package com.farriver.bwf.common.utilities;

import java.net.InetAddress;
import java.util.UUID;

public class UUIDUtil {
    private static final String sep = "-";

    public static String generate() {
        return format(System.currentTimeMillis())
                + "-"
                + format(System.currentTimeMillis() >> 4)
                + "-"
                + format(getIP())
                + "-"
                + formatInt(getCount());
    }

    public static void main(String[] args) {
        UUID.randomUUID().toString();

        System.out.println(generate());
    }

    protected static String format(int value) {
        int index = value % chars.length;
        value = value / chars.length;

        if (value > 0)
            return format(value) + chars[index];
        else
            return "" + chars[index];
    }

    protected static String formatInt(int value) {
        String re = format(value);
        re = "000000" + re;

        return re.substring(re.length() - 7);
    }

    static char[] chars = {
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
            'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
    };

    public static String format(Long value) {
        Long index = value % chars.length;
        value = value / chars.length;

        if (value > 0)
            return format(value) + chars[index.intValue()];
        else
            return "" + chars[index.intValue()];
    }

    public static int toInt(byte[] bytes) {
        int result = 0;

        for (int i = 0; i < 4; i++) {
            result = (result << 8) - Byte.MIN_VALUE + (int) bytes[i];
        }
        return result;
    }

    private static final int IP;

    static {
        int ipadd;
        try {
            ipadd = toInt(InetAddress.getLocalHost().getAddress());
        } catch (Exception e) {
            ipadd = 0;
        }
        IP = ipadd;
    }

    private static Integer counter = (Integer) 0;
    private static final int JVM = (int) (System.currentTimeMillis() >>> 8);

    protected static Integer getCount() {
        synchronized (UUIDUtil.class) {
            return counter = counter < 0 ? 0 : ++counter;
        }
    }

    protected static int getIP() {
        return IP;
    }
}