/*

* Copyright (c) 2004-2007 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:  Contains the CRsImageParser class definition.

*

*/

// RsImageParser.cpp: implementation of the CRsImageParser class.

//

//////////////////////////////////////////////////////////////////////

#include "crsimageparser.h"

#include "clog.h"

//////////////////////////////////////////////////////////////////////

// Construction/Destruction

//////////////////////////////////////////////////////////////////////

CRsImageParser* CRsImageParser::NewLC()

	{

	CRsImageParser* self = new (ELeave) CRsImageParser();

	CleanupStack::PushL(self);

	self->ConstructL();

	return self;

	}

void CRsImageParser::ConstructL()

	{

	User::LeaveIfError(iFs.Connect());

	}

CRsImageParser::~CRsImageParser()

	{

	iFs.Close();

	}

CRsImageParser::CRsImageParser()							

	{

	}

void CRsImageParser::ValidateL( const TDesC& aFileName, TBool& aValid, TInt& aErr )

	{

	LOG1("CRsImageParser::ValidateL aFileName: %S", &aFileName);				

	aValid = EFalse;

	TInt dataPos( 0 );

	TBuf8<9> imgData;

	TBool bAllDone( EFalse );

	TInt height( 0 );

	TInt width( 0 );

	TInt startOfDataOffset( 0 );

	TInt encoding( EUnknown );

	TInt size( 0 );

	RFile file;

	aErr = file.Open( iFs, aFileName, EFileRead | EFileShareReadersOnly );

	LOG1("CRsImageParser::ValidateL file.Open (shareread mode): %d", aErr);

	if ( aErr != KErrNone )

		{

		aErr = file.Open( iFs, aFileName, EFileRead | EFileShareAny );

		LOG1("CRsImageParser::ValidateL file.Open (shareany mode): %d", aErr);

		}

	// magic numbers used here are JPEG format related

	else // if ( aErr == KErrNone ) // 1 IF

		{

		CleanupClosePushL( file );

		aErr = file.Size( size );

		if( size && aErr == KErrNone ) // 2 IF

			{

			aErr = ReadData( file, dataPos, imgData );

			if( aErr == KErrNone && imgData.Length() == 9 ) // 3 IF

				{

				// First check for the JPEG header "FF D8"

				if( imgData[0] == 0xff && imgData[1] == 0xd8 ) // 4 IF

					{

					// Start skipping headers until we find the one we're looking for

					dataPos = (imgData[4] << 8) + imgData[5] + 4;

					aErr = ReadData( file, dataPos, imgData );

					while( aErr == KErrNone && imgData.Length() == 9 && imgData[0] == 0xff )

						{

						switch( imgData[1] )

							{

							case 0xda:

								// Start of data

								startOfDataOffset = dataPos + ((imgData[2] << 8) + imgData[3] + 2);

								bAllDone = ETrue;

								break;

							case EDiffArithLossless:

								encoding = imgData[1];

								height = (imgData[5] << 8) + imgData[6];

								width = (imgData[7] << 8) + imgData[8];

								break;

							default:

								break;

							} // SWITCH

							if( bAllDone )

								{

								break;

								}

							else

								{

								dataPos += (imgData[2] << 8) + imgData[3] + 2;

								aErr = ReadData( file, dataPos, imgData );

								}

						} // WHILE

					} // 4 IF

				else

					{

					// Not a JPG

					aErr = KErrCorrupt;

					}

				} // 3 IF

			} // 2 IF

		CleanupStack::PopAndDestroy( &file ); 

		} // 1 IF

	aValid = Validate( startOfDataOffset, width, height, size, encoding, aErr );

	LOG1("CRsImageParser::ValidateL aValid: %d", aValid);

	LOG1("CRsImageParser::ValidateL aErr: %d", aErr);

	LOG("CRsImageParser::ValidateL end");				

	}

TBool CRsImageParser::Validate( TInt aStartOfDataOffset, TInt aWidth, TInt aHeight, TInt aSize, TInt aEncoding, TInt aErr )

	{

	if ( aStartOfDataOffset && aWidth && aHeight && aSize && aEncoding && !aErr )

		{

		return ETrue;

		}

	else 

		{

		return EFalse;

		}

	}

TInt CRsImageParser::ReadData( RFile& aFile, TInt aStartByte, TDes8& aData )

	{

	LOG("CRsImageParser::ReadData begin");

	TInt err = aFile.Read( aStartByte, aData );

	LOG1("CRsImageParser::ReadData return: %d", err);

	return err;	

	}

//  End of File