// Copyright (c) 2001-2009 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:

//

#include "CHtmlToCrtConvBuffer.h"

#include "CHtmlToCrtConvAssertDefines.h"

const TInt KReadBufferSize = 256;

CHtmlToCrtConvBuffer::CHtmlToCrtConvBuffer(CCnvCharacterSetConverter& aCnvCharacterSetConverter)

:iCnvCharacterSetConverter(aCnvCharacterSetConverter)

	{

	}

CHtmlToCrtConvBuffer* CHtmlToCrtConvBuffer::NewL(const TDesC& aFile, RFs& aFsSession, CCnvCharacterSetConverter& aCnvCharacterSetConverter)

	{

	CHtmlToCrtConvBuffer* self=new(ELeave) CHtmlToCrtConvBuffer(aCnvCharacterSetConverter);

	CleanupStack::PushL(self);

	self->ConstructL(aFile, aFsSession);

	CleanupStack::Pop(self);

	return self;

	}

void CHtmlToCrtConvBuffer::ConstructL(const TDesC& aFile, RFs& aFsSession)

	{

	User::LeaveIfError(iFile.Open(aFsSession, aFile, EFileShareReadersOnly));

	iSourceBuffer=HBufC8::NewL(KReadBufferSize);

	iUnicodeBuffer=HBufC16::NewL(KReadBufferSize);

	}

CHtmlToCrtConvBuffer::~CHtmlToCrtConvBuffer()

	{

	iFile.Close();

	delete iSourceBuffer;

	delete iUnicodeBuffer;

	}

//===================================================================================================

//ReadCharacterL - returns EFalse if no character read, ie when end of file and end of buffer reached

//===================================================================================================

TBool CHtmlToCrtConvBuffer::ReadCharacterL(TChar& aCharacter, TInt& aBufferPosition, TBool& aEndOfBuffer)

	{

	ASSERT((iBufferPosition>=0 && iBufferPosition<=KReadBufferSize));

	aEndOfBuffer=EFalse;

	if (iBufferPosition < iUnicodeBuffer->Length())

		//character in buffer

		{

		aBufferPosition=iBufferPosition;

		aCharacter=(*iUnicodeBuffer)[iBufferPosition++];

		if (iBufferPosition==iUnicodeBuffer->Length())

			{

			aEndOfBuffer=ETrue;

			}

		return ETrue;

		}

	else

		//no characters remaining in buffer

		{

		aBufferPosition=0;

		if (FillBufferL())

			//file was not empty

			{

			aCharacter=(*iUnicodeBuffer)[iBufferPosition++];

			if (iBufferPosition==iUnicodeBuffer->Length())

				{

				aEndOfBuffer=ETrue;

				}

			return ETrue;

			}

		else

			//file was empty

			{

			aEndOfBuffer=ETrue;

			return EFalse;

			}

		}

	}

void CHtmlToCrtConvBuffer::GetPartOfBufferL(TPtrC16& aPartOfBuffer, TInt aStartPosition, TInt aEndPosition) const

	{

	TPtrC16 partOfBuffer(iUnicodeBuffer->Mid(aStartPosition,(aEndPosition - aStartPosition + 1)));

	aPartOfBuffer.Set(partOfBuffer);

	}

void CHtmlToCrtConvBuffer::GetToEndOfBufferL(TPtrC16& aPartOfBuffer, TInt aStartPosition) const

	{

	TPtrC16 partOfBuffer(iUnicodeBuffer->Mid(aStartPosition));

	aPartOfBuffer.Set(partOfBuffer);

	}

void CHtmlToCrtConvBuffer::GetSampleOfTextFromFileL(TDes8& aSample, TInt aLength, TInt aOffset)

	{

	TInt fileSize=0;

	User::LeaveIfError(iFile.Size(fileSize));

	//adjust aOffset - used to get sample of text from file, so should read aLength chars

	if(fileSize<aLength)

		aOffset=0;

	else if(fileSize<aOffset+aLength)

		aOffset=fileSize-aLength;

	User::LeaveIfError(iFile.Read(aOffset, aSample, aLength));

	ResetL();

	}

void CHtmlToCrtConvBuffer::ResetL()

	{

	//set read file position to start of file

	TInt pos=0;

	User::LeaveIfError(iFile.Seek(ESeekStart, pos));

	}

TBool CHtmlToCrtConvBuffer::FillBufferL()

	{

	iBufferPosition = 0;

	//iSourceBuffer contains any remaining unconverted characters from last call to ConvertToUnicode.

	TPtr8 sourcePtr(iSourceBuffer->Des());

	TInt sourceLength=iSourceBuffer->Length();

	TBool endOfFileReached=EFalse;

	//newBuffer gets characters from the file to fill the remaining space in iSourceBuffer

	HBufC8* newBuffer=HBufC8::NewLC(KReadBufferSize-sourceLength);

	TPtr8 newBufferPtr(newBuffer->Des());

	User::LeaveIfError(iFile.Read(newBufferPtr, KReadBufferSize-sourceLength));

	sourcePtr.Append(newBufferPtr);

	CleanupStack::PopAndDestroy(newBuffer);

	sourceLength=sourcePtr.Length();

	if(sourceLength < KReadBufferSize)

		{

		endOfFileReached=ETrue;

		if(sourcePtr.Length()==0)

			{

			return EFalse;

			}

		}

	TPtr16 unicodePtr(iUnicodeBuffer->Des());

	unicodePtr.Zero();

	DoConvertBufferL(sourcePtr, unicodePtr, sourceLength, endOfFileReached);

	return ETrue;

	}

//=============================================================================

//DoConvertBufferL - sets iUnicodeBuffer to contain the converted characters,

//and iSourceBuffer to contain only the unconverted characters.

//=============================================================================

void CHtmlToCrtConvBuffer::DoConvertBufferL(TPtr8& aSourcePtr, TPtr16& aUnicodePtr, TInt& aSourceLength, TBool& aEndOfFile)

	{

	HBufC16* tempUnicode=HBufC16::NewLC(aSourceLength);

	TPtr16 tempUnicodePtr(tempUnicode->Des());

	//returnValue = number of unconverted characters at end of buffer

	TInt returnValue=iCnvCharacterSetConverter.ConvertToUnicode(tempUnicodePtr, aSourcePtr, iState);

	if(!aEndOfFile)

		{

		if(returnValue==CCnvCharacterSetConverter::EErrorIllFormedInput)

			User::Leave(KErrCorrupt);

		}

	if(returnValue<0)//future-proof against 'TError' expanding

		User::Leave(KErrGeneral);

	aUnicodePtr.Append(tempUnicodePtr);

	CleanupStack::PopAndDestroy(tempUnicode);

	//set iSourceBuffer to contain only the unconverted characters

	aSourcePtr.Copy(aSourcePtr.Right(returnValue));

	aSourceLength=aSourcePtr.Length();

	}