// All credit goes to Rick Olson.
(function ($) {
	$.fn.relatizeDate = function () {
		return $(this).each(function () {
			$(this).text($.relatizeDate(this))
		})
	}

	$.relatizeDate = function (element) {
		var text = $(element).text();
		var date = new Date(text);
		return $.relatizeDate.timeAgoInWords(date);
	}

	// shortcut
	$r = $.relatizeDate

	$.extend($.relatizeDate, {
		shortDays: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
		days: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
		shortMonths: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
		months: ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],

		/**
		* Given a formatted string, replace the necessary items and return.
		* Example: Time.now().strftime("%B %d, %Y") => February 11, 2008
		* @param {String} format The formatted string used to format the results
		*/
		strftime: function (date, format) {
			var day = date.getDay(), month = date.getMonth();
			var hours = date.getHours(), minutes = date.getMinutes();

			var pad = function (num) {
				var string = num.toString(10);
				return new Array((2 - string.length) + 1).join('0') + string
			};

			return format.replace(/\%([aAbBcdHImMpSwyY])/g, function (part) {
				switch (part[1]) {
					case 'a': return $r.shortDays[day]; break;
					case 'A': return $r.days[day]; break;
					case 'b': return $r.shortMonths[month]; break;
					case 'B': return $r.months[month]; break;
					case 'c': return date.toString(); break;
					case 'd': return pad(date.getDate()); break;
					case 'H': return pad(hours); break;
					case 'I': return pad((hours + 12) % 12); break;
					case 'm': return pad(month + 1); break;
					case 'M': return pad(minutes); break;
					case 'p': return hours > 12 ? 'PM' : 'AM'; break;
					case 'S': return pad(date.getSeconds()); break;
					case 'w': return day; break;
					case 'y': return pad(date.getFullYear() % 100); break;
					case 'Y': return date.getFullYear().toString(); break;
				}
			})
		},

		timeAgoInWords: function (targetDate, includeTime) {
			return $r.distanceOfTimeInWords(targetDate, new Date(), includeTime);
		},

		/**
		* Return the distance of time in words between two Date's
		* Example: '5 days ago', 'about an hour ago'
		* @param {Date} fromTime The start date to use in the calculation
		* @param {Date} toTime The end date to use in the calculation
		* @param {Boolean} Include the time in the output
		*/
		distanceOfTimeInWords: function (fromTime, toTime, includeTime) {
			var delta = parseInt((toTime.getTime() - fromTime.getTime()) / 1000);
			if (delta < 60) {
				return 'less than a minute ago';
			} else if (delta < 120) {
				return 'about a minute ago';
			} else if (delta < (45 * 60)) {
				return (parseInt(delta / 60)).toString() + ' minutes ago';
			} else if (delta < (120 * 60)) {
				return 'about an hour ago';
			} else if (delta < (24 * 60 * 60)) {
				return 'about ' + (parseInt(delta / 3600)).toString() + ' hours ago';
			} else if (delta < (48 * 60 * 60)) {
				return '1 day ago';
			} else {
				var days = (parseInt(delta / 86400)).toString();
				if (days > 5) {
					var fmt = '%B %d, %Y'
					if (includeTime) fmt += ' %I:%M %p'
					return $r.strftime(fromTime, fmt);
				} else {
					return days + " days ago"
				}
			}
		}
	})
})(jQuery);