/*******************************************************************************
 * This file is part of logisim-evolution.
 *
 *   logisim-evolution is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   logisim-evolution is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with logisim-evolution.  If not, see <http://www.gnu.org/licenses/>.
 *
 *   Original code by Carl Burch (http://www.cburch.com), 2011.
 *   Subsequent modifications by :
 *     + Haute École Spécialisée Bernoise
 *       http://www.bfh.ch
 *     + Haute École du paysage, d'ingénierie et d'architecture de Genève
 *       http://hepia.hesge.ch/
 *     + Haute École d'Ingénierie et de Gestion du Canton de Vaud
 *       http://www.heig-vd.ch/
 *   The project is currently maintained by :
 *     + REDS Institute - HEIG-VD
 *       Yverdon-les-Bains, Switzerland
 *       http://reds.heig-vd.ch
 *******************************************************************************/

package com.cburch.draw.util;

import java.util.AbstractSet;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import com.cburch.draw.model.CanvasObject;

public class MatchingSet<E extends CanvasObject> extends AbstractSet<E> {
	private static class MatchIterator<E extends CanvasObject> implements
			Iterator<E> {
		private Iterator<Member<E>> it;

		MatchIterator(Iterator<Member<E>> it) {
			this.it = it;
		}

		public boolean hasNext() {
			return it.hasNext();
		}

		public E next() {
			return it.next().value;
		}

		public void remove() {
			it.remove();
		}

	}

	private static class Member<E extends CanvasObject> {
		E value;

		public Member(E value) {
			this.value = value;
		}

		@Override
		public boolean equals(Object other) {
			@SuppressWarnings("unchecked")
			Member<E> that = (Member<E>) other;
			return this.value.matches(that.value);
		}

		@Override
		public int hashCode() {
			return value.matchesHashCode();
		}
	}

	private Set<Member<E>> set;

	public MatchingSet() {
		set = new HashSet<Member<E>>();
	}

	public MatchingSet(Collection<E> initialContents) {
		set = new HashSet<Member<E>>(initialContents.size());
		for (E value : initialContents) {
			set.add(new Member<E>(value));
		}
	}

	@Override
	public boolean add(E value) {
		return set.add(new Member<E>(value));
	}

	@Override
	public boolean contains(Object value) {
		@SuppressWarnings("unchecked")
		E eValue = (E) value;
		return set.contains(new Member<E>(eValue));
	}

	@Override
	public Iterator<E> iterator() {
		return new MatchIterator<E>(set.iterator());
	}

	@Override
	public boolean remove(Object value) {
		@SuppressWarnings("unchecked")
		E eValue = (E) value;
		return set.remove(new Member<E>(eValue));
	}

	@Override
	public int size() {
		return set.size();
	}

}