/****************************************************************************
**
** https://www.qxorm.com/
** Copyright (C) 2013 XDL Team (ic-east.com)
**
** This file is part of the QxOrm library
**
** This software is provided 'as-is', without any express or implied
** warranty. In no event will the authors be held liable for any
** damages arising from the use of this software
**
** Commercial Usage
** Licensees holding valid commercial QxOrm licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and XDL Team
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file 'license.gpl3.txt' included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met : http://www.gnu.org/copyleft/gpl.html
**
** If you are unsure which license is appropriate for your use, or
** if you have questions regarding the use of this file, please contact :
** ic-east.com
**
****************************************************************************/

namespace qx
{
   namespace dao
   {
      namespace detail
      {

         template <class T>
         struct QxDao_Update_Optimized_Generic
         {

            static inline QSqlError update_optimized(const qx::QxSqlQuery &query, qx::dao::ptr<T> &ptr, QSqlDatabase *pDatabase, bool bUseExecBatch)
            {
               Q_UNUSED(bUseExecBatch); // Useful only with containers
               QStringList lstDiff;
               if (ptr.isNull() || !ptr.isDirty(lstDiff))
               {
                  return QSqlError();
               }
               return qx::dao::update_by_query(query, (*ptr), pDatabase, lstDiff);
            }
         };

         template <class T>
         struct QxDao_Update_Optimized_Container
         {

            static inline QSqlError update_optimized(const qx::QxSqlQuery &query, qx::dao::ptr<T> &ptr, QSqlDatabase *pDatabase, bool bUseExecBatch)
            {
               if (ptr.isNull() || (qx::trait::generic_container<T>::size(*ptr) <= 0))
               {
                  return QSqlError();
               }
               if (!ptr.getOriginal() || (qx::trait::generic_container<T>::size(*ptr) != qx::trait::generic_container<T>::size(*ptr.getOriginal())))
               {
                  return qx::dao::update_by_query(query, (*ptr), pDatabase);
               }

               QStringList lstDiffItem;
               QSqlError errorItem;
               QSqlDatabase db;
               bool bCheckDatabaseTransaction = true;

#ifdef _QX_ENABLE_MONGODB
               if (qx::QxSqlDatabase::getSingleton()->getDriverName() == "QXMONGODB")
               {
                  bCheckDatabaseTransaction = false;
               }
#endif // _QX_ENABLE_MONGODB

               if (bCheckDatabaseTransaction)
               {
                  db = (pDatabase ? (*pDatabase) : qx::QxSqlDatabase::getDatabase(errorItem));
                  if (errorItem.isValid())
                  {
                     return errorItem;
                  }
                  if (!pDatabase)
                  {
                     db.transaction();
                  }
               }

               typename T::const_iterator it2 = ptr.getOriginal()->begin();
               for (typename T::const_iterator it1 = ptr->begin(); it1 != ptr->end(); ++it1)
               {
                  lstDiffItem.clear();
                  qx::dao::detail::is_dirty((*it1), (*it2), lstDiffItem);
                  if (lstDiffItem.count() > 0)
                  {
                     errorItem = qx::dao::update_by_query(query, (*it1), (&db), lstDiffItem, bUseExecBatch);
                  }
                  if (errorItem.isValid())
                  {
                     break;
                  }
                  else
                  {
                     ++it2;
                  }
               }

               if (bCheckDatabaseTransaction)
               {
                  if (!pDatabase && !errorItem.isValid())
                  {
                     db.commit();
                  }
                  else if (!pDatabase)
                  {
                     db.rollback();
                  }
               }

               return errorItem;
            }
         };

         template <class T>
         struct QxDao_Update_Optimized
         {

            static inline QSqlError update_optimized(const qx::QxSqlQuery &query, qx::dao::ptr<T> &ptr, QSqlDatabase *pDatabase, bool bUseExecBatch = false)
            {
               typedef typename std::conditional<qx::trait::is_container<T>::value, qx::dao::detail::QxDao_Update_Optimized_Container<T>, qx::dao::detail::QxDao_Update_Optimized_Generic<T>>::type type_dao_1;

               QSqlError error = type_dao_1::update_optimized(query, ptr, pDatabase, bUseExecBatch);
               if (!error.isValid())
               {
                  qx::dao::detail::QxDao_Keep_Original<qx::dao::ptr<T>>::backup(ptr);
               }
               return error;
            }
         };

      } // namespace detail
   } // namespace dao
} // namespace qx
