int myPins[]= {6,7,8,9,10,11,12,13};
int pinCount=8;
const long period = 200;
unsigned long start_time = 0;
int trenutnaLED = 0;
int smer = 1;
const int buttonpin = 2;
bool dol = false;
bool lastButtonState = HIGH;
const int DebounceTime = 50;
unsigned long lastDebounce = 0;

void setup() {
  pinMode(buttonpin, INPUT_PULLUP);
  for (int thisPin=0; thisPin <pinCount; thisPin++){
    pinMode(myPins[thisPin],OUTPUT);
  }

}

void loop() {
  unsigned long  current_time = millis();
  bool button_state =digitalRead(buttonpin);

 if (button_state != lastButtonState) {
    lastDebounce = current_time;
  }

  if ((current_time - lastDebounce) > DebounceTime) {
    if (button_state == LOW && !dol) {
      dol = true;
      smer = -smer;
    }
    else if (button_state == HIGH && dol) {
      dol = false;
    }
  }

  lastButtonState = button_state;

  if (current_time - start_time >= period){
    start_time = current_time;
    for (int thisPin=0; thisPin <pinCount; thisPin++){
      digitalWrite(myPins[thisPin], LOW);     
    }
    digitalWrite(myPins[trenutnaLED], HIGH);
    trenutnaLED += smer;
    if (trenutnaLED >= 8) {
      trenutnaLED = 8 - 1;
      smer = -smer;
    } 
    else if (trenutnaLED < 0) {
      trenutnaLED = 0;
      smer = -smer;
    }
  }
}