Add iCal converter

app.ts

@@ -29,7 +29,7 @@ app.use(express.json());
 // Configure CORS
 let allowedHosts = [
 	'https://www.nachklang.art',
-	'https://calendar.nachklang.art',
+	'https://calendar.nachklang.art'
 ];
 app.use(cors({
 	origin: function (origin: any, callback: any) {

src/models/calendar/events/event.interface.ts

@@ -1,3 +1,13 @@
 export interface Event {
 	event_id: number;
+	calendar_id: number;
+	uuid: string;
+	name: string;
+	description: string;
+	start_datetime: Date;
+	end_datetime: Date;
+	created_date: Date;
+	location: string;
+	created_by: string;
+	url: string;
 }

src/models/calendar/events/events.router.ts

@@ -4,7 +4,7 @@
 
 import express, {Request, Response} from 'express';
 import * as EventService from './events.service';
-import {Event} from './event.interface';
+import * as iCalService from './icalgenerator.service';
 
 
 /**
@@ -13,13 +13,18 @@ import {Event} from './event.interface';
 
 export const eventsRouter = express.Router();
 
+/**
+ * Constants
+ */
+const fileNames = ['Nachklang_calendar', 'Nachklang_internal_calendar', 'Nachklang_management_calendar'];
+
 
 /**
  * Controller Definitions
  */
 
 // POST users/register
-eventsRouter.get('/all', async (req: Request, res: Response) => {
+eventsRouter.get('/json', async (req: Request, res: Response) => {
 	try {
 		// Get request params
 		let calendarId: number = parseInt(req.query.calendar as string ?? '', 10);
@@ -27,10 +32,31 @@ eventsRouter.get('/all', async (req: Request, res: Response) => {
 		// Get events
 		let events = await EventService.getAllEvents(calendarId);
 
-		// Send the session details back to the user
+		// Send the events back
 		res.status(200).send(events);
 	} catch (e: any) {
 		console.log('Error handling a request: ' + e.message);
 		res.status(500).send(JSON.stringify({'message': 'Internal Server Error. Try again later.'}));
 	}
 });
+
+eventsRouter.get('/ical', async (req: Request, res: Response) => {
+	try {
+		// Get request params
+		let calendarId: number = parseInt(req.query.calendar as string ?? '', 10);
+
+		// Get events
+		let events = await EventService.getAllEvents(calendarId);
+
+		// generate file name
+		let fileName = fileNames[calendarId];
+		let file = await iCalService.convertToIcal(events);
+
+		// Send the ical file back
+		res.set({'Content-Disposition': 'attachment; filename=' + fileName + '.ics'});
+		res.status(200).send(file);
+	} catch (e: any) {
+		console.log('Error handling a request: ' + e.message);
+		res.status(500).send(JSON.stringify({'message': 'Internal Server Error. Try again later.'}));
+	}
+});

src/models/calendar/events/icalgenerator.service.ts

@@ -0,0 +1,132 @@
+import {Event} from './event.interface';
+
+export const convertToIcal = async (events: Event[]): Promise<string> => {
+	try {
+		let ical: iCalFile = {body: []};
+		generateHeaderInfo(ical);
+		generateFooterInfo(ical);
+		for (let event of events) {
+			addEventToFile(ical, event);
+		}
+
+		return serializeIcalFile(ical);
+	} catch (err) {
+		throw err;
+	}
+};
+
+const serializeIcalFile = (ical: iCalFile): string => {
+	let returnString = '';
+
+	returnString += ical.header;
+	for (let event of ical.body) {
+		returnString += serializeIcalEvent(event);
+	}
+	returnString += ical.footer;
+
+	return returnString;
+};
+
+const serializeIcalEvent = (icalevent: iCalEvent): string => {
+	let returnString = '';
+
+	returnString += icalevent.header;
+	returnString += 'UID:' + icalevent.uid;
+	returnString += 'DTSTAMP:' + icalevent.created;
+	returnString += 'ORGANIZER:' + icalevent.organizer;
+	returnString += 'DTSTART;TZID=Europe/Berlin:' + icalevent.start;
+	returnString += 'DTEND;TZID=Europe/Berlin:' + icalevent.end;
+	returnString += 'SUMMARY:' + icalevent.summary;
+	returnString += 'DESCRIPTION:' + icalevent.description;
+	returnString += 'LOCATION:' + icalevent.location;
+	returnString += 'URL:' + icalevent.url;
+	returnString += icalevent.footer;
+
+	return returnString;
+};
+
+
+const generateHeaderInfo = (ical: iCalFile) => {
+	ical.header = 'BEGIN:VCALENDAR\n' +
+		'VERSION:2.0\n' +
+		'PRODID:-//hacksw/handcal//NONSGML v1.0//EN\n' +
+		'CALSCALE:GREGORIAN\n' +
+		'BEGIN:VTIMEZONE\n' +
+		'TZID:Europe/Berlin\n' +
+		'LAST-MODIFIED:20201011T015911Z\n' +
+		'TZURL:http://tzurl.org/zoneinfo-outlook/Europe/Berlin\n' +
+		'X-LIC-LOCATION:Europe/Berlin\n' +
+		'BEGIN:DAYLIGHT\n' +
+		'TZNAME:CEST\n' +
+		'TZOFFSETFROM:+0100\n' +
+		'TZOFFSETTO:+0200\n' +
+		'DTSTART:19700329T020000\n' +
+		'RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU\n' +
+		'END:DAYLIGHT\n' +
+		'BEGIN:STANDARD\n' +
+		'TZNAME:CET\n' +
+		'TZOFFSETFROM:+0200\n' +
+		'TZOFFSETTO:+0100\n' +
+		'DTSTART:19701025T030000\n' +
+		'RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU\n' +
+		'END:STANDARD\n' +
+		'END:VTIMEZONE\n';
+};
+
+const generateFooterInfo = (ical: iCalFile) => {
+	ical.footer = 'END:VCALENDAR';
+};
+
+const addEventToFile = (ical: iCalFile, event: Event) => {
+	ical.body.push(createIcalEvent(event));
+};
+
+const createIcalEvent = (event: Event): iCalEvent => {
+	return {
+		header: 'BEGIN:VEVENT\n',
+		uid: event.uuid + '\n',
+		created: formatDate(event.created_date) + 'Z\n',
+		organizer: event.created_by + '\n',
+		start: formatDate(event.start_datetime) + '\n',
+		end: formatDate(event.end_datetime) + '\n',
+		summary: event.name + '\n',
+		description: event.description + '\n',
+		location: event.location + '\n',
+		url: event.url + '\n',
+		footer: 'END:VEVENT\n'
+	};
+};
+
+const formatDate = (date: Date): string => {
+	let returnString = '';
+
+	returnString += date.getFullYear();
+	returnString += (date.getMonth() + 1).toString().padStart(2, '0'); // +1 Because JS sucks
+	returnString += date.getDate().toString().padStart(2, '0');
+	returnString += 'T';
+	returnString += date.getHours().toString().padStart(2, '0');
+	returnString += date.getMinutes().toString().padStart(2, '0');
+	returnString += date.getSeconds().toString().padStart(2, '0');
+
+	return returnString;
+};
+
+export interface iCalFile {
+	header?: string;
+	body: iCalEvent[];
+	footer?: string;
+}
+
+export interface iCalEvent {
+	header: string;
+	uid: string;
+	created: string;
+	organizer: string;
+	start: string;
+	end: string;
+	summary: string;
+	description: string;
+	location: string;
+	url: string;
+	footer: string;
+}