#include <Adafruit_NeoPixel.h>

#define PIN         6
#define NUMPIXELS  64

Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

struct PixelState {
  uint8_t r, g, b;           // base color
  float brightness;           // 0.0 to 1.0
  int direction;              // 1 = fade in, -1 = fade out
  unsigned long lastUpdate;   // last fade update
  int fadeSpeed;              // ms between brightness steps
};

PixelState pixelStates[NUMPIXELS];

void setup() {
  pixels.begin();
  pixels.show();

  for (int i = 0; i < NUMPIXELS; i++) {
    uint8_t baseBrightness = random(100, 200); // dimmer whites
    pixelStates[i].r = baseBrightness;
    pixelStates[i].g = baseBrightness;
    pixelStates[i].b = baseBrightness;
    pixelStates[i].brightness = 0.0;
    pixelStates[i].direction = 1; // start fading in
    pixelStates[i].lastUpdate = millis();
    pixelStates[i].fadeSpeed = random(40, 200); // slower, more natural twinkle
  }
}

void loop() {
  unsigned long currentMillis = millis();
  float overallFactor = 0.7; // scale max brightness to 70%

  for (int i = 0; i < NUMPIXELS; i++) {
    if (currentMillis - pixelStates[i].lastUpdate >= pixelStates[i].fadeSpeed) {
      pixelStates[i].lastUpdate = currentMillis;

      // adjust brightness
      pixelStates[i].brightness += 0.02 * pixelStates[i].direction;

      if (pixelStates[i].brightness >= 1.0) {
        pixelStates[i].brightness = 1.0;
        pixelStates[i].direction = -1; // start fading out
      } else if (pixelStates[i].brightness <= 0.0) {
        pixelStates[i].brightness = 0.0;
        pixelStates[i].direction = 1; // start fading in again
        // pick a new "star" brightness (mostly white)
        uint8_t baseBrightness = random(100, 160); // dimmer whites
        pixelStates[i].r = baseBrightness;
        pixelStates[i].g = baseBrightness;
        pixelStates[i].b = baseBrightness;
        pixelStates[i].fadeSpeed = random(40, 200); // slower, more natural twinkle
      }

      // apply brightness scaling with subtle flicker
      float flicker = random(95, 105) / 100.0; // 0.95 to 1.05 for gentle flicker
      uint8_t rVal = pixelStates[i].r * pixelStates[i].brightness * overallFactor * flicker;
      uint8_t gVal = pixelStates[i].g * pixelStates[i].brightness * overallFactor * flicker;
      uint8_t bVal = pixelStates[i].b * pixelStates[i].brightness * overallFactor * flicker;

      pixels.setPixelColor(i, pixels.Color(rVal, gVal, bVal));
    }
  }
  pixels.show();
}