diora-web/static/js/sw.js

/**
 * diora service worker — caches the app shell for offline use.
 */

const CACHE = 'diora-v12';
const PODCAST_CACHE = 'diora-podcast-v1';
const SHELL = [
  '/static/css/app.css',
  '/static/js/app.js',
  '/static/manifest.json',
];

// Install: pre-cache the app shell
self.addEventListener('install', function (event) {
  event.waitUntil(
    caches.open(CACHE).then(function (cache) {
      return cache.addAll(SHELL);
    })
  );
  // Activate immediately without waiting for old tabs to close
  self.skipWaiting();
});

// Activate: remove stale caches from previous versions
self.addEventListener('activate', function (event) {
  event.waitUntil(
    caches.keys().then(function (keys) {
      return Promise.all(
        keys.filter(function (key) { return key !== CACHE && key !== PODCAST_CACHE; })
            .map(function (key) { return caches.delete(key); })
      );
    }).then(function () {
      return self.clients.claim();
    }).then(function () {
      // Tell all open tabs to reload so they get the latest cached assets
      return self.clients.matchAll({type: 'window'}).then(function (clients) {
        clients.forEach(function (client) {
          client.postMessage({type: 'SW_ACTIVATED'});
        });
      });
    })
  );
});

// Fetch: serve from cache, fall back to network
self.addEventListener('fetch', function (event) {
  // Only handle GET requests; let POST/SSE etc. pass through
  if (event.request.method !== 'GET') return;

  const url = new URL(event.request.url);

  // Bypass for API/mutation endpoints
  if (url.pathname.startsWith('/radio/sse/') ||
      url.pathname.startsWith('/radio/record/') ||
      url.pathname.startsWith('/radio/affiliate/') ||
      url.pathname.startsWith('/admin/') ||
      url.pathname.startsWith('/podcasts/progress/') ||
      url.pathname.startsWith('/podcasts/queue/') ||
      url.pathname === '/podcasts/feeds/add' ||
      url.pathname.startsWith('/podcasts/feeds/add') ||
      url.pathname.includes('/remove') ||
      url.pathname.startsWith('/podcasts/feeds/refresh')) {
    return;
  }

  // Podcast audio: serve from podcast cache first, then network
  if (event.request.destination === 'audio') {
    event.respondWith(
      caches.open(PODCAST_CACHE).then(function (cache) {
        return cache.match(event.request).then(function (cached) {
          if (cached) return cached;
          return fetch(event.request).then(function (response) {
            return response;
          });
        });
      })
    );
    return;
  }

  // Cache-first for pre-defined shell assets
  const isShell = SHELL.some(function (s) { return url.pathname === s; });
  if (isShell) {
    event.respondWith(
      caches.match(event.request).then(function (cached) {
        return cached || fetch(event.request);
      })
    );
    return;
  }

  // Navigation requests (the HTML page itself): network-first, fall back to
  // last cached version so the app opens offline after being visited once.
  if (event.request.mode === 'navigate') {
    event.respondWith(
      fetch(event.request).then(function (response) {
        if (response.ok) {
          var clone = response.clone();
          caches.open(CACHE).then(function (cache) { cache.put(event.request, clone); });
        }
        return response;
      }).catch(function () {
        return caches.match(event.request);
      })
    );
  }
});