/*

* 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 SymBuildParsingLib.Tree;

using SymbianTree;

namespace SymBuildParsingLib.Token

{

	public class SymTokenUtils

	{

		#region Trim functions

		public static SymNode TrimEntireTree( SymNode aNode )

		{

			return Trim( aNode, true );

		}

		public static SymNode Trim( SymNode aNode )

		{

			return Trim( aNode, false );

		}

		public static void RemoveWhiteSpace( SymNode aNode, bool aRecurse )

		{

			int count = aNode.ChildCount;

			for( int i=count-1; i>=0; i-- )

			{

				SymNode basicNode = aNode[ i ];

				// If the node is whitespace, then remove it

				if	( basicNode is SymNodeToken )

				{

					SymNodeToken tokenNode = (SymNodeToken) basicNode;

					bool isWhiteSpace = ( tokenNode.Token.Class == SymToken.TClass.EClassWhiteSpace );

					//

					if	( isWhiteSpace )

					{

						System.Diagnostics.Debug.Assert( basicNode.HasChildren == false );

						basicNode.Remove();

					}

				}

				// Remove whitespace from this node's children

				if	( basicNode.HasChildren && aRecurse )

				{

					RemoveWhiteSpace( basicNode, aRecurse );

				}

			}

		}

		#endregion

		#region Internal methods

		public static SymNode Trim( SymNode aNode, bool aRecurse )

		{

			// Forward pass

			while( aNode.HasChildren )

			{

				SymNode n = aNode.FirstChild;

				if	( n is SymNodeToken )

				{

					SymNodeToken nodeToken = (SymNodeToken) n;

					bool isWhiteSpace = ( nodeToken.Token.Class == SymToken.TClass.EClassWhiteSpace );

					//

					if	( isWhiteSpace )

					{

						System.Diagnostics.Debug.Assert( n.HasChildren == false );

						nodeToken.Remove();

					}

					else

					{

						break;

					}

				}

				else

				{

					break;

				}

			}

			// Backward pass

			while( aNode.HasChildren )

			{

				SymNode n = aNode.LastChild;

				if	( n is SymNodeToken )

				{

					SymNodeToken nodeToken = (SymNodeToken) n;

					bool isWhiteSpace = ( nodeToken.Token.Class == SymToken.TClass.EClassWhiteSpace );

					//

					if	( isWhiteSpace )

					{

						System.Diagnostics.Debug.Assert( n.HasChildren == false );

						nodeToken.Remove();

					}

					else

					{

						break;

					}

				}

				else

				{

					break;

				}

			}

			// Child pass

			if	( aRecurse )

			{

				foreach( SymNode n in aNode )

				{

					if	( n.HasChildren )

					{

						Trim( n, aRecurse );

					}

				}

			}

			return aNode;

		}

		#endregion

	}

}