/*

* Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:    Definition of CGlxtnVolumeDatabase

*

*/

/**

 * @internal reviewed 30/07/2007 by Simon Brooks

 */

#ifndef GLXTNVOLUMEDATABASE_H

#define GLXTNVOLUMEDATABASE_H

#include <e32base.h>

#include <d32dbms.h>    // For RDbStoreDatabase

#include <f32file.h>    // For TDriveName

#include <glxmediaid.h>

#include "glxtnstd.h"   // For TGlxImageDataFormat

#include "mglxtnvolumedatabaseobserver.h"   // For TGlxtnThumbnailId

class CFileStore;

class CGlxtnFileInfo;

class MGlxtnVolumeDatabaseObserver;

const TInt KErrCorruptThumbnailDatabase = -10001;

const TInt KErrEofThumbnailDatabase = -10002;

/**

 * CGlxtnVolumeDatabase implements the database for a single volume.

 *

 * @author Dan Rhodes

 * @ingroup glx_thumbnail_creator

 */

NONSHARABLE_CLASS(CGlxtnVolumeDatabase) : public CActive

    {

public:

    /**

    * Static constructor.

    * @param aObserver Observer of database operations.

    * @param aFs File server handle.

    * @param aPath Full path to the database file to use.

    */

    static CGlxtnVolumeDatabase* NewLC(MGlxtnVolumeDatabaseObserver& aObserver,

                                       RFs& aFs, 

                                       const TDesC& aPath);

    /**

    * Destructor

    */

    ~CGlxtnVolumeDatabase();

    /**

    * Get the drive this database is stored on

    */

    const TDesC& Drive() const;

    /**

    * Look up thumbnail ID from Ids table

    * @param aMediaId Media item ID.

    */

    void GetThumbnailIdL( const TGlxMediaId& aMediaId );

    /**

    * Look up thumbnail ID from Items table.  If not found, add new record.

    * @param aInfo File info for media item.

    */

    void GetThumbnailIdL(const CGlxtnFileInfo* aInfo);

    /**

    * Retrieve the thumbnail id to be assigned to the next thumbnail that gets stored in teh database. 

    * @param None.

    */

    TGlxtnThumbnailId GetThumbnailId();

    /**

    * Add record to Ids table

    * @param aMediaId Media item ID.

    * @param aThumbId Thumbnail ID.

    */

    void StoreThumbnailIdL( const TGlxMediaId& aMediaId,

                            const TGlxtnThumbnailId& aThumbId );

    /**

    * Look up thumbnail from Thumbnails table

    * @param aThumbId Thumbnail ID.

    * @param aSize Thumbnail size.

    */

    void GetThumbnailL( const TGlxtnThumbnailId& aThumbId, const TSize& aSize );

    /**

    * Check if a particular thumbnail is in Thumbnails table

    * @param aThumbId Thumbnail ID.

    * @param aSize Thumbnail size.

    */

    void CheckAvailableL( const TGlxtnThumbnailId& aThumbId, const TSize& aSize );

    /**

    * Add record to Thumbnails table

    * @param aThumbId Thumbnail ID.

    * @param aSize Thumbnail size.

    * @param aFormat Thumbnail data format.

    * @param aData Thumbnail binary data.

    */

    void StoreThumbnailL( const TGlxtnThumbnailId& aThumbId, const TSize& aSize,

                        TGlxImageDataFormat aFormat, const TDesC8& aData );

    /**

    * Add record to Items table, if not found.

    * @param aThumbId Thumbnail Id.

    * @param aInfo File info for media item.

    */

    void StoreItemsL( const TGlxtnThumbnailId& aThumbId, const CGlxtnFileInfo* aInfo );

    /**

    * Initialize thumbnail identifier to the last known value plus one.

    */

    void InitializeThumbIdL();

    /**

    * Delete a record from the Ids table

    * @param aMediaId MediaId of record to delete.

    */

    void DeleteIdL( const TGlxMediaId& aMediaId );

    /**

    * Delete a record from the Thumbnails table

    * @param aThumbId ThumbId of records to delete.

    */

    void DeleteThumbnailsL( const TGlxtnThumbnailId& aThumbId );

    /**

    * Delete a record from the Items table

    * @param aThumbId ThumbId of record to delete.

    */

    void DeleteItemL( const TGlxtnThumbnailId& aThumbId );

    /**

    * Cleanup Database (remove entries that do not have corresponding file)

    */

    void CleanupDatabaseL();

protected:  // From CActive

    void DoCancel();

    void RunL();

    TInt RunError(TInt aError);

private:

    /**

    * Default constructor.

    * @param aObserver Observer of database operations.

    * @param aFs File server handle.

    */

    CGlxtnVolumeDatabase(MGlxtnVolumeDatabaseObserver& aObserver, RFs& aFs);

    /**

    * 2nd phase constructor.

    * @param aPath Full path to the database file to use.

    */

    void ConstructL(const TDesC& aPath);

    /**

    * Open an existing database.

    * @param aFs File server handle.

    * @param aPath Full path to the database file to use.

    */

    void OpenDbL(RFs& aFs, const TDesC& aFilename);

    /**

    * Create a new database.

    * @param aFs File server handle.

    * @param aPath Full path to the database file to use.

    */

    void CreateDbL(RFs& aFs, const TDesC& aFilename);

    /**

    * Add record to Items table

    * @return Thumbnail ID of new record.

    */

    TGlxtnThumbnailId DoAddItemL();

    /**

    * Evaluate a view based on a SQL query.

    * @param aQuery The SQL select statement.

    */

    void EvaluateQueryL( const TDbQuery &aQuery );

    /**

    * Execute a SQL data update statement.

    * @param aSql The SQL statement.

    */

    void UpdateDataL( const TDesC& aSql );

    /**

    * Test and cleanup a row in Items table

    */

    void CleanupRowL();

    /**

    * Modify SQL string to handle quotes correctly

    * @param aText String to be modified

    * @return New HBufC containing modified string

    */

    HBufC* QuoteSqlStringLC(const TDesC& aText);

private:

    enum TDatabaseState

        {

        EStateIdle, 

        EStateGettingIdFromMediaId, 

        EStateGettingIdFromFilename,

        EStateGettingThumbnail,

        EStateDeletingId,

        EStateDeletingThumbnails,

        EStateDeletingItem,

        EStateCheckingAvailability,

        EStateCleaning,

        EStateCleaningDeletingThumbnails

        };

    /** Observer of this database */

    MGlxtnVolumeDatabaseObserver& iObserver;

    /** File server session */

    RFs& iFs;

    /** Drive name of the volume */

    TDriveName iDrive;

    /** Handle to the database */

    RDbStoreDatabase iDatabase;

    /** Store used by the database */

    CFileStore* iStore;

    /** ID for next stored thumbnail */

    TUint iNextThumbId;

    /** File info for media item current query relates to (not owned) */

    const CGlxtnFileInfo* iInfo;

    /** Current state */

    TDatabaseState iState;

    /** View used for current query */

    RDbView iView;

    /** Updater to update a table */

    RDbUpdate iDbUpdater;

    /** Table used for query/deletion of rows in table */

    RDbTable iTable;

    /** Flag to determine if cleanup operation did anything requiring compacting */

    TBool iItemsCleaned;

    };

#endif  // GLXTNVOLUMEDATABASE_H