package plp.collection;

import java.util.*;

public class OrderedSet {
    private final Map table = new HashMap();
    private final AVL avl = new AVL();

    private void checkAbsent(Object o) 
	throws InvalidObjectException
    {
	if (table.containsKey(o)) {
	    throw new InvalidObjectException(o);
	}
    }
    
    public void insertAt(int rank, Object o) 
	throws InvalidObjectException, InvalidRankException
    {
	checkAbsent(o);
	table.put(o, avl.insertAt(o, rank));
    }

    private AVLPosition position(Object o) 
	throws InvalidObjectException
    {
	AVLPosition pos = (AVLPosition) table.get(o);
	if (pos == null) {
	    throw new InvalidObjectException(o);
	}
	return pos;
    }

    public void insertAfter(Object predecessor, Object o) 
	throws InvalidObjectException
    {
	checkAbsent(o);
	table.put(o, position(predecessor).insertAfter(o));
    }

    public void insertBefore(Object successor, Object o) 
	throws InvalidObjectException
    {
	checkAbsent(o);
	table.put(o, position(successor).insertBefore(o));
    }

    public void remove(Object o) 
	throws InvalidObjectException
    {
	position(o).remove();
	table.remove(o);
    }
    
    public void remove(int rank) 
	throws InvalidRankException
    {
	Object o = get(rank);
	try {
	    remove(o);
	} catch (InvalidObjectException e) {
	    throw new Error();
	}
    }

    public Object get(int rank) 
    	throws InvalidRankException
    {
	return avl.data(rank);
    }

    public int getRank(Object o) 
	throws InvalidObjectException
    {
	return position(o).rank();
    }

    public int size() {
	return table.size();
    }

    public Object [] toArray() {
	return avl.dfs();
    }

    public String toString() {
	String s = "";
	try {
	    for (int i = 0; i < size(); ++ i) {
		s += "(" + i + ":" + get(i) + ") ";
	    }
	} catch (InvalidRankException e) {
	    throw new Error();
	}
	return s;
    }
}