Rotatory anlegen: Morning-Meeting-Moderation auslosen und nach Nextcloud schreiben

Express-App mit JSON-Speicher unter VCH_DATA_DIR, Monatskalender mit Fotos,
Personen mit Rollen und Teilzeit-Freitagen, Abwesenheiten, Feiertage je
Bundesland, faire Zufallsauslosung mit Fixieren und Neu-Auslosen.

Nextcloud: CalDAV-Discovery, Zielkalender wählbar, Termine je Werktag
schreiben und aktualisieren, Abwesenheiten aus Kalender importieren,
Personen samt Fotos aus dem Systemadressbuch übernehmen.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

server/store.js

@@ -0,0 +1,63 @@
+import fs from 'node:fs';
+import path from 'node:path';
+
+const DEFAULT_STATE = () => ({
+  persons: [],
+  absences: [],
+  holidays: [],
+  assignments: {},
+  exported: {},
+  settings: {
+    meetingTime: '09:30',
+    durationMinutes: 15,
+    bundesland: 'BY',
+    calendarDisplayName: 'Morning Meeting',
+    inviteAttendees: false,
+    historyWindowDays: 60,
+    holidaysSeeded: false,
+    targetCalendarHref: '',
+    targetCalendarName: '',
+    absenceCalendarHref: '',
+    absenceCalendarName: '',
+  },
+});
+
+/** Bildtyp anhand der ersten Bytes erkennen. */
+export function imageMime(buffer) {
+  if (!buffer || buffer.length < 12) return null;
+  if (buffer[0] === 0xff && buffer[1] === 0xd8) return 'image/jpeg';
+  if (buffer[0] === 0x89 && buffer[1] === 0x50 && buffer[2] === 0x4e && buffer[3] === 0x47) return 'image/png';
+  if (buffer.subarray(0, 4).toString('ascii') === 'RIFF' && buffer.subarray(8, 12).toString('ascii') === 'WEBP') return 'image/webp';
+  if (buffer.subarray(0, 4).toString('ascii') === 'GIF8') return 'image/gif';
+  return null;
+}
+
+/** Einfacher JSON-Speicher mit atomarem Schreiben. Fotos liegen daneben im Ordner photos/. */
+export function createStore(dataDir) {
+  const file = path.join(dataDir, 'rotatory.json');
+  const photoDir = path.join(dataDir, 'photos');
+  fs.mkdirSync(photoDir, { recursive: true });
+
+  let state = DEFAULT_STATE();
+  if (fs.existsSync(file)) {
+    const loaded = JSON.parse(fs.readFileSync(file, 'utf8'));
+    state = { ...state, ...loaded, settings: { ...state.settings, ...(loaded.settings || {}) } };
+  }
+
+  function save() {
+    const tmp = file + '.tmp';
+    fs.writeFileSync(tmp, JSON.stringify(state, null, 2));
+    fs.renameSync(tmp, file);
+  }
+
+  const photoPath = (id) => path.join(photoDir, `${id}.jpg`);
+  return {
+    get state() { return state; },
+    save,
+    photoPath,
+    hasPhoto: (id) => fs.existsSync(photoPath(id)),
+    readPhoto: (id) => (fs.existsSync(photoPath(id)) ? fs.readFileSync(photoPath(id)) : null),
+    savePhoto: (id, buffer) => fs.writeFileSync(photoPath(id), buffer),
+    deletePhoto: (id) => { try { fs.unlinkSync(photoPath(id)); } catch {} },
+  };
+}