import java.util.LinkedList;

public class PhoneBook {

	private int index;
	private int numberOfEntries;
	private LinkedList<Entry> book = new LinkedList<Entry>();


	public PhoneBook(int maxSize){
	}

	final boolean addNewEntry(TelephoneNumber t, Person p, Address a){
		book.add(index, new Entry(t, p, a));
		return true;
	}

	final int getIndex(){
		return index;
	}

	final boolean removeMarkedEntry(){
		if (book.isEmpty()== true){
			return false;
		}else{
			//getMarkedEntry()
			book.remove(getMarkedEntry());

		return true;
		}
	}

	final int countEntries(){
		return book.size();
	}

	public Entry getFirstEntry(){
		if(book.size() > 0){
		return book.get(0);
		}
		return null;
		}

//	final Entry getFirstEntry(){
//		if (book.isEmpty()){
//			return null;
//		}else
//		return book.getLast();
//	}

	final Entry getLastEntry(){
		if (book.isEmpty()){
			return null;
		}else
        return book.getFirst();
	}

	final Entry getMarkedEntry(){
		if (book.isEmpty()== true){
			return null;
		}else
		return book.get(index);

	}

	final void markNextEntry(){
		index = index + 1;
	}

	final void markPreviousEntry(){
		if (book.isEmpty()== false && book.getFirst()!=book.get(index))
			book.get(index-1);
	}

	public final String toString(){
		return book.toString();
	}
}