/**

  * 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 "ShareSys.h"

 #include "HandleSys.h"

 #include "ExtensionSys.h"

 #include "LibrarySys.h"

 #include "PluginSys.h"

 #include "sm_stringutil.h"

 ShareSystem g_ShareSys;

 static unsigned int g_mark_serial = 0;

 ShareSystem::ShareSystem()

 {

 	m_IdentRoot.ident = 0;

 	m_TypeRoot = 0;

 	m_IfaceType = 0;

 	m_CoreType = 0;

 }

 IdentityToken_t *ShareSystem::CreateCoreIdentity()

 {

 	if (!m_CoreType)

 	{

 		m_CoreType = CreateIdentType("CORE");

 	}

 	return CreateIdentity(m_CoreType, this);

 }

 void ShareSystem::Initialize()

 {

 	TypeAccess sec;

 	g_HandleSys.InitAccessDefaults(&sec, NULL);

 	sec.ident = GetIdentRoot();

 	m_TypeRoot = g_HandleSys.CreateType("Identity", this, 0, &sec, NULL, NULL, NULL);

 	m_IfaceType = g_HandleSys.CreateType("Interface", this, 0, NULL, NULL, GetIdentRoot(), NULL);

 	/* Initialize our static identity handle */

 	m_IdentRoot.ident = g_HandleSys.CreateHandle(m_TypeRoot, NULL, NULL, GetIdentRoot(), NULL);

 	/* Add the Handle System and others... they are too innocent and pure to do it themselves */

 	AddInterface(NULL, &g_HandleSys);

 	AddInterface(NULL, &g_LibSys);

 }

 void ShareSystem::OnSourceModShutdown()

 {

 	if (m_CoreType)

 	{

 		g_HandleSys.RemoveType(m_CoreType, GetIdentRoot());

 	}

 	g_HandleSys.RemoveType(m_IfaceType, GetIdentRoot());

 	g_HandleSys.RemoveType(m_TypeRoot, GetIdentRoot());

 }

 IdentityType_t ShareSystem::FindIdentType(const char *name)

 {

 	HandleType_t type;

 	if (g_HandleSys.FindHandleType(name, &type))

 	{

 		if (g_HandleSys.TypeCheck(type, m_TypeRoot))

 		{

 			return type;

 		}

 	}

 	return 0;

 }

 IdentityType_t ShareSystem::CreateIdentType(const char *name)

 {

 	if (!m_TypeRoot)

 	{

 		return 0;

 	}

 	return g_HandleSys.CreateType(name, this, m_TypeRoot, NULL, NULL, GetIdentRoot(), NULL);

 }

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

 {

 	/* THIS WILL NEVER BE CALLED FOR ANYTHING WITH THE IDENTITY TYPE */

 }

 IdentityToken_t *ShareSystem::CreateIdentity(IdentityType_t type, void *ptr)

 {

 	if (!m_TypeRoot)

 	{

 		return 0;

 	}

 	/* :TODO: Cache? */

 	IdentityToken_t *pToken = new IdentityToken_t;

 	HandleSecurity sec;

 	sec.pOwner = sec.pIdentity = GetIdentRoot();

 	pToken->ident = g_HandleSys.CreateHandleInt(type, NULL, &sec, NULL, NULL, true);

 	pToken->ptr = ptr;

 	pToken->type = type;

 	return pToken;

 }

 bool ShareSystem::AddInterface(IExtension *myself, SMInterface *iface)

 {

 	if (!iface)

 	{

 		return false;

 	}

 	IfaceInfo info;

 	info.owner = myself;

 	info.iface = iface;

 	m_Interfaces.push_back(info);

 	return true;

 }

 bool ShareSystem::RequestInterface(const char *iface_name, 

 								   unsigned int iface_vers, 

 								   IExtension *myself, 

 								   SMInterface **pIface)

 {

 	/* See if the interface exists */

 	List<IfaceInfo>::iterator iter;

 	SMInterface *iface;

 	IExtension *iface_owner;

 	bool found = false;

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

 	{

 		IfaceInfo &info = (*iter);

 		iface = info.iface;

 		if (strcmp(iface->GetInterfaceName(), iface_name) == 0)

 		{

 			if (iface->GetInterfaceVersion() == iface_vers

 				|| iface->IsVersionCompatible(iface_vers))

 			{

 				iface_owner = info.owner;

 				found = true;

 				break;

 			}

 		}

 	}

 	if (!found)

 	{

 		return false;

 	}

 	/* Add a dependency node */

 	if (iface_owner)

 	{

 		IfaceInfo info;

 		info.iface = iface;

 		info.owner = iface_owner;

 		g_Extensions.BindDependency(myself, &info);

 	}

 	if (pIface)

 	{

 		*pIface = iface;

 	}

 	return true;

 }

 void ShareSystem::AddNatives(IExtension *myself, const sp_nativeinfo_t *natives)

 {

 	CNativeOwner *pOwner;

 	pOwner = g_Extensions.GetNativeOwner(myself);

 	pOwner->AddNatives(natives);

 }

 void ShareSystem::DestroyIdentity(IdentityToken_t *identity)

 {

 	HandleSecurity sec;

 	sec.pOwner = GetIdentRoot();

 	sec.pIdentity = GetIdentRoot();

 	g_HandleSys.FreeHandle(identity->ident, &sec);

 	delete identity;

 }

 void ShareSystem::DestroyIdentType(IdentityType_t type)

 {

 	g_HandleSys.RemoveType(type, GetIdentRoot());

 }

 void ShareSystem::RemoveInterfaces(IExtension *pExtension)

 {

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

 	while (iter != m_Interfaces.end())

 	{

 		if ((*iter).owner == pExtension)

 		{

 			iter = m_Interfaces.erase(iter);

 		}

 		else

 		{

 			iter++;

 		}

 	}

 }

 void ShareSystem::AddDependency(IExtension *myself, const char *filename, bool require, bool autoload)

 {

 	g_Extensions.AddDependency(myself, filename, require, autoload);

 }

 void ShareSystem::RegisterLibrary(IExtension *myself, const char *name)

 {

 	g_Extensions.AddLibrary(myself, name);

 }

 void ShareSystem::OverrideNatives(IExtension *myself, const sp_nativeinfo_t *natives)

 {

 	unsigned int i;

 	NativeEntry *pEntry;

 	CNativeOwner *pOwner;

 	pOwner = g_Extensions.GetNativeOwner(myself);

 	for (i = 0; natives[i].func != NULL && natives[i].name != NULL; i++)

 	{

 		if ((pEntry = FindNative(natives[i].name)) == NULL)

 		{

 			continue;

 		}

 		if (pEntry->owner != g_pCoreNatives)

 		{

 			continue;

 		}

 		if (pEntry->replacement.owner != NULL)

 		{

 			continue;

 		}

 		/* Now it's safe to add the override */

 		pEntry->replacement.func = natives[i].func;

 		pEntry->replacement.owner = pOwner;

 		pOwner->AddReplacedNative(pEntry);

 	}

 }

 NativeEntry *ShareSystem::FindNative(const char *name)

 {

 	NativeEntry **ppEntry;

 	if ((ppEntry = m_NtvCache.retrieve(name)) == NULL)

 	{

 		return NULL;

 	}

 	return *ppEntry;

 }

 void ShareSystem::BindNativesToPlugin(CPlugin *pPlugin, bool bCoreOnly)

 {

 	NativeEntry *pEntry;

 	sp_native_t *native;

 	uint32_t i, native_count;

 	IPluginContext *pContext;

 	pContext = pPlugin->GetBaseContext();

 	/* Generate a new serial ID, mark our dependencies with it. */

 	g_mark_serial++;

 	pPlugin->PropogateMarkSerial(g_mark_serial);

 	native_count = pContext->GetNativesNum();

 	for (i = 0; i < native_count; i++)

 	{

 		if (pContext->GetNativeByIndex(i, &native) != SP_ERROR_NONE)

 		{

 			continue;

 		}

 		/* If we're bound, check if there is a replacement available.  

 		 * If not, this native is totally finalized.

 		 */

 		if (native->status == SP_NATIVE_BOUND)

 		{

 			pEntry = (NativeEntry *)native->user;

 			assert(pEntry != NULL);

 			if (pEntry->replacement.owner == NULL

 				|| (pEntry->replacement.owner != NULL 

 				&&  pEntry->replacement.func == native->pfn))

 			{

 				continue;

 			}

 		}

 		/* Otherwise, the native must be in our cache. */

 		else if ((pEntry = FindNative(native->name)) == NULL)

 		{

 			continue;

 		}

 		if (bCoreOnly && pEntry->owner != g_pCoreNatives)

 		{

 			continue;

 		}

 		BindNativeToPlugin(pPlugin, native, i, pEntry);

 	}

 }

 void ShareSystem::BindNativeToPlugin(CPlugin *pPlugin, NativeEntry *pEntry)

 {

 	uint32_t i;

 	sp_native_t *native;

 	IPluginContext *pContext;

 	pContext = pPlugin->GetBaseContext();

 	if (pContext->FindNativeByName(pEntry->name, &i) != SP_ERROR_NONE)

 	{

 		return;

 	}

 	if (pContext->GetNativeByIndex(i, &native) != SP_ERROR_NONE)

 	{

 		return;

 	}

 	if (native->status == SP_NATIVE_BOUND)

 	{

 		return;

 	}

 	BindNativeToPlugin(pPlugin, native, i, pEntry);

 }

 void ShareSystem::BindNativeToPlugin(CPlugin *pPlugin, 

 									 sp_native_t *native,

 									 uint32_t index,

 									 NativeEntry *pEntry)

 {

 	/* Mark as bound... we do the rest next. */

 	native->status = SP_NATIVE_BOUND;

 	native->user = pEntry;

 	/* See if a replacement is available. */

 	if (pEntry->replacement.owner != NULL)

 	{

 		/* Perform a replacement bind. */

 		native->pfn = pEntry->replacement.func;

 		pEntry->replacement.owner->AddWeakRef(WeakNative(pPlugin, index, pEntry));

 	}

 	else

 	{

 		/* Perform a normal bind. */

 		native->pfn = pEntry->func;

 		/* We don't bother with dependency crap if the owner is Core. */

 		if (pEntry->owner != g_pCoreNatives)

 		{

 			/* The native is optional, this is a special case */

 			if ((native->flags & SP_NTVFLAG_OPTIONAL) == SP_NTVFLAG_OPTIONAL)

 			{

 				/* Only add if there is a valid owner. */

 				if (pEntry->owner != NULL)

 				{

 					pEntry->owner->AddWeakRef(WeakNative(pPlugin, index));

 				}

 				else

 				{

 					native->status = SP_NATIVE_UNBOUND;

 				}

 			}

 			/* Otherwise, we're a strong dependent and not a weak one */

 			else

 			{

 				/* See if this has already been marked as a dependent.

 				 * If it has, it means this relationship has already occurred, 

 				 * and there is no reason to do it again.

 				 */

 				if (pEntry->owner != pPlugin 

 					&& pEntry->owner->GetMarkSerial() != g_mark_serial)

 				{

 					/* This has not been marked as a dependency yet */

 					//pPlugin->AddDependency(pEntry->owner);

 					pEntry->owner->AddDependent(pPlugin);

 					pEntry->owner->SetMarkSerial(g_mark_serial);

 				}

 			}

 		}

 	}

 }

 NativeEntry *ShareSystem::AddNativeToCache(CNativeOwner *pOwner, const sp_nativeinfo_t *ntv)

 {

 	NativeEntry *pEntry;

 	if ((pEntry = FindNative(ntv->name)) == NULL)

 	{

 		pEntry = new NativeEntry;

 		pEntry->owner = pOwner;

 		pEntry->name = ntv->name;

 		pEntry->func = ntv->func;

 		pEntry->replacement.func = NULL;

 		pEntry->replacement.owner = NULL;

 		pEntry->fake = NULL;

 		m_NtvCache.insert(ntv->name, pEntry);

 		return pEntry;

 	}

 	if (pEntry->owner != NULL)

 	{

 		return NULL;

 	}

 	pEntry->owner = pOwner;

 	pEntry->func = ntv->func;

 	pEntry->name = ntv->name;

 	return pEntry;

 }

 void ShareSystem::ClearNativeFromCache(CNativeOwner *pOwner, const char *name)

 {

 	NativeEntry *pEntry;

 	if ((pEntry = FindNative(name)) == NULL)

 	{

 		return;

 	}

 	if (pEntry->owner != pOwner)

 	{

 		return;

 	}

 	if (pEntry->fake != NULL)

 	{

 		g_pSourcePawn2->DestroyFakeNative(pEntry->func);

 		delete pEntry->fake;

 		pEntry->fake = NULL;

 	}

 	pEntry->func = NULL;

 	pEntry->name = NULL;

 	pEntry->owner = NULL;

 	pEntry->replacement.func = NULL;

 	pEntry->replacement.owner = NULL;

 }

 NativeEntry *ShareSystem::AddFakeNative(IPluginFunction *pFunc, const char *name, SPVM_FAKENATIVE_FUNC func)

 {

 	FakeNative *pFake;

 	NativeEntry *pEntry;

 	SPVM_NATIVE_FUNC gate;

 	if ((pEntry = FindNative(name)) != NULL && pEntry->owner != NULL)

 	{

 		return NULL;

 	}

 	pFake = new FakeNative;

 	if ((gate = g_pSourcePawn2->CreateFakeNative(func, pFake)) == NULL)

 	{

 		delete pFake;

 		return NULL;

 	}

 	if (pEntry == NULL)

 	{

 		pEntry = new NativeEntry;

 		m_NtvCache.insert(name, pEntry);

 	}

 	pFake->call = pFunc;

 	pFake->ctx = pFunc->GetParentContext();

 	strncopy(pFake->name, name, sizeof(pFake->name));

 	pEntry->fake = pFake;

 	pEntry->func = gate;

 	pEntry->name = pFake->name;

 	pEntry->owner = g_PluginSys.GetPluginByCtx(pFake->ctx->GetContext());

 	pEntry->replacement.func = NULL;

 	pEntry->replacement.owner = NULL;

 	return pEntry;

 }