/**

 * 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 <stdlib.h>

#include "ExtensionSys.h"

#include "LibrarySys.h"

#include "ShareSys.h"

#include "Logger.h"

#include "sourcemm_api.h"

#include "sm_srvcmds.h"

#include "sm_stringutil.h"

CExtensionManager g_Extensions;

IdentityType_t g_ExtType;

void CExtension::Initialize(const char *filename, const char *path)

{

	m_pAPI = NULL;

	m_pIdentToken = NULL;

	unload_code = 0;

	m_bFullyLoaded = false;

	m_File.assign(filename);

	m_Path.assign(path);

}

CRemoteExtension::CRemoteExtension(IExtensionInterface *pAPI, const char *filename, const char *path)

{

	Initialize(filename, path);

	m_pAPI = pAPI;

}

CLocalExtension::CLocalExtension(const char *filename)

{

	m_PlId = 0;

	m_pLib = NULL;

	char path[PLATFORM_MAX_PATH];

	/* First see if there is an engine specific build! */

	g_SourceMod.BuildPath(Path_SM, 

		path, 

		PLATFORM_MAX_PATH, 

#if defined METAMOD_PLAPI_VERSION

#if SOURCE_ENGINE == SE_LEFT4DEAD

		"extensions/auto.2.l4d/%s",

#elif SOURCE_ENGINE == SE_ORANGEBOX

		"extensions/auto.2.ep2/%s",

#elif SOURCE_ENGINE == SE_DARKMESSIAH

		"extensions/auto.2.darkm/%s",

#else

		"extensions/auto.2.ep1/%s",

#endif //SOURCE_ENGINE == SE_LEFT4DEAD

#else  //METAMOD_PLAPI_VERSION

		"extensions/auto.1.ep1/%s",

#endif //METAMOD_PLAPI_VERSION

		filename);

	/* Try the "normal" version */

	if (!g_LibSys.IsPathFile(path))

	{

		g_SourceMod.BuildPath(Path_SM, path, PLATFORM_MAX_PATH, "extensions/%s", filename);

	}

	Initialize(filename, path);

}

bool CRemoteExtension::Load(char *error, size_t maxlength)

{

	if (!PerformAPICheck(error, maxlength))

	{

		m_pAPI = NULL;

		return false;

	}

	if (!CExtension::Load(error, maxlength))

	{

		m_pAPI = NULL;

		return false;

	}

	return true;

}

bool CLocalExtension::Load(char *error, size_t maxlength)

{

	m_pLib = g_LibSys.OpenLibrary(m_Path.c_str(), error, maxlength);

	if (m_pLib == NULL)

	{

		return false;

	}

	typedef IExtensionInterface *(*GETAPI)();

	GETAPI pfnGetAPI = NULL;

	if ((pfnGetAPI=(GETAPI)m_pLib->GetSymbolAddress("GetSMExtAPI")) == NULL)

	{

		m_pLib->CloseLibrary();

		m_pLib = NULL;

		snprintf(error, maxlength, "Unable to find extension entry point");

		return false;

	}

	m_pAPI = pfnGetAPI();

	/* Check pointer and version */

	if (!PerformAPICheck(error, maxlength))

	{

		m_pLib->CloseLibrary();

		m_pLib = NULL;

		m_pAPI = NULL;

		return false;

	}

	/* Load as MM:S */

	if (m_pAPI->IsMetamodExtension())

	{

		bool already;

		m_PlId = g_pMMPlugins->Load(m_Path.c_str(), g_PLID, already, error, maxlength);

	}

	if (!CExtension::Load(error, maxlength))

	{

		if (m_pAPI->IsMetamodExtension())

		{

			if (m_PlId)

			{

				char dummy[255];

				g_pMMPlugins->Unload(m_PlId, true, dummy, sizeof(dummy));

				m_PlId = 0;

			}

		}

		m_pLib->CloseLibrary();

		m_pLib = NULL;

		m_pAPI = NULL;

		return false;

	}

	return true;

}

void CRemoteExtension::Unload()

{

}

void CLocalExtension::Unload()

{

	if (m_pAPI != NULL && m_PlId)

	{

		char temp_buffer[255];

		g_pMMPlugins->Unload(m_PlId, true, temp_buffer, sizeof(temp_buffer));

		m_PlId = 0;

	}

	if (m_pLib != NULL)

	{

		m_pLib->CloseLibrary();

		m_pLib = NULL;

	}

}

bool CRemoteExtension::IsExternal()

{

	return true;

}

bool CLocalExtension::IsExternal()

{

	return false;

}

CExtension::~CExtension()

{

	DestroyIdentity();

}

bool CExtension::PerformAPICheck(char *error, size_t maxlength)

{

	if (!m_pAPI)

	{

		snprintf(error, maxlength, "No IExtensionInterface instance provided");

		return false;

	}

	if (m_pAPI->GetExtensionVersion() > SMINTERFACE_EXTENSIONAPI_VERSION)

	{

		snprintf(error, maxlength, "Extension version is too new to load (%d, max is %d)", m_pAPI->GetExtensionVersion(), SMINTERFACE_EXTENSIONAPI_VERSION);

		return false;

	}

	return true;

}

bool CExtension::Load(char *error, size_t maxlength)

{

	CreateIdentity();

	if (!m_pAPI->OnExtensionLoad(this, &g_ShareSys, error, maxlength, !g_SourceMod.IsMapLoading()))

	{

		DestroyIdentity();

		return false;

	}

	else

	{

		/* Check if we're past load time */

		if (!g_SourceMod.IsMapLoading())

		{

			m_pAPI->OnExtensionsAllLoaded();

		}

	}

	return true;

}

void CExtension::CreateIdentity()

{

	if (m_pIdentToken != NULL)

	{

		return;

	}

	m_pIdentToken = g_ShareSys.CreateIdentity(g_ExtType, this);

}

void CExtension::DestroyIdentity()

{

	if (m_pIdentToken == NULL)

	{

		return;

	}

	g_ShareSys.DestroyIdentity(m_pIdentToken);

	m_pIdentToken = NULL;

}

void CExtension::MarkAllLoaded()

{

	assert(m_bFullyLoaded == false);

	if (!m_bFullyLoaded)

	{

		m_bFullyLoaded = true;

		m_pAPI->OnExtensionsAllLoaded();

	}

}

void CExtension::AddPlugin(CPlugin *pPlugin)

{

	/* Unfortunately we have to do this :( */

	if (m_Dependents.find(pPlugin) != m_Dependents.end())

	{

		m_Dependents.push_back(pPlugin);

	}

}

void CExtension::SetError(const char *error)

{

	m_Error.assign(error);

}

IExtensionInterface *CExtension::GetAPI()

{

	return m_pAPI;

}

const char *CExtension::GetFilename()

{

	return m_File.c_str();

}

IdentityToken_t *CExtension::GetIdentity()

{

	return m_pIdentToken;

}

bool CRemoteExtension::IsLoaded()

{

	return (m_pAPI != NULL);

}

bool CLocalExtension::IsLoaded()

{

	return (m_pLib != NULL);

}

void CExtension::AddDependency(const IfaceInfo *pInfo)

{

	if (m_Deps.find(*pInfo) == m_Deps.end())

	{

		m_Deps.push_back(*pInfo);

	}

}

bool operator ==(const IfaceInfo &i1, const IfaceInfo &i2)

{

	return (i1.iface == i2.iface) && (i1.owner == i2.owner);

}

void CExtension::AddChildDependent(CExtension *pOther, SMInterface *iface)

{

	IfaceInfo info;

	info.iface = iface;

	info.owner = pOther;

	List<IfaceInfo>::iterator iter;

	for (iter = m_ChildDeps.begin();

		 iter != m_ChildDeps.end();

		 iter++)

	{

		IfaceInfo &other = (*iter);

		if (other == info)

		{

			return;

		}

	}

	m_ChildDeps.push_back(info);

}

ITERATOR *CExtension::FindFirstDependency(IExtension **pOwner, SMInterface **pInterface)

{

	List<IfaceInfo>::iterator iter = m_Deps.begin();

	if (iter == m_Deps.end())

	{

		return NULL;

	}

	if (pOwner)

	{

		*pOwner = (*iter).owner;

	}

	if (pInterface)

	{

		*pInterface = (*iter).iface;

	}

	List<IfaceInfo>::iterator *pIter = new List<IfaceInfo>::iterator(iter);

	return (ITERATOR *)pIter;

}

bool CExtension::FindNextDependency(ITERATOR *iter, IExtension **pOwner, SMInterface **pInterface)

{

	List<IfaceInfo>::iterator *pIter = (List<IfaceInfo>::iterator *)iter;

	List<IfaceInfo>::iterator _iter;

	if (_iter == m_Deps.end())

	{

		return false;

	}

	_iter++;

	if (pOwner)

	{

		*pOwner = (*_iter).owner;

	}

	if (pInterface)

	{

		*pInterface = (*_iter).iface;

	}

	*pIter = _iter;

	if (_iter == m_Deps.end())

	{

		return false;

	}

	return true;

}

void CExtension::FreeDependencyIterator(ITERATOR *iter)

{

	List<IfaceInfo>::iterator *pIter = (List<IfaceInfo>::iterator *)iter;

	delete pIter;

}

void CExtension::AddInterface(SMInterface *pInterface)

{

	m_Interfaces.push_back(pInterface);

}

bool CExtension::IsRunning(char *error, size_t maxlength)

{

	if (!IsLoaded())

	{

		if (error)

		{

			snprintf(error, maxlength, "%s", m_Error.c_str());

		}

		return false;

	}

	return m_pAPI->QueryRunning(error, maxlength);

}

void CExtension::AddLibrary(const char *library)

{

	m_Libraries.push_back(library);

}

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

 * EXTENSION MANAGER *

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

void CExtensionManager::OnSourceModAllInitialized()

{

	g_ExtType = g_ShareSys.CreateIdentType("EXTENSION");

	g_PluginSys.AddPluginsListener(this);

	g_RootMenu.AddRootConsoleCommand("exts", "Manage extensions", this);

	g_ShareSys.AddInterface(NULL, this);

}

void CExtensionManager::OnSourceModShutdown()

{

	g_RootMenu.RemoveRootConsoleCommand("exts", this);

	g_ShareSys.DestroyIdentType(g_ExtType);

}

void CExtensionManager::Shutdown()

{

	List<CExtension *>::iterator iter;

	while ((iter = m_Libs.begin()) != m_Libs.end())

	{

		UnloadExtension((*iter));

	}

}

void CExtensionManager::TryAutoload()

{

	char path[PLATFORM_MAX_PATH];

	g_SourceMod.BuildPath(Path_SM, path, sizeof(path), "extensions");

	IDirectory *pDir = g_LibSys.OpenDirectory(path);

	if (!pDir)

	{

		return;

	}

	const char *lfile;

	size_t len;

	while (pDir->MoreFiles())

	{

		if (pDir->IsEntryDirectory())

		{

			pDir->NextEntry();

			continue;

		}

		lfile = pDir->GetEntryName();

		len = strlen(lfile);

		if (len <= 9) /* size of ".autoload" */

		{

			pDir->NextEntry();

			continue;

		}

		if (strcmp(&lfile[len - 9], ".autoload") != 0)

		{

			pDir->NextEntry();

			continue;

		}

		char file[PLATFORM_MAX_PATH];

		len = UTIL_Format(file, sizeof(file), "%s", lfile);

		strcpy(&file[len - 9], ".ext." PLATFORM_LIB_EXT);

		LoadAutoExtension(file);

		pDir->NextEntry();

	}

}

IExtension *CExtensionManager::LoadAutoExtension(const char *path)

{

	if (!strstr(path, "." PLATFORM_LIB_EXT))

	{

		char newpath[PLATFORM_MAX_PATH];

		g_LibSys.PathFormat(newpath, sizeof(newpath), "%s.%s", path, PLATFORM_LIB_EXT);

		return LoadAutoExtension(newpath);

	}

	IExtension *pAlready;

	if ((pAlready=FindExtensionByFile(path)) != NULL)

	{

		return pAlready;

	}

	char error[256];

	CExtension *p = new CLocalExtension(path);

	/* We put us in the list beforehand so extensions that check for each other

	 * won't recursively load each other.

	 */

	m_Libs.push_back(p);

	if (!p->Load(error, sizeof(error)) || !p->IsLoaded())

	{

		g_Logger.LogError("[SM] Unable to load extension \"%s\": %s", path, error);

		p->SetError(error);

	}

	return p;

}

IExtension *CExtensionManager::FindExtensionByFile(const char *file)

{

	List<CExtension *>::iterator iter;

	CExtension *pExt;

	/* Chomp off the path */

	char lookup[PLATFORM_MAX_PATH];

	g_LibSys.GetFileFromPath(lookup, sizeof(lookup), file);

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

	{

		pExt = (*iter);

		char short_file[PLATFORM_MAX_PATH];

		g_LibSys.GetFileFromPath(short_file, sizeof(short_file), pExt->GetFilename());

		if (strcmp(lookup, short_file) == 0)

		{

			return pExt;

		}

	}

	/* If we got no results, test if there was a platform extension.

	 * If not, add one.

	 */

	if (!strstr(file, "." PLATFORM_LIB_EXT))

	{

		char path[PLATFORM_MAX_PATH];

		UTIL_Format(path, sizeof(path), "%s.%s", file, PLATFORM_LIB_EXT);

		return FindExtensionByFile(path);

	}

	return NULL;

}

IExtension *CExtensionManager::FindExtensionByName(const char *ext)

{

	List<CExtension *>::iterator iter;

	CExtension *pExt;

	IExtensionInterface *pAPI;

	const char *name;

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

	{

		pExt = (*iter);

		if (!pExt->IsLoaded())

		{

			continue;

		}

		if ((pAPI = pExt->GetAPI()) == NULL)

		{

			continue;

		}

		name = pAPI->GetExtensionName();

		if (!name)

		{

			continue;

		}

		if (strcmp(name, ext) == 0)

		{

			return pExt;

		}

	}

	return NULL;

}

IExtension *CExtensionManager::LoadExtension(const char *file, char *error, size_t maxlength)

{

	IExtension *pAlready;

	if ((pAlready=FindExtensionByFile(file)) != NULL)

	{

		return pAlready;

	}

	CExtension *pExt = new CLocalExtension(file);

	if (!pExt->Load(error, maxlength) || !pExt->IsLoaded())

	{

		pExt->Unload();

		delete pExt;

		return NULL;

	}

	/* :TODO: do QueryRunning check if the map is loaded */

	m_Libs.push_back(pExt);