/*

 * Copyright (c) 2002, 2014, 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

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 * questions.

 */

/*

 * @test

 * @bug 4726380 8037097

 * @summary Check that different sorts give equivalent results.

 * @run testng Correct

 * @key randomness

 */

import java.util.*;

import org.testng.annotations.Test;

import org.testng.annotations.DataProvider;

import static org.testng.Assert.fail;

import static org.testng.Assert.assertEquals;

public class Correct {

    static final Random rnd = new Random();

    static final int ITERATIONS = 1000;

    static final int TEST_SIZE = 1000;

    @Test

    public void testDefaultSort() {

        for (int i=0; i<ITERATIONS; i++) {

            int size = rnd.nextInt(TEST_SIZE) + 1;

            Integer[] array1 = getIntegerArray(size);

            Integer[] array2 = Arrays.copyOf(array1, array1.length);

            Arrays.sort(array1, array1.length/3, array1.length/2);

            stupidSort(array2, array2.length/3, array2.length/2);

            assertEquals(array1, array2, "Arrays did not match. size=" + size);

        }

    }

    @Test(dataProvider = "Comparators")

    public void testComparatorSort(Comparator<Integer> comparator) {

        for (int i=0; i<ITERATIONS; i++) {

            int size = rnd.nextInt(TEST_SIZE) + 1;

            Integer[] array1 = getIntegerArray(size);

            Integer[] array2 = Arrays.copyOf(array1, array1.length);

            Arrays.sort(array1, array1.length/3, array1.length/2, comparator);

            stupidSort(array2, array2.length/3, array2.length/2, comparator);

            assertEquals(array1, array2, "Arrays did not match. size=" + size);

        }

    }

    static Integer[] getIntegerArray(int size) {

        Integer[] blah = new Integer[size];

        for (int x=0; x<size; x++) {

            blah[x] = new Integer(rnd.nextInt());

        }

        return blah;

    }

    static void stupidSort(Integer[] a1, int from, int to) {

        if (from > to - 1 )

          return;

        for (int x=from; x<to; x++) {

            Integer lowest = a1[x];

            int lowestIndex = x;

            for (int y=x + 1; y<to; y++) {

                if (((Comparable)a1[y]).compareTo((Comparable)lowest) < 0) {

                    lowest = a1[y];

                    lowestIndex = y;

                }

            }

            if (lowestIndex != x) {

                swap(a1, x, lowestIndex);

            }

        }

    }

    static void stupidSort(Integer[] a1, int from, int to, Comparator<Integer> comparator) {

        if (from > to - 1 )

          return;

        for (int x=from; x<to; x++) {

            Integer lowest = a1[x];

            int lowestIndex = x;

            for (int y=x + 1; y<to; y++) {

                if (comparator.compare(a1[y], lowest) < 0) {

                    lowest = a1[y];

                    lowestIndex = y;

                }

            }

            if (lowestIndex != x) {

                swap(a1, x, lowestIndex);

            }

        }

    }

    static <T> void swap(T[] x, int a, int b) {

        T t = x[a];

        x[a] = x[b];

        x[b] = t;

    }

    @DataProvider(name = "Comparators", parallel = true)

    public static Iterator<Object[]> comparators() {

        Object[][] comparators = new Object[][] {

            new Object[] { Comparator.naturalOrder() },

            new Object[] { Comparator.<Integer>naturalOrder().reversed() },

            new Object[] { STANDARD_ORDER },

            new Object[] { STANDARD_ORDER.reversed() },

            new Object[] { REVERSE_ORDER },

            new Object[] { REVERSE_ORDER.reversed() },

            new Object[] { Comparator.comparingInt(Integer::intValue) }

        };

        return Arrays.asList(comparators).iterator();

    }

    private static final Comparator<Integer> STANDARD_ORDER = new Comparator<Integer>() {

        public int compare(Integer o1, Integer o2) {

            return  o1.compareTo(o2);

        }

    };

    private static final Comparator<Integer> REVERSE_ORDER = new Comparator<Integer>() {

        public int compare(Integer o1, Integer o2) {

            return - o1.compareTo(o2);

        }

    };

}