// Offline support: app shell + photos cached on the device. Data changes are queued by the page itself.
const V = "spike-v1";
const SHELL = ["/", "manifest.webmanifest", "icon-192.png", "icon-512.png",
  "img/chassis.webp", "img/suspension.webp", "img/wheels.webp", "img/plastics.webp", "img/electrics.webp",
  "img/exhaust-radiator-tank-airfilter.webp", "img/motord.webp"];
const okToCache = (r) => r && r.ok && !r.redirected && r.type === "basic";

self.addEventListener("install", (e) => {
  e.waitUntil(caches.open(V).then((c) => Promise.all(SHELL.map((u) => fetch(u, { credentials: "same-origin" }).then((r) => okToCache(r) && c.put(u, r)).catch(() => {})))).then(() => self.skipWaiting()));
});
self.addEventListener("activate", (e) => {
  e.waitUntil(caches.keys().then((ks) => Promise.all(ks.filter((k) => k !== V).map((k) => caches.delete(k)))).then(() => self.clients.claim()));
});
self.addEventListener("fetch", (e) => {
  const req = e.request, url = new URL(req.url);
  if (req.method !== "GET" || url.origin !== location.origin) return;
  if (url.pathname.startsWith("/api/") || url.pathname === "/login" || url.pathname === "/logout") return;
  if (url.pathname.startsWith("/uploads/photo-") || url.pathname.startsWith("/img/")) {
    e.respondWith(caches.match(req).then((hit) => hit || fetch(req).then((r) => { if (okToCache(r)) { const c = r.clone(); caches.open(V).then((ch) => ch.put(req, c)); } return r; })));
    return;
  }
  // everything else (page, drawings, manifest): network first, fall back to the saved copy
  e.respondWith(new Promise((resolve) => {
    const key = req.mode === "navigate" ? "/" : req;
    const fallback = () => caches.match(key, { ignoreSearch: url.pathname.startsWith("/uploads/") ? false : true }).then((hit) => resolve(hit || Response.error()));
    const timer = setTimeout(() => caches.match(key, { ignoreSearch: !url.pathname.startsWith("/uploads/") }).then((hit) => hit && resolve(hit)), 4000);
    fetch(req).then((r) => {
      clearTimeout(timer);
      if (okToCache(r)) { const c = r.clone(); caches.open(V).then((ch) => ch.put(key, c)); }
      resolve(r);
    }).catch(() => { clearTimeout(timer); fallback(); });
  }));
});