var TreeParents=new Object();
var TreeNames=new Object();
var TreeExpand=new Object();
var TreeID=new Object();
var TreeClickable=new Object();
var TreeChecked=new Object();


function DrawFromNode(field,node,inner)
	{
	var result="";
 	var i=0;
    var width=10;
    if (node==-1) {width=0;}
    var c=0;
    
	if (!inner) {result+="<table border=0 cellpadding=0 cellspacing=1><td width=" + width + ">&nbsp;</td><td class='treetext' id='" + field + "_node" + node + "'>";}
	//loop through all nodes with <node> as the parent
	for (i=0;i<TreeParents[field].length;i++)
		{
        if (TreeParents[field][i]==node)
            {
            if (TreeExpand[field][i]) {icon="<img xalign=middle width=11 height=11 hspace=3 src=admin/gfx/node_ex.gif";} else {icon="<img xalign=middle hspace=3 width=11 height=11 src=admin/gfx/node_unex.gif";}
    
    		c=CountChildren(field,i);
            if (c==0)
                {icon="<img xalign=top src=admin/gfx/sp.gif width=11 height=11 hspace=3>";}
            else
                {icon+=" onClick=\"ToggleNode('" + field + "'," + i + ");\">";}
        	icon2="";
            result+=icon + icon2;
            checked="";if (TreeChecked[field][i]==1) {checked="checked";}
            if (TreeClickable[field][i]) {result+="<input name='' type=checkbox id=checkbox" + i + " " + checked + " onclick=\"CheckNode('" + field + "'," + i + ");\">";}
            result+=DePath(TreeNames[field][i]);
            result+="<br>";
            if (TreeExpand[field][i] && c>0) {result+=DrawFromNode(field,i);}
            }
		}
	if (!inner) {result+="</td></tr></table>";}

	return result;
	}

function CheckNode(field,node)
	{
	if (TreeChecked[field][node]==0) 
		{
		TreeChecked[field][node]=1;
		//Make sure all parents are ticked
		
		/*
		var p=TreeParents[field][node];
		while (p>-1)
			{
			if (TreeChecked[field][p]==0)
				{
				CheckNode(field,p);
				unode=TreeParents[field][p];
				if (unode==-1) {DrawTree(field);} else {UpdateNode(field,unode);}
				}
			var p=TreeParents[field][p];
			}
		*/
		}
	else
		{
		TreeChecked[field][node]=0;ResetChildren(field,node);
		var p=TreeParents[field][node];
		if (p!=-1)
			{
			if ((CountTickedChildren(field,p)==0) && (TreeChecked[field][p]==1)) {CheckNode(field,p);UpdateNode(field,TreeParents[field][p]);}
			}
		UpdateNode(field,node);
		}
	UpdateStatusBox(field);
	UpdateHiddenField(field);
	}
	
function UpdateStatusBox(field)
	{
	var nodes="";
	for (i=0;i<TreeParents[field].length;i++)
		{
		if (TreeChecked[field][i]==1)
			{
			var c=CountTickedChildren(field,i);
			if (c==0)
				{
				nodes+=DescribeNode(field,i) + "<br/>";
				}	
			}	
		}
	if (nodes=="")
		{document.getElementById(field + "_statusbox").innerHTML="<b>" + nocategoriesmessage + "</b>";}
	else
		{
		document.getElementById(field + "_statusbox").innerHTML=nodes;
		}
	}
	
function StatusReset(field)
	{
	//Set the status box to empty
	document.getElementById(field + "_statusbox").innerHTML="";
	}

function DescribeNode(field,node)
	{
	// Returns a string containing the node's 'path'
	var path=DePath(TreeNames[field][node]);
	var p=TreeParents[field][node];
	while (p>-1)
		{
		path=DePath(TreeNames[field][p]) + " / " + path;
		var p=TreeParents[field][p];
		}
	return path;
	}
	
function ResetChildren(field,node)
	{
	var p=0;
    for (p=0;p<TreeParents[field].length;p++)
		{
		if (TreeParents[field][p]==node) {TreeChecked[field][p]=0;ResetChildren(field,p);UpdateNode(field,p);}	
		}
	}
	
function ToggleNode(field,node)
	{ 
	TreeExpand[field][node]=!TreeExpand[field][node];
	UpdateNode(field,TreeParents[field][node]);
	}

function UpdateNode(field,node)
    {
    if (document.getElementById(field + "_node" + node))
        {
        document.getElementById(field + "_node" + node).innerHTML=DrawFromNode(field,node,true);
        }
    }
    
function CountChildren(field,node)
	{
	var count=0;
	var i=0;
	for (i=0;i<TreeParents[field].length;i++)
		{
		if (TreeParents[field][i]==node) {count++;}	
		}
	return count;
	}

function CountTickedChildren(field,node)
	{
	var count=0;
	var i=0;
	for (i=0;i<TreeParents[field].length;i++)
		{
		if ((TreeParents[field][i]==node) && (TreeChecked[field][i]==1)) {count++;}	
		}
	return count;
	}

function CountCheckedRootLevels(field)
	{
	var count=0;
	var i=0;
	for (i=0;i<TreeParents[field].length;i++)
		{
		if ((TreeParents[field][i]==-1) && (TreeChecked[field][i]==1)) {count++;}	
		}
	return count;
	}

function DeselectAll(field)
	{
	var i=0;
	for (i=0;i<TreeParents[field].length;i++)
		{
		TreeChecked[field][i]=0;
		}
	DrawTree(field);
	UpdateStatusBox(field);
	UpdateHiddenField(field);
	}

function DrawTree(field)
	{
	document.getElementById(field + "_tree").innerHTML=DrawFromNode(field,-1,false);
	}

function AddNode(field,nodeparent,nodeid,nodename,nodeclickable,nodechecked,nodeexpand)
	{
    //try to find an empty space first
    var c=0;var found=false;
	for (c=0;c<TreeParents[field].length;c++)
		{
		if (TreeParents[field][c]==-100) {found=true;break;}	
		}
    if (found==false) {c=TreeParents[field].length;}
    
	TreeParents[field][c]=nodeparent;    
    TreeID[field][c]=nodeid;
	TreeNames[field][c]=nodename;
	TreeExpand[field][c]=false;
    TreeClickable[field][c]=nodeclickable;
    TreeChecked[field][c]=nodechecked;
    TreeExpand[field][c]=nodeexpand;
	}

function ResolveParents(field)
	{
	for (c=0;c<TreeParents[field].length;c++)
		{
    	//resolve nodeparent to internal node id
	    var p=0;found=false;
	    for (p=0;p<TreeID[field].length;p++)
			{
			if (TreeID[field][p]==TreeParents[field][c]) {found=true;break;}	
			}
	    if (found) {TreeParents[field][c]=p;}
	    if (TreeParents[field][c]==-1) {TreeParents[field][c]=-1;}
		}
	}

function UpdateHiddenField(field)
	{
	var f="";
	for (p=0;p<TreeID[field].length;p++)
		{
		if (TreeChecked[field][p]==1)
			{
			f+="," + TreeNames[field][p];
			}	
		}
	document.getElementById(field + "_category").value=f;
	// Update the result counter, if the function is available (e.g. on Advanced Search).
	if (typeof UpdateResultCount == 'function') {UpdateResultCount();}
	}
	
function DePath(path)
	{
	// Returns the last element in a tilda-separated path as produced by StaticSync for the various tree levels.
	return path.split('~').last();
	}