#include <Adafruit_NeoPixel.h>

#define LED_PIN     3      // Data pin
#define NUM_LEDS    30      // Total number of LEDs
#define BRIGHTNESS  150     // Brightness (0 to 255)
#define SMOKE_COLOR strip.Color(100, 100, 100) // Light gray smoke

Adafruit_NeoPixel strip(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  strip.begin();
  strip.setBrightness(BRIGHTNESS);
  strip.show(); // Initialize all pixels to 'off'
}

void loop() {
  driftSmokeEffect(12);  // Control speed of drift
}

void driftSmokeEffect(int delayTime) {
  int tailLength = 10;  // How long the smoke trail is

  // Drift right
  for (int i = 0; i < NUM_LEDS + tailLength; i++) {
    strip.clear();

    for (int j = 0; j < tailLength; j++) {
      int pixelIndex = i - j;
      if (pixelIndex >= 0 && pixelIndex < NUM_LEDS) {
        int fadeValue = map(j, 0, tailLength, 200, 20); // Brighter at head, dimmer at tail
        uint32_t smokeFade = strip.Color(fadeValue, fadeValue, fadeValue);
        strip.setPixelColor(pixelIndex, smokeFade);
      }
    }

    strip.show();
    delay(delayTime);
  }

  // Drift left
  for (int i = NUM_LEDS + tailLength - 1; i >= 0; i--) {
    strip.clear();

    for (int j = 0; j < tailLength; j++) {
      int pixelIndex = i - j;
      if (pixelIndex >= 0 && pixelIndex < NUM_LEDS) {
        int fadeValue = map(j, 0, tailLength, 200, 20);
        uint32_t smokeFade = strip.Color(fadeValue, fadeValue, fadeValue);
        strip.setPixelColor(pixelIndex, smokeFade);
      }
    }

    strip.show();
    delay(delayTime);
  }
}