/*
 * Copyright (C) 2008-2015 by Holger Arndt
 *
 * This file is part of the Universal Java Matrix Package (UJMP).
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership and licensing.
 *
 * UJMP is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * UJMP 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with UJMP; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

package org.ujmp.core.objectmatrix.calculation;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.ujmp.core.Matrix;

public class Shuffle extends AbstractObjectCalculation {
	private static final long serialVersionUID = -6935375114060680121L;

	private Matrix selection = null;

	public Shuffle(Matrix m) {
		super(m);
	}

	public Object getObject(long... coordinates) {
		if (selection == null) {
			List rows = new ArrayList();
			for (int i = 0; i < getSource().getRowCount(); i++) {
				rows.add(i);
			}
			Collections.shuffle(rows);
			selection = getSource().selectRows(Ret.LINK, rows);
		}
		return selection.getAsObject(coordinates);
	}

}