/*
 * Copyright (c) 2005, 2006, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.
 *
 * THIS FILE WAS MODIFIED BY SUN MICROSYSTEMS, INC.
 */


package com.sun.xml.internal.fastinfoset.algorithm;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import com.sun.xml.internal.org.jvnet.fastinfoset.EncodingAlgorithmException;
import com.sun.xml.internal.fastinfoset.CommonResourceBundle;

public class HexadecimalEncodingAlgorithm extends BuiltInEncodingAlgorithm {
    private static final char NIBBLE_TO_HEXADECIMAL_TABLE[] =
        {   '0','1','2','3','4','5','6','7',
            '8','9','A','B','C','D','E','F' };

    private static final int HEXADECIMAL_TO_NIBBLE_TABLE[] = {
        /*'0'*/ 0,
        /*'1'*/ 1,
        /*'2'*/ 2,
        /*'3'*/ 3,
        /*'4'*/ 4,
        /*'5'*/ 5,
        /*'6'*/ 6,
        /*'7'*/ 7,
        /*'8'*/ 8,
        /*'9'*/ 9, -1, -1, -1, -1, -1, -1, -1,
        /*'A'*/ 10,
        /*'B'*/ 11,
        /*'C'*/ 12,
        /*'D'*/ 13,
        /*'E'*/ 14,
        /*'F'*/ 15,
        /*'G'-'Z'*/-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
        /*'[' - '`'*/ -1, -1, -1, -1, -1, -1,
        /*'a'*/ 10,
        /*'b'*/ 11,
        /*'c'*/ 12,
        /*'d'*/ 13,
        /*'e'*/ 14,
        /*'f'*/ 15 };

    public final Object decodeFromBytes(byte[] b, int start, int length) throws EncodingAlgorithmException {
        final byte[] data = new byte[length];
        System.arraycopy(b, start, data, 0, length);
        return data;
    }

    public final Object decodeFromInputStream(InputStream s) throws IOException {
        throw new UnsupportedOperationException(CommonResourceBundle.getInstance().getString("message.notImplemented"));
    }


    public void encodeToOutputStream(Object data, OutputStream s) throws IOException {
        if (!(data instanceof byte[])) {
            throw new IllegalArgumentException(CommonResourceBundle.getInstance().getString("message.dataNotByteArray"));
        }

        s.write((byte[])data);
    }

    public final Object convertFromCharacters(char[] ch, int start, int length) {
        if (length == 0) {
            return new byte[0];
        }

        StringBuffer encodedValue = removeWhitespace(ch, start, length);
        int encodedLength = encodedValue.length();
        if (encodedLength == 0) {
            return new byte[0];
        }

        int valueLength = encodedValue.length() / 2;
        byte[] value = new byte[valueLength];

        int encodedIdx = 0;
        for (int i = 0; i < valueLength; ++i) {
            int nibble1 = HEXADECIMAL_TO_NIBBLE_TABLE[encodedValue.charAt(encodedIdx++) - '0'];
            int nibble2 = HEXADECIMAL_TO_NIBBLE_TABLE[encodedValue.charAt(encodedIdx++) - '0'];
            value[i] = (byte) ((nibble1 << 4) | nibble2);
        }

        return value;
    }

    public final void convertToCharacters(Object data, StringBuffer s) {
        if (data == null) {
            return;
        }
        final byte[] value = (byte[]) data;
        if (value.length == 0) {
            return;
        }

        s.ensureCapacity(value.length * 2);
        for (int i = 0; i < value.length; ++i) {
            s.append(NIBBLE_TO_HEXADECIMAL_TABLE[(value[i] >>> 4) & 0xf]);
            s.append(NIBBLE_TO_HEXADECIMAL_TABLE[value[i] & 0xf]);
        }
    }



    public final int getPrimtiveLengthFromOctetLength(int octetLength) throws EncodingAlgorithmException {
        return octetLength * 2;
    }

    public int getOctetLengthFromPrimitiveLength(int primitiveLength) {
        return primitiveLength / 2;
    }

    public final void encodeToBytes(Object array, int astart, int alength, byte[] b, int start) {
        System.arraycopy((byte[])array, astart, b, start, alength);
    }
}
