/* global Module */

/* Magic Mirror
 * Module: Calendar
 *
 * By Michael Teeuw http://michaelteeuw.nl
 * MIT Licensed.
 */

Module.register('calendar',{

	// Define module defaults
	defaults: {
		maximumEntries: 10, // Total Maximum Entries
		displaySymbol: true,
		defaultSymbol: 'calendar', // Fontawsome Symbol see http://fontawesome.io/cheatsheet/
		maxTitleLength: 25, 
		fetchInterval: 5 * 60 * 1000, // Update every 5 minutes.
		animationSpeed: 2000,
		fade: true, 
		fadePoint: 0.25, // Start on 1/4th of the list.
        calendars: [
			{
				symbol: 'calendar',
				url: 'http://www.calendarlabs.com/templates/ical/US-Holidays.ics',
			},
		],
		titleReplace: {
			'De verjaardag van ' : ''
		}
	},

	// Define required scripts.
	getStyles: function() {
		return ['calendar.css', 'font-awesome.css'];
	},

	// Define required scripts.
	getScripts: function() {
		return ['moment.js'];
	},

	// Override start method.
	start: function() {
		Log.log('Starting module: ' + this.name);

		// Set locale.
		moment.locale(config.language);

		for (var c in this.config.calendars) {
			var calendar = this.config.calendars[c];
			calendar.url = calendar.url.replace('webcal://', 'http://');
			this.addCalendar(calendar.url);
		}

		this.calendarData = {};
	},

	// Override socket notification handler.
	socketNotificationReceived: function(notification, payload) {
		if (notification === 'CALENDAR_EVENTS') {			
			if (this.hasCalendarURL(payload.url)) {
				this.calendarData[payload.url] = payload.events;
			}
		} else if(notification === 'FETCH_ERROR') {
			Log.error('Calendar Error. Could not fetch calendar: ' + payload.url);
		} else if(notification === 'INCORRECT_URL') {
			Log.error('Calendar Error. Incorrect url: ' + payload.url);
		} else {
			Log.log('Calendar received an unknown socket notification: '+notification);
		}

		this.updateDom(this.config.animationSpeed);
	},

	// Override dom generator.
	getDom: function() {

		var events = this.createEventList();
		var wrapper = document.createElement("table");
		wrapper.className = "small";

		if (events.length === 0) {
			wrapper.innerHTML = "Loading events ...";
			wrapper.className = "small dimmed";
			return wrapper;
		}

		for (var e in events) {
			var event = events[e];

			var eventWrapper = document.createElement("tr");
			eventWrapper.className = "normal";

			if (this.config.displaySymbol) {
				var symbolWrapper =  document.createElement("td");
				symbolWrapper.className = "symbol";
				var symbol =  document.createElement("span");
				symbol.className = "fa fa-" + this.symbolForUrl(event.url);
				symbolWrapper.appendChild(symbol);
				eventWrapper.appendChild(symbolWrapper);
			}

			var titleWrapper =  document.createElement("td");
			titleWrapper.innerHTML = this.titleTransform(event.title);
			titleWrapper.className = "title bright";
			eventWrapper.appendChild(titleWrapper);

			var timeWrapper =  document.createElement("td");
			timeWrapper.innerHTML = moment(event.startDate,'x').fromNow();
			timeWrapper.className = "time light";
			eventWrapper.appendChild(timeWrapper);

			wrapper.appendChild(eventWrapper);

			// Create fade effect.
			if (this.config.fade && this.config.fadePoint < 1) {
				if (this.config.fadePoint < 0) {
					this.config.fadePoint = 0;
				}
				var startingPoint = events.length * this.config.fadePoint;
				var steps = events.length - startingPoint;
				if (e >= startingPoint) {
					var currentStep = e - startingPoint;
					eventWrapper.style.opacity = 1 - (1 / steps * currentStep);
				}
			}
		}

		return wrapper;
	},

	/* hasCalendarURL(url)
	 * Check if this config contains the calendar url.
	 *
	 * argument url sting - Url to look for.
	 *
	 * return bool - Has calendar url
	 */
	hasCalendarURL: function(url) {
		for (var c in this.config.calendars) {
			var calendar = this.config.calendars[c];
			if (calendar.url === url) {
				return true;
			}
		}

		return false;
	},

	/* createEventList()
	 * Creates the sorted list of all events.
	 *
	 * return array - Array with events.
	 */
	createEventList: function() {
		var events = [];
		for (var c in this.calendarData) {
			var calendar = this.calendarData[c];
			for (var e in calendar) {
				var event = calendar[e];
				event.url = c;
				events.push(event);
			}
		}

		events.sort(function(a,b) {
			return a.startDate - b.startDate;
		});

		return events.slice(0, this.config.maximumEntries);
	},

	/* createEventList(url)
	 * Requests node helper to add calendar url.
	 *
	 * argument url sting - Url to add.
	 */
	addCalendar: function(url) {
		this.sendSocketNotification('ADD_CALENDAR', {
			url: url,
			maximumEntries: this.config.maximumEntries,
			fetchInterval: this.config.fetchInterval
		});
	},

	/* symbolForUrl(url)
	 * Retrieves the symbol for a specific url.
	 *
	 * argument url sting - Url to look for.
	 *
	 * return string - The Symbol
	 */
	symbolForUrl: function(url) {
		for (var c in this.config.calendars) {
			var calendar = this.config.calendars[c];
			if (calendar.url === url && typeof calendar.symbol === 'string')  {
				return calendar.symbol;
			}
		}

		return this.config.defaultSymbol;
	},

	/* shorten(string, maxLength)
	 * Shortens a sting if it's longer than maxLenthg.
	 * Adds an ellipsis to the end.
	 *
	 * argument string string - The string to shorten.
	 * argument maxLength number - The max lenth of the string.
	 *
	 * return string - The shortened string.
	 */
	shorten: function(string, maxLength) {
		if (string.length > maxLength) {
			return string.slice(0,maxLength) + "&hellip;";
		}

		return string;
	},

	/* titleTransform(title)
	 * Transforms the title of an event for usage.
	 * Replaces parts of the text as defined in config.titleReplace.
	 * Shortens title based on config.maxTitleLength
	 *
	 * argument title string - The title to transform.
	 *
	 * return string - The transformed title.
	 */
	titleTransform: function(title) {
		for (var needle in this.config.titleReplace) {
			var replacement = this.config.titleReplace[needle];
			title = title.replace(needle, replacement);
		}

		title = this.shorten(title, this.config.maxTitleLength);
		return title;
	}
});