/**

 * vim: set ts=4 :

 * =============================================================================

 * SourceMod

 * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.

 * =============================================================================

 *

 * This program is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, version 3.0, as published by the

 * Free Software Foundation.

 * 

 * 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/>.

 *

 * As a special exception, AlliedModders LLC gives you permission to link the

 * code of this program (as well as its derivative works) to "Half-Life 2," the

 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

 * by the Valve Corporation.  You must obey the GNU General Public License in

 * all respects for all other code used.  Additionally, AlliedModders LLC grants

 * this exception to all derivative works.  AlliedModders LLC defines further

 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

 * or <http://www.sourcemod.net/license.php>.

 *

 * Version: $Id$

 */

#include "HandleSys.h"

#include "PluginSys.h"

#include "UserMessages.h"

#include "smn_usermsgs.h"

HandleType_t g_WrBitBufType;

HandleType_t g_RdBitBufType;

Handle_t g_CurMsgHandle;

Handle_t g_ReadBufHandle;

bf_read g_ReadBitBuf;

int g_MsgPlayers[256];

bool g_IsMsgInExec = false;

typedef List<MsgListenerWrapper *> MsgWrapperList;

typedef List<MsgListenerWrapper *>::iterator MsgWrapperIter;

class UsrMessageNatives :

	public SMGlobalClass,

	public IHandleTypeDispatch,

	public IPluginsListener

{

public:

	~UsrMessageNatives();

public: //SMGlobalClass, IHandleTypeDispatch, IPluginListener

	void OnSourceModAllInitialized();

	void OnSourceModShutdown();

	void OnHandleDestroy(HandleType_t type, void *object);

	bool GetHandleApproxSize(HandleType_t type, void *object, unsigned int *pSize);

	void OnPluginUnloaded(IPlugin *plugin);

public:

	MsgListenerWrapper *CreateListener(IPluginContext *pCtx);

	bool FindListener(int msgid, IPluginContext *pCtx, IPluginFunction *pHook, bool intercept, MsgWrapperIter *iter);

	bool DeleteListener(IPluginContext *pCtx, MsgWrapperIter iter);

private:

	CStack<MsgListenerWrapper *> m_FreeListeners;

};

UsrMessageNatives::~UsrMessageNatives()

{

	CStack<MsgListenerWrapper *>::iterator iter;

	for (iter=m_FreeListeners.begin(); iter!=m_FreeListeners.end(); iter++)

	{

		delete (*iter);

	}

	m_FreeListeners.popall();

}

void UsrMessageNatives::OnSourceModAllInitialized()

{

	HandleAccess sec;

	g_HandleSys.InitAccessDefaults(NULL, &sec);

	sec.access[HandleAccess_Delete] = HANDLE_RESTRICT_IDENTITY;

	g_WrBitBufType = g_HandleSys.CreateType("BitBufWriter", this, 0, NULL, NULL, g_pCoreIdent, NULL);

	g_RdBitBufType = g_HandleSys.CreateType("BitBufReader", this, 0, NULL, &sec, g_pCoreIdent, NULL);

	g_ReadBufHandle = g_HandleSys.CreateHandle(g_RdBitBufType, &g_ReadBitBuf, NULL, g_pCoreIdent, NULL);

	g_PluginSys.AddPluginsListener(this);

}

void UsrMessageNatives::OnSourceModShutdown()

{

	HandleSecurity sec;

	sec.pIdentity = g_pCoreIdent;

	g_HandleSys.FreeHandle(g_ReadBufHandle, &sec);

	g_HandleSys.RemoveType(g_WrBitBufType, g_pCoreIdent);

	g_HandleSys.RemoveType(g_RdBitBufType, g_pCoreIdent);

	g_WrBitBufType = 0;

	g_RdBitBufType = 0;

}

void UsrMessageNatives::OnHandleDestroy(HandleType_t type, void *object)

{

}

bool UsrMessageNatives::GetHandleApproxSize(HandleType_t type, void *object, unsigned int *pSize)

{

	*pSize = sizeof(bf_read);

	return true;

}

void UsrMessageNatives::OnPluginUnloaded(IPlugin *plugin)

{

	MsgWrapperList *pList;

	if (plugin->GetProperty("MsgListeners", reinterpret_cast<void **>(&pList), true))

	{

		MsgWrapperIter iter;

		MsgListenerWrapper *pListener;

		for (iter=pList->begin(); iter!=pList->end(); iter++)

		{

			pListener = (*iter);

			if (g_UserMsgs.UnhookUserMessage(pListener->GetMessageId(), pListener, pListener->IsInterceptHook()))

			{

				m_FreeListeners.push(pListener);

			}

		}

		delete pList;

	}

}

MsgListenerWrapper *UsrMessageNatives::CreateListener(IPluginContext *pCtx)

{

	MsgWrapperList *pList;

	MsgListenerWrapper *pListener;

	IPlugin *pl = g_PluginSys.FindPluginByContext(pCtx->GetContext());

	if (m_FreeListeners.empty())

	{

		pListener = new MsgListenerWrapper;

	} else {

		pListener = m_FreeListeners.front();

		m_FreeListeners.pop();

	}

	if (!pl->GetProperty("MsgListeners", reinterpret_cast<void **>(&pList)))

	{

		pList = new List<MsgListenerWrapper *>;

		pl->SetProperty("MsgListeners", pList);

	}

	pList->push_back(pListener);

	return pListener;

}

bool UsrMessageNatives::FindListener(int msgid, IPluginContext *pCtx, IPluginFunction *pHook, bool intercept, MsgWrapperIter *iter)

{

	MsgWrapperList *pList;

	MsgWrapperIter _iter;

	MsgListenerWrapper *pListener;

	IPlugin *pl = g_PluginSys.FindPluginByContext(pCtx->GetContext());

	if (!pl->GetProperty("MsgListeners", reinterpret_cast<void **>(&pList)))

	{

		return false;

	}

	for (_iter=pList->begin(); _iter!=pList->end(); _iter++)

	{

		pListener = (*_iter);

		if ((msgid == pListener->GetMessageId()) 

			&& (intercept == pListener->IsInterceptHook()) 

			&& (pHook == pListener->GetHookedFunction()))

		{

			*iter = _iter;

			return true;

		}

	}

	return false;

}

bool UsrMessageNatives::DeleteListener(IPluginContext *pCtx, MsgWrapperIter iter)

{

	MsgWrapperList *pList;

	MsgListenerWrapper *pListener;

	IPlugin *pl = g_PluginSys.FindPluginByContext(pCtx->GetContext());

	if (!pl->GetProperty("MsgListeners", reinterpret_cast<void **>(&pList)))

	{

		return false;

	}

	pListener = (*iter);

	pList->erase(iter);

	m_FreeListeners.push(pListener);

	return true;

}

/***************************************

 *                                     *

 * USER MESSAGE WRAPPER IMPLEMENTATION *

 *                                     *

 ***************************************/

void MsgListenerWrapper::Initialize(int msgid, IPluginFunction *hook, IPluginFunction *notify, bool intercept)

{

	if (intercept)

	{

		m_Intercept = hook;

		m_Hook = NULL;

	} else {

		m_Hook = hook;

		m_Intercept = NULL;

	}

	if (notify)

	{

		m_Notify = notify;

	} else {

		m_Notify = NULL;

	}

	m_MsgId = msgid;

	m_IsInterceptHook = intercept;

}

size_t MsgListenerWrapper::_FillInPlayers(int *pl_array, IRecipientFilter *pFilter)

{

	size_t size = static_cast<size_t>(pFilter->GetRecipientCount());

	for (size_t i=0; i<size; i++)

	{

		pl_array[i] = pFilter->GetRecipientIndex(i);

	}

	return size;

}

bool MsgListenerWrapper::IsInterceptHook() const

{

	return m_IsInterceptHook;

}

int MsgListenerWrapper::GetMessageId() const

{

	return m_MsgId;

}

IPluginFunction *MsgListenerWrapper::GetHookedFunction() const

{

	if (m_Hook)

	{

		return m_Hook;

	} else {

		return m_Intercept;

	}

}

IPluginFunction *MsgListenerWrapper::GetNotifyFunction() const

{

	return m_Notify;

}

void MsgListenerWrapper::OnUserMessage(int msg_id, bf_write *bf, IRecipientFilter *pFilter)

{

	cell_t res;

	size_t size = _FillInPlayers(g_MsgPlayers, pFilter);

	g_ReadBitBuf.StartReading(bf->GetBasePointer(), bf->GetNumBytesWritten());

	m_Hook->PushCell(msg_id);

	m_Hook->PushCell(g_ReadBufHandle);

	m_Hook->PushArray(g_MsgPlayers, size);

	m_Hook->PushCell(size);

	m_Hook->PushCell(pFilter->IsReliable());

	m_Hook->PushCell(pFilter->IsInitMessage());

	m_Hook->Execute(&res);

}

ResultType MsgListenerWrapper::InterceptUserMessage(int msg_id, bf_write *bf, IRecipientFilter *pFilter)

{

	cell_t res = static_cast<cell_t>(Pl_Continue);

	size_t size = _FillInPlayers(g_MsgPlayers, pFilter);

	g_ReadBitBuf.StartReading(bf->GetBasePointer(), bf->GetNumBytesWritten());

	m_Intercept->PushCell(msg_id);

	m_Intercept->PushCell(g_ReadBufHandle);

	m_Intercept->PushArray(g_MsgPlayers, size);

	m_Intercept->PushCell(size);

	m_Intercept->PushCell(pFilter->IsReliable());

	m_Intercept->PushCell(pFilter->IsInitMessage());

	m_Intercept->Execute(&res);

	return static_cast<ResultType>(res);

}

void MsgListenerWrapper::OnUserMessageSent(int msg_id)

{

	if (!m_Notify)

	{

		return;

	}

	cell_t res;

	m_Notify->PushCell(msg_id);

	m_Notify->Execute(&res);

}

/***************************************

 *                                     *

 * USER MESSAGE NATIVE IMPLEMENTATIONS *

 *                                     *

 ***************************************/

static UsrMessageNatives s_UsrMessageNatives;

static cell_t smn_GetUserMessageId(IPluginContext *pCtx, const cell_t *params)

{

	char *msgname;

	pCtx->LocalToString(params[1], &msgname);

	return g_UserMsgs.GetMessageIndex(msgname);

}

static cell_t smn_GetUserMessageName(IPluginContext *pCtx, const cell_t *params)

{

	char *msgname;

	pCtx->LocalToPhysAddr(params[2], (cell_t **)&msgname);

	return g_UserMsgs.GetMessageName(params[1], msgname, params[3]);

}

static cell_t smn_StartMessage(IPluginContext *pCtx, const cell_t *params)

{

	char *msgname;

	cell_t *cl_array;

	int msgid;

	bf_write *pBitBuf;

	if (g_IsMsgInExec)

	{

		return pCtx->ThrowNativeError("Unable to execute a new message, there is already one in progress");

	}

	pCtx->LocalToString(params[1], &msgname);

	if ((msgid=g_UserMsgs.GetMessageIndex(msgname)) == INVALID_MESSAGE_ID)

	{

		return pCtx->ThrowNativeError("Invalid message name: \"%s\"", msgname);

	}

	pCtx->LocalToPhysAddr(params[2], &cl_array);

	pBitBuf = g_UserMsgs.StartMessage(msgid, cl_array, params[3], params[4]);

	if (!pBitBuf)

	{

		return pCtx->ThrowNativeError("Unable to execute a new message while in hook");

	}

	g_CurMsgHandle = g_HandleSys.CreateHandle(g_WrBitBufType, pBitBuf, pCtx->GetIdentity(), g_pCoreIdent, NULL);

	g_IsMsgInExec = true;

	return g_CurMsgHandle;

}

static cell_t smn_StartMessageEx(IPluginContext *pCtx, const cell_t *params)

{

	cell_t *cl_array;

	bf_write *pBitBuf;

	int msgid = params[1];

	if (g_IsMsgInExec)

	{

		return pCtx->ThrowNativeError("Unable to execute a new message, there is already one in progress");

	}

	if (msgid < 0 || msgid >= 255)

	{

		return pCtx->ThrowNativeError("Invalid message id supplied (%d)", msgid);

	}

	pCtx->LocalToPhysAddr(params[2], &cl_array);

	pBitBuf = g_UserMsgs.StartMessage(msgid, cl_array, params[3], params[4]);

	if (!pBitBuf)

	{

		return pCtx->ThrowNativeError("Unable to execute a new message while in hook");

	}

	g_CurMsgHandle = g_HandleSys.CreateHandle(g_WrBitBufType, pBitBuf, pCtx->GetIdentity(), g_pCoreIdent, NULL);

	g_IsMsgInExec = true;

	return g_CurMsgHandle;

}

static cell_t smn_EndMessage(IPluginContext *pCtx, const cell_t *params)

{

	HandleSecurity sec;

	if (!g_IsMsgInExec)

	{

		return pCtx->ThrowNativeError("Unable to end message, no message is in progress");

	}

	g_UserMsgs.EndMessage();

	sec.pOwner = pCtx->GetIdentity();

	sec.pIdentity = g_pCoreIdent;

	g_HandleSys.FreeHandle(g_CurMsgHandle, &sec);

	g_IsMsgInExec = false;

	return 1;

}

static cell_t smn_HookUserMessage(IPluginContext *pCtx, const cell_t *params)

{

	IPluginFunction *pHook, *pNotify;

	MsgListenerWrapper *pListener;

	bool intercept;

	int msgid = params[1];

	if (msgid < 0 || msgid >= 255)

	{

		return pCtx->ThrowNativeError("Invalid message id supplied (%d)", msgid);

	}

	pHook = pCtx->GetFunctionById(params[2]);

	if (!pHook)

	{

		return pCtx->ThrowNativeError("Invalid function id (%X)", params[2]);

	}

	pNotify = pCtx->GetFunctionById(params[4]);

	intercept = (params[3]) ? true : false;

	pListener = s_UsrMessageNatives.CreateListener(pCtx);

	pListener->Initialize(msgid, pHook, pNotify, intercept);

	g_UserMsgs.HookUserMessage(msgid, pListener, intercept);

	return 1;

}

static cell_t smn_UnhookUserMessage(IPluginContext *pCtx, const cell_t *params)

{

	IPluginFunction *pFunc;

	MsgListenerWrapper *pListener;

	MsgWrapperIter iter;

	bool intercept;

	int msgid = params[1];

	if (msgid < 0 || msgid >= 255)

	{

		return pCtx->ThrowNativeError("Invalid message id supplied (%d)", msgid);

	}

	pFunc = pCtx->GetFunctionById(params[2]);

	if (!pFunc)

	{

		return pCtx->ThrowNativeError("Invalid function id (%X)", params[2]);

	}

	intercept = (params[3]) ? true : false;

	if (!s_UsrMessageNatives.FindListener(msgid, pCtx, pFunc, intercept, &iter))

	{

		return pCtx->ThrowNativeError("Unable to unhook the current user message");

	}

	pListener = (*iter);

	if (!g_UserMsgs.UnhookUserMessage(msgid, pListener, intercept))

	{

		return pCtx->ThrowNativeError("Unable to unhook the current user message");

	}

	s_UsrMessageNatives.DeleteListener(pCtx, iter);

	return 1;

}

REGISTER_NATIVES(usrmsgnatives)

{

	{"GetUserMessageId",			smn_GetUserMessageId},

	{"GetUserMessageName",			smn_GetUserMessageName},

	{"StartMessage",				smn_StartMessage},

	{"StartMessageEx",				smn_StartMessageEx},

	{"EndMessage",					smn_EndMessage},

	{"HookUserMessage",				smn_HookUserMessage},

	{"UnhookUserMessage",			smn_UnhookUserMessage},

	{NULL,							NULL}

};