import java.util.NoSuchElementException;
import java.util.Iterator;

public class Kennel<T extends Husdyr> implements Iterable<T>{
  private Bur foran;

  public Kennel() {
    foran = new Bur(null);
  }

  private class Bur {
    T dyr;
    Bur neste;

    public Bur(T data) {
      dyr = data;
    }
  }

  public void sjekkInn(T dyr) {
    Bur ny = new Bur(dyr);

    Bur pos = foran;
    while (pos.neste != null) {
      pos = pos.neste;
    }
    pos.neste = ny;
  }

  public boolean taUt(int id) {
    Bur pos = foran;
    while (pos.neste != null) {
      if (pos.neste.dyr.hentId() == id) {
        pos.neste = pos.neste.neste;
        return true;
      }
      pos = pos.neste;
    }
    return false;
  }

  public void skrivAlle(){
    for(T dyr: this){
      System.out.println(dyr);
    }
    /*if (foran.neste == null){
      System.out.println("\nKennelen er tom");
      return;
    }
    Bur pos = foran.neste;
    System.out.println("\nDyr i kennelen:");
    while(pos != null){
      System.out.println(pos.dyr);
      pos = pos.neste;
    } */
  }

  public Iterator<T> iterator() {
    return new KennelIterator();
  }

  private class KennelIterator implements Iterator<T> {
    private Bur posisjon;

    public KennelIterator() {
      posisjon = foran;
    }

    @Override
    public boolean hasNext() {
      return posisjon.neste != null;
    }

    @Override
    public T next() {
      if (!hasNext()) {
        throw new NoSuchElementException();
      }

      posisjon = posisjon.neste;
      return posisjon.dyr;
    }

    @Override
    public void remove() {
      throw new UnsupportedOperationException();
    }
  }
}