/*

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

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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:    Contains cached MDS media items*

*/

#ifndef VCXMYVIDEOSVIDEOCACHE_H

#define VCXMYVIDEOSVIDEOCACHE_H

// INCLUDES

#include "vcxmyvideosmdsdb.h"

// FORWARD DECLARATIONS

class CVcxMyVideosCollectionPlugin;

class CMPXMedia;

class CVcxMyVideosDownloadCache;

// CONSTANTS

// CLASS DECLARATION

/**

* Used for storing MDS items to RAM for fast access.

*

* @lib mpxmyvideoscollectionplugin.lib

*/

NONSHARABLE_CLASS(CVcxMyVideosVideoCache) : public CBase

    {    

    public: // Constructors and destructor

        /**

        * Two-phased constructor

        * @param aMyVideosCollectionPlugin  Owner of this object.

        * @return                           Object constructed

        */

        static CVcxMyVideosVideoCache* NewL (

                CVcxMyVideosCollectionPlugin& aMyVideosCollectionPlugin );

        /**

        * Destructor

        */

        virtual ~CVcxMyVideosVideoCache();

    private:

        /**

        * Constructor

        */

        CVcxMyVideosVideoCache( CVcxMyVideosCollectionPlugin& aMyVideosCollectionPlugin );

        /**

        * Symbian 2nd phase constructor.

        */

        void ConstructL ();

        /**

        * Finds correct position in iVideoList for the new video.

        *

        * @param aMedia        Video to be inserted to the list.

        * @param aSortingOrder Sorting order.

        * @return              Position in the cache.

        */

        TInt FindCorrectPositionL( CMPXMedia& aMedia, TVcxMyVideosSortingOrder aSortingOrder );

        /**

        * Compares aNewVideo and aVideoInList in sizes, creation dates

        * or titles.

        *

        * @param aNewVideo     Video to be added to the list.

        * @param aVideoInList  Video in cache video list which is currently compared against

        *                      aNewVideo.

        * @param aSortingOrder Defines which attributes are compared. Size, Creation Date and Title

        *                      are possible.

        * @return              -1 if aVideoInList has smaller value, 1 if greater and 0 if equal.

        */

        TInt CompareL( CMPXMedia& aNewVideo, CMPXMedia& aVideoInList,

                TVcxMyVideosSortingOrder aSortingOrder );

        /**

        * Adds video to iVideoList to the correct position, according to sorting order.

        * MDS ID is used to identify the video.

        *

        * @param aVideo            Video to add.

        * @param aSortingOrder     Sorting order used.

        * @param aUpdateCategories If ETrue, then categories are updated.

        * @return                  KErrNone if added, KErrAlreadyExists if already exists and

        *                          was not added.

        */

        TInt AddToCorrectPlaceL( CMPXMedia& aVideo, TVcxMyVideosSortingOrder aSortingOrder,

                TBool aUpdateCategories = ETrue );

        /**

        * Moves a video to correct place on iVideoList, according to sorting order.

        * aVideo should be a refrence to iVideoList item. After the call the referenced

        * item is gone and the reference shouldn't be used anymore.

        *

        * @param aVideo        Video to move.

        * @param aSortingOrder Sorting order used.

        */                

        void MoveToCorrectPlaceL( CMPXMedia& aVideo,

                TVcxMyVideosSortingOrder aSortingOrder );

        /**

        * Removes video from iVideoList or iPartialVideoList.

        * MDS ID is used to identify the video.

        *

        * @param aVideo            Video to remove, MDS ID is read from here.

        * @param aUpdateCategories If ETrue, then categories are updated.

        * @return                  KErrNotFound if not found, KErrNone otherwise.

        */

        TInt RemoveL( CMPXMedia& aVideo, TBool aUpdateCategories = ETrue );

        /**

        * Fetches sorting order from Cenrep.

        * @return Sorting order.

        */

        TVcxMyVideosSortingOrder SortingOrderL();

        /**

        * Called when Title in video cache has been modified. 

        * Updates sorting order and category attributes if necessarry.

        * NOTICE that aVideoInCache is not allowed to own the media object, since this

        * function may change the pointer value to point to a new object.

        *

        * @param aVideoInCache  Video in cache which Title has been modified. aVideoInCache

        *                       is not allowed to own the data.

        */

        void HandleVideoTitleModifiedL( CMPXMedia*& aVideoInCache );

        /**

        * Deletes iPartialList.

        */ 

        void DeletePartialList();

        /**

        * Adds video to cache (iVideoList or iPartialVideoList). Ownership moves.

        *

        * @param aVideo             Video to add.

        * @param aSortingOrder      Sorting order.

        * @return                   KErrNone if added, KErrAlreadyExists if already exists and

        *                           was not added.

        */

        TInt AddL( CMPXMedia* aVideo, TVcxMyVideosSortingOrder aSortingOrder );

        /**

        * Adds video to iPartialVideoList. Ownership moves.

        *

        * @param aVideo  Video to add.

        * @return        KErrNone if item was added, KErrAlreadyExists if video

        *                was already on the list and was not added.

        */       

        TInt AddToPartialListL( CMPXMedia* aVideo );

        /**

        * Finds the array position of aVideo in iPartialVideoList .

        *

        * @param aVideo  Video which position is searched.

        * @return        Position, KErrNotFound if item is not in iPartialVideoList.

        */

        TInt PosOnPartialVideoListL( CMPXMedia& aVideo );

        /**

        * Finds the array position of aVideo in iVideoList.

        *

        * @param aVideo  Video which position is searched.

        * @return        Position, KErrNotFound if item is not in iVideoList.

        */

        TInt PosOnVideoListL( CMPXMedia& aVideo );

    public:            

        /**

        * Creates filtered video list from iVideoList. This is used for

        * showing video categories by origin.

        *

        * @param aOrigin Only videos with this origin are added to list,

        *                see values from TVcxMyVideosOrigin (in vcxmyvideosdefs.h).                

        * @return        New video list, containing videos from aOrigin.

        */

        CMPXMedia* CreateVideoListByOriginL( TUint8 aOrigin );

        /**

        * Appends items from aFromList to aToList if items origin is equal with

        * aOrigin. This is used when fetching other than All category from MDS.

        *

        * @param aToList    List to append

        * @param aFromList  List to append from.

        * @param aOrigin    Only items with this origin are copied.

        * @param aNewItemsStartIndex Start index in aFromList where from the copying is started.

        */

        void AppendToListL( CMPXMedia& aToList, CMPXMedia& aFromList,

                TUint8 aOrigin, TInt aNewItemsStartIndex );

        /**

        * Tries to find media with matching URI from the cached video list.

        *

        * @param aUri URI to compare

        * @return     Contains pointer to media if match found, NULL otherwise.

        *             Pointer ownership is not moved to the caller.

        */

        CMPXMedia* FindVideoByUriL( const TDesC& aUri );

        /**

        * Tries to find media with matching MdsId from iVideoList and iPartialVideoList.

        *

        * @param aMdsId ID to compare

        * @param aPos   If found from iVideoList, the position index is written here,

        *               KErrNotFound otherwise. If found from iPartialVideoList, then

        *               the value is still set to KErrNotFound.

        * @return       Contains pointer to media if match found, NULL otherwise.

        *               Pointer ownership is not moved to the caller.

        */

        CMPXMedia* FindVideoByMdsIdL( TUint32 aMdsId, TInt& aPos );

        /**

        * Tries to find media with matching download ID from iVideoList and iPartialVideoList.

        * If aDownloadId is 0, then NULL is returned.

        *

        * @param aDownloadId ID to compare

        * @return            Contains pointer to media if match found, NULL otherwise.

        *                    Pointer ownership is not moved to the caller.

        */

        CMPXMedia* FindVideoByDownloadIdL( TUint aDownloadId );

        /**

        * Gets medias from iVideoList and iPartialVideoList.

        *

        * @param aMdsIds  IDs of the items to fetch.

        * @return         Pointer to fetched items, KMPXMediaArrayContents

        *                 attribute contains the media items. Ownership

        *                 moves to caller.

        */

        CMPXMedia* GetVideosL( RArray<TUint32> aMdsIds );

        /**

        * Removes video from iVideoList (or from iPartialVideoList).

        *

        * @param aMdsId             MDS ID of the video to be removed.

        * @param aUpdateCategories  If ETrue, then categories are updated.

        * @return                   KErrNotFound if not found, KErrNone otherwise.

        */

        TInt RemoveL( TUint32 aMdsId, TBool aUpdateCategories = ETrue );

        /**

        * Removes videos from iVideoList.

        *

        * @param aUpdateCategories  If ETrue, then categories are updated.

        * @param aMdsIds            Array containing MDS IDs of the videos to be deleted.

        */

        void RemoveL( RArray<TUint32>& aMdsIds, TBool aUpdateCategories = ETrue );

        /**

        * Adds videos to cache (iVideoList or iPartialVideoList). After the function call aMdsIds

        * will contain only those items which were actually added to cache.

        *

        * @param aMdsIds                   Array containing MDS IDs of the videos to be added.

        * @param aListFetchingWasCanceled  This is set to EFalse if video list fetching from mds

        *                                  had to be cancelled. EFalse otherwise. 

        */

        void AddVideosFromMdsL( RArray<TUint32>& aMdsIds, TBool& aListFetchingWasCanceled );

        /**

        * Deletes old and creates new iVideoList. After the function call iVideoList exists,

        * but it might not contain any media items yet, only empty array.

        * Media items are added to the list asynchronoysly in

        * VcxMyVideosColletionPlugin::HandleCreateVideoListResp(), called by

        * VcxMyVideosMdsDb. When new items are added, they are synchronized with

        * Download Manager. Once iVideoList is complete, iVideoListIsPartial

        * is set to EFalse. During the video list fetching

        * VcxMyVideosMdsDb::iVideoListFetchingIsOngoing is ETrue.

        * If there is video list creation already ongoing

        * and the aSortingOrder is the same, nothing is done.

        * During the video list fetching iPartialVideoList items are moved to

        * iVideoList. When fetch is complete, iPartialVideoList is empty.

        *

        * @param aForce  If ETrue, then the list is always created from scratch, possible

        *                ongoing fetch is cancelled.

        */

        void CreateVideoListL( TBool aForce = EFalse );

        /**

        * Resets iVideoList (removes items, empty list is left) and cancels possible ongoing

        * asynchronous videolist fetching. iVideoListIsPartial is set to ETrue.

        * CVcxMyVideosCollection plugin variables are not touched. Caller is responsible to

        * either cancel the fetch from plugin, or restart fetch from mds in a way that

        * client gets its list. iVideoList media object remains pointing to same shared data.

        */

        void ResetVideoListL();

        /**

        * Updates video attributes in cache from aVideo. NOTE: iVideoList might be changed

        * if Size or Title values are modified and matching sorting order is currently on.

        * Pointers to iVideoList items should be refreshed after calling this with size and title

        * parameters.

        *

        * @param aVideo  Attributes are read from here and updated to cache if difference exists. 

        * @return        ETrue if any parameter was changed. 

        */

        TBool UpdateVideoL( CMPXMedia& aVideo );

        /**

        * iVideoList and its media array are deleted and recreated. New instances point to

        * different global heap position. Media objects stay the same and point to

        * same global heap.

        */

        void ReCreateVideoListL();

        /**

         * Replaces items in iVideoList with items from iPartialVideoList.

         * Called by iCollection when fetching videolist.

         */

        void CheckForPartialVideoListItemsL( TInt aNewItemsStartIndex );

    public:

        /**

        * Contains list of all videos in MDS. Used for caching MDS to RAM.

        */

        CMPXMedia* iVideoList;

        /**

        * Items fetched by MDS ID which don't (yet) have instance in iVideoList

        * are added here. When iVideoList instance is received from MDS, it is

        * replaced by item from iPartialVideoList and instance from iPartialVideoList

        * is removed.

        */

        RArray<CMPXMedia*> iPartialVideoList;

        /**

        * If ETrue then iVideoList does not contain all items from MDS.

        */

        TBool iVideoListIsPartial;

        /**

        * Sorting order which was used last time when list was queryed from MDS.

        */

        TVcxMyVideosSortingOrder iLastSortingOrder;

    private:

        /**

        * Circular buffer containing download id and media object pointer pairs.

        * Media object pointers are owned by iVideoList.

        * Used to speed up access to media objects which are used regularly during the

        * download.

        */

        CVcxMyVideosDownloadCache* iDownloadCache;

        /**

        * My Videos collection plugin, owner of this object.

        */

        CVcxMyVideosCollectionPlugin& iCollection;        

    };

#endif   // VCXMYVIDEOSVIDEOCACHE_H