/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.

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 3 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, see <http://www.gnu.org/licenses/>.

Additional permissions under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
non-source form of such a combination shall include the source code for
the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
/*****************************************************************************
*
*   $/Plasma20/Sources/Plasma/NucleusLib/pnSimpleNet/pnSimpleNet.cpp
*   
***/

#include "Pch.h"
#pragma hdrstop


/*****************************************************************************
*
*   Local types
*
***/

struct SimpleNetConn : AtomicRef {
	LINK(SimpleNetConn)			link;
	AsyncSocket					sock;
	AsyncCancelId				cancelId;
	unsigned					channelId;
	bool						abandoned;
	struct ConnectParam *		connectParam;

	SimpleNet_MsgHeader *		oversizeMsg;
	ARRAY(byte)					oversizeBuffer;

	~SimpleNetConn () {
		ASSERT(!link.IsLinked());
	}
};

struct SimpleNetChannel : AtomicRef, THashKeyVal<unsigned> {
	HASHLINK(SimpleNetChannel)	link;
	
	FSimpleNetOnMsg				onMsg;
	FSimpleNetOnError			onError;
	
	LISTDECL(SimpleNetConn, link)	conns;

	SimpleNetChannel (unsigned channel)
	: THashKeyVal<unsigned>(channel)
	{ }
	~SimpleNetChannel () {
		ASSERT(!link.IsLinked());
		ASSERT(!conns.Head());
	}
};

struct ConnectParam {
	SimpleNetChannel *		channel;
	FSimpleNetOnConnect		callback;
	void *					param;
	
	~ConnectParam () {
		if (channel)
			channel->DecRef();
	}
};


/*****************************************************************************
*
*   Local data
*
***/

static bool							s_running;
static CCritSect					s_critsect;
static FSimpleNetQueryAccept		s_queryAccept;
static void *						s_queryAcceptParam;

static HASHTABLEDECL(
	SimpleNetChannel,
	THashKeyVal<unsigned>,
	link
) s_channels;


/*****************************************************************************
*
*   Local functions
*
***/

//============================================================================
static void NotifyConnSocketConnect (SimpleNetConn * conn) {

	conn->TransferRef("Connecting", "Connected");
	
	conn->connectParam->callback(
		conn->connectParam->param,
		conn,
		kNetSuccess
	);
	
	DEL(conn->connectParam);
	conn->connectParam = nil;
}

//============================================================================
static void NotifyConnSocketConnectFailed (SimpleNetConn * conn) {

	s_critsect.Enter();
	{
		conn->link.Unlink();
	}
	s_critsect.Leave();

	conn->connectParam->callback(
		conn->connectParam->param,
		nil,
		kNetErrConnectFailed
	);
	
	DEL(conn->connectParam);
	conn->connectParam = nil;

	conn->DecRef("Connecting");
	conn->DecRef("Lifetime");
}

//============================================================================
static void NotifyConnSocketDisconnect (SimpleNetConn * conn) {

	bool abandoned;
	SimpleNetChannel * channel;
	s_critsect.Enter();
	{
		abandoned = conn->abandoned;
		if (nil != (channel = s_channels.Find(conn->channelId)))
			channel->IncRef();
		conn->link.Unlink();
	}
	s_critsect.Leave();
	
	if (channel && !abandoned) {
		channel->onError(conn, kNetErrDisconnected);
		channel->DecRef();
	}
	
	conn->DecRef("Connected");
}

//============================================================================
static bool NotifyConnSocketRead (SimpleNetConn * conn, AsyncNotifySocketRead * read) {

	SimpleNetChannel * channel;
	s_critsect.Enter();
	{
		if (nil != (channel = s_channels.Find(conn->channelId)))
			channel->IncRef();
	}
	s_critsect.Leave();
	
	if (!channel)
		return false;
		
	bool result = true;

    const byte * curr = read->buffer;
    const byte * term = curr + read->bytes;

	while (curr < term) {
		// Reading oversize msg?
		if (conn->oversizeBuffer.Count()) {
			unsigned spaceLeft = conn->oversizeMsg->messageBytes - conn->oversizeBuffer.Count();
			unsigned copyBytes = min(spaceLeft, term - curr);
			conn->oversizeBuffer.Add(curr, copyBytes);
			
			curr += copyBytes;

			// Wait until we have received the entire message
			if (copyBytes != spaceLeft)
				break;
				
			// Dispatch oversize msg
			if (!channel->onMsg(conn, conn->oversizeMsg)) {
				result = false;
				break;
			}
			
			conn->oversizeBuffer.SetCount(0);
			continue;
		}

		// Wait until we receive the entire message header
		if (term - curr < sizeof(SimpleNet_MsgHeader))
			break;

		SimpleNet_MsgHeader * msg = (SimpleNet_MsgHeader *) read->buffer;

		// Sanity check message size		
		if (msg->messageBytes < sizeof(*msg)) {
			result = false;
			break;
		}
		
		// Handle oversized messages
		if (msg->messageBytes > kAsyncSocketBufferSize) {
			
			conn->oversizeBuffer.SetCount(msg->messageBytes);
			conn->oversizeMsg = (SimpleNet_MsgHeader *) conn->oversizeBuffer.Ptr();
			*conn->oversizeMsg = *msg;			
			
			curr += sizeof(*msg);
			continue;
		}
		
		// Wait until we have received the entire message
		const byte * msgTerm = (const byte *) curr + msg->messageBytes;
		if (msgTerm > term)
			break;
		curr = msgTerm;

		// Dispatch msg
		if (!channel->onMsg(conn, msg)) {
			result = false;
			break;
		}
	}

	// Return count of bytes we processed
	read->bytesProcessed = curr - read->buffer;
	
	channel->DecRef();
	return result;
}

//============================================================================
static bool AsyncNotifySocketProc (
	AsyncSocket			sock,
	EAsyncNotifySocket	code,
	AsyncNotifySocket *	notify,
	void **				userState
) {
	bool result = true;
	SimpleNetConn * conn;

	switch (code) {
		case kNotifySocketListenSuccess: {

			AsyncNotifySocketListen * listen = (AsyncNotifySocketListen *) notify;

			const SimpleNet_ConnData & connect = *(const SimpleNet_ConnData *) listen->buffer;
			listen->bytesProcessed += sizeof(connect);

			SimpleNetChannel * channel;
			s_critsect.Enter();
			{
				if (nil != (channel = s_channels.Find(connect.channelId)))
					channel->IncRef();
			}
			s_critsect.Leave();
			
			if (!channel)
				break;
				
			conn = NEWZERO(SimpleNetConn);
			conn->channelId = channel->GetValue();
			conn->IncRef("Lifetime");
			conn->IncRef("Connected");
			conn->sock = sock;
			*userState = conn;
			
			bool accepted = s_queryAccept(
				s_queryAcceptParam,
				channel->GetValue(),
				conn,
				listen->remoteAddr
			);
			
			if (!accepted) {
				SimpleNetDisconnect(conn);
			}
			else {
				s_critsect.Enter();
				{
					channel->conns.Link(conn);
				}
				s_critsect.Leave();
			}
			
			channel->DecRef();
		}
		break;
		
		case kNotifySocketConnectSuccess: {
			conn = (SimpleNetConn *) notify->param;
			*userState = conn;
			bool abandoned;
			
			s_critsect.Enter();
			{
				conn->sock		= sock;
				conn->cancelId  = 0;
				abandoned		= conn->abandoned;
			}
			s_critsect.Leave();
			
			if (abandoned)
				AsyncSocketDisconnect(sock, true);
			else
				NotifyConnSocketConnect(conn);
		}
		break;

		case kNotifySocketConnectFailed:
			conn = (SimpleNetConn *) notify->param;
			NotifyConnSocketConnectFailed(conn);
		break;

		case kNotifySocketDisconnect:
			conn = (SimpleNetConn *) *userState;
			NotifyConnSocketDisconnect(conn);
		break;

		case kNotifySocketRead:
			conn = (SimpleNetConn *) *userState;
			result = NotifyConnSocketRead(conn, (AsyncNotifySocketRead *) notify);
		break;
	}

	return result;
}

//============================================================================
static void Connect (const NetAddress & addr, ConnectParam * cp) {

	SimpleNetConn * conn = NEWZERO(SimpleNetConn);
	conn->channelId = cp->channel->GetValue();
	conn->connectParam = cp;
	conn->IncRef("Lifetime");
	conn->IncRef("Connecting");

	s_critsect.Enter();
	{
		cp->channel->conns.Link(conn);
		
		SimpleNet_Connect connect;
		connect.hdr.connType	= kConnTypeSimpleNet;
		connect.hdr.hdrBytes	= sizeof(connect.hdr);
		connect.hdr.buildId		= BuildId();
		connect.hdr.buildType	= BuildType();
		connect.hdr.branchId	= BranchId();
		connect.hdr.productId	= ProductId();
		connect.data.channelId	= cp->channel->GetValue();
			
		AsyncSocketConnect(
			&conn->cancelId,
			addr,
			AsyncNotifySocketProc,
			conn,
			&connect,
			sizeof(connect)
		);
		
		conn = nil;	
		cp = nil;
	}
	s_critsect.Leave();
	
	DEL(conn);
	DEL(cp);
}

//============================================================================
static void AsyncLookupCallback (
	void *				param,
	const wchar			name[],
	unsigned			addrCount,
	const NetAddress	addrs[]
) {
	ref(name);
	
	ConnectParam * cp = (ConnectParam *)param;

	if (!addrCount) {
		if (cp->callback)
			cp->callback(cp->param, nil, kNetErrNameLookupFailed);
		DEL(cp);
		return;
	}

	Connect(addrs[0], (ConnectParam *)param);
}


/*****************************************************************************
*
*   Exported functions
*
***/

//============================================================================
void SimpleNetInitialize () {

	s_running = true;

	AsyncSocketRegisterNotifyProc(
		kConnTypeSimpleNet,
		AsyncNotifySocketProc
	);
}

//============================================================================
void SimpleNetShutdown () {

	s_running = false;

	ASSERT(!s_channels.Head());
	
	AsyncSocketUnregisterNotifyProc(
		kConnTypeSimpleNet,
		AsyncNotifySocketProc
	);
}

//============================================================================
void SimpleNetConnIncRef (SimpleNetConn * conn) {

	ASSERT(s_running);
	ASSERT(conn);
	
	conn->IncRef();
}

//============================================================================
void SimpleNetConnDecRef (SimpleNetConn * conn) {

	ASSERT(s_running);
	ASSERT(conn);
	
	conn->DecRef();
}

//============================================================================
bool SimpleNetStartListening (
	FSimpleNetQueryAccept	queryAccept,
	void *					param
) {
	ASSERT(s_running);
	ASSERT(queryAccept);
	ASSERT(!s_queryAccept);
	
	s_queryAccept		= queryAccept;
	s_queryAcceptParam	= param;
	
	NetAddress addr;
	NetAddressFromNode(0, kNetDefaultSimpleNetPort, &addr);
	return (0 != AsyncSocketStartListening(addr, nil));
}

//============================================================================
void SimpleNetStopListening () {

	ASSERT(s_running);

	NetAddress addr;
	NetAddressFromNode(0, kNetDefaultSimpleNetPort, &addr);
	AsyncSocketStopListening(addr, nil);

	s_queryAccept		= nil;
	s_queryAcceptParam	= nil;
}

//============================================================================
void SimpleNetCreateChannel (
	unsigned			channelId,
	FSimpleNetOnMsg		onMsg,
	FSimpleNetOnError	onError
) {
	ASSERT(s_running);

	SimpleNetChannel * channel = NEWZERO(SimpleNetChannel)(channelId);
	channel->IncRef();

	s_critsect.Enter();
	{
		#ifdef HS_DEBUGGING
		{
			SimpleNetChannel * existing = s_channels.Find(channelId);
			ASSERT(!existing);
		}
		#endif
		
		channel->onMsg		= onMsg;
		channel->onError	= onError;
		s_channels.Add(channel);
		channel->IncRef();
	}
	s_critsect.Leave();
	
	channel->DecRef();
}

//============================================================================
void SimpleNetDestroyChannel (unsigned channelId) {

	ASSERT(s_running);

	SimpleNetChannel * channel;
	s_critsect.Enter();
	{
		if (nil != (channel = s_channels.Find(channelId))) {
			s_channels.Unlink(channel);
			while (SimpleNetConn * conn = channel->conns.Head()) {
				SimpleNetDisconnect(conn);
				channel->conns.Unlink(conn);
			}
		}
	}
	s_critsect.Leave();

	if (channel)
		channel->DecRef();	
}

//============================================================================
void SimpleNetStartConnecting (
	unsigned			channelId,
	const wchar			addr[],
	FSimpleNetOnConnect	onConnect,
	void *				param
) {
	ASSERT(s_running);
	ASSERT(onConnect);
	
	ConnectParam * cp = NEW(ConnectParam);
	cp->callback	= onConnect;
	cp->param		= param;
	
	s_critsect.Enter();
	{
		if (nil != (cp->channel = s_channels.Find(channelId)))
			cp->channel->IncRef();
	}
	s_critsect.Leave();
	
	ASSERT(cp->channel);

	// Do we need to lookup the address?
	const wchar * name = addr;
	while (unsigned ch = *name) {
		++name;
		if (!(isdigit(ch) || ch == L'.' || ch == L':')) {

			AsyncCancelId cancelId;
			AsyncAddressLookupName(
				&cancelId,
				AsyncLookupCallback,
				addr,
				kNetDefaultSimpleNetPort,
				cp
			);
			break;
		}
	}
	if (!name[0]) {
		NetAddress netAddr;
		NetAddressFromString(&netAddr, addr, kNetDefaultSimpleNetPort);
		Connect(netAddr, cp);
	}
}

//============================================================================
void SimpleNetDisconnect (
	SimpleNetConn *	conn
) {
	ASSERT(s_running);
	ASSERT(conn);
	
	s_critsect.Enter();
	{
		conn->abandoned = true;
		if (conn->sock) {
			AsyncSocketDisconnect(conn->sock, true);
			conn->sock = nil;
		}
		else if (conn->cancelId) {
			AsyncSocketConnectCancel(AsyncNotifySocketProc, conn->cancelId);
			conn->cancelId = nil;
		}
	}
	s_critsect.Leave();

	conn->DecRef("Lifetime");
}

//============================================================================
void SimpleNetSend (
	SimpleNetConn *			conn,
	SimpleNet_MsgHeader *	msg
) {
	ASSERT(s_running);
	ASSERT(msg);
	ASSERT(msg->messageBytes != (dword)-1);
	ASSERT(conn);
	
	s_critsect.Enter();
	{
		if (conn->sock)
			AsyncSocketSend(conn->sock, msg, msg->messageBytes);
	}
	s_critsect.Leave();
}