/*
* LumaQQ - Java QQ Client
*
* Copyright (C) 2004 luma <stubma@163.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.tsinghua.lumaqq.qq.packets;

import java.nio.ByteBuffer;

import edu.tsinghua.lumaqq.qq.QQ;
import edu.tsinghua.lumaqq.qq.beans.QQUser;
import edu.tsinghua.lumaqq.qq.packets.in.AddFriendAuthResponseReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.AddFriendExReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.AdvancedSearchUserReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.AuthorizeReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.ChangeStatusReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.ClusterCommandReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.DeleteFriendReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.DownloadGroupFriendReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.FriendChangeStatusPacket;
import edu.tsinghua.lumaqq.qq.packets.in.FriendDataOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.FriendLevelOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.GetFriendListReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.GetOnlineOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.GetTempClusterOnlineMemberReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.GetUserInfoReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.GroupDataOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.KeepAliveReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.LoginReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.ModifyInfoReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.PrivacyDataOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.ReceiveIMPacket;
import edu.tsinghua.lumaqq.qq.packets.in.RemoveSelfReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.RequestKeyReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.RequestLoginTokenReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.SearchUserReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.SendIMReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.SendSMSReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.SignatureOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.SystemNotificationPacket;
import edu.tsinghua.lumaqq.qq.packets.in.TempSessionOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.UnknownInPacket;
import edu.tsinghua.lumaqq.qq.packets.in.UploadGroupFriendReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.UserPropertyOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.in.WeatherOpReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.out.AddFriendAuthResponsePacket;
import edu.tsinghua.lumaqq.qq.packets.out.AddFriendExPacket;
import edu.tsinghua.lumaqq.qq.packets.out.AdvancedSearchUserPacket;
import edu.tsinghua.lumaqq.qq.packets.out.AuthorizePacket;
import edu.tsinghua.lumaqq.qq.packets.out.ChangeStatusPacket;
import edu.tsinghua.lumaqq.qq.packets.out.ClusterCommandPacket;
import edu.tsinghua.lumaqq.qq.packets.out.DeleteFriendPacket;
import edu.tsinghua.lumaqq.qq.packets.out.DownloadGroupFriendPacket;
import edu.tsinghua.lumaqq.qq.packets.out.FriendDataOpPacket;
import edu.tsinghua.lumaqq.qq.packets.out.FriendLevelOpPacket;
import edu.tsinghua.lumaqq.qq.packets.out.GetFriendListPacket;
import edu.tsinghua.lumaqq.qq.packets.out.GetOnlineOpPacket;
import edu.tsinghua.lumaqq.qq.packets.out.GetUserInfoPacket;
import edu.tsinghua.lumaqq.qq.packets.out.GroupDataOpPacket;
import edu.tsinghua.lumaqq.qq.packets.out.KeepAlivePacket;
import edu.tsinghua.lumaqq.qq.packets.out.LoginPacket;
import edu.tsinghua.lumaqq.qq.packets.out.LogoutPacket;
import edu.tsinghua.lumaqq.qq.packets.out.ModifyInfoPacket;
import edu.tsinghua.lumaqq.qq.packets.out.PrivacyDataOpPacket;
import edu.tsinghua.lumaqq.qq.packets.out.ReceiveIMReplyPacket;
import edu.tsinghua.lumaqq.qq.packets.out.RemoveSelfPacket;
import edu.tsinghua.lumaqq.qq.packets.out.RequestKeyPacket;
import edu.tsinghua.lumaqq.qq.packets.out.RequestLoginTokenPacket;
import edu.tsinghua.lumaqq.qq.packets.out.SearchUserPacket;
import edu.tsinghua.lumaqq.qq.packets.out.SendIMPacket;
import edu.tsinghua.lumaqq.qq.packets.out.SendSMSPacket;
import edu.tsinghua.lumaqq.qq.packets.out.SignatureOpPacket;
import edu.tsinghua.lumaqq.qq.packets.out.TempSessionOpPacket;
import edu.tsinghua.lumaqq.qq.packets.out.UnknownOutPacket;
import edu.tsinghua.lumaqq.qq.packets.out.UploadGroupFriendPacket;
import edu.tsinghua.lumaqq.qq.packets.out.UserPropertyOpPacket;
import edu.tsinghua.lumaqq.qq.packets.out.WeatherOpPacket;

/**
 * 基本協議族解析器
 * 
 * @author luma
 */
public class BasicFamilyParser implements IParser {    
	private int offset;
	private int length;
	
	private PacketHistory history;

	public BasicFamilyParser() {
		history = new PacketHistory();
	}
    
	/* (non-Javadoc)
	 * @see edu.tsinghua.lumaqq.qq.packets.IParser#accept(java.nio.ByteBuffer)
	 */
	public boolean accept(ByteBuffer buf) {
		// 保存偏移
		offset = buf.position();
		int bufferLength = buf.limit() - buf.position();
		if(bufferLength <= 0)
		    return false;
		
		boolean accept = checkTcp(buf);
		if(!accept)
		    accept = checkUdp(buf);
		
		return accept;
	}
	
	/**
	 * 檢查一個包是否是udp包
	 * 
	 * @param buf
	 * 		ByteBuffer
	 * @return
	 * 		true表示是，false表示否
	 */
	private boolean checkUdp(ByteBuffer buf) {
		if(buf.get(offset) == QQ.QQ_HEADER_BASIC_FAMILY) {
			// 首先檢查是否UDP方式
		    length = buf.limit() - buf.position();
		    if(buf.get(offset + length - 1) == QQ.QQ_TAIL_BASIC_FAMILY) 
		    	return true;
		}
		return false;
	}
	
	/**
	 * 檢查一個包是否是tcp包
	 * 
	 * @param buf
	 * 		ByteBuffer
	 * @return
	 * 		true表示是
	 */
	private boolean checkTcp(ByteBuffer buf) {
	    // buffer length不大于2則連個長度字段都沒有
		int bufferLength = buf.limit() - buf.position();
		if(bufferLength < 2)
		    return false;
		
		// 如果可讀內容小于包長，則這個包還沒收完
        length = buf.getChar(offset);
        if(length <= 0 || length > bufferLength)
            return false;
                    
        // 再檢查包頭包尾
        if(buf.get(offset + 2) == QQ.QQ_HEADER_BASIC_FAMILY) {
            if(buf.get(offset + length - 1) == QQ.QQ_TAIL_BASIC_FAMILY) 
            	return true;
        }	        
        
        return false;
	}
	
    public int getLength(ByteBuffer buf) {
        return length;
    }
    
	public boolean isDuplicate(InPacket in) {
		return history.check(in, true);
	}

	/**
     * 得到包的命令和序號
     * 
     * @param buf
     */
    private char getCommand(ByteBuffer buf, QQUser user) {
	    if(!user.isUdp()) {
	        return buf.getChar(offset + 5);
	    } else {
	        return buf.getChar(offset + 3);
	    }
    }