/*

* Copyright (c) 2004-2008 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: 

*

*/

using System;

using System.Text;

using System.Collections;

using SymBuildParsingLib.Token;

using SymBuildParsingLib.Utils;

namespace SymBuildParsingLib.Lexer

{

	public class SymLexerWorkerWord : SymLexerWorker

	{

		#region Constructors & destructor

		public SymLexerWorkerWord( SymLexer aLexer )

			: base( aLexer )

		{

		}

		#endregion

		#region API

		#endregion

		#region SymLexerWorker Members

		public override bool ProcessCharacter( char aCharacter )

		{

			bool consumed = true;

			//

			if	( iCurrentWord.Length == 0 )

			{

				// First letter of new word. Just take the character

				AddToWord( aCharacter, CharacterClassType( aCharacter ) );

			}

			else if	( char.IsWhiteSpace( aCharacter ) )

			{

				// Was the last character also white space?

				bool lastCharWasWhiteSpace = char.IsWhiteSpace( LastCharacter );

				if	( lastCharWasWhiteSpace )

				{

					// We don't want to make a new word for each white space

					// character, so begin to group them here.

				}

				else

				{

					// Last character wasn't whitespace, so we must have ended

					// a word

					MakeWord();

				}

				AddToWord( aCharacter, SymToken.TClass.EClassWhiteSpace );

			}

			else if ( iCurrentWord.Length > 0 )

			{

				// We're already processing a word.

				bool thisCharIsLetterOrDigit = char.IsLetterOrDigit( aCharacter );

				bool lastCharWasLetterOrDigit = char.IsLetterOrDigit( LastCharacter );

				//

				if	( thisCharIsLetterOrDigit && lastCharWasLetterOrDigit )

				{

					// In the middle of an ascii word, keep going...

					AddToWord( aCharacter, SymToken.TClass.EClassAlphaNumeric );

				}

				else

				{

					// This char is text, but the last wasn't - make a new word

					// from what we have and use this character as the basis

					// for the next word.

					MakeWord();

					AddToWord( aCharacter, CharacterClassType( aCharacter ) );

				}

			}

			//

			return consumed;

		}

		public override void StartedNewLine( SymTextPosition aEOLPosition )

		{

			MakeWord();

		}

		#endregion

		#region Internal methods

		private static SymToken.TClass CharacterClassType( char aCharacter )

		{

			SymToken.TClass ret = SymToken.TClass.EClassSymbol;

			//

			if	( char.IsWhiteSpace( aCharacter ) )

			{

				ret = SymToken.TClass.EClassWhiteSpace;

			}

			else if ( char.IsLetterOrDigit( aCharacter ) )

			{

				ret = SymToken.TClass.EClassAlphaNumeric;

			}

			//

			return ret;

		}

		private void AddToWord( char aCharacter, SymToken.TClass aClassType )

		{

			iCurrentClass = aClassType;

			iCurrentWord.Append( aCharacter );

		}

		private void MakeWord()

		{

			if	( iCurrentWord.Length > 0 )

			{

				// Finished a word

				SymToken token = new SymToken( iCurrentWord.ToString(), iCurrentClass, Lexer.CurrentPosition );

				Lexer.FlushToken( token );

				// Reset 

				iCurrentWord.Remove( 0, iCurrentWord.Length );

				iCurrentClass = SymToken.TClass.EClassWhiteSpace;

			}

		}

		#endregion

		#region Internal properties

		private char LastCharacter

		{

			get

			{

				char ret = '\0';

				int length = iCurrentWord.Length;

				//

				if	( length > 0 )

				{

					ret = iCurrentWord[ length - 1 ];

				}

				//

				return ret;

			}

		}

		#endregion

		#region Internal enumerations

		private enum TCharClass

		{

			ECharClassWhiteSpace = 0,

			ECharClassText,

			ECharClassDigit,

			ECharClassComma,

			ECharClassPeriod,

			ECharClassHash,

			ECharClassSlash,

			ECharClassColon,

			ECharClassSemiColon,

			ECharClassTilde,

			ECharClassMathematic

		};

		#endregion

		#region Data members

		private StringBuilder iCurrentWord = new StringBuilder( 200 );

		private SymToken.TClass iCurrentClass = SymToken.TClass.EClassWhiteSpace;

		#endregion

	}

}