index.js

"use strict";

var fs = require("fs");
var path = require("path");
var ical = require("ical");
var groups = require("./data/groups");
var R = require("ramda");

var icsDir = "ics";
var eventJson = "data/events.json";

var isHiddenFile = R.pipe(R.lensIndex(0), R.eq("."));

function expandRecurrences(event) {
	var future = new Date(Date.now());
	future.setDate(future.getDate() + 365); // adding years gives you a date in the year "116", so just add days. leap years aren't important, we just want a rough future date

	if (event.rrule === undefined) {
		return [event];
	}
	return event.rrule.all(function(date) {
		return date < future;
	}).map(function(date) {
		var copy = R.clone(event);
		var duration = copy.end - copy.start;
		copy.start = date;
		copy.end = new Date(date);
		copy.end.setMilliseconds(copy.end.getMilliseconds() + duration);
		return copy;
	});
}

function enhanceEvent(group, event) {
	if (event.location) {
		event.mapQuery = event.location.replace("(", " ").replace(")", " ");
	}

	var start = event.start;
	event.startDate = start.toString();
	event.startDateJson = start.toJSON();

	var end = event.end;
	event.endDate = end.toString();
	event.endDateJson = end.toJSON();
	if (end < Date.now()) {
		event.expired = true;
	}

	event.group = group;
	event.groupName = groups[group].name;
	event.groupUrl = groups[group].web;

	delete event.rrule;

	return event;
}

var icsPath = R.curryN(2, path.join)(icsDir);

function loadCal(filename) {
	var group = filename.substr(0, filename.indexOf("."));
	return R.pipe(
		R.values,
		R.filter(R.propEq("type", "VEVENT")),
		R.chain(expandRecurrences),
		R.map(enhanceEvent.bind(this, group))
	)(ical.parseFile(icsPath(filename)));
}

function isOld(date) {
	var now = new Date(Date.now());
	now.setDate(now.getDate() - 1);
	return date < now;
}

function writeJson(filename, data) {
	fs.writeFileSync(filename, JSON.stringify(data, null, 4), { encoding: "UTF8" });
}

var events = R.pipe(
	R.reject(isHiddenFile),
	R.chain(loadCal),
	R.sortBy(R.prop("start")),
	R.reject(R.compose(isOld, R.prop("end")))
)(fs.readdirSync(icsDir));

writeJson(eventJson, events);