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

// OLED config
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_ADDR 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Pins
#define BUTTON_PIN 32
#define ANALOG_SENSOR_PIN 34

// Global loading progress
int loading_progress = 0;

// Struct untuk fuzzy range
struct FuzzyRange {
  float aman_min;
  float aman_max;
  float waspada_min;
  float waspada_mid;
  float waspada_max;
  float bahaya_min;
  float bahaya_max;
};

// Fungsi fuzzy
float fuzzy_aman(float x, float min, float max) {
  if (x <= min) return 1.0;
  if (x >= max) return 0.0;
  return (max - x) / (max - min);
}
float fuzzy_waspada(float x, float min, float mid, float max) {
  if (x <= min || x >= max) return 0.0;
  if (x <= mid) return (x - min) / (mid - min);
  return (max - x) / (max - mid);
}
float fuzzy_bahaya(float x, float min, float max) {
  if (x <= min) return 0.0;
  if (x >= max) return 1.0;
  return (x - min) / (max - min);
}

// Fuzzy evaluation
void fuzzyStatus(String nama, float ppm, FuzzyRange range, String &outputStr) {
  float u_aman    = fuzzy_aman(ppm, range.aman_min, range.aman_max);
  float u_waspada = fuzzy_waspada(ppm, range.waspada_min, range.waspada_mid, range.waspada_max);
  float u_bahaya  = fuzzy_bahaya(ppm, range.bahaya_min, range.bahaya_max);

  String status;
  if (u_aman >= u_waspada && u_aman >= u_bahaya) status = "AMAN";
  else if (u_waspada >= u_bahaya) status = "WASPADA";
  else status = "BAHAYA";

  // Simpan semua ke string global
  outputStr = "";
  outputStr += nama + "\n";
  outputStr += "PPM: " + String(ppm, 1) + "\n";
  outputStr += "A:" + String(u_aman, 2);
  outputStr += " W:" + String(u_waspada, 2);
  outputStr += " B:" + String(u_bahaya, 2) + "\n";
  outputStr += "Status: " + status;
}

// Loading progress bar
void progressBar(int delayPerStep, int targetProgress) {
  int start = loading_progress;
  int end = targetProgress;

  if (targetProgress > 0 && targetProgress <= 100 && targetProgress < start + 10) {
    end = start + targetProgress;
  }
  if (end > 100) end = 100;

  for (int i = start; i <= end; i += 5) {
    loading_progress = i;

    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);
    display.print("Mendeteksi MQ-2");
    display.setCursor(0, 12);
    display.print("Loading: ");
    display.print(loading_progress);
    display.println("%");

    display.drawRect(0, 28, 100, 10, SSD1306_WHITE);
    int barWidth = map(loading_progress, 0, 100, 0, 100);
    display.fillRect(0, 28, barWidth, 10, SSD1306_WHITE);

    display.display();
    delay(delayPerStep);
  }
}

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

  pinMode(BUTTON_PIN, INPUT_PULLUP); // Tombol aktif LOW
  pinMode(ANALOG_SENSOR_PIN, INPUT);

  // OLED setup
  if (!display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR)) {
    Serial.println("OLED gagal.");
    while (1);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 20);
  display.println("Siap memulai...");
  display.display();
}

void loop() {
  if (digitalRead(BUTTON_PIN) == LOW) {
    delay(50); // Debounce
    while (digitalRead(BUTTON_PIN) == LOW); // Tunggu dilepas

    loading_progress = 0;
    float ppm_MQ2 = 0;
    String output_MQ2;

    // MQ-2 Range
    FuzzyRange MQ2_range = {
      0, 40,
      30, 60, 90,
      80, 150
    };

    // 0–80%
    progressBar(300, 80);

    // Simulasi pembacaan sensor dari potensiometer
    int adcVal = analogRead(ANALOG_SENSOR_PIN); // 0–4095
    ppm_MQ2 = map(adcVal, 0, 4095, 0, 12000) / 100.0; // PPM: 0–120.00

    // Fuzzy
    fuzzyStatus("MQ-2", ppm_MQ2, MQ2_range, output_MQ2);

    // 80–100%
    progressBar(300, 100);

    // Tampilkan hasil
    display.clearDisplay();
    display.setTextSize(1);
    display.setCursor(0, 0);
    display.println(output_MQ2);
    display.display();

    Serial.println(output_MQ2);
    delay(3000); // Tahan hasil
  }
}