/*

* Copyright (c) 2006-2007 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:  Engine class to notify channel name/metadata changes to SongHistoryDb and UI

*

*/

/* ---------------------------------------------------------------------------

*  Version history:

*  Template version:

*  <ccm_history>

*

*  Version: 3, Thu Apr 14 12:00:00 2008 by Rohit

*  Ref:

*  Pc lint fixes

*

*  Version: 2, Thu Apr 10 20:00:00 2008 by Rohit

*  Ref:

*  Implemented SongHistory changes for channelwise songs

*

*  </ccm_history>

* ============================================================================

*/

#ifndef CIRSONGHISTORYENGINE_H

#define CIRSONGHISTORYENGINE_H

#include "irsonghistoryengpubsubnotifyhandler.h"

#include "irsonghistorydb.h"

class CIRSongHistoryEngPubSub;

class MSongHistoryUINotifyHandler;

class CIRMetaData;

class CIRSongHistoryInfo;

class RSongHistoryDb;

class MIRSongHistoryEngPubSubNotifyHandler;

enum TSongHistoryItemChange

{

	ENOCHANGE = 0,

	ECHANNELCHANGED,

	EMETADATACHANGED,

	EBLANKENTRIES

};

/**

* Engine component for Internet Radio SongHistory.

* This class is responsible for listening to relevant P&S keys and notifying the UI code whenever the listened keys change.

*/

NONSHARABLE_CLASS(CIRSongHistoryEngine) : public CBase,public MIRSongHistoryEngPubSubNotifyHandler

    {

    public:

    /**

    * Static constructor.

    * @param    aUiObserver   The observer to be notified of the changes in the keys.

    * @return   The newly created CIRSongHistoryEngine object.

    */

    	IMPORT_C static CIRSongHistoryEngine* NewL( MSongHistoryUINotifyHandler& aUiObserver );

    /**

    * Static constructor.

    * @param    aUiObserver   The observer to be notified of the changes in the keys.

    * @return   The newly created CIRSongHistoryEngine object.

    */

    	IMPORT_C static CIRSongHistoryEngine* NewLC( MSongHistoryUINotifyHandler& aUiObserver );

    /**

    * Destructor.

    */

 	   IMPORT_C ~CIRSongHistoryEngine();

    /**

    * Construction finalizer.

    * Must be called after CIRSongHistoryEngine::NewL.

    */

	   void ConstructL();

	//APIs to serve UI request

    /**

    * Invoked when UI request.

    * @param    aArray<CIRSongHistoryInfo>

    */

    	IMPORT_C void GetAllHistoryL( RPointerArray<CIRSongHistoryInfo>& aSongHistoryInfo );

    /**

    * Invoked when UI request.

    */

    	IMPORT_C TInt ClearAllHistory( );

    /**

    * Invoked when UI request.

    */

    	IMPORT_C TInt GetHistoryCount( );

    /**

    * Called by the UI when a particular channel has been removed from the ISDS.

    */

        IMPORT_C TInt SyncHistory(TInt aChannelId);

    /**

    * Called by the UI when a particular channel has been changed in the ISDS.

    */

        IMPORT_C void UpdateSongHistoryDb( TInt aChannelId,

    	                          const TDesC& aChannelName, 

						          const TDesC& aChannelUrl,

							      const TDesC& aMusicFlag);

        /* called by the UI when delete a particular channel

         * */

        IMPORT_C TInt DeleteOneHistory(TInt aIndex);

  public:

  //this function made public for our internal testing. Has to be private without IMPORT_C

		/**

		* Invoked when the listened key is changed.

		* @param    aCategory   The category of the key that changed.

		* @param    aKey        The key that changed.

		* @param    aText       The new value of the key.

		*/

			IMPORT_C void HandleMetaDataReceivedL( const CIRMetaData& aMetaData );

	private:

		/**

		* Invoked when the listened key is changed.

		* @param    aCategory   The category of the key that changed.

		* @param    aKey        The key that changed.

		* @param    aText       The new value of the key.

		* Single wrapper function to be implemented in the engine class instead of two.

		*/

			void HandlePropertyChangeL( const TUid& aCategory, TUint aKey,

											   const TDesC8& aText ) ;

		/**

		* Invoked when the listened key is changed.

		* @param    aCategory   The category of the key that changed.

		* @param    aKey        The key that changed.

		* @param    aError      The error value.

		*/

			void HandlePropertyChangeErrorL( const TUid& aCategory, TUint aKey,

										 TInt aError );

		/**

		 * Invoked when data needs to be added

		 * @param	aMetaData	MetaData that needs to be added

		 * @param	aChannelName Channel name that needs to be added

		 */

		TSongHistoryItemChange DetectSongHistoryItemChangesL(const CIRMetaData& aMetaData,

					 const RBuf& aChannelName, const RBuf& aChannelUrl);

	private:

		/**

		* Constructor.

		* @param    aObserver   The observer to be notified of the changes

		* in the keys.

		*/

			CIRSongHistoryEngine( MSongHistoryUINotifyHandler & aUiObserver );

    private:

		/** An instance of songhistory database. */

		CIRSongHistoryDb* iSongHistoryDb;

        /** The observer to be notified of the database changes to the UI */

		MSongHistoryUINotifyHandler & iUiObserver;

        /** CIRSongHistoryEngPubSub objects subscribing for propery change */

        CIRSongHistoryEngPubSub *iChannelNameSub;

        CIRSongHistoryEngPubSub *iMetaDataSub;

    };

#endif//CIRSONGHISTORYENGINE_H