package listadt;

import bookutil.Book;

/**
 * This class represents an empty node in the list adt implementation.
 */
public class BookListADTEmptyNode implements BookListADTNode {
  @Override
  public int count(){return 0;}


  @Override
  public String toString() { return "";}

  @Override
  public BookListADTNode addFront(Book book) {return new
          BookListADTElementNode(book,this);}

  @Override
  public BookListADTNode addBack(Book book) { return addFront(book);}

  @Override
  public BookListADTNode add(int index,Book book) throws IllegalArgumentException {
    if (index==0){
      return addFront(book);
    }
    throw new IllegalArgumentException("Invalid index to add an element");
  }

  @Override
  public BookListADTNode remove(Book b) {
    return this; //cannot remove from nothing!
  }

  @Override
  public Book get(int index) throws IllegalArgumentException {
    throw new IllegalArgumentException("Wrong index");
  }
}