/* NameSwapper Copyright (C) 1999-2002 Jochen Hoenicke.
 *
 * This program 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 2, or (at your option)
 * any later version.
 *
 * This program 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 this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id: NameSwapper.java.in,v 1.1.2.1 2002/05/28 17:34:17 hoenicke Exp $
 */

package alterrs.jode.obfuscator.modules;

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

import alterrs.jode.obfuscator.ClassIdentifier;
import alterrs.jode.obfuscator.FieldIdentifier;
import alterrs.jode.obfuscator.Identifier;
import alterrs.jode.obfuscator.LocalIdentifier;
import alterrs.jode.obfuscator.MethodIdentifier;
import alterrs.jode.obfuscator.PackageIdentifier;
import alterrs.jode.obfuscator.Renamer;

public class NameSwapper implements Renamer {
	private Random rand;
	private Set packs, clazzes, methods, fields, locals;

	public NameSwapper(boolean swapAll, long seed) {
		if (swapAll) {
			packs = clazzes = methods = fields = locals = new HashSet();
		} else {
			packs = new HashSet();
			clazzes = new HashSet();
			methods = new HashSet();
			fields = new HashSet();
			locals = new HashSet();
		}
	}

	public NameSwapper(boolean swapAll) {
		this(swapAll, System.currentTimeMillis());
	}

	private class NameGenerator implements Iterator {
		Collection pool;

		NameGenerator(Collection c) {
			pool = c;
		}

		public boolean hasNext() {
			return true;
		}

		public Object next() {
			int pos = rand.nextInt(pool.size());
			Iterator i = pool.iterator();
			while (pos > 0)
				i.next();
			return (String) i.next();
		}

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

	public final Collection getCollection(Identifier ident) {
		if (ident instanceof PackageIdentifier)
			return packs;
		else if (ident instanceof ClassIdentifier)
			return clazzes;
		else if (ident instanceof MethodIdentifier)
			return methods;
		else if (ident instanceof FieldIdentifier)
			return fields;
		else if (ident instanceof LocalIdentifier)
			return locals;
		else
			throw new IllegalArgumentException(ident.getClass().getName());
	}

	public final void addIdentifierName(Identifier ident) {
		getCollection(ident).add(ident.getName());
	}

	public Iterator generateNames(Identifier ident) {
		return new NameGenerator(getCollection(ident));
	}
}
