var dom = (document.getElementsByTagName) ? true : false;
var ie5 = (document.getElementsByTagName && document.all) ? true : false;
var arrowUp, arrowDown;

if (!Array.prototype.indexOf)
{
  Array.prototype.indexOf = function(elt /*, from*/)
  {
    var len = this.length;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++)
    {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}

if (ie5 || dom)
	initSortTable();

function initSortTable() {
	arrowUp = document.createElement("span");
	//var tn = document.createTextNode("5");
	var tn = document.createElement("img");
	tn.src = '/static/img/up.gif';
	tn.width = 8;
	arrowUp.appendChild(tn);
	arrowUp.className = "arrow";

	arrowDown = document.createElement("span");
	//var tn = document.createTextNode("6");
	var tn = document.createElement("img");
	tn.src = '/static/img/down.gif';
	tn.width = 8;
	arrowDown.appendChild(tn);
	arrowDown.className = "arrow";
}

function sortTable(tableNode, nCol, bDesc, sType) {
	var tBody = tableNode.tBodies[0];
	var trs = tBody.rows;
	var trl= trs.length;
	var a = new Array();

	// discover and save a copy of "const" columns
	var tHead = tableNode.tHead;
	var constColumns = new Array();
	var constColumnsData = new Array();
	for (var k=0; k<tHead.rows[0].cells.length; k++) {
		var tmp = tHead.rows[0].cells[k].getAttribute("type");
		if (tHead.rows[0].cells[k].getAttribute("type") == "const")
			constColumns.push(k);
	}
	for (var i=0; i<trs.length; i++) {
		for (var j=0; j<trs[i].cells.length; j++) {
			if (constColumns.indexOf(j) != -1) {
				if (constColumnsData[j] == null)
					constColumnsData[j] = new Array();
				constColumnsData[j].push(trs[i].cells[j].innerHTML);
			}
		}
	}
	
	// sorting
	for (var i = 0; i < trl; i++) {
		a[i] = trs[i];
	}
//	var start = new Date;
//	window.status = "Sorting data...";
	a.sort(compareByColumn(nCol,bDesc,sType));
//	window.status = "Sorting data done";
	// restore "const" columns
	for (var i=0; i<trl; i++) {
		for (var j=0; j<a[i].cells.length; j++) {
			if (constColumns.indexOf(j) != -1)
				a[i].cells[j].innerHTML = constColumnsData[j][i];
		}
	}

	for (var i = 0; i < trl; i++) {
		tBody.appendChild(a[i]);
//		window.status = "Updating row " + (i + 1) + " of " + trl +
//						" (Time spent: " + (new Date - start) + "ms)";
	}
	
	// check for onsort
	if (typeof tableNode.onsort == "string")
		tableNode.onsort = new Function("", tableNode.onsort);
	if (typeof tableNode.onsort == "function")
		tableNode.onsort();
}

function CaseInsensitiveString(s) {
	return String(s).toUpperCase();
}

function NumberAndString(ss) {
	var num = String(ss).match(/[\d\.]+/g);
	if (num == null) return Number(0);
	
	return Number(num[0]);
}

function NumberAndString2(ss) {
	var str = String(ss).match(/[A-Z]/gi);
	if (str == null) return String('');
	
	return String(str[0]).toUpperCase();
}

function compareNumberAndString(s1, s2) {
	var n1 = NumberAndString(s1);
	var n2 = NumberAndString(s2);
	
	var str1 = NumberAndString2(s1);
	var str2 = NumberAndString2(s2);
	
	if (n1 > n2)
		return +1;
	else if (n1 < n2)
		return -1;
	else {
		if (str1 > str2)
			return +1;
		else if (str1 < str2)
			return -1;
		return 0;
	}

	return 0;
}

function parseDate(s) {
	ars=s.split("-");
	//return Date.parse(s.replace(/\-/g, '/'));
	return Date.parse(ars[2]+'/'+ars[1]+'/'+ars[0]);
}

/* alternative to number function
 * This one is slower but can handle non numerical characters in
 * the string allow strings like the follow (as well as a lot more)
 * to be used:
 *    "1,000,000"
 *    "1 000 000"
 *    "100cm"
 */

function toNumber(s) {
    return Number(s.replace(/[^0-9\.]/g, ""));
}

function compareByColumn(nCol, bDescending, sType) {
	var c = nCol;
	var d = bDescending;
	
	var fTypeCast = String;
	
	if (sType == "Number")
		fTypeCast = Number;
	else if (sType == "Date")
		fTypeCast = parseDate;
	else if (sType == "CaseInsensitiveString")
		fTypeCast = CaseInsensitiveString;
	else if (sType == "NumberAndString")
		fTypeCast = NumberAndString;

	return function (n1, n2) {
		if (sType == "NumberAndString") {
			var comp = compareNumberAndString(getInnerText(n1.cells[c]), getInnerText(n2.cells[c]));
			if (comp > 0)
				return d ? +1 : -1;
			else if (comp < 0)
				return d ? -1 : +1;
			return 0;
		}
		
		if (fTypeCast(getInnerText(n1.cells[c])) < fTypeCast(getInnerText(n2.cells[c])))
			return d ? -1 : +1;
		if (fTypeCast(getInnerText(n1.cells[c])) > fTypeCast(getInnerText(n2.cells[c])))
			return d ? +1 : -1;
		return 0;
	};
}

function sortColumnWithHold(e) {
	// find table element
	var el = ie5 ? e.srcElement : e.target;
	var table = getParent(el, "TABLE");
	
	// backup old cursor and onclick
	var oldCursor = table.style.cursor;
	var oldClick = table.onclick;
	
	// change cursor and onclick	
	table.style.cursor = "wait";
	table.onclick = null;
	
	// the event object is destroyed after this thread but we only need
	// the srcElement and/or the target
	var fakeEvent = {srcElement : e.srcElement, target : e.target};
	
	// call sortColumn in a new thread to allow the ui thread to be updated
	// with the cursor/onclick
	window.setTimeout(function () {
		sortColumn(fakeEvent);
		// once done resore cursor and onclick
		table.style.cursor = oldCursor;
		table.onclick = oldClick;
	}, 100);
}

function sortColumn(e) {
	var tmp = e.target ? e.target : e.srcElement;
	var tHeadParent = getParent(tmp, "THEAD");
	var el = getParent(tmp, "TD");

	if (tHeadParent == null)
		return;
		
	if (el != null) {
		elType = el.getAttribute("type");
		if ((elType == "const") || (elType == "noSort"))
			return;
		
		var p = el.parentNode;
		var i;

		// typecast to Boolean
		el._descending = !Boolean(el._descending);

		if (tHeadParent.arrow != null) {
			if (tHeadParent.arrow.parentNode != el) {
				tHeadParent.arrow.parentNode._descending = null;	//reset sort order		
			}
			tHeadParent.arrow.parentNode.removeChild(tHeadParent.arrow);
		}

		if (el._descending)
			tHeadParent.arrow = arrowUp.cloneNode(true);
		else
			tHeadParent.arrow = arrowDown.cloneNode(true);

		el.appendChild(tHeadParent.arrow);

		// get the index of the td
		var cells = p.cells;
		var l = cells.length;
		for (i = 0; i < l; i++) {
			if (cells[i] == el) break;
		}

		var table = getParent(el, "TABLE");
		// can't fail
		
		sortTable(table, i, el._descending, elType);
	}
}

function getInnerText(el) {
	if (ie5) return el.innerText;	//Not needed but it is faster
	
	var str = "";
	
	var cs = el.childNodes;
	var l = cs.length;
	for (var i = 0; i < l; i++) {
		switch (cs[i].nodeType) {
			case 1: //ELEMENT_NODE
				str += getInnerText(cs[i]);
				break;
			case 3:	//TEXT_NODE
				str += cs[i].nodeValue;
				break;
		}		
	}
	
	return str;
}

function getParent(el, pTagName) {
	if (el == null) return null;
	else if (el.nodeType == 1 && el.tagName.toLowerCase() == pTagName.toLowerCase())	// Gecko bug, supposed to be uppercase
		return el;
	else
		return getParent(el.parentNode, pTagName);
}