/*====================================================================*\

Table-of-contents generator

\*====================================================================*/


// TABLE-OF-CONTENTS NODE CLASS


////////////////////////////////////////////////////////////////////////
//  Constructors
////////////////////////////////////////////////////////////////////////

	function TocNode( key )
	{
		this.key = key;
		this.htmlNodes = null;
		this.children = new Array( );
	}

	//------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Class methods
////////////////////////////////////////////////////////////////////////

	TocNode.compareKeys = function( key1, key2 )
	{
		if ( isNaN( Number( key1 ) ) || isNaN( Number( key2 ) ) )
			return ( (key1 == key2) ? 0
									: (key1 < key2) ? -1 : 1 );

		var value1 = Number( key1 );
		var value2 = Number( key2 );
		return ( (value1 == value2) ? 0
									: (value1 < value2) ? -1 : 1 );
	}

	//------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Instance methods
////////////////////////////////////////////////////////////////////////

	TocNode.prototype.add = function( keys, keyIndex, htmlNodes )
	{
		var key = keys[keyIndex];
		var node = null;
		for ( var i = 0; i < this.children.length; ++i )
		{
			var result = TocNode.compareKeys( key, this.children[i].key );
			if ( result < 0 )
			{
				node = new TocNode( key );
				this.children.splice( i, 0, node );
				break;
			}
			if ( result == 0 )
			{
				node = this.children[i];
				break;
			}
		}
		if ( !node )
		{
			node = new TocNode( key );
			this.children.push( node );
		}

		if ( ++keyIndex < keys.length )
			node.add( keys, keyIndex, htmlNodes );
		else
		{
			if ( node.htmlNodes )
				throw new Error( "Duplicate section ID" );
			node.htmlNodes = htmlNodes;
		}
	}

	//------------------------------------------------------------------

//----------------------------------------------------------------------


// TABLE OF CONTENTS CLASS


////////////////////////////////////////////////////////////////////////
//  Constructors
////////////////////////////////////////////////////////////////////////

	function Toc( )
	{
		try
		{
			this.tocRoot = null;
			var tocElement = document.getElementById( Toc.TOC_ROOT_ID );
			if ( tocElement )
			{
				while ( tocElement.hasChildNodes( ) )
					tocElement.removeChild( tocElement.firstChild );

				this.appendTocFragment( tocElement, false );
				this.appendTocFragment( tocElement, true );
			}
		}
		catch ( e )
		{
			if ( e instanceof Error )
				alert( e.name + ": " + e.message );
		}
	}

	//------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////
//  Constants
////////////////////////////////////////////////////////////////////////

	Toc.SECTION_ID_PREFIX	= "section";
	Toc.TOC_LEVEL_PREFIX	= "tocLevel";
	Toc.TOC_ROOT_ID			= "tocRoot";
	Toc.SEPARATOR			= "-";

////////////////////////////////////////////////////////////////////////
//  Instance methods
////////////////////////////////////////////////////////////////////////

	Toc.prototype.processElement = function( element, alphabetic )
	{
		var id = element.id;
		if ( id && (id.length > Toc.SECTION_ID_PREFIX.length) &&
			 (id.substring( 0, Toc.SECTION_ID_PREFIX.length ) == Toc.SECTION_ID_PREFIX) )
		{
			var keys = id.substring( Toc.SECTION_ID_PREFIX.length ).split( Toc.SEPARATOR );
			if ( isNaN( Number( keys[0] ) ) == alphabetic )
			{
				var htmlNodes = new Array( );
				for ( var i = 0; i < element.childNodes.length; ++i )
					htmlNodes.push( element.childNodes[i].cloneNode( true ) )

				try
				{
					this.tocRoot.add( keys, 0, htmlNodes );
				}
				catch ( e )
				{
					throw new Error( e.message + ": " + keys.join( Toc.SEPARATOR ) );
				}
			}
		}

		for ( var i = 0; i < element.childNodes.length; ++i )
		{
			if ( element.childNodes[i].nodeType == 1 )		// Node.ELEMENT_NODE
				this.processElement( element.childNodes[i], alphabetic );
		}
	}

	//------------------------------------------------------------------

	Toc.prototype.createListElement = function( tocNode, keys, keyIndex )
	{
		var ulElement = null;
		if ( tocNode.children.length > 0 )
		{
			ulElement = document.createElement( "ul" );
			ulElement.className = "toc";
			for ( var i = 0; i < tocNode.children.length; ++i )
			{
				var liElement = document.createElement( "li" );
				liElement.className = Toc.TOC_LEVEL_PREFIX + (keyIndex + 1);

				var newKeys = keys.concat( tocNode.children[i].key );
				var htmlNodes = tocNode.children[i].htmlNodes;
				if ( htmlNodes.length > 0 )
				{
					var aElement = document.createElement( "a" );
					aElement.setAttribute( "href",
										   "#" + Toc.SECTION_ID_PREFIX + newKeys.join( Toc.SEPARATOR ) );
					for ( var j = 0; j < htmlNodes.length; ++j )
						aElement.appendChild( htmlNodes[j] );
					liElement.appendChild( aElement );
				}

				var element = this.createListElement( tocNode.children[i], newKeys, keyIndex + 1 );
				if ( element )
					liElement.appendChild( element );

				ulElement.appendChild( liElement );
			}
		}
		return ulElement;
	}

	//------------------------------------------------------------------

	Toc.prototype.appendTocFragment = function( element, alphabetic )
	{
		this.tocRoot = new TocNode( null );
		this.processElement( document.documentElement, alphabetic );
		var listElement = this.createListElement( this.tocRoot, new Array( ), 0 );
		if ( listElement )
			element.appendChild( listElement );
	}

	//------------------------------------------------------------------

//----------------------------------------------------------------------