brk/websites/bitview/service-worker.js

const CACHE = "v1";
const ROOT = "/";
const API = "/api";

const BYPASS = new Set([
  "/changelog", "/crate", "/discord", "/github", "/health",
  "/install", "/mcp", "/nostr", "/service", "/status", "/version"
]);

// Match hashed filenames: name.abc12345.js/mjs/css
const HASHED_RE = /\.[0-9a-f]{8}\.(js|mjs|css)$/;

/** @type {ServiceWorkerGlobalScope} */
const sw = /** @type {any} */ (self);

const offline = () => new Response("Offline", {
  status: 503,
  headers: { "Content-Type": "text/plain" }
});

sw.addEventListener("install", (e) => {
  e.waitUntil(
    caches.open(CACHE)
      .then((c) => c.addAll([ROOT]))
      .then(() => sw.skipWaiting())
  );
});

sw.addEventListener("activate", (e) => {
  e.waitUntil(
    Promise.all([
      sw.clients.claim(),
      caches.keys().then((keys) =>
        Promise.all(keys.filter((k) => k !== CACHE).map((k) => caches.delete(k)))
      ),
    ])
  );
});

sw.addEventListener("fetch", (event) => {
  const req = event.request;
  const url = new URL(req.url);

  // Only handle same-origin GET requests
  if (req.method !== "GET" || url.origin !== location.origin) return;

  const path = url.pathname;

  // Bypass API and redirects
  if (path.startsWith(API) || BYPASS.has(path)) return;

  // Navigation: network-first for shell
  if (req.mode === "navigate") {
    event.respondWith(
      fetch(ROOT)
        .then((res) => {
          if (res.ok) caches.open(CACHE).then((c) => c.put(ROOT, res.clone()));
          return res;
        })
        .catch(() => caches.match(ROOT).then((c) => c || offline()))
    );
    return;
  }

  // Hashed assets: cache-first (immutable)
  if (HASHED_RE.test(path)) {
    event.respondWith(
      caches.match(req)
        .then((cached) =>
          cached ||
          fetch(req).then((res) => {
            if (res.ok) caches.open(CACHE).then((c) => c.put(req, res.clone()));
            return res;
          })
        )
        .catch(() => offline())
    );
    return;
  }

  // Other: network-first with cache fallback
  // SPA routes (no extension) fall back to ROOT, static assets get 503
  const isStatic = path.includes(".") && !path.endsWith(".html");
  event.respondWith(
    fetch(req)
      .then((res) => {
        if (res.ok) caches.open(CACHE).then((c) => c.put(req, res.clone()));
        return res;
      })
      .catch(() =>
        caches.match(req).then((cached) =>
          cached || (isStatic ? offline() : caches.match(ROOT).then((c) => c || offline()))
        )
      )
  );
});