#include "ServerSocket.h"
#include <iostream>
#include <algorithm>
#include <string>

using namespace std;


ServerSocket::ServerSocket(void) 
{	 
	try{
		InitSocket();
	}
	catch (exception ex)
	{
		//something maybe done here
	}
}

int ServerSocket::InitSocket()
{
	if (Startup() == ERR) return ERR;
	//Create Socket
	m_ServerSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if ( m_ServerSocket == INVALID_SOCKET )
    {
		throw "Create Socket Failed!";		
    }

	m_serverAddr.sin_family = AF_INET;
    m_serverAddr.sin_addr.s_addr = inet_addr(IP_ADDRESS);
	m_serverAddr.sin_port = htons(PORT);
	memset(m_serverAddr.sin_zero, 0x00, 8);

    //Bind Socket	
	if ( bind(m_ServerSocket, (struct sockaddr*)&m_serverAddr, sizeof(m_serverAddr)) != 0 ){
		closesocket(m_ServerSocket);
		throw "Bind Socket Failed!";		
	}
	
	if ( listen(m_ServerSocket, 10) != 0 ){
		closesocket(m_ServerSocket);
		throw "listen Socket Failed!";		
	}	
	return 0;
}

void CloseSock(std::pair<std::string, SOCKET> info)
{
	closesocket(info.second); //close the socket stored in a pair
}

ServerSocket::~ServerSocket(void)
{
	closesocket(m_ServerSocket);	
	for_each(m_clientInfo.begin(), m_clientInfo.end(), CloseSock);
	WSACleanup();
}

bool validateUser(string username, string password)
{
	std::tr1::shared_ptr<FILE> fd = getfd("user.dat", "rb");		
	if (NULL == fd.get()) return false;

	while (!feof(fd.get()))
	{
		User user;
		if (1 != fread(&user, sizeof(User), 1, fd.get())) return false;
		if (strcmp(user.username, username.c_str()) == 0 &&
			strcmp(user.password, password.c_str()) == 0 )
		{
			return true;
		}
	}	
	return false;
}

int ServerSocket::Accept(SOCKET* socket)
{
	struct sockaddr_in ClientAddr;
	int ClientAddrLen = sizeof(ClientAddr);	
	*socket = accept(m_ServerSocket, (struct sockaddr*)&ClientAddr, &ClientAddrLen);
	if ( *socket == INVALID_SOCKET )
	{
		throw "Accept Failed!";		
	}
	//validate user;
	char buff[MAX_PATH];
	RecvBuff(*socket, buff); 
	string str = string(buff);
	memset(buff, 0x00, MAX_PATH);
	basic_string<char>::size_type i = str.find_first_of('\1');
	if (!validateUser(str.substr(0, i) ,str.substr(i + 1)))	
	{
		strcpy(buff, "0");
		SendBuff(*socket, buff);
		closesocket(*socket);	
		return ERR;
	}		
	strcpy(buff, "1");
	SendBuff(*socket, buff);		
	m_clientAddrList.push_back(ClientAddr); 
	m_clientInfo[str.substr(0, i)] = *socket;
	return 0;
}

//if the user is not online, then send his or her task to
//a local file for this user on server and update the info of the user
//return value: 1 indicates the task is saved to the file while user info is not updated
//				-1 indicates neither did the task is saved, nor did the user info is updated
//				0 indicates both are done successfully
int SaveToLocal(std::string username, std::string data)
{
	//open the task file for the specific user
	std::string taskfile = username + "_task.dat";
	std::tr1::shared_ptr<FILE> fd = getfd(taskfile, "ab");
	if (NULL == fd.get()) return -1;

	Task task;
	decode_task(data, task); // decode the task

	//write the task to the file
	if (1 != fwrite(&task, sizeof(Task), 1, fd.get())) return -1;

	return 0;
}

//send data to specific user
//if the user is online send out immediately
//else save to corresponding local file
int ServerSocket::Send(std::string username, std::string data)
{
	std::map<std::string, SOCKET>::iterator pos = m_clientInfo.find(username);
	if (pos != m_clientInfo.end())
	{
		if( SendBuff(pos->second, data.c_str()) == ERR)
		{		
			m_clientInfo.erase(pos);
			return SaveToLocal(username, data);
		}	
		else return 0;
	}
	else
	{
		return SaveToLocal(username, data);
	}
}