/* ihasmail service worker: app-shell caching for installability & fast loads.
   API requests are never cached. */
const VERSION = "ihasmail-v2";
const SHELL = ["/", "/manifest.webmanifest", "/img/logo.png", "/img/icon-192.png", "/favicon.ico"];

self.addEventListener("install", (event) => {
  event.waitUntil(caches.open(VERSION).then((c) => c.addAll(SHELL)).then(() => self.skipWaiting()));
});

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

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

  // Hashed build assets: cache-first.
  if (url.pathname.startsWith("/assets/")) {
    event.respondWith(
      caches.match(req).then((hit) => hit || fetch(req).then((res) => {
        const copy = res.clone();
        caches.open(VERSION).then((c) => c.put(req, copy));
        return res;
      }))
    );
    return;
  }

  // Navigations & everything else: network-first, fall back to cached shell.
  if (req.mode === "navigate") {
    event.respondWith(fetch(req).catch(() => caches.match("/")));
    return;
  }
  event.respondWith(fetch(req).catch(() => caches.match(req)));
});