#include <Adafruit_NeoPixel.h>

#define ledPin 4
#define btnPin 2
#define bazPin 12
#define pixelCount 16
#define wait 50

volatile bool isRight = true;
volatile bool btnFlag = true;
volatile uint32_t prewMillis;
volatile uint8_t speedLvl = 1;
volatile bool isBlink = false;
volatile uint16_t bazTone = 1000;
volatile bool isWaitingTone = false;

uint8_t pixelPosition = 0;

Adafruit_NeoPixel led(pixelCount, ledPin, NEO_RGB + NEO_KHZ800);

void setup() {
  Serial.begin(9600);
  pinMode(btnPin, INPUT);
  pinMode(ledPin, OUTPUT);
  attachInterrupt(digitalPinToInterrupt(btnPin), btnPress, RISING);
}

void loop()
{
  if(isWaitingTone)
  {
    tone(bazPin, bazTone, 120);
    isWaitingTone = false;
  }
  circleFrame();
}

void circleFrame()
{
  for(int i = 0; i <= led.numPixels(); i++)
  {
    if(i == pixelPosition)
      led.setPixelColor(i, 255, 255, 255);
    else
      led.setPixelColor(i, 0, 0, 0);
  }
  led.show();
  if(isRight)
    pixelPosition = ++pixelPosition % pixelCount;
  else
    pixelPosition = --pixelPosition % pixelCount;
  if(speedLvl == 0)
  {
    isBlink = true;
    for(int j = 0; j < 3; j++)
    {
      for(int i = 0; i <= led.numPixels(); i++)
        led.setPixelColor(i, 255, 255, 255);
      led.show();
      tone(bazPin, bazTone);
      delay(120);
      noTone(bazPin);
      for(int i = 0; i <= led.numPixels(); i++)
        led.setPixelColor(i, 0, 0, 0);
      led.show();
      delay(120);
    }
    speedLvl++;
    bazTone = 1000;
    isBlink = false;
  }
  else
    delay(wait / speedLvl);
}

void btnPress()
{
  if(millis() - prewMillis >= 200)
  {
    btnFlag = true;
    prewMillis = millis();
  }
  if(btnFlag && !isBlink)
  {
    action();
    btnFlag = false;
  }
}

void action()
{
  isRight = !isRight;
  isWaitingTone = true;
  speedLvl = ++speedLvl % 5; 
  bazTone += 1000; 
}