/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.harmony.tests.java.util.zip;

import java.nio.ByteBuffer;
import java.util.zip.CRC32;

public class CRC32Test extends junit.framework.TestCase {

    /**
     * java.util.zip.CRC32#CRC32()
     */
    public void test_Constructor() {
        // test methods of java.util.zip.CRC32()
        CRC32 crc = new CRC32();
        assertEquals("Constructor of CRC32 failed", 0, crc.getValue());
    }

    /**
     * java.util.zip.CRC32#getValue()
     */
    public void test_getValue() {
        // test methods of java.util.zip.crc32.getValue()
        CRC32 crc = new CRC32();
        assertEquals("getValue() should return a zero as a result of constructing a CRC32 instance",
                0, crc.getValue());

        crc.reset();
        crc.update(Integer.MAX_VALUE);
        // System.out.print("value of crc " + crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 4278190080
        assertEquals("update(max) failed to update the checksum to the correct value ",
                4278190080L, crc.getValue());

        crc.reset();
        byte byteEmpty[] = new byte[10000];
        crc.update(byteEmpty);
        // System.out.print("value of crc"+crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 1295764014
        assertEquals("update(byte[]) failed to update the checksum to the correct value ",
                1295764014L, crc.getValue());

        crc.reset();
        crc.update(1);
        // System.out.print("value of crc"+crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 2768625435
        // assertEquals("update(int) failed to update the checksum to the correct
        // value ",2768625435L, crc.getValue());
        crc.reset();
        assertEquals("reset failed to reset the checksum value to zero", 0, crc
                .getValue());
    }

    /**
     * java.util.zip.CRC32#reset()
     */
    public void test_reset() {
        // test methods of java.util.zip.crc32.reset()
        CRC32 crc = new CRC32();
        crc.update(1);
        // System.out.print("value of crc"+crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 2768625435
        assertEquals("update(int) failed to update the checksum to the correct value ",
                2768625435L, crc.getValue());
        crc.reset();
        assertEquals("reset failed to reset the checksum value to zero", 0, crc
                .getValue());

    }

    /**
     * java.util.zip.CRC32#update(int)
     */
    public void test_updateI() {
        // test methods of java.util.zip.crc32.update(int)
        CRC32 crc = new CRC32();
        crc.update(1);
        // System.out.print("value of crc"+crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 2768625435
        assertEquals("update(1) failed to update the checksum to the correct value ",
                2768625435L, crc.getValue());

        crc.reset();
        crc.update(Integer.MAX_VALUE);
        // System.out.print("value of crc " + crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 4278190080
        assertEquals("update(max) failed to update the checksum to the correct value ",
                4278190080L, crc.getValue());

        crc.reset();
        crc.update(Integer.MIN_VALUE);
        // System.out.print("value of crc " + crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 3523407757
        assertEquals("update(min) failed to update the checksum to the correct value ",
                3523407757L, crc.getValue());
    }

    /**
     * java.util.zip.CRC32#update(byte[])
     */
    public void test_update$B() {
        // test methods of java.util.zip.crc32.update(byte[])
        byte byteArray[] = { 1, 2 };
        CRC32 crc = new CRC32();
        crc.update(byteArray);
        // System.out.print("value of crc"+crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 3066839698
        assertEquals("update(byte[]) failed to update the checksum to the correct value ",
                3066839698L, crc.getValue());

        crc.reset();
        byte byteEmpty[] = new byte[10000];
        crc.update(byteEmpty);
        // System.out.print("value of crc"+crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 1295764014
        assertEquals("update(byte[]) failed to update the checksum to the correct value ",
                1295764014L, crc.getValue());
    }

    /**
     * java.util.zip.CRC32#update(byte[], int, int)
     */
    public void test_update$BII() {
        // test methods of java.util.zip.update(byte[],int,int)
        byte[] byteArray = { 1, 2, 3 };
        CRC32 crc = new CRC32();
        int off = 2;// accessing the 2nd element of byteArray
        int len = 1;
        int lenError = 3;
        int offError = 4;
        crc.update(byteArray, off, len);
        // System.out.print("value of crc"+crc.getValue());
        // Ran JDK and discovered that the value of the CRC should be
        // 1259060791
        assertEquals("update(byte[],int,int) failed to update the checksum to the correct value ",
                1259060791L, crc.getValue());
        int r = 0;
        try {
            crc.update(byteArray, off, lenError);
        } catch (ArrayIndexOutOfBoundsException e) {
            r = 1;
        }
        assertEquals("update(byte[],int,int) failed b/c lenError>byte[].length-off",
                1, r);

        try {
            crc.update(byteArray, offError, len);
        } catch (ArrayIndexOutOfBoundsException e) {
            r = 2;
        }
        assertEquals("update(byte[],int,int) failed b/c offError>byte[].length",
                2, r);
    }


    private void assertChecksumFromByteBuffer(long expectedChecksum, ByteBuffer byteBuffer) {
        CRC32 checksum = new CRC32();
        checksum.update(byteBuffer);
        assertEquals("update(ByteBuffer) failed to update the checksum to the correct value ",
                     expectedChecksum, checksum.getValue());
        assertEquals(0, byteBuffer.remaining());
    }

    /**
     * java.util.zip.CRC32#update(ByteBuffer)
     */
    public void test_update$ByteBuffer() {
        // test methods of java.util.zip.update(ByteBuffer)
        // Heap ByteBuffer
        ByteBuffer byteBuffer = ByteBuffer.wrap(new byte[] {1,2,3,4});
        byteBuffer.position(2);
        assertChecksumFromByteBuffer(0x6d998525, byteBuffer);

        // Direct ByteBuffer
        byteBuffer.flip();
        byteBuffer = ByteBuffer.allocateDirect(4).put(byteBuffer);
        byteBuffer.flip();
        byteBuffer.position(2);
        assertChecksumFromByteBuffer(0x6d998525, byteBuffer);

        CRC32 checksum = new CRC32();
        try {
            checksum.update((ByteBuffer)null);
            fail();
        } catch (NullPointerException expected) {}
    }

    @Override
    protected void setUp() {

    }

    @Override
    protected void tearDown() {
    }

}
