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

void loop() {
  randomSeed(micros()); // seed random
  float ppm = random((0, 11001) / 100.0);

  float u_aman = fuzzy_aman(ppm);
  float u_waspada = fuzzy_waspada(ppm);
  float u_bahaya = fuzzy_bahaya(ppm);

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

  Serial.printf("PPM: %.1f | Status: %s\n", ppm, status.c_str());
  Serial.printf("  μAman     = %.2f\n", u_aman);
  Serial.printf("  μWaspada  = %.2f\n", u_waspada);
  Serial.printf("  μBahaya   = %.2f\n\n", u_bahaya);

  delay(2000);
}

float fuzzy_aman(float x) {
  if (x <= 30) return 1.0;
  if (x >= 40) return 0.0;
  return (40 - x) / 10.0;
}

float fuzzy_waspada(float x) {
  if (x <= 30 || x >= 90) return 0.0;
  if (x <= 60) return (x - 30) / 30.0;
  return (90 - x) / 30.0;
}

float fuzzy_bahaya(float x) {
  if (x <= 80) return 0.0;
  if (x >= 120) return 1.0;
  return (x - 80) / 40.0;
}