#include <Adafruit_NeoPixel.h>

#define LED_PIN 9
#define NUM_LED 16

int sensor = A1;

Adafruit_NeoPixel ring(NUM_LED, LED_PIN, NEO_GRB + NEO_KHZ800);

int pos = 0;

unsigned long previousPosMillis = 0;
int posTimer;

int trailFade;

bool refresh = false;

int smoothing = 0;
unsigned long previousSmoothMillis = 0;
int smoothTimer = 10;

void setup() {
  ring.begin();
  ring.setBrightness(255);

  Serial.begin(9600);
  pinMode(sensor, INPUT);
}

void loop() {

  if (millis() - previousSmoothMillis >= smoothTimer) {
    previousSmoothMillis = millis();
    Serial.println(analogRead(sensor));
    if (analogRead(sensor) < 512) {
      smoothing++;
      posTimer *= 1.1;
    } else  {
      smoothing--;
      posTimer *= 0.5;
    }
    smoothing = constrain(smoothing, 3, 60);
    posTimer = constrain(posTimer, 40, 100);
  }

  trailFade = smoothing;

  if (pos >= NUM_LED) {
    pos = 0;
  }

  if (refresh) {

    refresh = false;

    for (int i = 0; i < NUM_LED; i++) {
      if (i != pos) {
        uint32_t Color = ring.getPixelColor(i);
        ring.setPixelColor(i, max(Red(Color) - (trailFade * 0.66), 0), max(Green(Color) - trailFade, 0), max(Blue(Color) - trailFade, 0));
      } else {
        ring.setPixelColor(i, 255, 200, 0);
      }
    }
    ring.show();
  }

  if (millis() - previousPosMillis >= posTimer) {
    previousPosMillis = millis();
    refresh = true;
    pos++;
  }
}

uint8_t Red(uint32_t color) {
  return (color >> 16) & 0xFF;
}

// Returns the Green component of a 32-bit color
uint8_t Green(uint32_t color) {
  return (color >> 8) & 0xFF;
}

// Returns the Blue component of a 32-bit color
uint8_t Blue(uint32_t color) {
  return color & 0xFF;
}

/*
  {
  "version": 1,
  "author": "Anonymous maker",
  "editor": "wokwi",
  "parts": [
    { "type": "wokwi-arduino-uno", "id": "uno", "top": 0, "left": 0, "attrs": {} },
    {
      "type": "wokwi-led-ring",
      "id": "ring1",
      "top": -191.36,
      "left": 87.59,
      "attrs": { "pixels": "16" }
    },
    {
      "type": "wokwi-pushbutton",
      "id": "btn1",
      "top": 275,
      "left": 249.6,
      "attrs": { "color": "green" }
    },
    {
      "type": "wokwi-resistor",
      "id": "r1",
      "top": 320.75,
      "left": 38.4,
      "attrs": { "value": "1000" }
    }
  ],
  "connections": [
    [ "ring1:GND", "uno:GND.1", "black", [ "v0" ] ],
    [ "ring1:VCC", "uno:5V", "red", [ "v0" ] ],
    [ "uno:9", "ring1:DIN", "green", [ "v0" ] ],
    [ "btn1:1.l", "uno:A1", "green", [ "h0" ] ],
    [ "uno:5V", "btn1:2.l", "red", [ "v0" ] ],
    [ "btn1:1.l", "r1:2", "green", [ "h0" ] ],
    [ "r1:1", "uno:GND.2", "green", [ "v0" ] ]
  ],
  "dependencies": {}
  }
*/