/*
 *      Copyright (C) 2005-2008 Team XBMC
 *      http://www.xbmc.org
 *
 *  This Program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  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 XBMC; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *  http://www.gnu.org/copyleft/gpl.html
 *
 */

#include "Database.h"
#include "Util.h"
#include "Settings.h"
#include "AdvancedSettings.h"
#include "Crc32.h"
#include "FileSystem/SpecialProtocol.h"
#include "AutoPtrHandle.h"
#include "utils/log.h"

using namespace AUTOPTR;
using namespace dbiplus;

#define MAX_COMPRESS_COUNT 20

CDatabase::CDatabase(void)
{
  m_bOpen = false;
  m_iRefCount = 0;
  m_sqlite = true;
}

CDatabase::~CDatabase(void)
{
  Close();
}

void CDatabase::Split(const CStdString& strFileNameAndPath, CStdString& strPath, CStdString& strFileName)
{
  strFileName = "";
  strPath = "";
  int i = strFileNameAndPath.size() - 1;
  while (i > 0)
  {
    char ch = strFileNameAndPath[i];
    if (ch == ':' || ch == '/' || ch == '\\') break;
    else i--;
  }
  strPath = strFileNameAndPath.Left(i);
  strFileName = strFileNameAndPath.Right(strFileNameAndPath.size() - i);
}

uint32_t CDatabase::ComputeCRC(const CStdString &text)
{
  Crc32 crc;
  crc.ComputeFromLowerCase(text);
  return crc;
}

CStdString CDatabase::FormatSQL(CStdString strStmt, ...)
{
  //  %q is the sqlite format string for %s.
  //  Any bad character, like "'", will be replaced with a proper one
  strStmt.Replace("%s", "%q");
  //  the %I64 enhancement is not supported by sqlite3_vmprintf
  //  must be %ll instead
  strStmt.Replace("%I64", "%ll");

  va_list args;
  va_start(args, strStmt);
  char *szSql = sqlite3_vmprintf(strStmt.c_str(), args);
  va_end(args);

  CStdString strResult;
  if (szSql) {
    strResult = szSql;
    sqlite3_free(szSql);
  }

  return strResult;
}

bool CDatabase::Open()
{
  DatabaseSettings db_fallback;
  return Open(db_fallback);
}

bool CDatabase::Open(DatabaseSettings &dbSettings)
{
  if (IsOpen())
  {
    m_iRefCount++;
    return true;
  }

  m_sqlite = true;
  
  if ( dbSettings.type.Equals("mysql") )
  {
    // check we have all information before we cancel the fallback
    if ( ! (dbSettings.host.IsEmpty() || dbSettings.user.IsEmpty() || dbSettings.pass.IsEmpty()) )
      m_sqlite = false;
    else
      CLog::Log(LOGINFO, "essential mysql database information is missing (eg. host, user, pass)");
  }

  // set default database name if appropriate
  if ( dbSettings.name.IsEmpty() )
    dbSettings.name = GetDefaultDBName();

  // always safely fallback to sqlite3
  if (m_sqlite)
  {
    dbSettings.type = "sqlite3";
    dbSettings.host = _P(g_settings.GetDatabaseFolder());
  }

  // create the appropriate database structure
  if (dbSettings.type.Equals("sqlite3"))
  {
    m_pDB.reset( new SqliteDatabase() ) ;
  }
  else if (dbSettings.type.Equals("mysql"))
  {
    m_pDB.reset( new MysqlDatabase() ) ;
  }
  else
  {
    CLog::Log(LOGERROR, "Unable to determine database type: %s", dbSettings.type.c_str());
    return false;
  }

  // host name is always required
  m_pDB->setHostName(dbSettings.host.c_str());

  if (!dbSettings.port.IsEmpty())
    m_pDB->setPort(dbSettings.port.c_str());

  if (!dbSettings.user.IsEmpty())
    m_pDB->setLogin(dbSettings.user.c_str());

  if (!dbSettings.pass.IsEmpty())
    m_pDB->setPasswd(dbSettings.pass.c_str());

  // database name is always required
  m_pDB->setDatabase(dbSettings.name.c_str());

  // create the datasets
  m_pDS.reset(m_pDB->CreateDataset());
  m_pDS2.reset(m_pDB->CreateDataset());

  if (m_pDB->connect() != DB_CONNECTION_OK)
  {
    CLog::Log(LOGERROR, "Unable to open database at host: %s db: %s (old version?)", dbSettings.host.c_str(), dbSettings.name.c_str());
    return false;
  }

  // test if db already exists, if not we need to create the tables
  if (!m_pDB->exists())
  {
    if (dbSettings.type.Equals("sqlite3"))
    {
      //  Modern file systems have a cluster/block size of 4k.
      //  To gain better performance when performing write
      //  operations to the database, set the page size of the
      //  database file to 4k.
      //  This needs to be done before any table is created.
      m_pDS->exec("PRAGMA page_size=4096\n");

      //  Also set the memory cache size to 16k
      m_pDS->exec("PRAGMA default_cache_size=4096\n");
    }
    CreateTables();
  }

  // Mark our db as open here to make our destructor to properly close the file handle
  m_bOpen = true;

  // Database exists, check the version number
  int version = 0;
  m_pDS->query("SELECT idVersion FROM version\n");
  if (m_pDS->num_rows() > 0)
    version = m_pDS->fv("idVersion").get_asInt();

  if (version < GetMinVersion())
  {
    CLog::Log(LOGNOTICE, "Attempting to update the database %s from version %i to %i", dbSettings.name.c_str(), version, GetMinVersion());
    if (UpdateOldVersion(version) && UpdateVersionNumber())
      CLog::Log(LOGINFO, "Update to version %i successfull", GetMinVersion());
    else
    {
      CLog::Log(LOGERROR, "Can't update the database %s from version %i to %i", dbSettings.name.c_str(), version, GetMinVersion());
      Close();
      return false;
    }
  }
  else if (version > GetMinVersion())
  {
    CLog::Log(LOGERROR, "Can't open the database %s as it is a NEWER version than what we were expecting!", dbSettings.name.c_str());
    Close();
    return false;
  }

  // sqlite3 post connection operations
  if (dbSettings.type.Equals("sqlite3"))
  {
    m_pDS->exec("PRAGMA cache_size=4096\n");
    m_pDS->exec("PRAGMA synchronous='NORMAL'\n");
    m_pDS->exec("PRAGMA count_changes='OFF'\n");
  }

  m_iRefCount++;
  return true;
}

bool CDatabase::IsOpen()
{
  return m_bOpen;
}

void CDatabase::Close()
{
  if (!m_bOpen)
    return ;

  if (m_iRefCount > 1)
  {
    m_iRefCount--;
    return ;
  }

  m_iRefCount--;
  m_bOpen = false;

  if (NULL == m_pDB.get() ) return ;
  if (NULL != m_pDS.get()) m_pDS->close();
  m_pDB->disconnect();
  m_pDB.reset();
  m_pDS.reset();
  m_pDS2.reset();
}

bool CDatabase::Compress(bool bForce /* =true */)
{
  if (!m_sqlite)
    return true;

  try
  {
    if (NULL == m_pDB.get()) return false;
    if (NULL == m_pDS.get()) return false;
    if (!bForce)
    {
      m_pDS->query("select iCompressCount from version");
      if (!m_pDS->eof())
      {
        int iCount = m_pDS->fv(0).get_asInt();
        if (iCount > MAX_COMPRESS_COUNT)
          iCount = -1;
        m_pDS->close();
        CStdString strSQL=FormatSQL("update version set iCompressCount=%i\n",++iCount);
        m_pDS->exec(strSQL.c_str());
        if (iCount != 0)
          return true;
      }
    }

    if (!m_pDS->exec("vacuum\n"))
      return false;
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "%s - Compressing the database failed", __FUNCTION__);
    return false;
  }
  return true;
}

void CDatabase::Interupt()
{
  m_pDS->interrupt();
}

void CDatabase::BeginTransaction()
{
  try
  {
    if (NULL != m_pDB.get())
      m_pDB->start_transaction();
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "database:begintransaction failed");
  }
}

bool CDatabase::CommitTransaction()
{
  try
  {
    if (NULL != m_pDB.get())
      m_pDB->commit_transaction();
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "database:committransaction failed");
    return false;
  }
  return true;
}

void CDatabase::RollbackTransaction()
{
  try
  {
    if (NULL != m_pDB.get())
      m_pDB->rollback_transaction();
  }
  catch (...)
  {
    CLog::Log(LOGERROR, "database:rollbacktransaction failed");
  }
}

bool CDatabase::InTransaction()
{
  if (NULL != m_pDB.get()) return false;
  return m_pDB->in_transaction();
}

bool CDatabase::CreateTables()
{

    CLog::Log(LOGINFO, "creating version table");
    m_pDS->exec("CREATE TABLE version (idVersion integer, iCompressCount integer)\n");
    CStdString strSQL=FormatSQL("INSERT INTO version (idVersion,iCompressCount) values(%i,0)\n", GetMinVersion());
    m_pDS->exec(strSQL.c_str());

    return true;
}

bool CDatabase::UpdateVersionNumber()
{
  try
  {
    CStdString strSQL=FormatSQL("UPDATE version SET idVersion=%i\n", GetMinVersion());
    m_pDS->exec(strSQL.c_str());
  }
  catch(...)
  {
    return false;
  }

  return true;
}