/*

<script language="javascript1.2" src="/searchajax.js"></script>
<script language="javascript1.2">ajaxpage = '/searchlist/groups/';</script>

<form method="POST" action="/searchajax.js"><table>
	<tr><th>Search For:</th><td><input type="text" size="30"
	 name="search" value=""
	 id="searchlistinput" /></td></tr>
	<script> sli1 = new SimilarsSearchBox('searchlistinput'); </script>
	<tr><td colspan="2"><input type="submit" name="searchgroups" value="Search Groups"></td></tr>

	<tr><th colspan="2"><textarea id="outspace" rows=10 cols=50></textarea></th></tr>
</table></form>

*/


// ******************
//  THESE VARS _MUST_ BE DEFINED IN CALLING PAGE!!!!
//   ___AFTER___ INCLUDING THIS FILE
// ******************

var ajaxpage = '/searchlist.php';
var search_field = 'search';





// shortcut var for clearing the similars list
function clearSimilars (f) { f.listbox.style.display = 'none';
 while (f.list.hasChildNodes()) { f.list.removeChild(f.list.lastChild); } }


// do the actual search list box drawing after we have the list
function drawSimilars (f, similarslist)
{
	// have to reset each time we redraw the list
	//  and clean out any existing list items
	f.idx = -1; clearSimilars(f);

	// build the html for each similar
	for (var i = 0; i < similarslist.length; i++)
	{
		// this is the line item for this term
		//  but we need to make sure it's not disabled
		var sLI = document.createElement('li');
		sLI.listDisabled = (similarslist[i].count > 0 ? false : true);

		// if this line item is disabled, it lacks mousing features
		if (!sLI.listDisabled)
		{
			// create a mousing version of the up/down arrow key highlighting
			sLI.listIndex = i; sLI.onmouseover = function()
			 { highlightSimilar(f, 'f.idx = '+this.listIndex+';'); }

			// create a link to use the mouse directly to these results
			var sLIa = document.createElement('a');
			sLIa.innerHTML = similarslist[i].term;
			sLIa.setAttribute('href', similarslist[i].url);
			sLI.appendChild(sLIa);
		}

		// if disabled, the text goes directly into the line item
		else { sLI.innerHTML = similarslist[i].term; }

		// add this line item to the list
		f.list.appendChild(sLI);
	}

	// and finally display it
	f.listbox.style.display = 'block';
}


// send this value to the server to get the similars list
function showSimilars (e, f)// + '/' + vCode
 { sendAJAXrequest(ajaxpage, function (data) { drawSimilars(f, data); }, 't=' + encodeURIComponent(f.box.value)); }


// hide/remove the similars list
function hideSimilars (e, f)
{
	// we have to delay for a split second,
	//  in case this comes from a click on one of the links
	// (the click will only get looked for after the blur happens
	//  and without the box there, the click never happens!)
	// HOWEVER, this creates a new problem: obj ceases to exist
	//  if the page changes, so we need the try/catch
	setTimeout(function() { try { if (f.list) { clearSimilars(f); } } catch (r) {} }, 100);
}


// turn off current highlighting, highlight new item
function highlightSimilar (f, edgecode)
{
	// unhighlight the old item
	if (f.idx >= 0) { f.list.childNodes[f.idx].className = ''; }

	// try the next/prev item, but if it's disabled,
	//  go one more until you find an undisabled one in the list
	// NOTE: if the eval comes after orig assignment,
	//  you'll crash the browser when nothing is selected yet (origIndex == -1)
	eval(edgecode); origIndex = f.idx;
	while (f.list.childNodes[f.idx].listDisabled)
	 { eval(edgecode); if (origIndex == f.idx) { break; } }

	// make sure we found an undisabled item in the list
	if (!f.list.childNodes[f.idx].listDisabled)
	{
		f.list.childNodes[f.idx].className = 'similarsHighlight';
		f.box.value = f.list.childNodes[f.idx].lastChild.innerHTML;
		f.url_link = f.list.childNodes[f.idx].lastChild.href;
	}

	// these arrow keystrokes should be ignored
	return false;
}

// highlight previous item
function prevSimilar (f) { return highlightSimilar(f,
 'if (--f.idx < 0) { f.idx = f.list.childNodes.length-1; }'); }

// highlight next item
function nextSimilar (f) { return highlightSimilar(f,
 'if (++f.idx >= f.list.childNodes.length) { f.idx = 0; }'); }


// take action on keystrokes in searchbox
function checkSearchKeys (e, f)
{
	// generic IE compatibility
	if (!e) { e = window.event; }

	// up/down step through similars
	if (e.keyCode == 38) { return prevSimilar(f); }  // up
	if (e.keyCode == 40) { return nextSimilar(f); }  // down

	// all other keys pressed BUT ENTER should be processed
	if (e.keyCode != 13) { showSimilars(e, f); }
	// enter tells us to load that option, if an option has been selected
	if (e.keyCode == 13 && typeof(f.url_link) != 'undefined') { window.location = f.url_link; }

	// normal keystrokes should definitely be allowed
	return true;
}





// closure making func -- easier to pass dynamic html objects to event handlers
//  might need this:  http://laurens.vd.oever.nl/weblog/items2005/closures/
function eventClosure (func, obj) { return function (e) { func(e, obj); }; }


function SimilarsSearchBox (idName)
{
	// get the search input box
	this.box = document.getElementById(idName);
	this.box.style.display = 'block';

	// list index tracking var
	this.idx = 0;

	// create the actual space where the similars get shown
	this.listbox = document.createElement('div');
	this.listbox.className = 'searchlistbox';

	// the list where all the suggestions go
	this.list = document.createElement('ul');
	this.list.className = 'nonlist';
	clearSimilars(this);  // initialize it empty

	// now put the list and listbox on to the page
	this.listbox.appendChild(this.list);
	this.box.parentNode.appendChild(this.listbox);

	// assign all the event handlers
	this.box.onfocus = eventClosure(showSimilars, this);
	this.box.onblur = eventClosure(hideSimilars, this);
	this.box.onkeyup = eventClosure(checkSearchKeys, this);
}