking Sensor.");
    return; 
  }

  // Paparan LCD (Baris 1)
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temp, 1); 
  lcd.print("C ");
  lcd.setCursor(9, 0);
  lcd.print("H:");
  lcd.print(humidity, 0);
  lcd.print("%   ");

  // Logik Kawalan (Baris 2)
  lcd.setCursor(0, 1);
  if (temp < 35.0) {
    lcd.print("Stat: HEATING  ");
    digitalWrite(PIN_HEATER, HIGH); 
    digitalWrite(LED_RED, HIGH);    
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_BLUE, LOW);
    noTone(PIN_BUZZER);             
    ventServo.write(0);             
  } 
  else if (temp >= 35.0 && temp <= 37.5) {
    lcd.print("Stat: IDEAL    ");
    digitalWrite(PIN_HEATER, LOW);  
    digitalWrite(LED_RED, LOW);
    digitalWrite(LED_GREEN, HIGH);  
    digitalWrite(LED_BLUE, LOW);
    noTone(PIN_BUZZER);
    ventServo.write(0);
  } 
  else {
    lcd.print("ALARM: TOO HOT!");
    digitalWrite(PIN_HEATER, LOW);  
    digitalWrite(LED_RED, LOW);
    digitalWrite(LED_GREEN, LOW);
    digitalWrite(LED_BLUE, HIGH);   
    tone(PIN_BUZZER, 1000); 
    ventServo.write(90);          
  }

  delay(2000); // WAJIB 2 saat untuk DHT22
}