/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed 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 com.hoho.android.usbserial.util;

/**
 * Clone of Android's HexDump class, for use in debugging. Cosmetic changes
 * only.
 */
public class HexDump {
    private final static char[] HEX_DIGITS = {
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
    };

    public static String dumpHexString(byte[] array) {
        return dumpHexString(array, 0, array.length);
    }

    public static String dumpHexString(byte[] array, int offset, int length) {
        StringBuilder result = new StringBuilder();

        byte[] line = new byte[16];
        int lineIndex = 0;

        result.append("\n0x");
        result.append(toHexString(offset));

        for (int i = offset; i < offset + length; i++) {
            if (lineIndex == 16) {
                result.append(" ");

                for (int j = 0; j < 16; j++) {
                    if (line[j] > ' ' && line[j] < '~') {
                        result.append(new String(line, j, 1));
                    } else {
                        result.append(".");
                    }
                }

                result.append("\n0x");
                result.append(toHexString(i));
                lineIndex = 0;
            }

            byte b = array[i];
            result.append(" ");
            result.append(HEX_DIGITS[(b >>> 4) & 0x0F]);
            result.append(HEX_DIGITS[b & 0x0F]);

            line[lineIndex++] = b;
        }

        if (lineIndex != 16) {
            int count = (16 - lineIndex) * 3;
            count++;
            for (int i = 0; i < count; i++) {
                result.append(" ");
            }

            for (int i = 0; i < lineIndex; i++) {
                if (line[i] > ' ' && line[i] < '~') {
                    result.append(new String(line, i, 1));
                } else {
                    result.append(".");
                }
            }
        }

        return result.toString();
    }

    public static String toHexString(byte b) {
        return toHexString(toByteArray(b));
    }

    public static String toHexString(byte[] array) {
        return toHexString(array, 0, array.length);
    }

    public static String toHexString(byte[] array, int offset, int length) {
        char[] buf = new char[length * 2];

        int bufIndex = 0;
        for (int i = offset; i < offset + length; i++) {
            byte b = array[i];
            buf[bufIndex++] = HEX_DIGITS[(b >>> 4) & 0x0F];
            buf[bufIndex++] = HEX_DIGITS[b & 0x0F];
        }

        return new String(buf);
    }

    public static String toHexString(int i) {
        return toHexString(toByteArray(i));
    }

    public static byte[] toByteArray(byte b) {
        byte[] array = new byte[1];
        array[0] = b;
        return array;
    }

    public static byte[] toByteArray(int i) {
        byte[] array = new byte[4];

        array[3] = (byte) (i & 0xFF);
        array[2] = (byte) ((i >> 8) & 0xFF);
        array[1] = (byte) ((i >> 16) & 0xFF);
        array[0] = (byte) ((i >> 24) & 0xFF);

        return array;
    }

    private static int toByte(char c) {
        if (c >= '0' && c <= '9')
            return (c - '0');
        if (c >= 'A' && c <= 'F')
            return (c - 'A' + 10);
        if (c >= 'a' && c <= 'f')
            return (c - 'a' + 10);

        throw new RuntimeException("Invalid hex char '" + c + "'");
    }

    public static byte[] hexStringToByteArray(String hexString) {
        int length = hexString.length();
        byte[] buffer = new byte[length / 2];

        for (int i = 0; i < length; i += 2) {
            buffer[i / 2] = (byte) ((toByte(hexString.charAt(i)) << 4) | toByte(hexString
                    .charAt(i + 1)));
        }

        return buffer;
    }
}
