#include <FastLED.h>

// =================================================================================================
//                                    CONFIGURATION
// =================================================================================================
#define DATA_PIN    2       // The pin your data line is connected to
#define LED_TYPE    WS2812B
#define COLOR_ORDER GRB
#define NUM_LEDS    60      // The number of LEDs in your strip
#define BRIGHTNESS  250     // Brightness limit (0-255)

// =================================================================================================
//                            >>>>> TUNABLE PARAMETERS <<<<<
// =================================================================================================
// Experiment with these values to change the look of the fireworks!

// --- TIMING & SPEED ---
#define ANIMATION_SPEED_DELAY 25  // Overall animation speed. Higher value = slower animation. (Original: 10)
#define GRAVITY             -0.015  // How fast sparks fall down.
#define DRAG                0.98    // Air resistance. Lower value = sparks slow down faster.
#define SPARK_FADE_RATE     10      // How fast sparks fade. Lower value = sparks last longer. (Original: 15)

// --- QUANTITY & DENSITY ---
#define BURST_FREQUENCY     25      // How often new bursts appear. Lower value = more frequent bursts. (Original: 40)
#define SPARKS_PER_BURST_MIN 10     // Minimum number of sparks in a new burst. (Original: 5)
#define SPARKS_PER_BURST_MAX 21     // Maximum number of sparks in a new burst. (Original: 11)

// --- COLOR ---
#define HUE_ROTATION_SPEED  0.1     // How fast the colors change for new bursts.
// =================================================================================================


// =================================================================================================
//                                     SPARK HELPER CLASS
// =================================================================================================
class Spark {
  public:
    bool active;
    float position;
    float velocity;
    uint8_t hue;
    uint8_t brightness;

    Spark() : active(false) {}

    void ignite(float start_pos, float start_vel, uint8_t start_hue) {
      position = start_pos;
      velocity = start_vel;
      hue = start_hue;
      brightness = 255;
      active = true;
    }

    void update() {
      if (!active) return;
      position += velocity;
      velocity += GRAVITY;
      velocity *= DRAG;
      if (brightness > SPARK_FADE_RATE) {
        brightness -= SPARK_FADE_RATE;
      } else {
        brightness = 0;
        active = false;
      }
    }

    void draw(CRGB leds[]) {
      if (active && position >= 0 && position < NUM_LEDS) {
        leds[(int)position] += CHSV(hue, 255, brightness);
      }
    }
};
// =================================================================================================
//                                    MAIN SKETCH LOGIC
// =================================================================================================

CRGB leds[NUM_LEDS];
Spark sparks[NUM_LEDS];
float currentHue = 0;

void setup() {
  delay(1000);
  FastLED.addLeds<LED_TYPE, DATA_PIN, COLOR_ORDER>(leds, NUM_LEDS)
         .setCorrection(TypicalLEDStrip);
  FastLED.setBrightness(BRIGHTNESS);
}

void create_new_spark_burst() {
  float start_pos = (float)random(0, NUM_LEDS);
  int sparks_to_create = random(SPARKS_PER_BURST_MIN, SPARKS_PER_BURST_MAX);
  
  for(int i = 0; i < sparks_to_create; i++) {
    float start_vel = (float)random(-100, 100) / 100.0f;
    for (int j = 0; j < NUM_LEDS; j++) {
      if (!sparks[j].active) {
        sparks[j].ignite(start_pos, start_vel, (uint8_t)currentHue);
        break;
      }
    }
  }
}

void loop() {
  FastLED.clear();
  
  for (int i = 0; i < NUM_LEDS; i++) {
    sparks[i].update();
    sparks[i].draw(leds);
  }

  if (random(0, BURST_FREQUENCY) == 0) {
    create_new_spark_burst();
  }

  currentHue += HUE_ROTATION_SPEED;
  if (currentHue >= 256) {
    currentHue = 0;
  }
  
  FastLED.show();
  delay(ANIMATION_SPEED_DELAY);
}