// ===== PIN DEFINITIONS =====
#define RED_PIN    15
#define GREEN_PIN  2
#define BLUE_PIN   4
#define LED_PIN    5

// ===== PWM SETTINGS =====
#define PWM_FREQ  5000
#define PWM_RES   8   // 8-bit (0–255)

// ===== FUNCTION: HSV to RGB =====
void hsvToRgb(int hue, int &r, int &g, int &b) {
  int region = hue / 43;
  int remainder = (hue - (region * 43)) * 6;

  int p = 0;
  int q = (255 * (255 - remainder)) >> 8;
  int t = (255 * remainder) >> 8;

  switch (region) {
    case 0: r = 255; g = t;   b = 0;   break;
    case 1: r = q;   g = 255; b = 0;   break;
    case 2: r = 0;   g = 255; b = t;   break;
    case 3: r = 0;   g = q;   b = 255; break;
    case 4: r = t;   g = 0;   b = 255; break;
    default:r = 255; g = 0;   b = q;   break;
  }
}

void setup() {
  // Attach PWM directly to pins (NEW API)
  ledcAttach(RED_PIN,   PWM_FREQ, PWM_RES);
  ledcAttach(GREEN_PIN, PWM_FREQ, PWM_RES);
  ledcAttach(BLUE_PIN,  PWM_FREQ, PWM_RES);
  ledcAttach(LED_PIN,   PWM_FREQ, PWM_RES);
}

void loop() {
  static int hue = 0;
  static int ledBrightness = 10;
  static int fadeDir = 1;

  int r, g, b;
  hsvToRgb(hue, r, g, b);

  // RGB rainbow
  ledcWrite(RED_PIN,   r);
  ledcWrite(GREEN_PIN, g);
  ledcWrite(BLUE_PIN,  b);

  // Breathing LED (never fully off)
  ledcWrite(LED_PIN, ledBrightness);

  ledBrightness += fadeDir;
  if (ledBrightness >= 255 || ledBrightness <= 10) {
    fadeDir = -fadeDir;
  }

  hue++;
  if (hue >= 256) hue = 0;

  delay(30); // slow rainbow + fade
}