/*
  Copyright (C) 2000-2005 SKYRIX Software AG

  This file is part of OpenGroupware.org.

  OGo 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, or (at your option) any
  later version.

  OGo 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 OGo; see the file COPYING.  If not, write to the
  Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/

#ifndef __LSFoundation_SkyAttributeDataSource_H__
#define __LSFoundation_SkyAttributeDataSource_H__

#import <EOControl/EODataSource.h>

/*
  SkyAttributeDataSource
  
  A datasource which fetches extended object attributes. It takes a "primary"
  datasource which returns the objects and then uses the property manager to
  fill the "primary objects" with the extended properties.
  So this datasource does not only fetch the properties, but also the objects
  itself.
  
  TODO: add exact documentation, add feature documentation

  hints:
    -restrictionQualifierString
    -restrictionPrimaryKeyName
    -restrictionEntityName
       --> look at SkyObjectPropertyManager.h

    -namespaces  --> NSSet of namespaces for the objects
*/

@class NSSet, NSMutableDictionary, NSString;
@class EOFetchSpecification, EODataSource;

@interface SkyAttributeDataSource : EODataSource
{
@protected
  id                   context;
  EOFetchSpecification *fetchSpecification;
  NSSet                *namespaces;
  EODataSource         *source;
  NSMutableDictionary  *_gid2ObjCache;
  NSString             *globalIdKey;
  BOOL                 verifyIds;
  NSArray              *dbKeys;
  NSString             *defaultNamespace;
  NSMutableDictionary  *_evaluateAttributeQualifierCache;
  NSMutableDictionary  *_evaluateDBQualifierCache;
  NSMutableDictionary  *_evaluateQualifierCache;
}

- (id)initWithDataSource:(EODataSource *)_ds context:(id)_context;

/* operation */

- (NSArray *)fetchObjects;

/* accessors */

- (void)setFetchSpecification:(EOFetchSpecification *)_fSpec;
- (EOFetchSpecification *)fetchSpecification;

/*
  If the fetchSpecification qualifier contains attributes
  (like "name LIKE '*.gif" AND {http://www.skyrix.com}versionCount > 100")
  then the SkyPropertyManager fetches the matching object ids.
  Now the SkyAttributeDataSource build an OR-qualifier (with globaIdKey)
  to fetch the objects from the source. If globaIdKey is not set,
  SkyAttributeDataSource try to get it from the model.
*/
- (void)setGlobalIDKey:(NSString *)_gidKey;
- (NSString *)globalIDKey;

/*
  If verifyIds is set, then all globalIds from the SkyPropertyManager will
  be verify with the source (or-qualifier with ids). Else fetchObjects will
  sometimes returns the expected objects (like from the source) or only 
  globaIDs.
  Source must support the fetchSpec hint 'fetch_primary_key_qualifier'
  (primary_key in (1, 2, 3)) and must return objects which support -globaID
  or -valueForKey:@"globaID"
*/
- (void)setVerifyIds:(BOOL)_bool;
- (BOOL)verifyIds;

/*
  if dbKeys is set, all non-dbKeys in the qualifier without namespace got the
  defaultNamespace
*/
- (void)setDbKeys:(NSArray *)_keys;
- (NSArray *)dbKeys;

- (void)setDefaultNamespace:(NSString *)_ns;
- (NSString *)defaultNamespace;

 @end

#endif /* __LSFoundation_SkyAttributeDataSource_H__ */