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

// LCD I2C
LiquidCrystal_I2C lcd(0x27, 16, 2);

// DHT Sensor
#define DHTPIN 2
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// Komponen
#define BUZZER_PIN 3
#define LED_MERAH 8
#define LED_HIJAU 9
#define MQ2_PIN A0 // MQ-2 Sensor analog pin

void setup() {
  lcd.init();
  lcd.backlight();
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(LED_MERAH, OUTPUT);
  pinMode(LED_HIJAU, OUTPUT);

  lcd.setCursor(0, 0);
  lcd.print(" DHT22 & MQ-2 ");
  delay(2000);
  lcd.clear();

  dht.begin();
}

// mu_DINGIN(x)
float cold(float x) {
  if (x <= 18) return 1;
  else if (x > 18 && x <= 24) return (24.0 - x) / (24.0 - 18.0);
  else return 0;
}

// mu_NORMAL(x)
float normal(float x) {
  if (x <= 24 || x >= 30) return 0;
  else if (x > 24 && x <= 30) return (x - 24.0) / (30.0 - 24.0);
  else if (x > 24 && x < 30) return (30.0 - x) / (30.0 - 24.0);
  else return 0;
}

// mu_PANAS(x)
float hot(float x) {
  if (x <= 30) return 0;
  else if (x > 30 && x <= 36) return (x - 30.0) / (36.0 - 30.0);
  else return 1;
}

void loop() {
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  int mq2Value = analogRead(MQ2_PIN); // Baca nilai dari sensor gas

  if (isnan(h) || isnan(t)) {
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error     ");
    noTone(BUZZER_PIN);
    digitalWrite(LED_MERAH, LOW);
    digitalWrite(LED_HIJAU, LOW);
    delay(1000);
    return;
  }

  // Tampilkan suhu dan kelembaban
  lcd.setCursor(0, 0);
  lcd.print("S:");
  lcd.print(t);
  lcd.print((char)223);
  lcd.print("C ");

  lcd.print("G:");
  lcd.print(mq2Value);

  lcd.setCursor(0, 1);
  lcd.print("H:");
  lcd.print(h);
  lcd.print("% ");

  // Fuzzy suhu
  float mu_cold = cold(t);
  float mu_normal = normal(t);
  float mu_hot = hot(t);

  float output = (mu_cold * 20 + mu_normal * 50 + mu_hot * 90) / 
                 (mu_cold + mu_normal + mu_hot + 0.0001);

  // Ambang gas (atur sesuai hasil eksperimen, misalnya > 300 dianggap bahaya)
  bool gasBahaya = mq2Value > 500;

  // Logika gabungan suhu panas atau gas bahaya
  if (output > 70 || gasBahaya) {
    tone(BUZZER_PIN, 2000);
    digitalWrite(LED_MERAH, HIGH);
    digitalWrite(LED_HIJAU, LOW);
  } else {
    noTone(BUZZER_PIN);
    digitalWrite(LED_MERAH, LOW);
    digitalWrite(LED_HIJAU, HIGH);
  }

  delay(1000);
}