/**

 * vim: set ts=4 :

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

 * SourceMod SQLite Extension

 * 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 <sm_platform.h>

#include "extension.h"

#include "SqDriver.h"

#include "SqDatabase.h"

SqDriver g_SqDriver;

unsigned int strncopy(char *dest, const char *src, size_t count)

{

	if (!count)

	{

		return 0;

	}

	char *start = dest;

	while ((*src) && (--count))

	{

		*dest++ = *src++;

	}

	*dest = '\0';

	return (dest - start);

}

int busy_handler(void *unused1, int unused2)

{

#if defined PLATFORM_WINDOWS

	Sleep(100);

#elif defined PLATFORM_LINUX

	usleep(100000);

#endif

	return 1;

}

SqDriver::SqDriver()

{

	m_Handle = BAD_HANDLE;

	m_pOpenLock = NULL;

	m_bThreadSafe = false;

}

void SqDriver::Initialize()

{

	m_pOpenLock = threader->MakeMutex();

	InitializeThreadSafety();

}

void SqDriver::Shutdown()

{

	if (m_pOpenLock)

	{

		m_pOpenLock->DestroyThis();

	}

	if (m_bThreadSafe)

	{

		sqlite3_enable_shared_cache(0);

	}

}

bool SqDriver::IsThreadSafe()

{

	return true;

}

bool SqDriver::InitializeThreadSafety()

{

	if (m_bThreadSafe)

	{

		return true;

	}

	if (sqlite3_threadsafe() == 0)

	{

		return false;

	}

	if (sqlite3_enable_shared_cache(1) != SQLITE_OK)

	{

		return false;

	}

	m_bThreadSafe = true;

	return true;

}

void SqDriver::ShutdownThreadSafety()

{

	return;

}

IdentityToken_t *SqDriver::GetIdentity()

{

	return myself->GetIdentity();

}

const char *SqDriver::GetProductName()

{

	return "SQLite";

}

const char *SqDriver::GetIdentifier()

{

	return "sqlite";

}

Handle_t SqDriver::GetHandle()

{

	if (m_Handle == BAD_HANDLE)

	{

		m_Handle = dbi->CreateHandle(DBHandle_Driver, this, myself->GetIdentity());

	}

	return m_Handle;

}

inline bool IsPathSepChar(char c)

{

#if defined PLATFORM_WINDOWS

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

#elif defined PLATFORM_LINUX

	return (c == '/');

#endif

}

IDatabase *SqDriver::Connect(const DatabaseInfo *info, bool persistent, char *error, size_t maxlength)

{

	/* We wrap most of the open process in a mutex just to be safe */

	m_pOpenLock->Lock();

	/* Format our path */

	char path[PLATFORM_MAX_PATH];

	size_t len = libsys->PathFormat(path, sizeof(path), "sqlite/%s", info->database);

	/* Chop any filename off */

	for (size_t i = len-1;

		 i >= 0 && i <= len-1;

		 i--)

	{

		if (IsPathSepChar(path[i]))

		{

			path[i] = '\0';

			break;

		}

	}

	/* Test the full path */

	char fullpath[PLATFORM_MAX_PATH];

	g_pSM->BuildPath(Path_SM, fullpath, sizeof(fullpath), "data/%s", path);

	if (!libsys->IsPathDirectory(fullpath))

	{

		/* Make sure the data folder exists */

		len = g_pSM->BuildPath(Path_SM, fullpath, sizeof(fullpath), "data");

		if (!libsys->IsPathDirectory(fullpath))

		{

			if (!libsys->CreateFolder(fullpath))

			{

				strncopy(error, "Could not create or open \"data\" folder\"", maxlength);

				m_pOpenLock->Unlock();

				return NULL;

			}

		}

		/* The data folder exists - create each subdir as needed! */

		char *cur_ptr = path;

		do

		{

			/* Find the next suitable path */

			char *next_ptr = cur_ptr;

			while (*next_ptr != '\0')

			{

				if (IsPathSepChar(*next_ptr))

				{

					*next_ptr = '\0';

					next_ptr++;

					break;

				}

				next_ptr++;

			}

			if (*next_ptr == '\0')

			{

				next_ptr = NULL;

			}

			len += libsys->PathFormat(&fullpath[len], sizeof(fullpath)-len, "/%s", cur_ptr);

			if (!libsys->IsPathDirectory(fullpath) && !libsys->CreateFolder(fullpath))

			{

				break;

			}

			cur_ptr = next_ptr;

		} while (cur_ptr);

	}

	/* Build the FINAL path. */

	g_pSM->BuildPath(Path_SM, fullpath, sizeof(fullpath), "data/sqlite/%s.sq3", info->database);

	/* If we're requesting a persistent connection, see if something is already open */

	if (persistent)

	{

		/* See if anything in the cache matches */

		List<SqDbInfo>::iterator iter;

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

		{

			if ((*iter).path.compare(fullpath) == 0)

			{

				(*iter).db->IncReferenceCount();

				m_pOpenLock->Unlock();

				return (*iter).db;

			}

		}

	}

	/* Try to open a new connection */

	sqlite3 *sql;

	int err = sqlite3_open(fullpath, &sql);

	if (err != SQLITE_OK)

	{

		strncopy(error, sqlite3_errmsg(sql), maxlength);

		sqlite3_close(sql);

		m_pOpenLock->Unlock();

		return NULL;

	}

	sqlite3_busy_handler(sql, busy_handler, NULL);

	SqDatabase *pdb = new SqDatabase(sql, persistent);

	if (persistent)

	{

		SqDbInfo pinfo;

		pinfo.path = fullpath;

		pinfo.db = pdb;

		m_Cache.push_back(pinfo);

	}

	m_pOpenLock->Unlock();

	return pdb;

}

void SqDriver::RemovePersistent(IDatabase *pdb)

{

	List<SqDbInfo>::iterator iter;

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

	{

		if ((*iter).db == pdb)

		{

			iter = m_Cache.erase(iter);

			return;

		}

	}

}