/*
 *
 * (C) 2003-2012 Anope Team
 * Contact us at team@anope.org
 *
 * Please read COPYING and README for further details.
 *
 * Based on the original code of Epona by Lara.
 * Based on the original code of Services by Andy Church.
 */

#include "services.h"
#include "anope.h"
#include "socketengine.h"
#include "sockets.h"
#include "logger.h"
#include "config.h"

#ifdef _AIX
# undef FD_ZERO
# define FD_ZERO(p) memset((p), 0, sizeof(*(p)))
#endif /* _AIX */

static int MaxFD;
static unsigned FDCount;
static fd_set ReadFDs;
static fd_set WriteFDs;

void SocketEngine::Init()
{
	MaxFD = 0;
	FDCount = 0;
	FD_ZERO(&ReadFDs);
	FD_ZERO(&WriteFDs);
}

void SocketEngine::Shutdown()
{
	Process();

	for (std::map<int, Socket *>::const_iterator it = Sockets.begin(), it_end = Sockets.end(); it != it_end;)
	{
		Socket *s = it->second;
		++it;
		delete s;
	}
	Sockets.clear();
}

void SocketEngine::AddSocket(Socket *s)
{
	if (s->GetFD() > MaxFD)
		MaxFD = s->GetFD();
	FD_SET(s->GetFD(), &ReadFDs);
	Sockets[s->GetFD()] = s;
	++FDCount;
}

void SocketEngine::DelSocket(Socket *s)
{
	if (s->GetFD() == MaxFD)
		--MaxFD;
	FD_CLR(s->GetFD(), &ReadFDs);
	FD_CLR(s->GetFD(), &WriteFDs);
	Sockets.erase(s->GetFD());
	--FDCount;
}

void SocketEngine::MarkWritable(Socket *s)
{
	if (s->HasFlag(SF_WRITABLE))
		return;
	FD_SET(s->GetFD(), &WriteFDs);
	s->SetFlag(SF_WRITABLE);
}

void SocketEngine::ClearWritable(Socket *s)
{
	if (!s->HasFlag(SF_WRITABLE))
		return;
	FD_CLR(s->GetFD(), &WriteFDs);
	s->UnsetFlag(SF_WRITABLE);
}

void SocketEngine::Process()
{
	fd_set rfdset = ReadFDs, wfdset = WriteFDs, efdset = ReadFDs;
	timeval tval;
	tval.tv_sec = Config->ReadTimeout;
	tval.tv_usec = 0;

#ifdef _WIN32
	/* We can use the socket engine to "sleep" services for a period of
	 * time between connections to the uplink, which allows modules,
	 * timers, etc to function properly. Windows, being as useful as it is,
	 * does not allow to select() on 0 sockets and will immediately return error.
	 * Thus:
	 */
	if (FDCount == 0)
	{
		sleep(tval.tv_sec);
		return;
	}
#endif

	int sresult = select(MaxFD + 1, &rfdset, &wfdset, &efdset, &tval);
	Anope::CurTime = time(NULL);

	if (sresult == -1)
	{
		Log() << "SockEngine::Process(): error: " << Anope::LastError();
	}
	else if (sresult)
	{
		int processed = 0;
		for (std::map<int, Socket *>::const_iterator it = Sockets.begin(), it_end = Sockets.end(); it != it_end && processed != sresult;)
		{
			Socket *s = it->second;
			++it;

			bool has_read = FD_ISSET(s->GetFD(), &rfdset), has_write = FD_ISSET(s->GetFD(), &wfdset), has_error = FD_ISSET(s->GetFD(), &efdset);
			if (has_read || has_write || has_error)
				++processed;

			if (has_error)
			{
				s->ProcessError();
				s->SetFlag(SF_DEAD);
				delete s;
				continue;
			}

			if (!s->Process())
				continue;

			if (has_read && !s->ProcessRead())
				s->SetFlag(SF_DEAD);

			if (has_write && !s->ProcessWrite())
				s->SetFlag(SF_DEAD);

			if (s->HasFlag(SF_DEAD))
				delete s;
		}
	}
}