// ==UserScript==
// @name          Reddit sorter
// @namespace     http://jeffpalm.com/sortit
// @description	  Sorts reddit articles inline
// @include       http://*reddit.com/*
// ==/UserScript==

/*
 * Copyright 2006 Jeffrey Palm.
 */

var VERSION = 0.1;

// --------------------------------------------------
// misc
// --------------------------------------------------

function $n(tag,on) {
	var e = document.createElement(tag);
	if (on) on.appendChild(e);
	return e;
}

function $t(text,on) {
	var e = document.createTextNode(text);
	if (on) on.appendChild(e);
	return e;
}

function insertBefore(newNode,target) {
	// http://lists.xml.org/archives/xml-dev/200201/msg00873.html
  var parent   = target.parentNode;
	var refChild = target; //target.nextSibling;	
	if(refChild) parent.insertBefore(newNode, refChild);
	else parent.appendChild(newNode);	
}

// --------------------------------------------------
// main
// --------------------------------------------------

function main() {
	addLinkAtTop();
}

function addLinkAtTop() {
	//
	// Create the new node
	//
	var span = $n("span");
	span.appendChild($t("["));
	var a = $n("a");
	span.appendChild(a);
	a.href = "#";
	a.addEventListener('click',doSorting,true);
	a.appendChild($t('sort'));
	
	span.appendChild($t("]"));

	tab = document.getElementById("topbar");
	tr = $n("tr",tab);
	td = $n("td",tab);
	td.appendChild(span);
	tab.insertBefore(tr,tab.firstChild);
}


function doSorting() {
	//
	// we'll keep those trs with a parent with id=siteTable
	// and is=site* or class=(even|odd)Row
	// we'll keep them together so the first element will
	// be the 'site' tr, the second the 'row' tr
	//
	var siteTR;
	var rowTR1 = 0;
	var rowTR2 = 0;
	var trs = document.getElementsByTagName("tr");
	var scores2trs = new Array(); // this holds pairs of trs and a score
	var debug = true;
	for (i=0; i<trs.length; i++) {
		var tr = trs[i];
		//
		// make sure we're in the right table
		//
		if (!tr.parentNode) continue;
		if (!tr.parentNode.id == "siteTable") continue;
		//
		// decide which TR this is
		//
		if (tr.id && tr.id.match(/^site.*/)) {
			siteTR = tr;
		} else if (tr.className && (tr.className == "oddRow" || tr.className == "evenRow")) {
			//
			// the first 'row' tr will NOT have the points
			//
			if (rowTR1 == 0) {
				rowTR1 = tr;
			} else {
				rowTR2 = tr;
				//
				// <span id="score1008506">316 points</span>
				//
				scoreId = siteTR.id.replace(/site/,'score');
				scoreSpan = document.getElementById(scoreId);
				if (scoreSpan) {
					scoreHTML = scoreSpan.innerHTML;
					score = scoreHTML.replace(/\s+.*/,''); // take away the points
				} else {
					rowTR1 = 0;
					rowTR2 = 2;
					siteTR = 0;
				}
			}
		} else if (tr.firstChild && tr.firstChild.className && 
							 (tr.firstChild.className == "oddRow spacing" ||
								tr.firstChild.className == "evenRow spacing")) {

			//
			// if we both row TRs and a site TR this one is spacing
			//
			spacingTR = tr;
			scores2trs[score] = new Array(siteTR,rowTR1,rowTR2,spacingTR);
			//
			// reset the values
			//
			siteTR = 0;
			rowTR1 = 0;
			rowTR2 = 0;
			score  = 0;
		}
	}
	//
	// everyone's parent
	// set on the first go round
	//
	var parent;
	//
	// go three the pairs and remove each and then
	// add in order of their score
	//
	for (i in scores2trs) {
		group = scores2trs[i];
		//
		// remember the parent
		//
		if (!parent) parent = group[0].parentNode;
		//
		// remove the kids
		//
		for (j in group) {
			if (group[j].parentNode) group[j].parentNode.removeChild(group[j]);
		}
	}
	//
	// sort them by scores
	// http://www.javascriptkit.com/javatutors/arraysort3.shtml
	//
	scores = new Array();
	for (i in scores2trs) scores.push(i);
	scores.sort(function (a,b) {return b-a;});
	//
	// add all the groups to parent
	//
	for (i=0; i<scores.length; i++) {
		//
		// this is ugly but i'm not sure (for <v> in ...)
		// is assured to do things in order
		//
		group = scores2trs[scores[i]];
		siteTR    = group[0];
		rowTR1    = group[1];
		rowTR2    = group[2];
		spacingTR = group[3];
		parent.appendChild(siteTR);
		parent.appendChild(rowTR1);
		parent.appendChild(rowTR2);
		parent.appendChild(spacingTR);
	}
}

try {main();} catch (e) {alert(e);}