/**

 * 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 "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();

	}