/********************************************************************
created:	2006/07/28
filename: 	Server.cpp
author:		李創
http://www.cppblog.com/converse/

purpose:	
*********************************************************************/

#pragma comment(lib, "WS2_32")

#include <WinSock2.h>
#include <stdio.h>
#include <assert.h>
#include "../CommonDef.h"

char	g_szNewFileName[MAXFILEDIRLENGTH];
char	g_szBuff[MAX_PACKET_SIZE + 1];
long	g_lLength;
char*	g_pBuff = NULL;

// 初始化socket庫
bool InitSocket();
// 關閉socket庫
bool CloseSocket();
// 解析消息進行相應的處理
bool ProcessMsg(SOCKET sClient);
// 監聽Client的消息
void ListenToClient();
// 打開文件
bool OpenFile(CCSDef::TMSG_HEADER* pMsgHeader, SOCKET sClient);
// 傳送文件
bool SendFile(SOCKET sClient);
// 讀取文件進入緩沖區
bool ReadFile(SOCKET sClient);

int main()
{
	InitSocket();
	ListenToClient();
	CloseSocket();

	return 0;
}

void ListenToClient()
{
	// 創建socket套接字
	SOCKET sListen = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (SOCKET_ERROR == sListen)
	{
		printf("Init Socket Error!\n");
		return;
	}

	// 綁定socket到一個本地地址
	sockaddr_in sin;
	sin.sin_family	= AF_INET;
	sin.sin_port	= htons(PORT);
	sin.sin_addr.S_un.S_addr = INADDR_ANY;
	if (::bind(sListen, (LPSOCKADDR)&sin, sizeof(sockaddr_in)) == SOCKET_ERROR)
	{
		printf("Bind Error!\n");
		return;
	}

	// 設置socket進入監聽狀態
	if (::listen(sListen, 10) == SOCKET_ERROR)
	{
		printf("Listen Error!\n");
		return;
	}

	printf("Listening To Client...\n");

	// 循環接收client端的連接請求
	sockaddr_in ClientAddr;
	int nAddrLen = sizeof(sockaddr_in);
	SOCKET sClient;

	while (INVALID_SOCKET == (sClient = ::accept(sListen, (sockaddr*)&ClientAddr, &nAddrLen)))
	{
	}

	while (true == ProcessMsg(sClient))
	{
	}

	// 關閉同客戶端的連接
	::closesocket(sClient);

	::closesocket(sListen);
}

bool InitSocket()
{
	// 初始化socket dll
	WSADATA wsaData;
	WORD socketVersion = MAKEWORD(2, 2);
	if (::WSAStartup(socketVersion, &wsaData) != 0)
	{
		printf("Init socket dll error\n");
		return false;
	}

	return true;
}

bool CloseSocket()
{
	// 釋放winsock庫
	::WSACleanup();

	if (NULL != g_pBuff)
	{
		delete [] g_pBuff;
		g_pBuff = NULL;
	}

	return true;
}

bool ProcessMsg(SOCKET sClient)
{
	int nRecv = ::recv(sClient, g_szBuff, MAX_PACKET_SIZE + 1, 0);
	if (nRecv > 0)
	{
		g_szBuff[nRecv] = '\0';
	}

	// 解析命令
	CCSDef::TMSG_HEADER* pMsgHeader = (CCSDef::TMSG_HEADER*)g_szBuff;
	switch (pMsgHeader->cMsgID)
	{
	case MSG_FILENAME:			// 文件名
		{
			OpenFile(pMsgHeader, sClient);
		}
		break;
	case MSG_CLIENT_READY:		// 客戶端準備好了,開始傳送文件
		{
			SendFile(sClient);
		}
		break;
	case MSG_SENDFILESUCCESS:	// 傳送文件成功
		{
			printf("Send File Success!\n");
			return false;
		}
		break;
	case MSG_FILEALREADYEXIT_ERROR:	// 要保存的文件已經存在了
		{
			printf("The file reay to send already exit!\n");
			return false;
		}
		break;
	}

	return true;
}

bool ReadFile(SOCKET sClient)
{
	if (NULL != g_pBuff)
	{
		return true;
	}

	// 打開文件
	FILE *pFile;
	if (NULL == (pFile = fopen(g_szNewFileName, "rb")))		// 打開文件失敗
	{
		printf("Cannot find the file, request the client input file name again\n");
		CCSDef::TMSG_ERROR_MSG tMsgErrorMsg(MSG_OPENFILE_ERROR);
		::send(sClient, (char*)(&tMsgErrorMsg), sizeof(CCSDef::TMSG_ERROR_MSG), 0);
		return false;
	}

	// 把文件的長度傳回到client去
	fseek(pFile, 0, SEEK_END);
	g_lLength = ftell(pFile);
	printf("File Length = %d\n", g_lLength);
	CCSDef::TMSG_FILELENGTH tMsgFileLength(g_lLength);
	::send(sClient, (char*)(&tMsgFileLength), sizeof(CCSDef::TMSG_FILELENGTH), 0);

	// 處理文件全路徑名,把文件名分解出來
	char szDrive[_MAX_DRIVE], szDir[_MAX_DIR], szFname[_MAX_FNAME], szExt[_MAX_EXT];
	_splitpath(g_szNewFileName, szDrive, szDir, szFname, szExt);
	strcat(szFname,szExt);
	CCSDef::TMSG_FILENAME tMsgFileName;
	strcpy(tMsgFileName.szFileName, szFname);
	printf("Send File Name: %s\n", tMsgFileName.szFileName);
	::send(sClient, (char*)(&tMsgFileName), sizeof(CCSDef::TMSG_FILENAME), 0);

	// 分配緩沖區讀取文件內容
	g_pBuff = new char[g_lLength + 1];
	if (NULL == g_pBuff)
	{
		return false;
	}

	fseek(pFile, 0, SEEK_SET);
	fread(g_pBuff, sizeof(char), g_lLength, pFile);
	g_pBuff[g_lLength] = '\0';
	fclose(pFile);

	return true;
}

// 打開文件
bool OpenFile(CCSDef::TMSG_HEADER* pMsgHeader, SOCKET sClient)
{
	CCSDef::TMSG_FILENAME* pRequestFilenameMsg = (CCSDef::TMSG_FILENAME*)pMsgHeader;

	// 對文件路徑名進行一些處理
	char *p1, *p2;
	for (p1 = pRequestFilenameMsg->szFileName, p2 = g_szNewFileName;
		'\0' != *p1;
		++p1, ++p2)
	{
		if ('\n' != *p1)
		{
			*p2 = *p1;
		}
		if ('\\' == *p2)
		{
			*(++p2) = '\\';
		}
	}
	*p2 = '\0';

	ReadFile(sClient);

	return true;
}

// 傳送文件
bool SendFile(SOCKET sClient)
{
	if (NULL == g_pBuff)
	{
		ReadFile(sClient);
	}

	int nPacketBufferSize = MAX_PACKET_SIZE - 2 * sizeof(int);	// 每個數據包存放文件的buffer大小
	// 如果文件的長度大于每個數據包所能傳送的buffer長度那么就分塊傳送
	for (int i = 0; i < g_lLength; i += nPacketBufferSize)
	{		
		CCSDef::TMSG_FILE tMsgFile;
		tMsgFile.tFile.nStart = i;
		if (i + nPacketBufferSize + 1> g_lLength)
		{
			tMsgFile.tFile.nSize  = g_lLength - i;
		}
		else
		{
			tMsgFile.tFile.nSize  = nPacketBufferSize;
		}
		//printf("start = %d, size = %d\n", tMsgFile.tFile.nStart, tMsgFile.tFile.nSize);
		memcpy(tMsgFile.tFile.szBuff, g_pBuff + tMsgFile.tFile.nStart, tMsgFile.tFile.nSize);
		::send(sClient, (char*)(&tMsgFile), sizeof(CCSDef::TMSG_FILE), 0);
		Sleep(0.5);
	}

	delete [] g_pBuff;
	g_pBuff = NULL;

	return true;
}