/*
 * *************************************************************************************
 *  Copyright (C) 2008 EsperTech, Inc. All rights reserved.                            *
 *  http://esper.codehaus.org                                                          *
 *  http://www.espertech.com                                                           *
 *  ---------------------------------------------------------------------------------- *
 *  The software in this package is published under the terms of the GPL license       *
 *  a copy of which has been included with this distribution in the license.txt file.  *
 * *************************************************************************************
 */

package com.espertech.esper.collection;

import junit.framework.TestCase;
import java.util.Arrays;
import java.util.NoSuchElementException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class TestNumberSetPermutationEnumeration extends TestCase
{
    public void testInvalid()
    {
        try
        {
            new PermutationEnumeration(0);
            fail();
        }
        catch (IllegalArgumentException ex)
        {
            // expected
        }        
    }

    public void testNext()
    {
        final int[] numberSet = new int[] {10, 11, 12};
        final int[][] expectedValues = new int[][] {
            { 10, 11, 12 },
            { 10, 12, 11 },
            { 11, 10, 12 },
            { 11, 12, 10 },
            { 12, 10, 11 },
            { 12, 11, 10 }};
        tryPermutation(numberSet, expectedValues);
    }

    private void tryPermutation(int[] numberSet, int[][] expectedValues)
    {
        NumberSetPermutationEnumeration enumeration = new NumberSetPermutationEnumeration(numberSet);

        int count = 0;
        while(enumeration.hasMoreElements())
        {
            int[] result = enumeration.nextElement();
            int[] expected = expectedValues[count];

            log.debug(".tryPermutation result=" + Arrays.toString(result));
            log.debug(".tryPermutation expected=" + Arrays.toString(expected));

            count++;
            assertTrue("Mismatch in count=" + count, Arrays.equals(result, expected));
        }
        assertEquals(count, expectedValues.length);

        try
        {
            enumeration.nextElement();
            fail();
        }
        catch (NoSuchElementException ex)
        {
            // Expected
        }
    }

    private static Log log = LogFactory.getLog(TestNumberSetPermutationEnumeration.class);
}