package safeluck.drive.evaluation.platformMessage.utils;


import com.safeluck.aykj.utils.ArrayUtils;

/**
 * Created by zw on 2017/7/8.
 * 蓝牙协议转义
 */

public class MessageEscaper {

    public  byte[] escape(byte[] source_bytes)
    {
        byte[] return_bytes = new byte[source_bytes.length*2];

        int size = source_bytes.length;
        int pos = 0;
        for (int i = 0; i < size; i++)
        {
            if (i == 0||i==size-1)
            {
                return_bytes[pos++] = source_bytes[i];
                continue;
            }
            if (source_bytes[i] == 0x7d)
            {
                return_bytes[pos++] = 0x7d;
                return_bytes[pos++] = 0x01;
            }
            else if (source_bytes[i] == 0x7e)
            {
                return_bytes[pos++] = 0x7d;
                return_bytes[pos++] = 0x02;
            }
            else
            {
                return_bytes[pos++] = source_bytes[i];
            }
        }

        return ArrayUtils.subArray(return_bytes,0,pos);


    }

    public  byte[] unescape(byte[] cmd_bytes)
    {
        //转义还原
        int len = cmd_bytes.length;
        byte[] return_bytes = new byte[cmd_bytes.length];

        //int len = ByteHelper.HexString2Byte(cmd, cmd_bytes);
        int pos = 0;
        for (int i = 0; i < len; i++)
        {
            if (i == len - 1)
            {
                return_bytes[pos++] = cmd_bytes[i];
                continue;
            }

            if (cmd_bytes[i] == 0x7d && cmd_bytes[i + 1] == 0x02)
            {
                return_bytes[pos++] = 0x7e;
                i++;
                continue;
            }
            else if (cmd_bytes[i] == 0x7d && cmd_bytes[i + 1] == 0x01)
            {
                return_bytes[pos++] = 0x7d;
                i++;
                continue;
            }
            else
            {
                return_bytes[pos++] = cmd_bytes[i];
            }
        }
        return ArrayUtils.subArray(return_bytes,0,pos);


    }

}