sw.js

const CACHE_NAME = "web3-retro-v2";
const STATIC_ASSETS = [
  "./",
  "./index.html",
  "./manifest.webmanifest",
  "./jquery-4.0.0.min.js",
  "./wasm/retro_wasm.js",
  "./wasm/retro_tools.wasm",
  "./brython.min.js",
  "./brython_stdlib.js",
  "./README.md"
];

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

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

async function networkFirst(request) {
  try {
    const response = await fetch(request);
    if (response && response.ok) {
      const cache = await caches.open(CACHE_NAME);
      cache.put(request, response.clone());
    }
    return response;
  } catch (error) {
    const cached = await caches.match(request);
    return cached || caches.match("./index.html");
  }
}

async function staleWhileRevalidate(request) {
  const cached = await caches.match(request);
  const fetchPromise = fetch(request)
    .then(async (response) => {
      if (response && response.ok) {
        const cache = await caches.open(CACHE_NAME);
        cache.put(request, response.clone());
      }
      return response;
    })
    .catch(() => cached);

  return cached || fetchPromise;
}

self.addEventListener("fetch", (event) => {
  if (event.request.method !== "GET") {
    return;
  }

  const requestUrl = new URL(event.request.url);
  if (requestUrl.origin !== self.location.origin) {
    return;
  }

  const isDocument = event.request.mode === "navigate" || event.request.destination === "document";

  if (isDocument) {
    event.respondWith(networkFirst(event.request));
    return;
  }

  event.respondWith(staleWhileRevalidate(event.request));
});