hub/public/sw.js

// App-shell cache only; Seafile/API traffic always goes to the network.
const CACHE = 'hub-v64';
const SHARE = 'hub-share'; // files shared into the app from other apps, held until the person picks a folder
const SHELL = ['/icon.svg', '/manifest.webmanifest', '/icons/icon-192.png', '/icons/apple-touch-icon.png'];

// Install: keep the icons, and (when signed in) the page itself with the scripts and styles it names, so the app opens offline.
async function precache() {
  const c = await caches.open(CACHE);
  await c.addAll(SHELL);
  try {
    const r = await fetch('/', { credentials: 'same-origin', redirect: 'manual' });
    if (r.ok) {
      const html = await r.clone().text();
      await c.put('/', r);
      const urls = [...html.matchAll(/(?:src|href)="(\/[^"]+\.(?:js|css)(?:\?[^"]*)?)"/g)].map(m => m[1]);
      await Promise.all(urls.map(u => c.add(u).catch(() => {})));
    }
  } catch { /* signed out or offline: it is cached the first time it is used */ }
}
self.addEventListener('install', e => { e.waitUntil(precache()); self.skipWaiting(); });
self.addEventListener('activate', e => {
  e.waitUntil(caches.keys().then(ks => Promise.all(ks.filter(k => k !== CACHE).map(k => caches.delete(k)))));
  self.clients.claim();
});
// Podcast episodes saved on this device (see offline.js): answer from them, including the byte ranges an audio player asks for; otherwise use the network as normal.
async function offlineAudio(req) {
  const hit = await (await caches.open('hub-offline')).match(req.url);
  if (!hit) return fetch(req);
  const blob = await hit.blob(), size = blob.size, type = hit.headers.get('content-type') || 'audio/mpeg', m = /^bytes=(\d*)-(\d*)$/.exec(req.headers.get('range') || '');
  if (!m) return new Response(blob, { status: 200, headers: { 'content-type': type, 'content-length': size, 'accept-ranges': 'bytes' } });
  let a = m[1] === '' ? Math.max(0, size - +m[2]) : +m[1], b = m[1] === '' || m[2] === '' ? size - 1 : Math.min(+m[2], size - 1);
  if (a > b || a >= size) return new Response(null, { status: 416, headers: { 'content-range': 'bytes */' + size } });
  return new Response(blob.slice(a, b + 1), { status: 206, headers: { 'content-type': type, 'content-length': b - a + 1, 'content-range': `bytes ${a}-${b}/${size}`, 'accept-ranges': 'bytes' } });
}
// Share target: other apps send files here (POST); keep them and open the app, which asks where to put them.
async function takeShare(request) {
  try {
    const form = await request.formData(), c = await caches.open(SHARE);
    for (const k of await c.keys()) await c.delete(k);
    let i = 0;
    for (const f of form.getAll('files')) if (f && f.name) await c.put('/share-files/' + (i++), new Response(f, { headers: { 'x-name': encodeURIComponent(f.name), 'content-type': f.type || 'application/octet-stream' } }));
  } catch { /* nothing usable was shared */ }
  return Response.redirect(self.location.origin + '/#/files', 303);
}
self.addEventListener('fetch', e => {
  const u = new URL(e.request.url);
  if (e.request.method === 'POST' && u.origin === location.origin && u.pathname === '/share-target') return e.respondWith(takeShare(e.request));
  if (e.request.method === 'GET' && u.origin === location.origin && /^\/api\/podcast\/podcasts\/[^/]+\/file$/.test(u.pathname)) return e.respondWith(offlineAudio(e.request));
  if (e.request.method === 'GET' && u.origin === location.origin && /^\/plex\/library\/parts\//.test(u.pathname)) return e.respondWith(offlineAudio(e.request)); // (albums saved on this device)
  if (e.request.method !== 'GET' || u.origin !== location.origin || u.pathname.startsWith('/sf/') || u.pathname.startsWith('/plex/') || u.pathname.startsWith('/api/')) return;
  e.respondWith(fetch(e.request).then(r => {
    if (r.ok) { const copy = r.clone(); caches.open(CACHE).then(c => c.put(e.request, copy)); }
    return r;
  }).catch(() => caches.match(e.request)));
});

// Push reminders (see push.js on the server)
self.addEventListener('push', e => {
  let d = {}; try { d = e.data.json(); } catch {}
  e.waitUntil(self.registration.showNotification(d.title || 'NE Hub', { body: d.body || '', icon: '/icons/icon-192.png', badge: '/icons/icon-192.png', tag: d.tag, data: { url: d.url || '#/home' } }));
});
self.addEventListener('notificationclick', e => {
  e.notification.close();
  const url = '/' + ((e.notification.data && e.notification.data.url) || '');
  e.waitUntil(self.clients.matchAll({ type: 'window', includeUncontrolled: true }).then(cs => {
    const c = cs.find(x => new URL(x.url).origin === self.location.origin);
    if (c) { c.focus(); return c.navigate(url); }
    return self.clients.openWindow(url);
  }));
});