/*

* Copyright (c) 2005-2009 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:  This is find engine to manage object searching,*

*/

#ifndef __MDSFINDENGINE_H__

#define __MDSFINDENGINE_H__

#include <e32base.h>

#include "mdscommoninternal.h"

// FORWARD DECLARATIONS

class CMdSFindSequence;

class CMdSServerSession;

class CMdSObjectLockList;

class CMdCSerializationBuffer;

class CMdsSchema;

class CMdSServer;

// CLASS DECLARATION

/**

* CMdSFindEngine.

*  Class for searching objects from metadata database.

*/

class CMdSFindEngine : public CBase

    {

    public: // Constructors and destructors

        /**

        * NewL.

        * Two-phased constructor.

        * @param aQueryId query id

        * @param aParent the session back reference

        * @param aLockList list of locked objects

        * @param aSchemaNew schema reference

        * 

        * @return Pointer to created CMdSFindEngine object.

        */

        static CMdSFindEngine* NewL(

        	TUint32 aQueryId, 

            CMdSServerSession& aParent,

            CMdSObjectLockList& aLockList,

            CMdsSchema& aSchemaNew);

        /**

        * NewLC.

        * Two-phased constructor.

        * @param aQueryId query id

        * @param aParent the session back reference

        * @param aLockList list of locked objects

        * @param aSchemaNew schema reference

        * @return Pointer to created CMdSFindEngine object.

        */

        static CMdSFindEngine* NewLC(

        	TUint32 aQueryId, 

            CMdSServerSession& aParent,

            CMdSObjectLockList& aLockList,

            CMdsSchema& aSchemaNew);

        /**

        * 2nd phase constructor

        */

        void ConstructL( CMdsSchema& aSchema );

        /**

        * ~CMdSFindEngine.

        * Destructor.

        */

        virtual ~CMdSFindEngine();

    public:

	    /**

	    * Returns query's ID

	    * @return query ID

	    */

	    TUint32 QueryId();

        /**

        * Creates the result set and sets message pointer

        * @param aMessage message for asynchronous client messaging

        */

        void CreateResultSet(RMessage2 aMessage);

        /**

        * Sets parameters for the find. Ownership is transferred.

        */

        void SetFindParams( TUint32 aNotifyCount );

        /**

        * Sets serialized criteria buffer for the find. Ownership is transferred.

        */

        void SetFindCriteria( CMdCSerializationBuffer* aSerializedCriteria );

	    /**

	    * Initiates find

	    * @param aUserLevel defines user's access rights

	    * @return error code or KErrNone

	    */

        TInt FindL( TUserLevel aUserLevel );

	    /**

	    * Continues ongoing sync find

        * @return error code or KErrNone

	    */

        TInt ContinueL();

	    /** 

	    * Initiates asynchronous find

        * @param aUserLevel defines user's access rights

	    */

        void FindAsyncL( TUserLevel aUserLevel );

	    /** 

	    * Continues ongoing find

	    */

	    void ContinueAsync();

	    /** 

	    * Cancels find

	    */

        void Cancel( TInt aError );

        /**

        * Transfer result set to client

        * @aError error code or KErrNone

        */

        void SetComplete( TInt aError );

        /**

        * Transfer results to client and completes find

        * @aError error code or KErrNone

        */

        void FindComplete( TInt aError );

		const CMdCSerializationBuffer& ResultsL() const;

		/**

		 * Locks query result objects.

		 * @param aLockList list of objects that must be locked

		 */

		void LockFindResultObjectsL( CMdSObjectLockList& aLockList );

		/**

		 * Sets result mode.

		 * @param aResultModeItems ETrue if result mode is item mode

		 */

		void SetResultMode( TBool aResultModeItems );

	    /**

	    * Returns whether find engine is complete or not.

	    * Completed sequence can be safely delete.

	    */

		TBool IsComplete() const;

	    /**

	    * Returns whether find engine's query is complete or not.

	    */

		TBool IsQueryComplete();

		CMdSServer& GetServer() const;

    private: // Constructors and destructors

        /**

        * CMdSManipulationEngine.

        * C++ default constructor.

        * @param .

        */

        CMdSFindEngine(

        	TUint32 aQueryId, 

            CMdSServerSession& aParent,

            CMdSObjectLockList& aLockList);

    private: // Data

    	TUint32 iQueryId;

        CMdSServerSession& iParent;

        CMdSObjectLockList& iLockList;

        CMdSFindSequence* iSequence;

		CMdCSerializationBuffer* iSerializedCriteria;

        RMessage2 iMessage;

        TBool iAsyncPending;

        // if last query result was Items result

        TBool iLastResultModeItems;

    };

#endif //__MDSFINDENGINE_H__