const CACHE_NAME = "annotator-yolo-v5";
const PRECACHE = [
  "./",
  "./index.html",
  "./manifest.json",
  "./sw.js",
  "./icon.svg",
  "./icon-192.png",
  "./icon-512.png",
  "./README.md"
];

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

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

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

  if (request.mode === "navigate") {
    event.respondWith((async () => {
      try {
        const fresh = await fetch(request);
        const cache = await caches.open(CACHE_NAME);
        cache.put("./index.html", fresh.clone());
        return fresh;
      } catch {
        return (await caches.match(request)) || (await caches.match("./index.html"));
      }
    })());
    return;
  }

  if (url.origin === location.origin) {
    event.respondWith((async () => {
      const cached = await caches.match(request);
      if (cached) return cached;
      const fresh = await fetch(request);
      const cache = await caches.open(CACHE_NAME);
      cache.put(request, fresh.clone());
      return fresh;
    })());
  }
});