/*
 * Copyright (C) 2013 University of Dundee & Open Microscopy Environment.
 * All rights reserved.
 *
 * 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 of the License, 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; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

package ome.services.blitz.test.utests;

import ome.services.blitz.util.ChecksumAlgorithmMapper;
import ome.util.checksum.ChecksumProvider;
import ome.util.checksum.ChecksumProviderFactory;
import ome.util.checksum.ChecksumProviderFactoryImpl;
import ome.util.checksum.ChecksumType;
import omero.model.ChecksumAlgorithm;

import org.testng.Assert;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

/**
 * Test that the text of the {@link ChecksumAlgorithm} enumeration values correctly
 * indicates the bit width of hash codes from the corresponding checksum algorithm.
 * @author m.t.b.carroll@dundee.ac.uk
 * @since 5.0
 */
public class ChecksumBitwidthTest {
    private ChecksumProviderFactory checksumProviderFactory;

    @BeforeMethod
    public void setupChecksumProviderFactory() {
        checksumProviderFactory = new ChecksumProviderFactoryImpl();
    }

    /**
     * Test that the bit width suffixing the checksum algorithm name matches
     * the size of the checksums actually generated by the corresponding algorithm.
     */
    @Test
    public void testBitWidthsSame() {
        for (final ChecksumAlgorithm algorithm : ChecksumAlgorithmMapper.getAllChecksumAlgorithms()) {
            final String algorithmName = algorithm.getValue().getValue();
            final int expectedBitWidth = Integer.parseInt(algorithmName.substring(algorithmName.lastIndexOf('-') + 1));

            final ChecksumType checksumType = ChecksumAlgorithmMapper.getChecksumType(algorithm);
            final ChecksumProvider checksumProvider = checksumProviderFactory.getProvider(checksumType);
            final int actualBitWidth = checksumProvider.checksumAsBytes().length << 3;

            Assert.assertEquals(actualBitWidth, expectedBitWidth, 
                    "bit width of checksum should match that suggested by checksum name " + algorithmName);
        }
    }

    @AfterMethod
    public void teardownChecksumProviderFactory() {
        checksumProviderFactory = null;
    }
}