/*

 * Copyright (c) 2001, 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

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 */

package com.sun.jmx.snmp.internal;

import com.sun.jmx.snmp.SnmpDefinitions;

/**

 * Utility class used to deal with various data representations.

 * <p><b>This API is a Sun Microsystems internal API  and is subject

 * to change without notice.</b></p>

 * @since 1.5

 */

public class SnmpTools implements SnmpDefinitions {

    /**

     * Translates a binary representation in an ASCII one. The returned string is an hexadecimal string starting with 0x.

     * @param data Binary to translate.

     * @return Translated binary.

     */

    static public String binary2ascii(byte[] data, int length)

    {

        if(data == null) return null;

        final int size = (length * 2) + 2;

        byte[] asciiData = new byte[size];

        asciiData[0] = (byte) '0';

        asciiData[1] = (byte) 'x';

        for (int i=0; i < length; i++) {

            int j = i*2;

            int v = (data[i] & 0xf0);

            v = v >> 4;

            if (v < 10)

                asciiData[j+2] = (byte) ('0' + v);

            else

                asciiData[j+2] = (byte) ('A' + (v - 10));

            v = ((data[i] & 0xf));

            if (v < 10)

                asciiData[j+1+2] = (byte) ('0' + v);

            else

                asciiData[j+1+2] = (byte) ('A' + (v - 10));

        }

        return new String(asciiData);

    }

    /**

     * Translates a binary representation in an ASCII one. The returned string is an hexadecimal string starting with 0x.

     * @param data Binary to translate.

     * @return Translated binary.

     */

    static public String binary2ascii(byte[] data)

    {

        return binary2ascii(data, data.length);

    }

    /**

     * Translates a stringified representation in a binary one. The passed string is an hexadecimal one starting with 0x.

     * @param str String to translate.

     * @return Translated string.

     */

    static public byte[] ascii2binary(String str) {

        if(str == null) return null;

        String val = str.substring(2);

        int size = val.length();

        byte []buf = new byte[size/2];

        byte []p = val.getBytes();

        for(int i = 0; i < (size / 2); i++)

        {

            int j = i * 2;

            byte v = 0;

            if (p[j] >= '0' && p[j] <= '9') {

                v = (byte) ((p[j] - '0') << 4);

            }

            else if (p[j] >= 'a' && p[j] <= 'f') {

                v = (byte) ((p[j] - 'a' + 10) << 4);

            }

            else if (p[j] >= 'A' && p[j] <= 'F') {

                v = (byte) ((p[j] - 'A' + 10) << 4);

            }

            else

                throw new Error("BAD format :" + str);

            if (p[j+1] >= '0' && p[j+1] <= '9') {

                //System.out.println("ascii : " + p[j+1]);

                v += (p[j+1] - '0');

                //System.out.println("binary : " + v);

            }

            else if (p[j+1] >= 'a' && p[j+1] <= 'f') {

                //System.out.println("ascii : " + p[j+1]);

                v += (p[j+1] - 'a' + 10);

                //System.out.println("binary : " + v+1);

            }

            else if (p[j+1] >= 'A' && p[j+1] <= 'F') {

                //System.out.println("ascii : " + p[j+1]);

                v += (p[j+1] - 'A' + 10);

                //System.out.println("binary : " + v);

            }

            else

                throw new Error("BAD format :" + str);

            buf[i] = v;

        }

        return buf;

    }

}