//*************************************************************************
// OutPacket.cpp: implementation of the COutPacket class.
// Version : 1.000
// Date : July 2007
// Author : Ye Feng
// Email :  vcye23@gmail.com
//
//    This program is free software; you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation; either version 2 of the License, or
//    (at your option) any later version.
//
//    This program 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 for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with this program; if not, write to the Free Software
//    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
//
/////////////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "OutPacket.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

/**
 * 创建一个基本输出包
 * 
 * @param command
 *         包命令
 * @param ack
 *         包是否需要回复
 * @param user
 *         QQ用户对象
 */
COutPacket::COutPacket(BYTE bHeader, short sCommand, bool bAck, CQQUser *pQQUser) :
    m_bHeader(bHeader),
    m_sSource(QQ.QQ_CLIENT_VERSION),
    m_sSequence(pQQUser->GetNextSequence()),
    m_sCommand(sCommand),
    m_bAck(bAck),
    m_pQQUser(pQQUser)
{

}

/**
 * 从buf中构造一个OutPacket，用于调试。这个buf里面可能包含了抓包软件抓来的数据
 * 
 * @param buf
 *             ByteBuffer
 * @throws PacketParseException
 *             解析出错
 */
COutPacket::COutPacket(BYTE *pbBuf, size_t iBufLen) :
    m_pQQUser(NULL)
{

}

COutPacket::~COutPacket()
{

}

/**
 * 将整个包转化为字节流, 并写入指定的ByteBuffer对象.
 * 一般而言, 前后分别需要写入包头部和包尾部.
 * 
 * @param buf
 *         将包写入的ByteBuffer对象.
 */
size_t COutPacket::FillBuffer(BYTE* pbBuf, size_t iBufLen) const
{
    // 保存当前pos
    BYTE* pbBufStart = pbBuf;
    size_t iHeaderLen;
    size_t iTailLen;

    // 填充头部
    iHeaderLen = PutHeader(pbBuf, iBufLen);
    pbBuf += iHeaderLen;
    iBufLen -= iHeaderLen;

    BYTE pbBody[MAX_SEND_PACKET_SIZE];
    size_t iBodyLen;
    BYTE pbEncryptedBody[MAX_SEND_PACKET_SIZE];
    size_t iEncryptedBodyLen;

    // 填充包体
    iBodyLen = PutBody(pbBody, sizeof(pbBody));
    // 加密包体
    iEncryptedBodyLen = EncryptBody(pbBody, iBodyLen, pbEncryptedBody, sizeof(pbEncryptedBody));
    if( iEncryptedBodyLen == -1 )
        return -1;
    // 加密内容写入最终buf
    memcpy(pbBuf, pbEncryptedBody, iEncryptedBodyLen);
    pbBuf += iEncryptedBodyLen;
    iBufLen -= iEncryptedBodyLen;

    // 填充尾部
    iTailLen = PutTail(pbBuf, iBufLen);
    pbBuf += iTailLen;
    iBufLen -= iTailLen;

    // 回填
    PostFill(pbBufStart, iHeaderLen + iEncryptedBodyLen + iTailLen);
    return iHeaderLen + iEncryptedBodyLen + iTailLen;

}