// JavaScript Document
/*
 * Date Format 1.2.3
 * (c) 2007-2009 Steven Levithan <stevenlevithan.com>
 * MIT license
 *
 * Includes enhancements by Scott Trenda <scott.trenda.net>
 * and Kris Kowal <cixar.com/~kris.kowal/>
 *
 * Accepts a date, a mask, or a date and a mask.
 * Returns a formatted version of the given date.
 * The date defaults to the current date/time.
 * The mask defaults to dateFormat.masks.default.
 */

var dateFormat = function () {
	var	token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
		timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
		timezoneClip = /[^-+\dA-Z]/g,
		pad = function (val, len) {
			val = String(val);
			len = len || 2;
			while (val.length < len) val = "0" + val;
			return val;
		};

	// Regexes and supporting functions are cached through closure
	return function (date, mask, utc) {
		
		var dF = dateFormat;

		// You can't provide utc if you skip other args (use the "UTC:" mask prefix)
		if (arguments.length == 1 && Object.prototype.toString.call(date) == "[object String]" && !/\d/.test(date)) {
			mask = date;
			date = undefined;
		}
		
		// Passing date through Date applies Date.parse, if necessary
		date = date ? new Date(date) : new Date;
		if (isNaN(date)) throw SyntaxError("invalid date");
		
		mask = String(dF.masks[mask] || mask || dF.masks["default"]);

		// Allow setting the utc argument via the mask
		if (mask.slice(0, 4) == "UTC:") {
			mask = mask.slice(4);
			utc = true;
		}

		var	_ = utc ? "getUTC" : "get",
			d = date[_ + "Date"](),
			D = date[_ + "Day"](),
			m = date[_ + "Month"](),
			y = date[_ + "FullYear"](),
			H = date[_ + "Hours"](),
			M = date[_ + "Minutes"](),
			s = date[_ + "Seconds"](),
			L = date[_ + "Milliseconds"](),
			o = utc ? 0 : date.getTimezoneOffset(),
			flags = {
				d:    d,
				dd:   pad(d),
				ddd:  dF.i18n.dayNames[D],
				dddd: dF.i18n.dayNames[D + 7],
				m:    m + 1,
				mm:   pad(m + 1),
				mmm:  dF.i18n.monthNames[m],
				mmmm: dF.i18n.monthNames[m + 12],
				yy:   String(y).slice(2),
				yyyy: y,
				h:    H % 12 || 12,
				hh:   pad(H % 12 || 12),
				H:    H,
				HH:   pad(H),
				M:    M,
				MM:   pad(M),
				s:    s,
				ss:   pad(s),
				l:    pad(L, 3),
				L:    pad(L > 99 ? Math.round(L / 10) : L),
				t:    H < 12 ? "a"  : "p",
				tt:   H < 12 ? "am" : "pm",
				T:    H < 12 ? "A"  : "P",
				TT:   H < 12 ? "AM" : "PM",
				Z:    utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""),
				o:    (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
				S:    ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
			};

		return mask.replace(token, function ($0) {
			return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1);
		});
	};
}();

// Some common format strings
dateFormat.masks = {
	"default":      "ddd mmm dd yyyy HH:MM:ss",
	shortDate:      "m/d/yy",
	mediumDate:     "mmm d, yyyy",
	longDate:       "mmmm d, yyyy",
	fullDate:       "dddd, mmmm d, yyyy",
	shortTime:      "h:MM TT",
	mediumTime:     "h:MM:ss TT",
	longTime:       "h:MM:ss TT Z",
	isoDate:        "yyyy-mm-dd",
	isoTime:        "HH:MM:ss",
	isoDateTime:    "yyyy-mm-dd'T'HH:MM:ss",
	isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"
};

// Internationalization strings
dateFormat.i18n = {
	dayNames: [
		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
		"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
	],
	monthNames: [
		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
	]
};

// For convenience...
Date.prototype.format = function (mask, utc) {
	return dateFormat(this, mask, utc);
};


// Parser to convert isoDateTime to format accetable for Safari and IE
function parseISODate (input) {
    var iso = /^(\d{4})(?:-?W(\d+)(?:-?(\d+)D?)?|(?:-(\d+))?-(\d+))(?:[T ](\d+):(\d+)(?::(\d+)(?:\.(\d+))?)?)?(?:Z(-?\d*))?$/;

    var parts = input.match(iso);

    if (parts == null) {
        throw new Error("Invalid Date");
    }

    var year = Number(parts[1]);

    if (typeof parts[2] != "undefined") {
        /* Convert weeks to days, months 0 */
        var weeks = Number(parts[2]) - 1;
        var days  = Number(parts[3]);

        if (typeof days == "undefined") {
            days = 0;
        }

        days += weeks * 7;

        var months = 0;
    }
    else {
        if (typeof parts[4] != "undefined") {
            var months = Number(parts[4]) - 1;
        }
        else {
            /* it's an ordinal date... */
            var months = 0;
        }

        var days   = Number(parts[5]);
    }

    if (typeof parts[6] != "undefined" &&
        typeof parts[7] != "undefined")
    {
        var hours        = Number(parts[6]);
        var minutes      = Number(parts[7]);

        if (typeof parts[8] != "undefined") {
            var seconds      = Number(parts[8]);

            if (typeof parts[9] != "undefined") {
                var fractional   = Number(parts[9]);
                var milliseconds = fractional / 100;
            }
            else {
                var milliseconds = 0
            }
        }
        else {
            var seconds      = 0;
            var milliseconds = 0;
        }
    }
    else {
        var hours        = 0;
        var minutes      = 0;
        var seconds      = 0;
        var fractional   = 0;
        var milliseconds = 0;
    }

    if (typeof parts[10] != "undefined") {
        /* Timezone adjustment, offset the minutes appropriately */
        var localzone = -(new Date().getTimezoneOffset());
        var timezone  = parts[10] * 60;

        minutes = Number(minutes) + (timezone - localzone);
    }

    return new Date(year, months, days, hours, minutes, seconds, milliseconds);
}

// This is a comparison function that will result in dates being sorted in
// ASCENDING order. As you can see, JavaScript's native comparison operators
// can be used to compare dates. This was news to me.
var date_sort_asc = function (date1, date2) {
  if (date1 > date2) return 1;
  if (date1 < date2) return -1;
  return 0;
};

function listEvents(root) {
    var feed = root.feed;
	var numOfEntries = 5;
    var entries = feed.entry || [];
    var html = ['<ul>'];
	
	var sorter = [];
	var keys = [];
	var today = new Date();
	var counter = 0;
	
	
	for (var i=0; i<25; i++) {
		var entry = entries[i];
		var sortDate = (entry['gd$when']) ? entry['gd$when'][0].startTime : "";
		var title = entry.title.$t;
		sortDate = sortDate.slice(0, 23);
		a = parseISODate(sortDate);
		if (a>today) {
			sorter[counter] = a;
			sorter[counter].key = i;
			counter++;	
		}
	}
	 
	sorter.sort(date_sort_asc);
	
	
	// Now let's output the results to the page to show that the dates are now
	// sorted in ascending order.
	/*for (var i = 0; i < sorter.length; i++) {
  		alert(i + ': ' + sorter[i].key);
	}*/

     for (var i = 0; i < 5; ++i) {
	  a = sorter[i].key;
	  var entry = entries[a];
      var title = entry.title.$t;
	  var where = (entry['gd$where'][0].valueString);
      var start = (entry['gd$when']) ? entry['gd$when'][0].startTime : "";
	  
	  
	  // removes the '-07:00' from the startTime
	  start = start.slice(0, 23);
	  // using a parser to convert isoDateTime to a format acceptable for Safari and IE
	  d = parseISODate(start);
	  // dateFormat allows to convert to multiple formats
	  var when = dateFormat(d, "mediumDate");	
	  html.push('<li>', when, ' ', where, ' ', title, '</li>');
    }

    html.push('</ul>');
    document.getElementById("agenda").innerHTML = html.join("");
	
 }