/*
 * 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.axis2.databinding.types ;


import java.io.ByteArrayOutputStream;
import java.io.Serializable;

/** Custom class for supporting primitive XSD data type hexBinary. */
public class HexBinary implements Serializable {

    private static final long serialVersionUID = -5082403899986720767L;

    byte[] m_value;

    public HexBinary() {
    }

    public HexBinary(String string) {
        m_value = decode(string);
    }

    public HexBinary(byte[] bytes) {
        m_value = bytes;
    }

    public byte[] getBytes() {
        return m_value;
    }

    public String toString() {
        return encode(m_value);
    }

    public int hashCode() {
        //TODO: How do we hash this?
        return super.hashCode();
    }

    public boolean equals(Object object) {
        //TODO: Is this good enough?
        String s1 = object.toString();
        String s2 = this.toString();
        return s1.equals(s2);
    }

    // public static final String ERROR_ODD_NUMBER_OF_DIGITS =
    //Messages.getMessage("oddDigits00");
    //public static final String ERROR_BAD_CHARACTER_IN_HEX_STRING =
    //        Messages.getMessage("badChars01");

    // Code from Ajp11, from Apache's JServ

    // Table for HEX to DEC byte translation
    public static final int[] DEC = {
            -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, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            00, 01, 02, 03, 04, 05, 06, 07, 8, 9, -1, -1, -1, -1, -1, -1,
            -1, 10, 11, 12, 13, 14, 15, -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, 10, 11, 12, 13, 14, 15, -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, -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, -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, -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, -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, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    };

    /**
     * Convert a String of hexadecimal digits into the corresponding byte array by encoding each two
     * hexadecimal digits as a byte.
     *
     * @param digits Hexadecimal digits representation
     * @throws IllegalArgumentException if an invalid hexadecimal digit is found, or the input
     *                                  string contains an odd number of hexadecimal digits
     */
    public static byte[] decode(String digits) {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        for (int i = 0; i < digits.length(); i += 2) {
            char c1 = digits.charAt(i);
            if ((i + 1) >= digits.length())
                throw new IllegalArgumentException
                        ();//ERROR_ODD_NUMBER_OF_DIGITS);
            char c2 = digits.charAt(i + 1);
            byte b = 0;
            if ((c1 >= '0') && (c1 <= '9'))
                b += ((c1 - '0') * 16);
            else if ((c1 >= 'a') && (c1 <= 'f'))
                b += ((c1 - 'a' + 10) * 16);
            else if ((c1 >= 'A') && (c1 <= 'F'))
                b += ((c1 - 'A' + 10) * 16);
            else
                throw new IllegalArgumentException
                        ();//ERROR_BAD_CHARACTER_IN_HEX_STRING);
            if ((c2 >= '0') && (c2 <= '9'))
                b += (c2 - '0');
            else if ((c2 >= 'a') && (c2 <= 'f'))
                b += (c2 - 'a' + 10);
            else if ((c2 >= 'A') && (c2 <= 'F'))
                b += (c2 - 'A' + 10);
            else
                throw new IllegalArgumentException
                        ();//ERROR_BAD_CHARACTER_IN_HEX_STRING);
            baos.write(b);
        }
        return (baos.toByteArray());

    }


    /**
     * Convert a byte array into a printable format containing a String of hexadecimal digit
     * characters (two per byte).
     *
     * @param bytes Byte array representation
     */
    public static String encode(byte bytes[]) {

        StringBuffer sb = new StringBuffer(bytes.length * 2);
        for (int i = 0; i < bytes.length; i++) {
            sb.append(convertDigit(bytes[i] >> 4));
            sb.append(convertDigit(bytes[i] & 0x0f));
        }
        return (sb.toString());

    }

    /**
     * Convert 4 hex digits to an int, and return the number of converted bytes.
     *
     * @param hex Byte array containing exactly four hexadecimal digits
     * @throws IllegalArgumentException if an invalid hexadecimal digit is included
     */
    public static int convert2Int(byte[] hex) {
        // Code from Ajp11, from Apache's JServ

        // assert b.length==4
        // assert valid data
        int len;
        if (hex.length < 4) return 0;
        if (DEC[hex[0]] < 0)
            throw new IllegalArgumentException();//ERROR_BAD_CHARACTER_IN_HEX_STRING);
        len = DEC[hex[0]];
        len = len << 4;
        if (DEC[hex[1]] < 0)
            throw new IllegalArgumentException();//ERROR_BAD_CHARACTER_IN_HEX_STRING);
        len += DEC[hex[1]];
        len = len << 4;
        if (DEC[hex[2]] < 0)
            throw new IllegalArgumentException();//ERROR_BAD_CHARACTER_IN_HEX_STRING);
        len += DEC[hex[2]];
        len = len << 4;
        if (DEC[hex[3]] < 0)
            throw new IllegalArgumentException();//ERROR_BAD_CHARACTER_IN_HEX_STRING);
        len += DEC[hex[3]];
        return len;
    }

    /**
     * [Private] Convert the specified value (0 .. 15) to the corresponding hexadecimal digit.
     *
     * @param value Value to be converted
     */
    private static char convertDigit(int value) {

        value &= 0x0f;
        if (value >= 10)
            return ((char)(value - 10 + 'a'));
        else
            return ((char)(value + '0'));

    }
}