/***************************************************************************
 *   Copyright (C) 2007 by Lothar May                                      *
 *                                                                         *
 *   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.             *
 ***************************************************************************/

#include <net/socket_helper.h>
#include <net/serveracceptthread.h>
#include <net/servercontext.h>
#include <net/ircthread.h>
#include <net/connectdata.h>
#include <net/serverlobbythread.h>
#include <net/serverexception.h>
#include <net/socket_msg.h>
#include <net/socket_startup.h>
#include <core/loghelper.h>

#include <boost/algorithm/string/predicate.hpp>

#define ACCEPT_TIMEOUT_MSEC			50
#define NET_SERVER_LISTEN_BACKLOG	5

using namespace std;

ServerAcceptThread::ServerAcceptThread(ServerCallback &serverCallback)
: m_serverCallback(serverCallback)
{
	m_context.reset(new ServerContext);
}

ServerAcceptThread::~ServerAcceptThread()
{
}

void
ServerAcceptThread::Init(unsigned serverPort, bool ipv6, bool sctp, const string &pwd, const string &logDir, boost::shared_ptr<ServerLobbyThread> lobbyThread)
{
	if (IsRunning())
	{
		assert(false);
		return;
	}

	ServerContext &context = GetContext();

	context.SetProtocol(sctp ? SOCKET_IPPROTO_SCTP : 0);
	// If a "dual stack" is available, the pokerth server always uses ipv6.
	// In this case, ipv4 requests will be mapped to ipv6.
	context.SetAddrFamily(socket_has_dual_stack() ? AF_INET6 : (ipv6 ? AF_INET6 : AF_INET));
	context.SetServerPort(serverPort);

	m_lobbyThread = lobbyThread;
	GetLobbyThread().Init(pwd, logDir);
}

ServerCallback &
ServerAcceptThread::GetCallback()
{
	return m_serverCallback;
}

void
ServerAcceptThread::Main()
{
	try
	{
		Listen();

		while (!ShouldTerminate())
		{
			// The main server thread is simple. It only accepts connections.
			AcceptLoop();
		}
	} catch (const PokerTHException &e)
	{
		GetCallback().SignalNetServerError(e.GetErrorId(), e.GetOsErrorCode());
		LOG_ERROR(e.what());
	}
}

void
ServerAcceptThread::Listen()
{
	ServerContext &context = GetContext();

	if (context.GetServerPort() < 1024)
		throw ServerException(__FILE__, __LINE__, ERR_SOCK_INVALID_PORT, 0);

#ifdef _WIN32
	context.SetSocket(WSASocket(context.GetAddrFamily(), SOCK_STREAM, context.GetProtocol(), 0, 0, WSA_FLAG_OVERLAPPED));
#else
	context.SetSocket(socket(context.GetAddrFamily(), SOCK_STREAM, context.GetProtocol()));
#endif

	if (!IS_VALID_SOCKET(context.GetSocket()))
		throw ServerException(__FILE__, __LINE__, ERR_SOCK_CREATION_FAILED, SOCKET_ERRNO());

	unsigned long mode = 1;
	if (IOCTLSOCKET(context.GetSocket(), FIONBIO, &mode) == SOCKET_ERROR)
		throw ServerException(__FILE__, __LINE__, ERR_SOCK_CREATION_FAILED, SOCKET_ERRNO());

	// The following three calls are optional. If they fail, we don't care.
	int reuse = 1;
	setsockopt(context.GetSocket(), SOL_SOCKET, SO_REUSEADDR, (char *)&reuse, sizeof(reuse));
	int nodelay = 1;
	setsockopt(context.GetSocket(), SOL_SOCKET, TCP_NODELAY, (char *)&nodelay, sizeof(nodelay));
	// Enable dual-stack socket on Windows Vista.
	int ipv6only = 0;
	setsockopt(context.GetSocket(), IPPROTO_IPV6, IPV6_V6ONLY, (char *)&ipv6only, sizeof(ipv6only));

	context.GetServerSockaddr()->ss_family = context.GetAddrFamily();

	const char *localAddr = (context.GetAddrFamily() == AF_INET6) ? "::0" : "0.0.0.0";
	if (!socket_string_to_addr(
			localAddr,
			context.GetAddrFamily(),
			(struct sockaddr *)context.GetServerSockaddr(),
			context.GetServerSockaddrSize()))
	{
		throw ServerException(__FILE__, __LINE__, ERR_SOCK_SET_ADDR_FAILED, 0);
	}
	if (!socket_set_port(
			context.GetServerPort(),
			context.GetAddrFamily(),
			(struct sockaddr *)context.GetServerSockaddr(),
			context.GetServerSockaddrSize()))
	{
		throw ServerException(__FILE__, __LINE__, ERR_SOCK_SET_PORT_FAILED, 0);
	}

	if (!IS_VALID_BIND(bind(
			context.GetSocket(),
			(const struct sockaddr *)context.GetServerSockaddr(),
			context.GetServerSockaddrSize())))
	{
		throw ServerException(__FILE__, __LINE__, ERR_SOCK_BIND_FAILED, SOCKET_ERRNO());
	}

	if (!IS_VALID_LISTEN(listen(context.GetSocket(), NET_SERVER_LISTEN_BACKLOG)))
	{
		throw ServerException(__FILE__, __LINE__, ERR_SOCK_LISTEN_FAILED, SOCKET_ERRNO());
	}
}

void
ServerAcceptThread::AcceptLoop()
{
	ServerContext &context = GetContext();

	fd_set readSet;
	struct timeval timeout;

	FD_ZERO(&readSet);
	FD_SET(context.GetSocket(), &readSet);

	timeout.tv_sec  = 0;
	timeout.tv_usec = ACCEPT_TIMEOUT_MSEC * 1000;
	int selectResult = select(context.GetSocket() + 1, &readSet, NULL, NULL, &timeout);
	if (!IS_VALID_SELECT(selectResult))
	{
		throw ServerException(__FILE__, __LINE__, ERR_SOCK_SELECT_FAILED, SOCKET_ERRNO());
	}
	if (selectResult > 0) // accept is possible
	{
		boost::shared_ptr<ConnectData> tmpData(new ConnectData);
		tmpData->SetSocket(accept(context.GetSocket(), NULL, NULL));

		if (!IS_VALID_SOCKET(tmpData->GetSocket()))
		{
			throw ServerException(__FILE__, __LINE__, ERR_SOCK_ACCEPT_FAILED, SOCKET_ERRNO());
		}
		unsigned long mode = 1;
		if (IOCTLSOCKET(tmpData->GetSocket(), FIONBIO, &mode) == SOCKET_ERROR)
		{
			throw ServerException(__FILE__, __LINE__, ERR_SOCK_CREATION_FAILED, SOCKET_ERRNO());
		}

		// Retrieve peer address.
		socklen_t addrLen = (socklen_t)tmpData->GetPeerAddrSize();
		if (getpeername(tmpData->GetSocket(), tmpData->GetPeerAddr(), &addrLen) != 0)
		{
			// Something went wrong with the connection, just continue (socket will be closed).
			LOG_ERROR("getpeername() failed: " << SOCKET_ERRNO());
		}
		else
		{
			// Set the size of the peer address.
			tmpData->SetPeerAddrSize(addrLen);

			// Optional calls - don't check return value.
			// Enable keepalive - won't be of much use but better than nothing.
			int keepalive = 1;
			setsockopt(tmpData->GetSocket(), SOL_SOCKET, SO_KEEPALIVE, (char *)&keepalive, sizeof(keepalive));

	#ifdef SO_NOSIGPIPE
			int nosigpipe = 1;
			setsockopt(tmpData->GetSocket(), SOL_SOCKET, SO_NOSIGPIPE, (char *)&nosigpipe, sizeof(nosigpipe));
	#endif

			GetLobbyThread().AddConnection(tmpData);
		}
	}
}

const ServerContext &
ServerAcceptThread::GetContext() const
{
	assert(m_context.get());
	return *m_context;
}

ServerContext &
ServerAcceptThread::GetContext()
{
	assert(m_context.get());
	return *m_context;
}

ServerLobbyThread &
ServerAcceptThread::GetLobbyThread()
{
	assert(m_lobbyThread.get());
	return *m_lobbyThread;
}

