/*
                             This file is part of the Opie Project
                             Copyright (C) Stefan Eilers <eilers.stefan@epost.de>
              =.             Copyright (C) The Opie Team <opie-devel@handhelds.org>
            .=l.
           .>+-=
 _;:,     .>    :=|.         This program is free software; you can
.> <`_,   >  .   <=          redistribute it and/or  modify it under
:`=1 )Y*s>-.--   :           the terms of the GNU Library General Public
.="- .-=="i,     .._         License as published by the Free Software
 - .   .-<_>     .<>         Foundation; either version 2 of the License,
     ._= =}       :          or (at your option) any later version.
    .%`+i>       _;_.
    .i_,=:_.      -<s.       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
..}^=.=       =       ;      Library General Public License for more
++=   -.     .`     .:       details.
 :     =  ...= . :.=-
 -.   .:....=;==+<;          You should have received a copy of the GNU
  -_. . .   )=.  =           Library General Public License along with
    --        :-=`           this library; see the file COPYING.LIB.
                             If not, write to the Free Software Foundation,
                             Inc., 59 Temple Place - Suite 330,
                             Boston, MA 02111-1307, USA.
*/
/*
 * =====================================================================
 * ToDo: Use plugins
 * =====================================================================
 */
#ifndef OPIE_BACKENDFACTORY_H_
#define OPIE_BACKENDFACTORY_H_

/* OPIE */
#include <opie2/opimaccessbackend.h>
#include <opie2/opimglobal.h>
#include <opie2/otodoaccessxml.h>
#include <opie2/otodoaccessvcal.h>
#include <opie2/ocontactaccessbackend_xml.h>
#include <opie2/ocontactaccessbackend_vcard.h>
#include <opie2/odatebookaccessbackend_xml.h>
#include <opie2/odebug.h>

#ifdef __USE_SQL
#include <opie2/otodoaccesssql.h>
#include <opie2/ocontactaccessbackend_sql.h>
#include <opie2/odatebookaccessbackend_sql.h>
#endif

#include <qpe/config.h>

/* QT */
#include <qstring.h>
#include <qasciidict.h>



using namespace Opie;
using namespace Opie::Pim;

namespace Opie {

class OBackendPrivate;

/**
 * This class is our factory. It will give us the default implementations
 * of at least Todolist, Contacts and Datebook. In the future this class will
 * allow users to switch the backend with ( XML->SQLite ) without the need
 * to recompile.#
 * This class - as the whole PIM Api - is making use of templates
 *
 * <pre>
 *   OPimTodoAccessBackend* backend = OBackEndFactory<OPimTodoAccessBackend>::Default( OPimGlobal::TODOLIST, QString::null );
 *   backend->load();
 * </pre>
 *
 * @author Stefan Eilers
 * @version 0.1
 */
 template<class T>
	 class OBackendFactory
	 {
	 public:
             OBackendFactory() {};

		 /**
		  * Returns a selected backend implementation
		  * @param type the type of the backend
		  * @param database the type of the used database
		  * @param appName The name of your application. It will be passed on to the backend.
		  * @param filename Filename of the database file if you don't want to access the default
		  * @see OPimGlobal()
		  */
		 static T* create( OPimGlobal::PimType type, OPimGlobal::DatabaseStyle database,
				   const QString& appName, const QString& filename = QString::null ){
			owarn << "Selected backend for " << type << " is: " <<
database << oendl;

                        // If we should use the dafult database style, we have to request it
			 OPimGlobal::DatabaseStyle use_database = database;
			 if ( use_database == OPimGlobal::DEFAULT ){
				 use_database = defaultDB( type );
			 }

			 switch ( type ){
			 case OPimGlobal::TODOLIST:

				 switch ( use_database ){
				 default: // Use SQL if something weird is given.
					 // Fall through !!
				 case OPimGlobal::SQL:
#ifdef __USE_SQL
					 return (T*) new OPimTodoAccessBackendSQL( filename );
					 break;
#else
					 owarn << "OBackendFactory:: sql Backend for TODO not implemented! Using XML instead!" << oendl;
					 // Fall through !!
#endif
				 case OPimGlobal::XML:
					 return (T*) new OPimTodoAccessXML( appName, filename );
					 break;
				 case OPimGlobal::VCARD:
					 return (T*) new OPimTodoAccessVCal( filename );
					 break;
				 }
			 case OPimGlobal::CONTACTLIST:
				 switch ( use_database ){
				 default: // Use SQL if something weird is given.
					 // Fall through !!
				 case OPimGlobal::SQL:
#ifdef __USE_SQL
					 return (T*) new OPimContactAccessBackend_SQL( appName, filename );
					 break;
#else
					 owarn << "OBackendFactory:: sql Backend for CONTACT not implemented! Using XML instead!" << oendl;
					 // Fall through !!
#endif
				 case OPimGlobal::XML:
					 return (T*) new OPimContactAccessBackend_XML( appName, filename );
					 break;
				 case OPimGlobal::VCARD:
					 return (T*) new OPimContactAccessBackend_VCard( appName, filename );
					 break;
				 }
			 case OPimGlobal::DATEBOOK:
				 switch ( use_database ){
				 default: // Use SQL if something weird is given.
					 // Fall through !!
				 case OPimGlobal::SQL:
#ifdef __USE_SQL
					 return (T*) new ODateBookAccessBackend_SQL( appName, filename );
					 break;
#else
					 owarn << "OBackendFactory:: sql Backend for DATEBOOK not implemented! Using XML instead!" << oendl;
					 // Fall through !!
#endif
				 case OPimGlobal::XML:
					 return (T*) new ODateBookAccessBackend_XML( appName, filename );
					 break;
				 case OPimGlobal::VCARD:
					 owarn << "OBackendFactory:: VCal Backend for DATEBOOK not implemented!" << oendl;
					 return (T*) NULL;
					 break;
				 }
			 default:
				 return (T*) NULL;
			 }

		 }

		 /**
		  * Returns the style of the default database which is used to contact PIM data.
		  * @param type the type of the backend
		  * @see OPimGlobal()
		  */
		 static OPimGlobal::DatabaseStyle defaultDB( OPimGlobal::PimType type ){
			 QString group_name;
			 switch ( type ){
			 case OPimGlobal::TODOLIST:
				 group_name = "todo";
				 break;
			 case OPimGlobal::CONTACTLIST:
				 group_name = "contact";
				 break;
			 case OPimGlobal::DATEBOOK:
				 group_name = "datebook";
				 break;
			 default:
				 group_name = "unknown";
			 }

			 Config config( "pimaccess" );
			 config.setGroup ( group_name );
			 QString db_String = config.readEntry( "usebackend", "xml" );

			 QAsciiDict<int> dictDbTypes( OPimGlobal::_END_DatabaseStyle );
			 dictDbTypes.setAutoDelete( TRUE );

			 dictDbTypes.insert( "xml", new int (OPimGlobal::XML) );
			 dictDbTypes.insert( "sql", new int (OPimGlobal::SQL) );
			 dictDbTypes.insert( "vcard", new int (OPimGlobal::VCARD) );

			 int* db_find = dictDbTypes[ db_String ];

			 if ( !db_find )
				 return OPimGlobal::UNKNOWN;

			 return (OPimGlobal::DatabaseStyle) *db_find;
		 }


		 /**
		  * Returns the default backend implementation for backendName. Which one is used, is defined
		  * by the configfile "pimaccess.conf".
		  * @param type The type of the backend (@see OPimGlobal())
		  * @param appName The name of your application. It will be passed on to the backend
		  * @see OPimGlobal()
		  */
		 static T* defaultBackend( OPimGlobal::PimType type, const QString& appName ){
			 return create( type, OPimGlobal::DEFAULT, appName );
		 }
	 private:
		 OBackendPrivate* d;

	 };

}

#endif