text: /* Magic Mirror
   * Node Helper: Calendar - CalendarFetcher
   *
   * By Michael Teeuw http://michaelteeuw.nl
   * MIT Licensed.
   */
  
  var ical = require("./vendor/ical.js");
  var moment = require("moment");
  
  var CalendarFetcher = function(url, reloadInterval, maximumEntries, maximumNumberOfDays) {
  	var self = this;
  
  	var reloadTimer = null;
  	var events = [];
  
  	var fetchFailedCallback = function() {};
  	var eventsReceivedCallback = function() {};
  
  	/* fetchCalendar()
  	 * Initiates calendar fetch.
  	 */
  	var fetchCalendar = function() {
  
  		clearTimeout(reloadTimer);
  		reloadTimer = null;
  
  		var opts = {
  			headers: {
  				'User-Agent': 'Mozilla/5.0 (Node.js 6.0.0) MagicMirror/v2 (https://github.com/MichMich/MagicMirror/)'
  			}
  		}
  		ical.fromURL(url, opts, function(err, data) {
  			if (err) {
  				fetchFailedCallback(self, err);
  				scheduleTimer();
  				return;
  			}
  
  			//console.log(data);
  			newEvents = [];
  
  			var limitFunction = function(date, i) {return i < maximumEntries;};
  
  			for (var e in data) {
  				var event = data[e];
  				var now = new Date();
  				var today = moment().startOf("day").toDate();
  				var future = moment().startOf("day").add(maximumNumberOfDays, "days").subtract(1,"seconds").toDate(); // Subtract 1 second so that events that start on the middle of the night will not repeat.
  
  				// FIXME:
  				// Ugly fix to solve the facebook birthday issue.
  				// Otherwise, the recurring events only show the birthday for next year.
  				var isFacebookBirthday = false;
  				if (typeof event.uid !== "undefined") {
  					if (event.uid.indexOf("@facebook.com") !== -1) {
  						isFacebookBirthday = true;
  					}
  				}
  
  				if (event.type === "VEVENT") {
  
  					var startDate = (event.start.length === 8) ? moment(event.start, "YYYYMMDD") : moment(new Date(event.start));
  					var endDate;
  					if (typeof event.end !== "undefined") {
  						endDate = (event.end.length === 8) ? moment(event.end, "YYYYMMDD") : moment(new Date(event.end));
  					} else {
  						if (!isFacebookBirthday) {
  							endDate = startDate;
  						} else {
  							endDate = moment(startDate).add(1, 'days');
  						}
  					}
  
  					// calculate the duration f the event for use with recurring events.
  					var duration = parseInt(endDate.format("x")) - parseInt(startDate.format("x"));
  
  					if (event.start.length === 8) {
  						startDate = startDate.startOf("day");
  					}
  
  					var title = "Event";
  					if (event.summary) {
  						title = (typeof event.summary.val !== "undefined") ? event.summary.val : event.summary;
  					} else if(event.description) {
  						title = event.description;
  					}
  
  					if (typeof event.rrule != "undefined" && !isFacebookBirthday) {
  						var rule = event.rrule;
  						var dates = rule.between(today, future, true, limitFunction);
  
  						for (var d in dates) {
  							startDate = moment(new Date(dates[d]));
  							endDate  = moment(parseInt(startDate.format("x")) + duration, 'x');
  							if (endDate.format("x") > now) {
  								newEvents.push({
  									title: title,
  									startDate: startDate.format("x"),
  									endDate: endDate.format("x"),
  									fullDayEvent: isFullDayEvent(event),
  									firstYear: event.start.getFullYear()
  								});
  							}
  						}
  					} else {
  						// console.log("Single event ...");
  						// Single event.
  						var fullDayEvent = (isFacebookBirthday) ? true : isFullDayEvent(event);
  
  						if (!fullDayEvent && endDate < new Date()) {
  							//console.log("It's not a fullday event, and it is in the past. So skip: " + title);
  							continue;
  						}
  
  						if (fullDayEvent && endDate <= today) {
  							//console.log("It's a fullday event, and it is before today. So skip: " + title);
  							continue;
  						}
  
  						if (startDate > future) {
  							//console.log("It exceeds the maximumNumberOfDays limit. So skip: " + title);
  							continue;
  						}
  
  						// Every thing is good. Add it to the list.					
  						newEvents.push({
  							title: title,
  							startDate: startDate.format("x"),
  							endDate: endDate.format("x"),
  							fullDayEvent: fullDayEvent
  						});
  						
  					}
  				}
  			}
  
  			newEvents.sort(function(a, b) {
  				return a.startDate - b.startDate;
  			});
  
  			//console.log(newEvents);
  
  			events = newEvents.slice(0, maximumEntries);
  
  			self.broadcastEvents();
  			scheduleTimer();
  		});
  	};
  
  	/* scheduleTimer()
  	 * Schedule the timer for the next update.
  	 */
  	var scheduleTimer = function() {
  		//console.log('Schedule update timer.');
  		clearTimeout(reloadTimer);
  		reloadTimer = setTimeout(function() {
  			fetchCalendar();
  		}, reloadInterval);
  	};
  
  	/* isFullDayEvent(event)
  	 * Checks if an event is a fullday event.
  	 *
  	 * argument event obejct - The event object to check.
  	 *
  	 * return bool - The event is a fullday event.
  	 */
  	var isFullDayEvent = function(event) {
  		if (event.start.length === 8) {
  			return true;
  		}
  
  		var start = event.start || 0;
  		var startDate = new Date(start);
  		var end = event.end || 0;
  
  		if (end - start === 24 * 60 * 60 * 1000 && startDate.getHours() === 0 && startDate.getMinutes() === 0) {
  			// Is 24 hours, and starts on the middle of the night.
  			return true;			
  		}
  
  		return false;
  	};
  
  	/* public methods */
  
  	/* startFetch()
  	 * Initiate fetchCalendar();
  	 */
  	this.startFetch = function() {
  		fetchCalendar();
  	};
  
  	/* broadcastItems()
  	 * Broadcast the exsisting events.
  	 */
  	this.broadcastEvents = function() {
  		//console.log('Broadcasting ' + events.length + ' events.');
  		eventsReceivedCallback(self);
  	};
  
  	/* onReceive(callback)
  	 * Sets the on success callback
  	 *
  	 * argument callback function - The on success callback.
  	 */
  	this.onReceive = function(callback) {
  		eventsReceivedCallback = callback;
  	};
  
  	/* onError(callback)
  	 * Sets the on error callback
  	 *
  	 * argument callback function - The on error callback.
  	 */
  	this.onError = function(callback) {
  		fetchFailedCallback = callback;
  	};
  
  	/* url()
  	 * Returns the url of this fetcher.
  	 *
  	 * return string - The url of this fetcher.
  	 */
  	this.url = function() {
  		return url;
  	};
  
  	/* events()
  	 * Returns current available events for this fetcher.
  	 *
  	 * return array - The current available events for this fetcher.
  	 */
  	this.events = function() {
  		return events;
  	};
  
  };
  
  
  module.exports = CalendarFetcher;