/*
TableSort by frequency-decoder.com
Released under a creative commons nc-sa license (http://creativecommons.org/licenses/by-nc-sa/2.5/)
Please credit frequency decoder in any derivitive work. Thanks.
Changes
-------
14/02/2006 :	Added the 'sort onload' functionality. Integrated John Resigs addEvent function (http://ejohn.org/projects/flexible-javascript-events/).
15/02/2006 :	Added the ability to 'force' the script to use a specified sort algorithm.
		Added a check for identical cell data (no sort is ran should all of a columns cells contain identical data).
*/
function addEvent(obj, type, fn) {
	if( obj.attachEvent ) {
	obj["e"+type+fn] = fn;
	obj[type+fn] = function(){obj["e"+type+fn]( window.event );}
	obj.attachEvent( "on"+type, obj[type+fn] );
	} else
	obj.addEventListener( type, fn, false );
}
var fdTableSort = {
	regExp_Currency: /^[£$€]/,
	regExp_Number: /^(\-)?[0-9]+(\.[0-9]*)?$/,
	pos: -1,
	init: function() {
		if (!document.getElementsByTagName) return;
		var tables = document.getElementsByTagName('table');
		var sortable, headers;
		for(var t = 0, tbl; tbl = tables[t]; t++) {
		headers = tbl.getElementsByTagName('th');
		sortable = false;
			for (var z=0, th; th = headers[z]; z++) {
				if(th.className.match('sortable')) {
					if(tbl.className.match('sortable-onload') && !sortable) sortable = th;
					th.onclick = fdTableSort.sortWrapper;
					th.appendChild(document.createElement('span'));
				}
			}
			if(sortable) fdTableSort.initSort(sortable);
		}
	},
	sortWrapper: function(e) {
	fdTableSort.initSort(this);
	},
	initSort: function(thNode) {
	var curr = thNode;
	fdTableSort.pos = 0;
	// Get the column position
		while(curr.previousSibling) {
			if(curr.previousSibling.nodeType != 3) fdTableSort.pos++;
			curr = curr.previousSibling;
		}
		// Remove any old "reverse" class we might have previously added
		var thCollection = curr.parentNode.getElementsByTagName('th');
		var span;
		for(var i=0, th; th = thCollection[i]; i++) {
			if(i != fdTableSort.pos) {
			th.className = th.className.replace('reverseSort','');
			// Remove arrow
			span = th.getElementsByTagName('span');
				if(span.length > 0) {
				span = span[span.length - 1];
					if(span.firstChild) span.removeChild(span.firstChild);
					span.appendChild(document.createTextNode("\u00a0\u00a0"));
				}
			}
		}
		// Get the table
		var tableElem = thNode;
		while(tableElem.tagName.toLowerCase() != 'table' && tableElem.parentNode) {
		tableElem = tableElem.parentNode;
		}
		// Has a row color been defined in the table's className?
		var style;
		if(tableElem.className.match(/style-(.+)/)) {
		style = tableElem.className.match(/style-(.+)/)[1];
		}
		// Has the table a tbody ?
		// N.B. By definition, tables can have multiple tbody tags
		// this script assumes only one.
		if(tableElem.getElementsByTagName('tbody')) {
		tableElem = tableElem.getElementsByTagName('tbody')[0];
		}
		// Get the tr tags
		var trs = tableElem.getElementsByTagName('tr');
		var trCollection = new Array();
		// If the current tr has any th child elements then skip it..
		for(var i = 0, tr; tr = trs[i]; i++) {
			if(tr.getElementsByTagName('th').length == 0) trCollection.push(tr);
		}
		// Try to get the column data type
		var sortFunction;
		var txt = null;
		var identical = true;
		var firstTxt = "";
		for(i = 0; i < trCollection.length; i++) {
		cellTxt = fdTableSort.getInnerText(trCollection[i].getElementsByTagName('td')[fdTableSort.pos]);
			if(i > 0 && txt != cellTxt) identical = false;
			txt = cellTxt;
			if(firstTxt == "") firstTxt = txt;
		}
		if(thNode.className.match('sortable-numeric')) sortFunction = fdTableSort.sortNumeric;
		else if(thNode.className.match('sortable-currency')) sortFunction = fdTableSort.sortCurrency;
		else if(thNode.className.match('sortable-date')) sortFunction = fdTableSort.sortDate;
		else if(fdTableSort.dateFormat(firstTxt) != 0) sortFunction = fdTableSort.sortDate;
		else if(firstTxt.match(fdTableSort.regExp_Number)) sortFunction = fdTableSort.sortNumeric;
		else if(firstTxt.match(fdTableSort.regExp_Currency)) sortFunction = fdTableSort.sortCurrency;
		else sortFunction = fdTableSort.sortCaseInsensitive;
		// Call the JavaScript array.sort method, passing in our bespoke sort function
		if(!identical) trCollection.sort(sortFunction);
		// Do we need to reverse the sort?
		var arrow;
		if(thNode.className.match('reverseSort') && !identical) {
		trCollection.reverse();
		thNode.className = thNode.className.replace('reverseSort','');
		arrow = " \u2191";
		} else {
		thNode.className = thNode.className.replace('reverseSort','');
		thNode.className = thNode.className + ' reverseSort';
		arrow = " \u2193";
		}
		span = thNode.getElementsByTagName('span');
		if(span.length > 0) {
		span = span[span.length - 1];
			if(span.firstChild) span.removeChild(span.firstChild);
			span.appendChild(document.createTextNode(arrow));
		}
		if(identical) return;
		for(var i = 0, tr; tr = trCollection[i]; i++) {
			if(style) {
				tr.className = tr.className.replace(style,'');
				tr.className = (i % 2 != 0) ? tr.className + " " + style : tr.className;
			}
			tableElem.appendChild(tr);
		}
	},
	getInnerText: function(el) {
		if (typeof el == "string" || typeof el == "undefined") return el;
		if(el.innerText) return el.innerText;
		var txt = '', i;
		for (i = el.firstChild; i; i = i.nextSibling) {
			if (i.nodeType == 3) txt += i.nodeValue;
			else if (i.nodeType == 1) txt += fdTableSort.getInnerText(i);
		}
		return txt;
	},
	dateFormat: function(dateIn) {
		var y, m, d, res;
		if(dateIn.match(/^(0[1-9]|1[012])([- \/.])(0[1-9]|[12][0-9]|3[01])([- \/.])(\d\d?\d\d)$/)) {
			res = dateIn.match(/^(0[1-9]|1[012])([- \/.])(0[1-9]|[12][0-9]|3[01])([- \/.])(\d\d?\d\d)$/);
			y = res[5];
			m = res[1];
			d = res[3];
		} else if(dateIn.match(/^(0[1-9]|[12][0-9]|3[01])([- \/.])(0[1-9]|1[012])([- \/.])(\d\d?\d\d)$/)) {
			res = dateIn.match(/^(0[1-9]|[12][0-9]|3[01])([- \/.])(0[1-9]|1[012])([- \/.])(\d\d?\d\d)$/);
			y = res[5];
			m = res[3];
			d = res[1];
		} else if(dateIn.match(/^(\d\d?\d\d)([- \/.])(0[1-9]|1[012])([- \/.])(0[1-9]|[12][0-9]|3[01])$/)) {
			res = dateIn.match(/^(\d\d?\d\d)([- \/.])(0[1-9]|1[012])([- \/.])(0[1-9]|[12][0-9]|3[01])$/);
			y = res[1];
			m = res[3];
			d = res[5];
		} else return 0;
		if(m.length == 1) m = "0" + m;
		if(d.length == 1) d = "0" + d;
		if(y.length != 4) y = (parseInt(y) < 50) ? '20' + y : '19' + y;
		return y+m+d;
	},
	sortDate: function(a,b) {
		aa = fdTableSort.dateFormat(fdTableSort.getInnerText(a.getElementsByTagName('td')[fdTableSort.pos]));
		bb = fdTableSort.dateFormat(fdTableSort.getInnerText(b.getElementsByTagName('td')[fdTableSort.pos]));
		// Added 15/02/2006 : If mixed type row then treat the date as being bigger
		if(aa == 0 && bb != 0) return -1;
		else if(bb == 0 && aa != 0) return 1;
		if (aa == bb) return 0;
		if (aa < bb) return -1;
		return 1;
	},
	sortCurrency:function(a,b) {
		aa = fdTableSort.getInnerText(a.getElementsByTagName('td')[fdTableSort.pos]).replace(/[^0-9.]/g,'');
		bb = fdTableSort.getInnerText(b.getElementsByTagName('td')[fdTableSort.pos]).replace(/[^0-9.]/g,'');
		// Added 15/02/2006 : If mixed type row then treat the number as being bigger
		if((isNaN(aa) || aa == "") && !isNaN(bb)) return -1;
		else if((isNaN(bb) || bb == "") && !isNaN(aa)) return 1;
		if(isNaN(aa) || aa == "") aa = 0;
		if(isNaN(bb) || bb == "") bb = 0;
		return parseFloat(aa) - parseFloat(bb);
	},
	sortNumeric:function (a,b) {
		aa = parseFloat(fdTableSort.getInnerText(a.getElementsByTagName('td')[fdTableSort.pos]));
		bb = parseFloat(fdTableSort.getInnerText(b.getElementsByTagName('td')[fdTableSort.pos]));
		// Added 15/02/2006 : If mixed type row then treat the number as being bigger
		if((isNaN(aa) || aa == "") && !isNaN(bb)) return -1;
		else if((isNaN(bb) || bb == "") && !isNaN(aa)) return 1;
		if(isNaN(aa) || aa == "") aa = 0;
		if(isNaN(bb) || bb == "") bb = 0;
		return aa-bb;
	},
	sortCaseInsensitive:function (a,b) {
		aa = fdTableSort.getInnerText(a.getElementsByTagName('td')[fdTableSort.pos]).toLowerCase();
		bb = fdTableSort.getInnerText(b.getElementsByTagName('td')[fdTableSort.pos]).toLowerCase();
		if(aa == bb) return 0;
		if(aa < bb) return -1;
		return 1;
	}
}
addEvent(window, "load", fdTableSort.init);