/**

  * vim: set ts=4 :

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

  * SourceMod

  * Copyright (C) 2004-2007 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 <ISmmPluginExt.h>

 #include <stdarg.h>

 #include <string.h>

 #include <stdio.h>

 #if defined _MSC_VER

 	#define DLL_EXPORT				extern "C" __declspec(dllexport)

 	#define openlib(lib)			LoadLibrary(lib)

 	#define closelib(lib)			FreeLibrary(lib)

 	#define findsym(lib, sym)		GetProcAddress(lib, sym)

 	#define PLATFORM_EXT			".dll"

 	#define vsnprintf				_vsnprintf

 	#define PATH_SEP_CHAR			"\\"

 	inline bool IsPathSepChar(char c) 

 	{

 		return (c == '/' || c == '\\');

 	}

 	#include <Windows.h>

 #else

 	#define DLL_EXPORT				extern "C" __attribute__((visibility("default")))

 	#define openlib(lib)			dlopen(lib, RTLD_NOW)

 	#define closelib(lib)			dlclose(lib)

 	#define findsym(lib, sym)		dlsym(lib, sym)

 	#define PLATFORM_EXT			".so"

 	typedef void *					HINSTANCE;

 	#define PATH_SEP_CHAR			"/"

 	inline bool IsPathSepChar(char c) 

 	{

 		return (c == '/');

 	}

 	#include <dlfcn.h>

 #endif

 #define METAMOD_API_MAJOR			2

 #define FILENAME_1_4_EP1			"sourcemod.1.ep1" PLATFORM_EXT

 #define FILENAME_1_6_EP2			"sourcemod.2.ep2" PLATFORM_EXT

 #define FILENAME_1_6_EP1			"sourcemod.2.ep1" PLATFORM_EXT

 HINSTANCE g_hCore = NULL;

 bool load_attempted = false;

 size_t UTIL_Format(char *buffer, size_t maxlength, const char *fmt, ...);

 class FailPlugin : public SourceMM::ISmmFailPlugin

 {

 public:

 	int GetApiVersion()

 	{

 		return fail_version;

 	}

 	bool Load(SourceMM::PluginId id, SourceMM::ISmmAPI *ismm, char *error, size_t maxlength, bool late)

 	{

 		if (error != NULL && maxlength != 0)

 		{

 			UTIL_Format(error, maxlength, "%s", error_buffer);

 		}

 		return false;

 	}

 	int fail_version;

 	char error_buffer[512];

 } s_FailPlugin;

 size_t UTIL_Format(char *buffer, size_t maxlength, const char *fmt, ...)

 {

 	va_list ap;

 	va_start(ap, fmt);

 	size_t len = vsnprintf(buffer, maxlength, fmt, ap);

 	va_end(ap);

 	if (len >= maxlength)

 	{

 		len = maxlength - 1;

 		buffer[len] = '\0';

 	}

 	return len;

 }

 METAMOD_PLUGIN *_GetPluginPtr(const char *path, int fail_api)

 {

 	METAMOD_FN_ORIG_LOAD fn;

 	METAMOD_PLUGIN *pl;

 	int ret;

 	if (!(g_hCore=openlib(path)))

 	{

 #if defined __linux__

 		UTIL_Format(s_FailPlugin.error_buffer, 

 			sizeof(s_FailPlugin.error_buffer),

 			"%s",

 			dlerror());

 #else

 		DWORD err = GetLastError();

 		if (FormatMessageA(

 				FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,

 				NULL,

 				err,

 				MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

 				s_FailPlugin.error_buffer,

 				sizeof(s_FailPlugin.error_buffer),

 				NULL)

 			== 0)

 		{

 			UTIL_Format(s_FailPlugin.error_buffer, 

 				sizeof(s_FailPlugin.error_buffer),

 				"unknown error %x",

 				err);

 		}

 #endif

 		s_FailPlugin.fail_version = fail_api;

 		return (METAMOD_PLUGIN *)&s_FailPlugin;

 	}

 	if (!(fn=(METAMOD_FN_ORIG_LOAD)findsym(g_hCore, "CreateInterface")))

 	{

 		goto error;

 	}

 	pl = (METAMOD_PLUGIN *)fn(METAMOD_PLAPI_NAME, &ret);

 	if (!pl)

 	{

 		goto error;

 	}

 	return pl;

 error:

 	closelib(g_hCore);

 	g_hCore = NULL;

 	return NULL;

 }

 bool GetFileOfAddress(void *pAddr, char *buffer, size_t maxlength)

 {

 #if defined _MSC_VER

 	MEMORY_BASIC_INFORMATION mem;

 	if (!VirtualQuery(pAddr, &mem, sizeof(mem)))

 		return false;

 	if (mem.AllocationBase == NULL)

 		return false;

 	HMODULE dll = (HMODULE)mem.AllocationBase;

 	GetModuleFileName(dll, (LPTSTR)buffer, maxlength);

 #else

 	Dl_info info;

 	if (!dladdr(pAddr, &info))

 		return false;

 	if (!info.dli_fbase || !info.dli_fname)

 		return false;

 	const char *dllpath = info.dli_fname;

 	snprintf(buffer, maxlength, "%s", dllpath);

 #endif

 	return true;

 }

 DLL_EXPORT METAMOD_PLUGIN *CreateInterface_MMS(const MetamodVersionInfo *mvi, const MetamodLoaderInfo *mli)

 {

 	char *filename;

 	load_attempted = true;

 	if (mvi->api_major > METAMOD_API_MAJOR)

 	{

 		return NULL;

 	}

 	switch (mvi->source_engine)

 	{

 	case SOURCE_ENGINE_ORANGEBOX:

 		{

 			filename = FILENAME_1_6_EP2;

 			break;

 		}

 	case SOURCE_ENGINE_EPISODEONE:

 	case SOURCE_ENGINE_ORIGINAL:

 		{

 			filename = FILENAME_1_6_EP1;

 			break;

 		}

 	default:

 		{

 			return NULL;

 		}

 	}

 	char abspath[256];

 	UTIL_Format(abspath, sizeof(abspath), "%s" PATH_SEP_CHAR "%s", mli->pl_path, filename);

 	return _GetPluginPtr(abspath, METAMOD_FAIL_API_V2);

 }

 DLL_EXPORT void UnloadInterface_MMS()

 {

 	if (g_hCore)

 	{

 		closelib(g_hCore);

 		g_hCore = NULL;

 	}

 }

 DLL_EXPORT void *CreateInterface(const char *iface, int *ret)

 {

 	/**

 	 * If a load has already been attempted, bail out immediately.

 	 */

 	if (load_attempted)

 	{

 		return NULL;

 	}

 	if (strcmp(iface, METAMOD_PLAPI_NAME) == 0)

 	{

 		char thisfile[256];

 		char targetfile[256];

 		if (!GetFileOfAddress((void *)CreateInterface_MMS, thisfile, sizeof(thisfile)))

 		{

 			return NULL;

 		}

 		size_t len = strlen(thisfile);

 		for (size_t iter=len-1; iter>=0 && iter<len; iter--)

 		{

 			if (IsPathSepChar(thisfile[iter]))

 			{

 				thisfile[iter] = '\0';

 				break;

 			}

 		}

 		UTIL_Format(targetfile, sizeof(targetfile), "%s" PATH_SEP_CHAR FILENAME_1_4_EP1, thisfile);

 		return _GetPluginPtr(targetfile, METAMOD_FAIL_API_V1);

 	}

 	return NULL;

 }

 #if defined _MSC_VER

 BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved)

 {

 	if (fdwReason == DLL_PROCESS_DETACH)

 	{

 		UnloadInterface_MMS();

 	}

 	return TRUE;

 }

 #else

 __attribute__((destructor)) static void gcc_fini()

 {

 	UnloadInterface_MMS();

 }

 #endif