/*

 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.util.Random;

/** Abstract supertype for tests that need random numbers within a given range. */

public class AbstractRandomTest {

    private static Long getSystemSeed() {

        Long seed = null;

        try {

            // note that Long.valueOf(null) also throws a NumberFormatException

            // so if the property is undefined this will still work correctly

            seed = Long.valueOf(System.getProperty("seed"));

        } catch (NumberFormatException e) {

            // do nothing: seed is still null

        }

        return seed;

    }

    private static long getSeed() {

        Long seed = getSystemSeed();

        if (seed == null) {

            seed = (new Random()).nextLong();

        }

        System.out.println("Seed from AbstractRandomTest.getSeed = "+seed+"L");

        return seed;

    }

    private static Random random = new Random(getSeed());

    protected static int randomRange(int lower, int upper) {

        if (lower > upper)

            throw new IllegalArgumentException("lower > upper");

        int diff = upper - lower;

        int r = lower + random.nextInt(diff);

        return r - (r % 8); // round down to multiple of 8 (align for longs)

    }

}