/*

* Copyright (c) 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:  CMdEManager declaration

*

*/

#ifndef CMDEMANAGER_H

#define CMDEMANAGER_H

#include <e32base.h>

#include <mdesession.h>

#include <mdequery.h>

#include "playlistitem.h"

class MMdEManagerObserver

    {

public:

    virtual void AlbumsReaded( TInt aError ) = 0;

    virtual void AlbumReplaced( TInt aError ) = 0;

    };

class CMdEManager : public CBase,

                        MMdESessionObserver,

                        MMdEQueryObserver

    {

public:

    // Cancel and destroy

    ~CMdEManager();

    // Two-phased constructor.

    static CMdEManager* NewL( MMdEManagerObserver& aObserver );

public:

    /**

	 * Start enumerating albums. Calls MMdEManagerObserver::AlbumsReaded when ready.

	 * This needs to be called before any other operations.

	 */ 

    void GetAlbumsL();

    RPointerArray<CPlaylistItem>& AlbumsArray(){ return iAlbums; };

    const CPlaylistItem& AlbumL( TInt aAlbumId ) const;

    void CreateAlbumL( CPlaylistItem& aAlbum );

    void ReplaceAlbumL( TInt aAlbumId, CPlaylistItem& aAlbum );

    void DeleteAlbumL( TInt aAlbumId );

	/**

	 * Cancels any outstanding request if any.

	 */

    void Cancel();

private:

    void StartProcessingAlbumsL();

    void ProcessNextAlbumL();

    void FindItemsOnAlbumL( TItemId aAlbumObjectId );

private: // from MMdESessionObserver

    /**

     * Called to notify the observer that opening the session has been 

     * completed and, if the opening succeeded, the session is ready for use.

     *

     * @param aSession session

     * @param aError   <code>KErrNone</code>, if opening the session succeeded;

     *                 or one of the system-wide error codes, if opening the 

     *                 session failed

     */

    void HandleSessionOpened(CMdESession& aSession, TInt aError);

    /**

     * Called to notify the observer about errors, which are not a direct 

     * consequence of the operations initiated by the client but caused by 

     * some external source (e.g., other clients). The error cannot be 

     * recovered and all on-going operations initiated by the client have been 

     * aborted. Any attempts to continue using the session will cause a panic. 

     * The client should close the session immediately and try to open a new 

     * session, if it needs to continue using the metadata engine.

     *

     * @param aSession session

     * @param aError one of the system-wide error codes

     */

    void HandleSessionError(CMdESession& aSession, TInt aError);

private: // from MMdEQueryObserver

    /**

     * Called to notify the observer that new results have been received 

     * in the query.

     *

     * @param aQuery              Query instance that received new results.

     * @param aFirstNewItemIndex  Index of the first new item that was added

     *                            to the result item array.

     * @param aNewItemCount       Number of items added to the result item 

     *                            array.

     */

    void HandleQueryNewResults(CMdEQuery& aQuery,

                                       TInt aFirstNewItemIndex,

                                       TInt aNewItemCount);

    /**

     * Called to notify the observer that the query has been completed,

     * or that an error has occured.

     *

     * @param aQuery  Query instance.

     * @param aError  <code>KErrNone</code>, if the query was completed

     *                successfully. Otherwise one of the system-wide error 

     *                codes.

     */

    void HandleQueryCompleted(CMdEQuery& aQuery, TInt aError);

private:

    CMdEManager( MMdEManagerObserver& aObserver );

    void ConstructL();

    void HandleAlbumQueryCompletedL( CMdEObjectQuery& aQuery );

    void HandleObjectQueryCompletedL( CMdEObjectQuery& aQuery );

    void HandleRelationQueryCompletedL( CMdERelationQuery& aQuery );

private:

    enum TCMdEManagerState

        {

        EUninitialized,             // Uninitialized / initialization is ongoing

        EWaitingToEnumerateAlbums,  // Initializing and starting collecting albums info

        EEnumeratingAlbums,         // Album enumeration is ongoing

        EReplacingAlbum,            // Replacing album (searching removed relation id:s)

        EIdle                       // Ready for next operation

        };

private:

    MMdEManagerObserver& iObserver;

    TCMdEManagerState   iState;

    CMdESession*        iMde;

    CMdEObjectQuery*    iAlbumQuery;

    CMdEObjectQuery*    iObjectQuery;

    CMdERelationQuery*  iContainmentQuery;

    RPointerArray<CPlaylistItem> iAlbumsInProgress;

    RPointerArray<CPlaylistItem> iAlbums;

    };

#endif // CMDEMANAGER_H