/*

* Copyright (c) 2005 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:  

*       Class wrapping a calendar db, taking care of initialization etc.

*

*/

#ifndef __CMRUTILSCALDBBASE_H__

#define __CMRUTILSCALDBBASE_H__

//  INCLUDES

#include <e32base.h>

#include <calprogresscallback.h>

#include <calcommon.h>

// FORWARD DECLARATIONS

class CCalEntryView;

class CCalInstanceView;

class CCalEntry;

class CCalInstance;

class CMRUtilsCalDbBase;

class CCalSession;

// CLASS DECLARATION

/**

* Observer interface for handling calendar database status.

*/

class MMRUtilsCalDbObserver

    {

    public: // Data types

        /**

        * Enumeration for database status.

        */

        enum TDbStatus

            {

            EUninitialized       = 0x0000, // nothing done yet

            EReseting            = 0x0002, // db reset ongoing

            EInitEntryView       = 0x0004, // init entry view

            EInitInstanceView    = 0x0008, // init instance view

            EFinishedOk          = 0x0010, // init succeeded

            EFinishedError       = 0x0020  // init failed

            };

    public: // New functions

        /**

        * Callback method for handling database status.

        * @param aNotifier for identifying the notifying database

        * @param aStatus new current status of the database

        */

        virtual void HandleCalDbStatus( const CMRUtilsCalDbBase* aNotifier,

                                        TDbStatus aStatus ) = 0;

    };

/**

* Abstract base class representing a calendar database.

*/

class CMRUtilsCalDbBase

: public CBase, 

  public MCalProgressCallBack

    {

    public: // Constructors and destructors

        /**

        * Destructor.

        */

        ~CMRUtilsCalDbBase();

    public: // New functions

        /**

        * Entry view accessor. Ownership not transferred.

        * @return entry view, may be NULL

        */

        const CCalEntryView* EntryView() const;

        /**

        * Instance view accessor. Ownership not transferred.

        * @return instance view, may be NULL        

        */        

        const CCalInstanceView* InstanceView() const;

        /**

        * Session accessor. Ownership not transferred.

        * @return session, may be NULL        

        */        

        const CCalSession* Session() const;

        /**

        * Entry view accessor. Ownership not transferred.

        * @return entry view, may be NULL

        */

        CCalEntryView* EntryView();

        /**

        * Instance view accessor. Ownership not transferred.

        * @return instance view, may be NULL        

        */        

        CCalInstanceView* InstanceView();

        /**

        * Session accessor. Ownership not transferred.

        * @return session, may be NULL        

        */        

        CCalSession* Session();        

        /**

        * Database status getter.

        * @return current database status

        */

        MMRUtilsCalDbObserver::TDbStatus DbStatus();

        /**

        * CCalEntryView lacks fetch with time range. This method provides such

        * functionality. In case of repeating entries the entire sequence must

        * be within range (but modifying entries are considered separately).

        * If database doesn't have both instance and entry view then this

        * method leaves with KErrNotSupported.

        * @param aCalEntryArray fetched entries, caller owns array items

        * @param aCalTimeRange time range

        */

        void FetchWithRangeL( RPointerArray<CCalEntry>& aCalEntryArray,

                              const CalCommon::TCalTimeRange& aCalTimeRange,

                              TBool aFetchFullCopy = ETrue );

        /**

        * Reset database, causes asynchronous db initialization

        * which is notified through MMRUtilsCalDbObserver interface.

        * Calling this method requires that there are no external

        * open references for the session.

        * The default implementation leaves with KErrNotSupported.

        */        

        virtual void ResetDbL();

        /**

        * Tests whether given entry fits completely within given time range.

        * @param aEntry entry to test

        * @param aCalTimeRange criterion

        * @return ETrue if fits, EFalse if exceeds from either end

        */

        static TBool IsCompletelyWithinRangeL(

            const CCalEntry& aEntry,

            const CalCommon::TCalTimeRange& aCalTimeRange );

        /**

        * Wrapper which traps leaving CompareL(), and in leave situation

        * returns that objects are equal since that is a safer interpretation

        * and avoids duplicates in database.

        * In real life CompareL() is not expected to ever leave.

        * @param aFirst entry

        * @param aSecond entry

        * @return zero if the objects are equal, a negative value if aFirst is

        *         less than aSecond and a positive value otherwise

        */

        static TInt Compare( const CCalEntry& aFirst,

                             const CCalEntry& aSecond );

        /**

        * Helper which allows ordering entries in an array. That is implemented

        * by evaluating GUID and RECURRENCE-ID of the two entries.

        * @param aFirst entry

        * @param aSecond entry

        * @return zero if the objects are equal, a negative value if aFirst is

        *         less than aSecond and a positive value otherwise

        */                             

        static TInt CompareL( const CCalEntry& aFirst,

                              const CCalEntry& aSecond );

    protected: // From MCalProgressCallBack

    	void Progress( TInt aPercentageCompleted );

        TBool NotifyProgress();

	    // This method must be implemented by the subclasses:

        // void Completed( TInt aError );

    protected: // Constructors and destructors

       /**

        * C++ default constructor.

        * @param aDbObserver database observer reference

        * @param aCmdObserver asynchronous command observer reference

        */

        CMRUtilsCalDbBase( MMRUtilsCalDbObserver& aDbObserver,

                           MCalProgressCallBack& aCmdObserver );        

    protected: // data

        // Current database status

        MMRUtilsCalDbObserver::TDbStatus iDbStatus;          

        // This callback is used for notifying about database status

        MMRUtilsCalDbObserver& iDbObserver;

        // This callback is used for notifying about asynchronous

        // command progress, Note: currently not used for anything!

        MCalProgressCallBack& iCmdObserver;

        // Managed by the subclass

        CCalEntryView* iCalEntryView;

        // Managed by the subclass

        CCalInstanceView* iCalInstanceView;    

        // Managed by the subclass

        CCalSession* iCalSession;            

    };

#endif // __CMRUTILSCALDBBASE_H__

// End of File