#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define DHTPIN 15
#define DHTTYPE DHT22

#define FAN1 2
#define FAN2 4
#define LED_WARNING 14
#define BUZZER 12
#define MQ2_PIN 34

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1

DHT dht(DHTPIN, DHTTYPE);
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup() {
  Serial.begin(115200);
  dht.begin();

  pinMode(FAN1, OUTPUT);
  pinMode(FAN2, OUTPUT);
  pinMode(LED_WARNING, OUTPUT);
  pinMode(BUZZER, OUTPUT);

  digitalWrite(FAN1, HIGH);  // relay mati (aktif LOW)
  digitalWrite(FAN2, HIGH);
  digitalWrite(LED_WARNING, LOW);
  digitalWrite(BUZZER, LOW);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("OLED tidak ditemukan!"));
    while (1);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Sistem Mulai...");
  display.display();
  delay(1000);
}

void loop() {
  float suhu = dht.readTemperature();
  float kelembapan = dht.readHumidity();
  int gas = analogRead(MQ2_PIN);

  if (isnan(suhu) || isnan(kelembapan)) {
    Serial.println("Gagal membaca sensor DHT22!");
    return;
  }

  Serial.print("Suhu: "); Serial.print(suhu); Serial.print(" C, ");
  Serial.print("RH: "); Serial.print(kelembapan); Serial.print(" %, ");
  Serial.print("Gas: "); Serial.println(gas);

  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("Suhu : "); display.print(suhu); display.println(" C");
  display.print("RH   : "); display.print(kelembapan); display.println(" %");
  display.print("Gas  : "); display.println(gas);

  bool kelembapanTinggi = kelembapan > 80;
  bool gasTerdeteksi = gas > 2000;

  if (kelembapanTinggi || gasTerdeteksi) {
    digitalWrite(FAN1, LOW); // Kipas ON
    digitalWrite(FAN2, LOW);
    display.println("Kipas: AKTIF");
  } else {
    digitalWrite(FAN1, HIGH); // Kipas OFF
    digitalWrite(FAN2, HIGH);
    display.println("Kipas: OFF");
  }

  if (gasTerdeteksi) {
    display.println("ASAP TERDETEKSI!");
    Serial.println("⚠️  Gas/Asap tinggi!");

    // LED berkedip & buzzer aktif
    for (int i = 0; i < 3; i++) {
      digitalWrite(LED_WARNING, HIGH);
      digitalWrite(BUZZER, HIGH);
      delay(300);
      digitalWrite(LED_WARNING, LOW);
      digitalWrite(BUZZER, LOW);
      delay(300);
    }
  } else {
    digitalWrite(LED_WARNING, LOW);
    digitalWrite(BUZZER, LOW);
  }

  display.display();
  delay(2000);
}