/*
   24 LED NeoPixel Ring Demo
   Arduino Nano + WS2812B 24 LED Ring

   Library Required:
   Adafruit NeoPixel
*/

#include <Adafruit_NeoPixel.h>

#define LED_PIN    6
#define LED_COUNT  24

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

uint8_t mode = 0;
unsigned long lastChange = 0;
const unsigned long demoTime = 5000; // 5 seconds per effect

// =======================================================

void setup() {
  strip.begin();
  strip.setBrightness(180);
  strip.show();
}

// =======================================================

void loop() {

  switch (mode) {
    case 0: rainbowCycle(); break;
    case 1: colorChase(); break;
    case 2: breatheEffect(); break;
    case 3: meteorRain(); break;
    case 4: theaterChaseRainbow(); break;
    case 5: sparkleEffect(); break;
  }

  if (millis() - lastChange > demoTime) {
    lastChange = millis();
    mode++;
    if (mode > 5) mode = 0;
    strip.clear();
    strip.show();
  }
}

// =======================================================
// Rainbow Cycle
// =======================================================

void rainbowCycle() {
  static uint16_t j = 0;

  for (int i = 0; i < LED_COUNT; i++) {
    strip.setPixelColor(
      i,
      Wheel(((i * 256 / LED_COUNT) + j) & 255)
    );
  }

  strip.show();
  j++;
  delay(20);
}

// =======================================================
// Color Chase
// =======================================================

void colorChase() {
  static int pos = 0;

  strip.clear();

  for (int t = 0; t < 5; t++) {
    int idx = (pos - t + LED_COUNT) % LED_COUNT;

    uint8_t b = 255 - t * 50;

    strip.setPixelColor(idx, strip.Color(0, b, 255));
  }

  strip.show();

  pos++;
  if (pos >= LED_COUNT) pos = 0;

  delay(60);
}

// =======================================================
// Breathing Effect
// =======================================================

void breatheEffect() {

  for (int b = 10; b < 255; b += 5) {
    strip.fill(strip.Color(b, 0, b));
    strip.show();
    delay(15);
  }

  for (int b = 255; b > 10; b -= 5) {
    strip.fill(strip.Color(b, 0, b));
    strip.show();
    delay(15);
  }
}

// =======================================================
// Meteor Rain
// =======================================================

void meteorRain() {

  static int pos = 0;

  for (int i = 0; i < LED_COUNT; i++) {

    uint32_t c = strip.getPixelColor(i);

    uint8_t r = (c >> 16) & 0xFF;
    uint8_t g = (c >> 8) & 0xFF;
    uint8_t b = c & 0xFF;

    r = r > 20 ? r - 20 : 0;
    g = g > 20 ? g - 20 : 0;
    b = b > 20 ? b - 20 : 0;

    strip.setPixelColor(i, r, g, b);
  }

  strip.setPixelColor(pos, 255, 180, 80);

  strip.show();

  pos++;
  if (pos >= LED_COUNT) pos = 0;

  delay(40);
}

// =======================================================
// Theater Chase Rainbow
// =======================================================

void theaterChaseRainbow() {

  static int step = 0;

  strip.clear();

  for (int i = 0; i < LED_COUNT; i++) {

    if ((i + step) % 3 == 0) {

      strip.setPixelColor(
        i,
        Wheel((i * 10 + step * 10) & 255)
      );
    }
  }

  strip.show();

  step++;
  delay(80);
}

// =======================================================
// Sparkle
// =======================================================

void sparkleEffect() {

  for (int i = 0; i < LED_COUNT; i++) {

    uint32_t c = strip.getPixelColor(i);

    uint8_t r = (c >> 16) & 0xFF;
    uint8_t g = (c >> 8) & 0xFF;
    uint8_t b = c & 0xFF;

    r = r > 30 ? r - 30 : 0;
    g = g > 30 ? g - 30 : 0;
    b = b > 30 ? b - 30 : 0;

    strip.setPixelColor(i, r, g, b);
  }

  int pixel = random(LED_COUNT);

  strip.setPixelColor(
    pixel,
    random(256),
    random(256),
    random(256)
  );

  strip.show();

  delay(50);
}

// =======================================================
// Color Wheel
// =======================================================

uint32_t Wheel(byte WheelPos) {

  WheelPos = 255 - WheelPos;

  if (WheelPos < 85) {
    return strip.Color(
             255 - WheelPos * 3,
             0,
             WheelPos * 3
           );
  }

  if (WheelPos < 170) {

    WheelPos -= 85;

    return strip.Color(
             0,
             WheelPos * 3,
             255 - WheelPos * 3
           );
  }

  WheelPos -= 170;

  return strip.Color(
           WheelPos * 3,
           255 - WheelPos * 3,
           0
         );
}