/*
 * Copyright (C) 2009 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.etk.component.database;

/**
 * Created by The eXo Platform SAS Author : Tuan Nguyen
 * tuan08@users.sourceforge.net Apr 4, 2006 The DBTableManager is an interface
 * to help the developer to check if a table is existed or not and create/drop a
 * table. We can implement more one more DBTableManager according to the
 * database type and versio
 */
abstract public class DBTableManager
{
   /**
    * This method should: 1. Extract the table information such table name and
    * table fields from the class T, the information are annotated in the class T
    * 2. Generate the sql statement and create the table
    * 
    * @param <T>
    * @param type
    * @param dropIfExist
    * @throws Exception
    */
   abstract public <T extends DBObject> void createTable(Class<T> type, boolean dropIfExist) throws Exception;

   /**
    * This method should: 1. Extract the table information from the class T, the
    * information are annotated in the class T 2. Generate the sql statement and
    * drop the table
    * 
    * @param <T>
    * @param type
    * @throws Exception
    */
   abstract public <T extends DBObject> void dropTable(Class<T> type) throws Exception;

   /**
    * This method should: 1. Extract the table information from the class T, the
    * information are annotated in the class T 2. Check to see if the table is
    * existed in the database system
    * 
    * @param <T>
    * @param type
    * @return
    * @throws Exception
    */
   abstract public <T extends DBObject> boolean hasTable(Class<T> type) throws Exception;

   /**
    * This method should check the database type and version and create a
    * corresponded DBTableManager
    * 
    * @param datasource
    * @return
    */
   final static public DBTableManager createDBTableManager(ExoDatasource datasource)
   {
      if (datasource.getDatabaseType() == ExoDatasource.HSQL_DB_TYPE)
      {
         return new StandardSQLTableManager(datasource);
      }
      else if (ExoDatasource.ORACLE_DB_TYPE == datasource.getDatabaseType())
      {
         return new OracleTableManager(datasource);
      }
      else if (ExoDatasource.SQL_SERVER_TYPE == datasource.getDatabaseType())
      {
         return new MSSQLServerTableManager(datasource);
      }
      return new StandardSQLTableManager(datasource);
   }
}