/**

  * 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 "Database.h"

 #include "HandleSys.h"

 #include "ShareSys.h"

 #include "sourcemod.h"

 #include "sm_stringutil.h"

 #include "Logger.h"

 #include "ExtensionSys.h"

 #include <stdlib.h>

 #include "ThreadSupport.h"

 #define DBPARSE_LEVEL_NONE		0

 #define DBPARSE_LEVEL_MAIN		1

 #define DBPARSE_LEVEL_DATABASE	2

 DBManager g_DBMan;

 static bool s_OneTimeThreaderErrorMsg = false;

 DBManager::DBManager() 

 : m_StrTab(512), m_ParseLevel(0), m_ParseState(0), m_pDefault(NULL)

 {

 }

 void DBManager::OnSourceModAllInitialized()

 {

 	HandleAccess sec;

 	g_HandleSys.InitAccessDefaults(NULL, &sec);

 	sec.access[HandleAccess_Delete] |= HANDLE_RESTRICT_IDENTITY;

 	sec.access[HandleAccess_Clone] |= HANDLE_RESTRICT_IDENTITY;

 	m_DriverType = g_HandleSys.CreateType("IDriver", this, 0, NULL, &sec, g_pCoreIdent, NULL);

 	m_DatabaseType = g_HandleSys.CreateType("IDatabase", this, 0, NULL, NULL, g_pCoreIdent, NULL);

 	g_ShareSys.AddInterface(NULL, this);

 	g_SourceMod.BuildPath(Path_SM, m_Filename, sizeof(m_Filename), "configs/databases.cfg");

 	m_pConfigLock = g_pThreader->MakeMutex();

 	m_pThinkLock = g_pThreader->MakeMutex();

 	m_pQueueLock = g_pThreader->MakeMutex();

 	g_PluginSys.AddPluginsListener(this);

 }

 void DBManager::OnSourceModLevelChange(const char *mapName)

 {

 	SMCError err;

 	SMCStates states = {0, 0};

 	/* We lock and don't give up the lock until we're done.

 	 * This way the thread's search won't be searching through a

 	 * potentially empty/corrupt list, which would be very bad.

 	 */

 	m_pConfigLock->Lock();

 	if ((err = textparsers->ParseFile_SMC(m_Filename, this, &states)) != SMCError_Okay)

 	{

 		g_Logger.LogError("[SM] Detected parse error(s) in file \"%s\"", m_Filename);

 		if (err != SMCError_Custom)

 		{

 			const char *txt = textparsers->GetSMCErrorString(err);

 			g_Logger.LogError("[SM] Line %d: %s", states.line, txt);

 		}

 	}

 	m_pConfigLock->Unlock();

 }

 void DBManager::OnSourceModShutdown()

 {

 	KillWorkerThread();

 	g_PluginSys.RemovePluginsListener(this);

 	m_pConfigLock->DestroyThis();

 	m_pThinkLock->DestroyThis();

 	m_pQueueLock->DestroyThis();

 	g_HandleSys.RemoveType(m_DatabaseType, g_pCoreIdent);

 	g_HandleSys.RemoveType(m_DriverType, g_pCoreIdent);

 }

 unsigned int DBManager::GetInterfaceVersion()

 {

 	return SMINTERFACE_DBI_VERSION;

 }

 const char *DBManager::GetInterfaceName()

 {

 	return SMINTERFACE_DBI_NAME;

 }

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

 {

 	if (type == m_DriverType)

 	{

 		/* Ignore */

 		return;

 	}

 	if (g_HandleSys.TypeCheck(type, m_DatabaseType))

 	{

 		IDatabase *pdb = (IDatabase *)object;

 		pdb->Close();

 	}

 }

 void DBManager::ReadSMC_ParseStart()

 {

 	m_confs.clear();

 	m_ParseLevel = 0;

 	m_ParseState = DBPARSE_LEVEL_NONE;

 	m_StrTab.Reset();

 	m_DefDriver.clear();

 }

 ConfDbInfo s_CurInfo;

 SMCResult DBManager::ReadSMC_NewSection(const SMCStates *states, const char *name)

 {

 	if (m_ParseLevel)

 	{

 		m_ParseLevel++;

 		return SMCResult_Continue;

 	}

 	if (m_ParseState == DBPARSE_LEVEL_NONE)

 	{

 		if (strcmp(name, "Databases") == 0)

 		{

 			m_ParseState = DBPARSE_LEVEL_MAIN;

 		} else {

 			m_ParseLevel++;

 		}

 	} else if (m_ParseState == DBPARSE_LEVEL_MAIN) {

 		s_CurInfo = ConfDbInfo();

 		s_CurInfo.name = m_StrTab.AddString(name);

 		m_ParseState = DBPARSE_LEVEL_DATABASE;

 	} else if (m_ParseState == DBPARSE_LEVEL_DATABASE) {

 		m_ParseLevel++;

 	}

 	return SMCResult_Continue;

 }

 SMCResult DBManager::ReadSMC_KeyValue(const SMCStates *states, const char *key, const char *value)

 {

 	if (m_ParseLevel)

 	{

 		return SMCResult_Continue;

 	}

 	if (m_ParseState == DBPARSE_LEVEL_MAIN)

 	{

 		if (strcmp(key, "driver_default") == 0)

 		{

 			m_DefDriver.assign(value);

 		}

 	} else if (m_ParseState == DBPARSE_LEVEL_DATABASE) {

 		if (strcmp(key, "driver") == 0)

 		{

 			if (strcmp(value, "default") != 0)

 			{

 				s_CurInfo.driver = m_StrTab.AddString(value);

 			}

 		} else if (strcmp(key, "database") == 0) {

 			s_CurInfo.database = m_StrTab.AddString(value);

 		} else if (strcmp(key, "host") == 0) {

 			s_CurInfo.host = m_StrTab.AddString(value);

 		} else if (strcmp(key, "user") == 0) {

 			s_CurInfo.user = m_StrTab.AddString(value);

 		} else if (strcmp(key, "pass") == 0) {

 			s_CurInfo.pass = m_StrTab.AddString(value);

 		} else if (strcmp(key, "timeout") == 0) {

 			s_CurInfo.info.maxTimeout = atoi(value);

 		} else if (strcmp(key, "port") == 0) {

 			s_CurInfo.info.port = atoi(value);

 		}

 	}

 	return SMCResult_Continue;

 }

 #define ASSIGN_VAR(var) \

 	if (s_CurInfo.var == -1) { \

 		s_CurInfo.info.var = ""; \

 	} else { \

 		s_CurInfo.info.var = m_StrTab.GetString(s_CurInfo.var); \

 	}

 SMCResult DBManager::ReadSMC_LeavingSection(const SMCStates *states)

 {

 	if (m_ParseLevel)

 	{

 		m_ParseLevel--;

 		return SMCResult_Continue;

 	}

 	if (m_ParseState == DBPARSE_LEVEL_DATABASE)

 	{

 		/* Set all of the info members to either a blank string

 		 * or the string pointer from the string table.

 		 */

 		ASSIGN_VAR(driver);

 		ASSIGN_VAR(database);

 		ASSIGN_VAR(host);

 		ASSIGN_VAR(user);

 		ASSIGN_VAR(pass);

 		/* Save it.. */

 		m_confs.push_back(s_CurInfo);

 		/* Go up one level */

 		m_ParseState = DBPARSE_LEVEL_MAIN;

 	} else if (m_ParseState == DBPARSE_LEVEL_MAIN) {

 		m_ParseState = DBPARSE_LEVEL_NONE;

 		return SMCResult_Halt;

 	}

 	return SMCResult_Continue;

 }

 #undef ASSIGN_VAR

 void DBManager::ReadSMC_ParseEnd(bool halted, bool failed)

 {

 }

 bool DBManager::Connect(const char *name, IDBDriver **pdr, IDatabase **pdb, bool persistent, char *error, size_t maxlength)

 {

 	ConfDbInfo *pInfo = GetDatabaseConf(name);

 	if (!pInfo)

 	{

 		if (pdr)

 		{

 			*pdr = NULL;

 		}

 		*pdb = NULL;

 		UTIL_Format(error, maxlength, "Configuration \"%s\" not found", name);

 		return false;

 	}

 	const char *dname = pInfo->info.driver;

 	if (!pInfo->realDriver)

 	{

 		/* Try to assign a real driver pointer */

 		if (pInfo->info.driver[0] == '\0')

 		{

 			if (!m_pDefault && m_DefDriver.size() > 0)

 			{

 				m_pDefault = FindOrLoadDriver(m_DefDriver.c_str());

 			}

 			dname = m_DefDriver.size() ? m_DefDriver.c_str() : "default";

 			pInfo->realDriver = m_pDefault;

 		} else {

 			pInfo->realDriver = FindOrLoadDriver(pInfo->info.driver);

 		}

 	}

 	if (pInfo->realDriver)

 	{

 		if (pdr)

 		{

 			*pdr = pInfo->realDriver;

 		}

 		*pdb = pInfo->realDriver->Connect(&pInfo->info, persistent, error, maxlength);

 		return (*pdb != NULL);

 	}

 	if (pdr)

 	{

 		*pdr = NULL;

 	}

 	*pdb = NULL;

 	UTIL_Format(error, maxlength, "Driver \"%s\" not found", dname);

 	return false;

 }

 void DBManager::AddDriver(IDBDriver *pDriver)

 {

 	 /* Let's kill the worker.  Join the thread and let the queries flush.

 	  * This is kind of stupid but we just want to unload safely.

 	  * Rather than recreate the worker, we'll wait until someone throws 

 	  * another query through.

 	  */

 	KillWorkerThread();

 	 m_drivers.push_back(pDriver);

 }

 void DBManager::RemoveDriver(IDBDriver *pDriver)

 {

 	/* Again, we're forced to kill the worker.  How rude!

 	 * Doing this flushes the queue, and thus we don't need to 

 	 * clean anything else.  

 	 */

 	KillWorkerThread();

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

 	{

 		if (m_drivers[i] == pDriver)

 		{

 			m_drivers.erase(m_drivers.iterAt(i));

 			break;

 		}

 	}

 	/* Make sure NOTHING references this! */

 	List<ConfDbInfo>::iterator iter;

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

 	{

 		ConfDbInfo &db = (*iter);

 		if (db.realDriver == pDriver)

 		{

 			db.realDriver = NULL;

 		}

 	}

 	/* Now that the driver is gone, we have to test the think queue.

 	 * Whatever happens therein is up to the db op!

 	 */

 	Queue<IDBThreadOperation *>::iterator qiter = m_ThinkQueue.begin();

 	Queue<IDBThreadOperation *> templist;

 	while (qiter != m_ThinkQueue.end())

 	{

 		IDBThreadOperation *op = (*qiter);

 		if (op->GetDriver() == pDriver)

 		{

 			templist.push(op);

 			qiter = m_ThinkQueue.erase(qiter);

 		} else {

 			qiter++;

 		}

 	}

 	for (qiter = templist.begin();

 		 qiter != templist.end();

 		 qiter++)

 	{

 		IDBThreadOperation *op = (*qiter);

 		op->CancelThinkPart();

 		op->Destroy();

 	}

 }

 IDBDriver *DBManager::GetDefaultDriver()

 {

 	if (!m_pDefault && m_DefDriver.size() > 0)

 	{

 		m_pDefault = FindOrLoadDriver(m_DefDriver.c_str());

 	}

 	return m_pDefault;

 }

 Handle_t DBManager::CreateHandle(DBHandleType dtype, void *ptr, IdentityToken_t *pToken)

 {

 	HandleType_t type = 0;

 	if (dtype == DBHandle_Driver)

 	{

 		type = m_DriverType;

 	} else if (dtype == DBHandle_Database) {

 		type = m_DatabaseType;

 	} else {

 		return BAD_HANDLE;

 	}

 	return g_HandleSys.CreateHandle(type, ptr, pToken, g_pCoreIdent, NULL);

 }

 HandleError DBManager::ReadHandle(Handle_t hndl, DBHandleType dtype, void **ptr)

 {

 	HandleType_t type = 0;

 	if (dtype == DBHandle_Driver)

 	{

 		type = m_DriverType;

 	} else if (dtype == DBHandle_Database) {

 		type = m_DatabaseType;

 	} else {

 		return HandleError_Type;

 	}

 	HandleSecurity sec(NULL, g_pCoreIdent);

 	return g_HandleSys.ReadHandle(hndl, type, &sec, ptr);

 }

 HandleError DBManager::ReleaseHandle(Handle_t hndl, DBHandleType type, IdentityToken_t *token)

 {

 	HandleSecurity sec(token, g_pCoreIdent);

 	return g_HandleSys.FreeHandle(hndl, &sec);

 }

 unsigned int DBManager::GetDriverCount()

 {

 	return (unsigned int)m_drivers.size();

 }

 IDBDriver *DBManager::GetDriver(unsigned int index)

 {

 	if (index >= m_drivers.size())

 	{

 		return NULL;

 	}

 	return m_drivers[index];

 }

 const DatabaseInfo *DBManager::FindDatabaseConf(const char *name)

 {

 	ConfDbInfo *info = GetDatabaseConf(name);

 	if (!info)

 	{

 		return NULL;

 	}

 	return &info->info;

 }

 ConfDbInfo *DBManager::GetDatabaseConf(const char *name)

 {

 	List<ConfDbInfo>::iterator iter;

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

 	{

 		ConfDbInfo &conf = (*iter);

 		if (strcmp(m_StrTab.GetString(conf.name), name) == 0)

 		{

 			return &conf;

 		}

 	}

 	return NULL;

 }

 IDBDriver *DBManager::FindOrLoadDriver(const char *name)

 {

 	size_t last_size = m_drivers.size();

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

 	{

 		if (strcmp(m_drivers[i]->GetIdentifier(), name) == 0)

 		{

 			return m_drivers[i];

 		}

 	}

 	char filename[PLATFORM_MAX_PATH];

 	UTIL_Format(filename, sizeof(filename), "dbi.%s.ext", name);

 	IExtension *pExt = g_Extensions.LoadAutoExtension(filename);

 	if (!pExt || !pExt->IsLoaded() || m_drivers.size() <= last_size)

 	{

 		return NULL;

 	}

 	/* last_size is now gauranteed to be a valid index.

 	 * The identifier must match the name.

 	 */

 	if (strcmp(m_drivers[last_size]->GetIdentifier(), name) == 0)

 	{

 		return m_drivers[last_size];

 	}

 	return NULL;

 }

 void DBManager::KillWorkerThread()

 {

 	if (m_pWorker)

 	{

 		m_pWorker->Stop(false);

 		g_pThreader->DestroyWorker(m_pWorker);

 		m_pWorker = NULL;

 		s_OneTimeThreaderErrorMsg = false;

 	}

 }

 static IdentityToken_t *s_pAddBlock = NULL;

 bool DBManager::AddToThreadQueue(IDBThreadOperation *op, PrioQueueLevel prio)

 {

 	if (s_pAddBlock && op->GetOwner() == s_pAddBlock)

 	{

 		return false;

 	}

 	if (!m_pWorker)

 	{

 		m_pWorker = g_pThreader->MakeWorker(this, true);

 		if (!m_pWorker)

 		{

 			if (!s_OneTimeThreaderErrorMsg)

 			{

 				g_Logger.LogError("[SM] Unable to create db threader (error unknown)");

 				s_OneTimeThreaderErrorMsg = true;

 			}

 			return false;

 		}

 		if (!m_pWorker->Start())

 		{

 			if (!s_OneTimeThreaderErrorMsg)

 			{

 				g_Logger.LogError("[SM] Unable to start db threader (error unknown)");

 				s_OneTimeThreaderErrorMsg = true;

 			}

 			g_pThreader->DestroyWorker(m_pWorker);

 			m_pWorker = NULL;

 			return false;

 		}

 	}

 	/* Add to the queue */

 	{

 		m_pQueueLock->Lock();

 		Queue<IDBThreadOperation *> &queue = m_OpQueue.GetQueue(prio);

 		queue.push(op);

 		m_pQueueLock->Unlock();

 	}

 	/* Make the thread */

 	m_pWorker->MakeThread(this);

 	return true;

 }

 void DBManager::OnWorkerStart(IThreadWorker *pWorker)

 {

 	m_drSafety.clear();

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

 	{

 		if (m_drivers[i]->IsThreadSafe())

 		{

 			m_drSafety.push_back(m_drivers[i]->InitializeThreadSafety());

 		} else {

 			m_drSafety.push_back(false);

 		}

 	}

 }

 void DBManager::OnWorkerStop(IThreadWorker *pWorker)

 {

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

 	{

 		if (m_drSafety[i])

 		{

 			m_drivers[i]->ShutdownThreadSafety();

 		}

 	}

 	m_drSafety.clear();

 }

 void DBManager::RunThread(IThreadHandle *pThread)

 {

 	IDBThreadOperation *op = NULL;

 	/* Get something from the queue */

 	{

 		m_pQueueLock->Lock();

 		Queue<IDBThreadOperation *> &queue = m_OpQueue.GetLikelyQueue();

 		if (!queue.empty())

 		{

 			op = queue.first();

 			queue.pop();

 		}

 		m_pQueueLock->Unlock();

 	}

 	/* whoa.  hi.  did we get something? we should have. */

 	if (!op)

 	{

 		/* wtf? */

 		return;

 	}

 	op->RunThreadPart();

 	m_pThinkLock->Lock();

 	m_ThinkQueue.push(op);

 	m_pThinkLock->Unlock();

 }

 void DBManager::RunFrame()

 {

 	/* Don't bother if we're empty */

 	if (!m_ThinkQueue.size())

 	{

 		return;

 	}

 	/* Dump one thing per-frame so the server stays sane. */

 	m_pThinkLock->Lock();

 	IDBThreadOperation *op = m_ThinkQueue.first();

 	m_ThinkQueue.pop();

 	m_pThinkLock->Unlock();

 	op->RunThinkPart();

 	op->Destroy();

 }

 void DBManager::OnTerminate(IThreadHandle *pThread, bool cancel)

 {

 	/* Do nothing */

 }

 void DBManager::OnSourceModIdentityDropped(IdentityToken_t *pToken)

 {

 	s_pAddBlock = pToken;

 	/* Kill the thread so we can flush everything into the think queue... */

 	KillWorkerThread();

 	/* Run all of the think operations.

  	 * Unlike the driver unloading example, we'll let these calls go through, 

 	 * since a plugin unloading is far more normal.

 	 */

 	Queue<IDBThreadOperation *>::iterator iter = m_ThinkQueue.begin();

 	Queue<IDBThreadOperation *> templist;

 	while (iter != m_ThinkQueue.end())

 	{

 		IDBThreadOperation *op = (*iter);

 		if (op->GetOwner() == pToken)

 		{

 			templist.push(op);

 			iter = m_ThinkQueue.erase(iter);

 		} else {

 			iter++;

 		}

 	}

 	for (iter = templist.begin();

 		iter != templist.end();

 		iter++)

 	{

 		IDBThreadOperation *op = (*iter);

 		op->RunThinkPart();

 		op->Destroy();

 	}

 	s_pAddBlock = NULL;

 }

 void DBManager::OnPluginUnloaded(IPlugin *plugin)

 {

 	/* Kill the thread so we can flush everything into the think queue... */

 	KillWorkerThread();

 	/* Mark the plugin as being unloaded so future database calls will ignore threading... */

 	plugin->SetProperty("DisallowDBThreads", NULL);

 	/* Run all of the think operations.

 	 * Unlike the driver unloading example, we'll let these calls go through, 

 	 * since a plugin unloading is far more normal.

 	 */

 	Queue<IDBThreadOperation *>::iterator iter = m_ThinkQueue.begin();

 	Queue<IDBThreadOperation *> templist;

 	while (iter != m_ThinkQueue.end())

 	{

 		IDBThreadOperation *op = (*iter);

 		if (op->GetOwner() == plugin->GetIdentity())

 		{

 			templist.push(op);

 			iter = m_ThinkQueue.erase(iter);

 		} else {

 			iter++;

 		}

 	}

 	for (iter = templist.begin();

 		 iter != templist.end();

 		 iter++)

 	{

 		IDBThreadOperation *op = (*iter);

 		op->RunThinkPart();

 		op->Destroy();

 	}

 }

 void DBManager::LockConfig()

 {

 	m_pConfigLock->Lock();

 }

 void DBManager::UnlockConfig()

 {

 	m_pConfigLock->Unlock();

 }

 const char *DBManager::GetDefaultDriverName()

 {

 	return m_DefDriver.c_str();

 }