/** @file

* Copyright (c) 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:  Handles download of a file

*

*/

#ifndef C_CHTTPDOWNLOADWORKER_H

#define C_CHTTPDOWNLOADWORKER_H

// User include files

#include "httptransferworker.h"

#include "httptransferobserver.h"

#include "httptransferbase.h"

// forward declarations

class MHttpWorkerObserver;

/**

 * This class downloads on single file.

 *

 * @lib httptransfer.lib

 * @since S60 v3.2

 */

NONSHARABLE_CLASS ( CHttpDownloadWorker ) : public CHttpTransferWorker, MHttpNotifyTimerObserver

    {

public:

    /**

     * Constructor

     *

     * @since S60 v3.2

     * @param aObserver Transfer observer

     * @param aIAPId IAP id

     * @param aBuffersize Size of the buffer

     * @param aCallback Call back to workerobserver

     */

    static CHttpDownloadWorker* NewL( MHttpTransferObserver& aObserver,

                                      TUint aIAPId,

                                      TUint aBufferSize,

                                      MHttpWorkerObserver& aCallback );

    /**

     * Constructor

     *

     * @since S60 v3.2

     * @param aObserver Transfer observer

     * @param aIAPId IAP id

     * @param aBufferSize Size of the buffer

     * @param aCallback Call back to workerobserver

     */

    static CHttpDownloadWorker* NewLC( MHttpTransferObserver& aObserver,

                                       TUint aIAPId,

                                       TUint aBufferSize,

                                       MHttpWorkerObserver& aCallback );

    /**

     * Destructor

     *

     * @since S60 v3.2

     */

    virtual ~CHttpDownloadWorker();

// from base class CHttpTransferWorker

    /**

     * From base class CHttpTransferWorker

     * Stops the transfer of the file

     *

     * @since S60 v3.2

     */

    void CancelTransfer();

    /**

     * From base class CHttpTransferWorker

     * Starts the processing of a file.

     * Asynchronous.

     *

     * @since S60 v3.2

     */

    virtual void StartProcessL();

    /**

     * From base class CHttpTransferWorker

     * Called by framework to notify about transaction events.

     *

     * @since S60 v3.2

     * @param aTransaction Transaction, where the event occured.

     * @param aEvent Occured event.

     */

    void MHFRunL( RHTTPTransaction aTransaction,

                  const THTTPEvent& aEvent );

    /**

     * From base class CHttpTransferWorker

     * Called by framework when leave occurs in handling of 

     * transaction event.

     *

     * @since S60 v3.2

     * @param aError The leave code that occured.

     * @param aTransaction The transaction that was being processed 

     * @param aEvent The event that was being processed

     * @return Error code

     */

    TInt MHFRunError( TInt aError, 

                      RHTTPTransaction aTransaction,

                      const THTTPEvent& aEvent );

private:

    /**

     * Deletes partially downloaded file from file system.

     *

     * @since S60 v3.2

     */

    void DeleteFileL();

    /**

     * Checks disk space

     * @param aSize to be written to file

     * @since S60 v3.2

     */

    void CheckDiskSpaceL(TInt aSize);

    /**

     * Writes the last part of body into a file

     *

     * @since S60 v3.2

     */

    void WriteTailIntoFileL();

    /**

     * Handles the HTTP response data

     *

     * @since S60 v3.2

     * @param aTransaction HTTP transaction

     */

    void HandleResponseDataL( RHTTPTransaction aTransaction );

    /**

     * Sends HTTP GET request

     *

     * @since S60 v3.2

     */

    void HttpGetL();

    /**

     * Performs the actions needed when download is finished

     *

     * @since @S60 v3.2

     * @param aTransaction HTTP transaction

     */

    void FinishDownload( RHTTPTransaction aTransaction );

    /**

     * Default constructor

     *

     * @since S60 v3.2

     * @param aIAPId IAP id

     * @param aBufferSize Size of the buffer

     * @param aObserver Transfer observer

     * @param aCallback Call back for workerobserver

     */

    CHttpDownloadWorker( TUint aIAPId,

                         TUint aBufferSize,

                         MHttpTransferObserver& aObserver,

                         MHttpWorkerObserver& aCallback );

    /**

     * Second phase constructor

     *

     * @since S60 v3.2

     */

    void ConstructL();

    /**

     * Terminates the transfer and informs the client through

     * TransferComplete.

     *

     * @since S60 v3.2

     * @param aError Error code

     */

    void CompleteAndNotifyL( TInt aError );

    /**

    * Callback function for timer expirations.

    * @since Series60 5.0 HN

    * @param aTimer Timer that has expired.

    **/

    void TimerEventL( CHttpNotifyTimer* aTimer );

private: 

    /**

     * Size of the downloaded file

     */ 

    TInt iFileSizeFromHeader;

    /**

     * Amount of transferred bytes

     */     

    TInt iBytesTransferred;

    /**

     * Response body

     * Own.

     */

    HBufC8* iResponseBody;

    /**

    * Timeout timer for current session

    */

    CHttpNotifyTimer* iSessionTimer;

    };

#endif // C_CHTTPDOWNLOADWORKER_H