// Bump this on every release that changes the app shell or the vendored
// engine build — it's the only thing that invalidates old caches, since
// none of the cached URLs below are content-hashed by us.
const CACHE_VERSION = "v2";
const SHELL_CACHE = `shell-${CACHE_VERSION}`;
const ENGINE_CACHE = `engine-${CACHE_VERSION}`;

const SHELL_ASSETS = [
  "/",
  "/play/",
  "/manifest.webmanifest",
  "/icons/icon-192.png",
  "/icons/icon-512.png",
];

self.addEventListener("install", (event) => {
  event.waitUntil(
    caches
      .open(SHELL_CACHE)
      .then((cache) => cache.addAll(SHELL_ASSETS))
      .then(() => self.skipWaiting()),
  );
});

self.addEventListener("activate", (event) => {
  event.waitUntil(
    caches
      .keys()
      .then((keys) =>
        Promise.all(
          keys
            .filter((key) => key !== SHELL_CACHE && key !== ENGINE_CACHE)
            .map((key) => caches.delete(key)),
        ),
      )
      .then(() => self.clients.claim()),
  );
});

self.addEventListener("fetch", (event) => {
  const url = new URL(event.request.url);
  if (event.request.method !== "GET" || url.origin !== self.location.origin) return;

  // The engine's .wasm/.data/.js are large and effectively immutable per
  // release (they aren't content-hashed), so once fetched they're served
  // straight from cache — cache-busting happens by bumping CACHE_VERSION.
  if (url.pathname.startsWith("/vendor/vpinball-wasm/")) {
    event.respondWith(
      caches.open(ENGINE_CACHE).then((cache) =>
        cache.match(event.request).then(
          (hit) =>
            hit ??
            fetch(event.request).then((response) => {
              cache.put(event.request, response.clone());
              return response;
            }),
        ),
      ),
    );
    return;
  }

  event.respondWith(
    caches.match(event.request).then(
      (hit) =>
        hit ??
        fetch(event.request).then((response) => {
          if (response.ok) {
            const clone = response.clone();
            caches.open(SHELL_CACHE).then((cache) => cache.put(event.request, clone));
          }
          return response;
        }),
    ),
  );
});