#include <Arduino.h>
// =====================================================
// ESP32 + MQ-135 + MQ-7 + OLED SSD1306 (0.96" 128x64)
// Bahasa Indonesia | Stabil | Client-ready
// =====================================================

#include <Wire.h>
#include <MQUnifiedsensor.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// ================= OLED CONFIG =================
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
#define OLED_ADDR     0x3C

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// ================= MQ CONFIG ===================
#define BOARD            "ESP-32"
#define VOLTAGE          3.3
#define ADC_BITS         12

#define PIN_MQ135        34
#define PIN_MQ7          35

#define RATIO_CLEAN_MQ135 3.6
#define RATIO_CLEAN_MQ7   27.5

MQUnifiedsensor MQ135(BOARD, VOLTAGE, ADC_BITS, PIN_MQ135, "MQ-135");
MQUnifiedsensor MQ7(BOARD, VOLTAGE, ADC_BITS, PIN_MQ7, "MQ-7");

// ================= HELPER ======================
float readAverage(MQUnifiedsensor &sensor, int samples = 5) {
  float sum = 0;
  for (int i = 0; i < samples; i++) {
    sensor.update();
    sum += sensor.readSensor();
    delay(50);
  }
  return sum / samples;
}

// =====================================================
void setup() {
  Serial.begin(115200);
  delay(500);

  // ================= OLED INIT =================
  Wire.begin(21, 22);
  if (!display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)) {
    Serial.println("❌ OLED tidak ditemukan!");
    while (true) delay(1000);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Monitoring Udara");
  display.println("ESP32 + MQ");
  display.println("Kalibrasi...");
  display.display();

  // ================= KALIBRASI =================
  Serial.println("Mulai kalibrasi sensor...");
  Serial.println("Pastikan udara bersih (±1-2 menit)");

  // MQ135
  MQ135.setRegressionMethod(1);
  MQ135.init();
  float r0_135 = 0;
  for (int i = 0; i < 10; i++) {
    MQ135.update();
    r0_135 += MQ135.calibrate(RATIO_CLEAN_MQ135);
    delay(600);
  }
  r0_135 /= 10;
  MQ135.setR0(r0_135);

  // MQ7
  MQ7.setRegressionMethod(1);
  MQ7.init();
  float r0_7 = 0;
  for (int i = 0; i < 10; i++) {
    MQ7.update();
    r0_7 += MQ7.calibrate(RATIO_CLEAN_MQ7);
    delay(600);
  }
  r0_7 /= 10;
  MQ7.setR0(r0_7);

  if (r0_135 <= 0 || r0_7 <= 0) {
    Serial.println("❌ Kalibrasi gagal!");
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("ERROR KALIBRASI");
    display.display();
    while (true) delay(1000);
  }

  Serial.println("Kalibrasi selesai!");

  display.clearDisplay();
  display.setCursor(0, 0);
  display.println("Kalibrasi OK");
  display.println("Mulai Monitor");
  display.display();
  delay(2000);
}

// =====================================================
void loop() {

  // =============== MQ135 =================
  MQ135.setA(110.47); MQ135.setB(-2.862);
  float co2 = readAverage(MQ135);
  if (co2 < 0) co2 = 0;

  MQ135.setA(605.18); MQ135.setB(-3.937);
  float benzene = readAverage(MQ135);
  if (benzene < 0) benzene = 0;

  // =============== MQ7 ===================
  MQ7.setA(99.042); MQ7.setB(-1.518);
  float co = readAverage(MQ7);
  if (co < 0) co = 0;

  // ========== AIR QUALITY ESTIMATION =====
  int aq = 100;

  if (co2 > 700)  aq -= map(co2, 700, 2000, 0, 50);
  if (co2 > 2000) aq -= map(co2, 2000, 5000, 50, 80);

  if (co > 10) aq -= map(co, 10, 50, 0, 30);
  if (co > 50) aq -= 30;

  if (benzene > 5) aq -= map(benzene, 5, 50, 0, 40);

  aq = constrain(aq, 0, 100);

  String status;
  if (aq >= 90)      status = "Sangat Baik";
  else if (aq >= 70) status = "Baik";
  else if (aq >= 50) status = "Sedang";
  else if (aq >= 30) status = "Buruk";
  else               status = "Sangat Buruk";

  // =============== OLED DISPLAY ==========
  display.clearDisplay();
  display.setCursor(0, 0);

  display.print("CO2: ");
  display.print(co2, 0);
  display.println(" ppm");

  display.print("CO : ");
  display.print(co, 1);
  display.println(" ppm");

  display.print("BZ : ");
  display.print(benzene, 1);
  display.println(" ppm");

  display.print("AQ : ");
  display.print(aq);
  display.print("% ");
  display.println(status);

  display.display();

  // =============== SERIAL =================
  Serial.println("===== STATUS UDARA =====");
  Serial.print("CO2 : "); Serial.print(co2); Serial.println(" ppm");
  Serial.print("CO  : "); Serial.print(co);  Serial.println(" ppm");
  Serial.print("BZ  : "); Serial.print(benzene); Serial.println(" ppm");
  Serial.print("AQ  : "); Serial.print(aq); Serial.print("% "); Serial.println(status);
  Serial.println("========================\n");

  delay(5000);
}