package com.xmr.util;

/**
 *
 * @author Adil
 * Credit to Jordan
 */
public class WiredEncoding {
    public static byte NEGATIVE = 72;
    public static byte POSITIVE = 73;
    public static int MAX_INTEGER_BYTE_AMOUNT = 6;

    public static byte[] EncodeInt32(int i)
    {
        byte[] wf = new byte[WiredEncoding.MAX_INTEGER_BYTE_AMOUNT];

        int pos = 0;
        int numBytes = 1;
        int startPos = pos;
        int negativeMask = i >= 0 ? 0 : 4;

        i = Math.abs(i);

        wf[pos++] = (byte)(64 + (i & 3));

        for (i >>= 2; i != 0; i >>= WiredEncoding.MAX_INTEGER_BYTE_AMOUNT)
        {
            numBytes++;
            wf[pos++] = (byte)(64 + (i & 0x3f));
        }
        wf[startPos] = (byte)(wf[startPos] | numBytes << 3 | negativeMask);

        byte[] bzData = new byte[numBytes];

        for (int x = 0; x < numBytes; x++)
        {
            bzData[x] = wf[x];
        }

        return bzData;
    }

    public static int DecodeInt32(byte[] bzData, int totalBytes)
    {
        int pos = 0;
        int v = 0;

        boolean negative = (bzData[pos] & 4) == 4;

        totalBytes = bzData[pos] >> 3 & 7;
        v = bzData[pos] & 3;

        pos++;

        int shiftAmount = 2;

        for (int b = 1; b < totalBytes; b++)
        {
            v |= (bzData[pos] & 0x3f) << shiftAmount;
            shiftAmount = 2 + 6 * b;
            pos++;
        }

        if (negative == true)
        {
            v *= -1;
        }

        return v;
    }
}