// 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') );

 }