/**

 * 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: $Id$

 */

#ifndef _INCLUDE_SOURCEMOD_FORWARDSYSTEM_H_

#define _INCLUDE_SOURCEMOD_FORWARDSYSTEM_H_

#include <IForwardSys.h>

#include <IPluginSys.h>

#include "sm_globals.h"

#include <sh_list.h>

#include <sh_stack.h>

#include "sourcemod.h"

using namespace SourceHook;

typedef List<IPluginFunction *>::iterator FuncIter;

/* :TODO: a global name max define for sourcepawn, should mirror compiler's sNAMEMAX */

#define FORWARDS_NAME_MAX		64

struct ByrefInfo

{

	unsigned int cells;

	cell_t *orig_addr;

	int flags;

	int sz_flags;

};

struct FwdParamInfo

{

	cell_t val;

	ByrefInfo byref;

	ParamType pushedas;

};

class SourceMod::IForwardFilter

{

public:

	virtual void Preprocess(IPluginFunction *fun, FwdParamInfo *params)

	{

	}

};

class FuncIteratorGuard

{

	bool triggered;

	FuncIteratorGuard **pprev;

	FuncIter *iter;

	FuncIteratorGuard *next;

public:

	FuncIteratorGuard(FuncIteratorGuard **pprev, FuncIter *iter)

		: triggered(false), pprev(pprev), iter(iter), next(*pprev)

	{

		*pprev = this;

	}

	~FuncIteratorGuard()

	{

		*pprev = next;

	}

	inline bool Triggered()

	{

		bool t = triggered;

		triggered = false;

		return t;

	}

	/**

	 * This should not read from |this| before the NULL check, because FwdSys

	 * can call (NULL)->FixIteratorChain().

	 */

	void FixIteratorChain(FuncIter &other)

	{

		FuncIteratorGuard *guard = this;

		while (guard != NULL)

		{

			if (*guard->iter == other)

			{

				*(guard->iter) = ++(*(guard->iter));

				guard->triggered = true;

			}

			guard = guard->next;

		}

	}

};

class CForward : public IChangeableForward

{

public: //ICallable

	virtual int PushCell(cell_t cell);

	virtual int PushCellByRef(cell_t *cell, int flags);

	virtual int PushFloat(float number);

	virtual int PushFloatByRef(float *number, int flags);

	virtual int PushArray(cell_t *inarray, unsigned int cells, int flags);

	virtual int PushString(const char *string);

	virtual int PushStringEx(char *buffer, size_t length, int sz_flags, int cp_flags);

	virtual void Cancel();

public: //IForward

	virtual const char *GetForwardName();

	virtual unsigned int GetFunctionCount();

	virtual ExecType GetExecType();

	virtual int Execute(cell_t *result, IForwardFilter *filter);

public: //IChangeableForward

	virtual bool RemoveFunction(IPluginFunction *func);

	virtual unsigned int RemoveFunctionsOfPlugin(IPlugin *plugin);

	virtual bool AddFunction(IPluginFunction *func);

	virtual bool AddFunction(IPluginContext *ctx, funcid_t index);

	virtual bool RemoveFunction(IPluginContext *ctx, funcid_t index);

public:

	static CForward *CreateForward(const char *name, 

								   ExecType et, 

								   unsigned int num_params, 

								   const ParamType *types, 

								   va_list ap);

private:

	void _Int_PushArray(cell_t *inarray, unsigned int cells, int flags);

	void _Int_PushString(cell_t *inarray, unsigned int cells, int sz_flags, int cp_flags);

	inline int SetError(int err)

	{

		m_errstate = err;

		return err;

	}

protected:

	/* :TODO: I want a caching list type here.

	 * Destroying these things and using new/delete for their members feels bad.

	 */

	mutable List<IPluginFunction *> m_functions;

	mutable List<IPluginFunction *> m_paused;

	FuncIteratorGuard *m_IterGuard;

	/* Type and name information */

	FwdParamInfo m_params[SP_MAX_EXEC_PARAMS];

	ParamType m_types[SP_MAX_EXEC_PARAMS];

	char m_name[FORWARDS_NAME_MAX+1];

	unsigned int m_numparams;

	unsigned int m_varargs;

	ExecType m_ExecType;

	/* State information */

	unsigned int m_curparam;

	int m_errstate;

};

class CForwardManager : 

	public IForwardManager,

	public IPluginsListener,

	public SMGlobalClass

{

	friend class CForward;

public:

	~CForwardManager();

public: //IForwardManager

	IForward *CreateForward(const char *name, 

		ExecType et, 

		unsigned int num_params, 

		const ParamType *types, 

		...);

	IChangeableForward *CreateForwardEx(const char *name, 

		ExecType et, 

		int num_params, 

		const ParamType *types, 

		...);

	IForward *FindForward(const char *name, IChangeableForward **ifchng);

	void ReleaseForward(IForward *forward);

public: //IPluginsListener

	void OnPluginLoaded(IPlugin *plugin);

	void OnPluginUnloaded(IPlugin *plugin);

	void OnPluginPauseChange(IPlugin *plugin, bool paused);

public: //SMGlobalClass

	void OnSourceModAllInitialized();

protected:

	CForward *ForwardMake();

	void ForwardFree(CForward *fwd);

private:

	CStack<CForward *> m_FreeForwards;

	List<CForward *> m_managed;

	List<CForward *> m_unmanaged;

};

extern CForwardManager g_Forwards;

#endif //_INCLUDE_SOURCEMOD_FORWARDSYSTEM_H_