// pod_lexer.cpp

// 

// Copyright (c) 2009 - 2010 Accenture. All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the "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:

// Accenture - Initial contribution

//

#include "pod_lexer.h"

TPodLexer::TPodLexer(const TDesC& aString)

	: iLex(aString), iAttributes(0), iAttributeStackIndex(0)

	{

	}

void TPodLexer::NextTokenL(TPtrC& aToken, TTokenType& aTokenType, TUint& aAttributes, TBool& aEop, TBool& aEos)

	{

	aTokenType = ETextBlock;

	iScratch.Zero();

	TBool finished(EFalse);

	TBool setAttributes(ETrue);

	while (!iLex.Eos() && !finished && (iScratch.Length() < (iScratch.MaxLength() - 1)))

		{

		iLex.Mark();

		TUint16 sequenceIdentifier;

		if ((iAttributeStackIndex > 0) && (iLex.Peek() == '>'))

			{

			if (iScratch.Length() > 0)

				{

				aAttributes = iAttributes;

				setAttributes = EFalse;

				finished = ETrue;

				}

			else

				{

				iLex.Get();

				aTokenType = EAttributePop;

				aAttributes = PopAttribute();

				setAttributes = EFalse;

				finished = ETrue;

				}

			}

		else if (IsInteriorSequenceStart(sequenceIdentifier))

			{

			if (iScratch.Length() > 0)

				{

				iLex.UnGetToMark();

				finished = ETrue;

				}

			else

				{

				switch (sequenceIdentifier)

					{

					case 'B':

						PushAttribute(EBold);

						aAttributes = EBold;

						setAttributes = EFalse;

						aTokenType = EAttributePush;

						finished = ETrue;

						break;

					case 'C':

						PushAttribute(ECode);

						aAttributes = ECode;

						setAttributes = EFalse;

						aTokenType = EAttributePush;

						finished = ETrue;

						break;

					case 'E':

						if (iLex.Remainder().Length() >= 3)

							{

							if (iLex.Remainder().Left(3) == _L("gt>"))

								{

								iLex.Inc(3);

								iScratch.Append('>');

								}

							else if (iLex.Remainder().Left(3) == _L("lt>"))

								{

								iLex.Inc(3);

								iScratch.Append('<');

								}

							else

								{

								TUint num;

								TInt err = iLex.Val(num);

								if (err == KErrNone)

									{

									iScratch.Append(num);

									}

								else

									{

									User::Leave(err);

									}

								}

							}

						break;

					case 'F':

						PushAttribute(EFileName);

						aAttributes = EFileName;

						setAttributes = EFalse;

						aTokenType = EAttributePush;

						finished = ETrue;

						break;

					case 'I':

						PushAttribute(EItalic);

						aAttributes = EItalic;

						setAttributes = EFalse;

						aTokenType = EAttributePush;

						finished = ETrue;

						break;

					case 'L':

						iLex.Mark();

						SkipToClosingAngleBracket();

						iLex.UnGet();

						iScratch.Copy(iLex.MarkedToken());

						iLex.Get();

						aTokenType = ELink;

						finished = ETrue;

						break;

					case 'S':

					case 'X':

						PushAttribute(ENull);

						aAttributes = ENull;

						setAttributes = EFalse;

						aTokenType = EAttributePush;

						finished = ETrue;

						break;

					case 'Z':

						if (iLex.Peek() == '>')

							{

							iLex.Inc();

							iLex.Mark();

							}

						else

							{

							User::Leave(KErrArgument);

							}

						break;

					}

				}

			}

		else

			{

			iScratch.Append(iLex.Get());

			}

		}

	if (setAttributes)

		{

		aAttributes = iAttributes;

		}

	aToken.Set(iScratch);

	aEop = Eop();

	aEos = iLex.Eos();

	}

TInt TPodLexer::SkipToClosingAngleBracket()

	{

	TInt numSkippedChars = 0;

	while (!iLex.Eos())

		{

		TUint16 sequenceIdentifier;

		if (IsInteriorSequenceStart(sequenceIdentifier))

			{

			numSkippedChars = SkipToClosingAngleBracket();

			}

		else if (iLex.Get() == '>')

			{

			break;

			}

		else

			{

			++numSkippedChars;

			}

		}

	return numSkippedChars;

	}

TBool TPodLexer::Eop()

	{

	_LIT(KParagraphEnd, "\r\n\r\n");

	return ((iLex.Remainder().Length() >= 4) && (iLex.Remainder().Left(4) == KParagraphEnd));

	}

TBool TPodLexer::IsInteriorSequenceStart(TUint16& aSequenceIdentifier)

	{

	if (iLex.Remainder().Length() >= 2)

		{

		TUint16 first = iLex.Get();

		TUint16 second = iLex.Get();

		if (second == '<')

			{

			switch (first)

				{

				case 'B':

				case 'C':

				case 'E':

				case 'F':

				case 'I':

				case 'L':

				case 'S':

				case 'X':

				case 'Z':

					aSequenceIdentifier = first;

					return ETrue;

				}

			}

		iLex.Inc(-2);

		}

	return EFalse;

	}

void TPodLexer::PushAttribute(TAttribute aAttribute)

	{

	iAttributes |= aAttribute;

	iAttributeStack[iAttributeStackIndex++] = aAttribute;

	}

TPodLexer::TAttribute TPodLexer::PopAttribute()

	{

	TAttribute poppedAttribute = iAttributeStack[--iAttributeStackIndex];

	iAttributes &= ~poppedAttribute;

	return poppedAttribute;

	}