// Copyright (c) 2008-2009 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 FILES

// 

//

#include <e32std.h>

#include <bafl/qpcodec.h>

/**

Decode the string

@param aSrcString source string

@param rDestString Destination string

@return  KErrNone  if decode is complete

@return  KErrCorrupt if string is not QuotedPrintable compliant

*/

EXPORT_C TInt QuotedPrintableCodec::Decode( const TDesC8& aSrcString, TDes8& rDestString )

	{

#ifdef _DEBUG

	TInt KPanicInvalidSMTPLine = 6;

	_LIT(KDllName,"MultipartParser");

#endif

	const TUint8 KImcvSP			= ' ';

	const TUint8 KImcvCR			= '\r';

	const TUint8 KImcvLF			= '\n';	

	const TUint8 KImcvTab			= '\t';

	const TUint8 KImcvEquals		= '=';

	TUint8 qpCharacter = KImcvEquals;

	TInt error = KErrNone;

	__ASSERT_DEBUG(aSrcString.Length(), User::Panic( KDllName ,KPanicInvalidSMTPLine));

	rDestString = KNullDesC8;

	TPtrC8 source( aSrcString.Ptr(), aSrcString.Length() );

	const TUint8* pSource = source.Ptr();

	const TUint8* pEnd = pSource+aSrcString.Length();

	// find out if this is a blank line, if so then we'll add a paragraph delimiter instead

	// assume it's blank and then look for non-blank characters

	// avoid the CRLF at the end of the line (we know it's there thanks to the assertion above)

	TBool blankLine = ETrue; 

	while (pSource < pEnd-2) 

		{

		if (*pSource!=KImcvSP && *pSource!=KImcvTab)

			{

			blankLine = EFalse;

			break;

			}

		pSource++;

		}

	if ( blankLine )

		{

		rDestString.Copy( aSrcString );

		return KErrNone;

		}

	TInt outputLength=0;

	TUint8 loBits;

	TUint8 hiBits;

	TUint8 asciiValue;

	pSource = source.Ptr();	// reset to start of source data

	const TUint8 zero = '0';

	const TUint8 alphaAdjust = 55;  // 'A' is ascii 65 so we need to subtract 55 from 

									// alphabetical hex digits to get their numeric value

	while( pSource < pEnd )

		{

		if (*pSource != qpCharacter )

			{

			//  Quoted character or Attachment bound, just bung it on & move to the next one

			// *ptr++ = *pSource;

			outputLength++;

			rDestString.Append( *pSource );

			}

		else	// check for encoded character

			{

			// start looking at the next two characters, if they are there.

			if ( pSource+2 < pEnd )

				{

				pSource++;

				// check for '=' at EOL => this is a soft break, so remove it

				if (*pSource != KImcvCR) 

					{

					if(*pSource != KImcvLF) 

						{

					 	 // now decode hex value into ASCII code : hi-order bits come first

						 hiBits = (TUint8)(0x0F & (IsDigit( *pSource ) ? (TUint8)(*pSource-zero) : (TUint8)(*pSource-alphaAdjust)));

						 pSource++;

						 loBits = (TUint8)(0x0F & (IsDigit( *pSource ) ? (TUint8)(*pSource-zero) : (TUint8)(*pSource-alphaAdjust)));

						 asciiValue = (TUint8)( (hiBits<<4) + loBits);

						 // bung the character thus formed onto the decoded string

						 rDestString.Append( asciiValue );

						 // *ptr++ = asciiValue;

						 outputLength++;

						}

					}

				else

					{

					pSource++;

					if(*pSource != KImcvLF)

						{

						error=KErrCorrupt;

						pSource-=2;

						rDestString.Append( *pSource );

						pSource++;

						rDestString.Append( *pSource );

						pSource++;

						outputLength+=2;

						}

					}

				}

			else

				{

				// copy the rest of the data & use up the input string in the process.

				while (pSource < pEnd)

					{

					error=KErrCorrupt; // not QP compliant

					//*ptr++ = *pSource++;

					outputLength++;

					rDestString.Append( *pSource );

					pSource++;

					}

				}

			} // check for '=' char

		pSource++;  // next source charactery

	} // while

	rDestString.SetLength(outputLength);

	return error;

	}

/**

Check for digit

@param aChar charcter to be check

@return  ETrue if passed charcter is digit

@return  EFalse if passed charcter is not digit

*/	

TBool QuotedPrintableCodec::IsDigit( TChar aChar )

{

	return ( (aChar >= '0') && (aChar <= '9') );

}