refactor(calendar): extract ICS parser into shared ics-parser.js module
This commit is contained in:
Ulas Kalayci
@@ -0,0 +1,143 @@
|
||||
import { nextOccurrence } from './recurrence.js';
|
||||
|
||||
function unfoldLines(ics) {
|
||||
return ics.replace(/\r?\n[ \t]/g, '');
|
||||
}
|
||||
|
||||
function parseICS(ics) {
|
||||
const unfolded = unfoldLines(ics);
|
||||
const events = [];
|
||||
const vEventRe = /BEGIN:VEVENT([\s\S]*?)END:VEVENT/g;
|
||||
let match;
|
||||
while ((match = vEventRe.exec(unfolded)) !== null) {
|
||||
const block = match[1];
|
||||
const get = (prop) => {
|
||||
const re = new RegExp(`^${prop}(?:;[^:]*)?:(.*)$`, 'im');
|
||||
const m = re.exec(block);
|
||||
return m ? m[1].trim() : null;
|
||||
};
|
||||
const uid = get('UID');
|
||||
const summary = get('SUMMARY') || '(kein Titel)';
|
||||
const description = get('DESCRIPTION') || null;
|
||||
const location = get('LOCATION') || null;
|
||||
const rrule = get('RRULE') ? `RRULE:${get('RRULE')}` : null;
|
||||
const parseDTLine = (prop) => {
|
||||
const re = new RegExp(`^${prop}((?:;[^:]*)*):(.*)$`, 'im');
|
||||
const m = block.match(re);
|
||||
if (!m) return { value: null, tzid: null };
|
||||
const params = m[1];
|
||||
const value = m[2].trim();
|
||||
const tzMatch = params.match(/;TZID=([^;:]+)/i);
|
||||
return { value, tzid: tzMatch ? tzMatch[1].trim() : null };
|
||||
};
|
||||
const dtStartLine = parseDTLine('DTSTART');
|
||||
const dtEndLine = parseDTLine('DTEND');
|
||||
const dtStartRaw = dtStartLine.value;
|
||||
const dtEndRaw = dtEndLine.value;
|
||||
const allDay = /^DTSTART;VALUE=DATE:/im.test(block);
|
||||
const dtstart = dtStartRaw ? formatICSDate(dtStartRaw, allDay, dtStartLine.tzid) : null;
|
||||
let dtend = dtEndRaw ? formatICSDate(dtEndRaw, allDay, dtEndLine.tzid) : null;
|
||||
if (allDay && dtend) {
|
||||
const d = new Date(dtend + 'T00:00:00');
|
||||
d.setDate(d.getDate() - 1);
|
||||
dtend = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
|
||||
}
|
||||
if (!dtend && dtstart) {
|
||||
const durMatch = /^DURATION(?:;[^:]*)?:(.*)$/im.exec(block);
|
||||
if (durMatch) dtend = applyDuration(dtstart, durMatch[1].trim(), allDay);
|
||||
}
|
||||
if (!uid || !dtstart) continue;
|
||||
events.push({ uid, summary, description, location, dtstart, dtend, rrule, allDay });
|
||||
}
|
||||
return events;
|
||||
}
|
||||
|
||||
function tzLocalToUTC(localStr, tzid) {
|
||||
try {
|
||||
const fakeUTC = new Date(localStr + 'Z');
|
||||
const parts = new Intl.DateTimeFormat('en-US', {
|
||||
timeZone: tzid, year: 'numeric', month: 'numeric', day: 'numeric',
|
||||
hour: 'numeric', minute: 'numeric', second: 'numeric', hour12: false,
|
||||
}).formatToParts(fakeUTC);
|
||||
const get = (type) => {
|
||||
const part = parts.find(p => p.type === type);
|
||||
const v = part ? part.value : '0';
|
||||
return v === '24' ? 0 : parseInt(v, 10);
|
||||
};
|
||||
const tzDisplayedAsUTC = Date.UTC(
|
||||
get('year'), get('month') - 1, get('day'), get('hour'), get('minute'), get('second')
|
||||
);
|
||||
const offsetMs = fakeUTC.getTime() - tzDisplayedAsUTC;
|
||||
return new Date(fakeUTC.getTime() + offsetMs).toISOString().replace('.000Z', 'Z');
|
||||
} catch { return localStr; }
|
||||
}
|
||||
|
||||
function formatICSDate(val, allDay, tzid) {
|
||||
if (allDay || /^\d{8}$/.test(val)) {
|
||||
return `${val.slice(0, 4)}-${val.slice(4, 6)}-${val.slice(6, 8)}`;
|
||||
}
|
||||
const y = val.slice(0, 4), mo = val.slice(4, 6), d = val.slice(6, 8);
|
||||
const h = val.slice(9, 11), mi = val.slice(11, 13), s = val.slice(13, 15) || '00';
|
||||
if (val.endsWith('Z')) return `${y}-${mo}-${d}T${h}:${mi}:${s}Z`;
|
||||
if (tzid) return tzLocalToUTC(`${y}-${mo}-${d}T${h}:${mi}:${s}`, tzid);
|
||||
return `${y}-${mo}-${d}T${h}:${mi}:${s}`;
|
||||
}
|
||||
|
||||
function applyDuration(dtstart, dur, allDay) {
|
||||
const m = /^P(?:(\d+)W)?(?:(\d+)D)?(?:T(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)S)?)?$/.exec(dur);
|
||||
if (!m) return null;
|
||||
const weeks = parseInt(m[1] || '0', 10), days = parseInt(m[2] || '0', 10);
|
||||
const hours = parseInt(m[3] || '0', 10), mins = parseInt(m[4] || '0', 10);
|
||||
const secs = parseInt(m[5] || '0', 10);
|
||||
const base = new Date(dtstart.includes('T') ? dtstart : dtstart + 'T00:00:00');
|
||||
base.setDate(base.getDate() + weeks * 7 + days);
|
||||
base.setHours(base.getHours() + hours, base.getMinutes() + mins, base.getSeconds() + secs);
|
||||
if (allDay) {
|
||||
base.setDate(base.getDate() - 1);
|
||||
return `${base.getFullYear()}-${String(base.getMonth() + 1).padStart(2, '0')}-${String(base.getDate()).padStart(2, '0')}`;
|
||||
}
|
||||
return base.toISOString().replace('.000Z', 'Z');
|
||||
}
|
||||
|
||||
function expandRRULE(vevent, windowStart, windowEnd) {
|
||||
if (!vevent.rrule) return [];
|
||||
const results = [];
|
||||
const startDate = vevent.dtstart.slice(0, 10);
|
||||
const timeSuffix = vevent.allDay ? '' : (vevent.dtstart.slice(10) || '');
|
||||
let durationMs = null;
|
||||
if (vevent.dtend) {
|
||||
const s = new Date(vevent.allDay ? vevent.dtstart + 'T00:00:00Z' : vevent.dtstart);
|
||||
const e = new Date(vevent.allDay ? vevent.dtend + 'T00:00:00Z' : vevent.dtend);
|
||||
if (!isNaN(s) && !isNaN(e)) durationMs = e - s;
|
||||
}
|
||||
let current = startDate, iterations = 0;
|
||||
const MAX_ITER = 1500;
|
||||
while (current <= windowEnd && iterations < MAX_ITER) {
|
||||
iterations++;
|
||||
if (current >= windowStart) {
|
||||
const occStart = current + timeSuffix;
|
||||
let occEnd = null;
|
||||
if (durationMs !== null) {
|
||||
if (vevent.allDay) {
|
||||
const d = new Date(current + 'T00:00:00Z');
|
||||
d.setUTCMilliseconds(d.getUTCMilliseconds() + durationMs);
|
||||
occEnd = d.toISOString().slice(0, 10);
|
||||
} else {
|
||||
occEnd = new Date(new Date(occStart).getTime() + durationMs)
|
||||
.toISOString().replace('.000Z', 'Z');
|
||||
}
|
||||
}
|
||||
results.push({
|
||||
uid: `${vevent.uid}__${current}`, summary: vevent.summary,
|
||||
description: vevent.description, location: vevent.location,
|
||||
dtstart: occStart, dtend: occEnd, rrule: null, allDay: vevent.allDay,
|
||||
});
|
||||
}
|
||||
const next = nextOccurrence(current, vevent.rrule);
|
||||
if (!next || next <= current) break;
|
||||
current = next;
|
||||
}
|
||||
return results;
|
||||
}
|
||||
|
||||
export { unfoldLines, parseICS, formatICSDate, tzLocalToUTC, applyDuration, expandRRULE };
|
||||
Reference in New Issue
Block a user