// Minimal service worker for the AtomCMS-Next PWA. Cache-first for immutable
// static assets, network-first for navigations (with a cached fallback so the
// shell still loads offline). Bump CACHE to invalidate.
const CACHE = "atom-v1";

self.addEventListener("install", () => {
	self.skipWaiting();
});

self.addEventListener("activate", (event) => {
	event.waitUntil(
		caches
			.keys()
			.then((keys) =>
				Promise.all(
					keys.filter((k) => k !== CACHE).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;

	// Cache-first for immutable static assets.
	if (
		url.pathname.startsWith("/assets/") ||
		url.pathname.startsWith("/_next/static/")
	) {
		event.respondWith(
			caches.open(CACHE).then((cache) =>
				cache.match(req).then(
					(hit) =>
						hit ||
						fetch(req).then((res) => {
							if (res.ok) cache.put(req, res.clone());
							return res;
						}),
				),
			),
		);
		return;
	}

	// Network-first for page navigations; fall back to cache, then the shell.
	if (req.mode === "navigate") {
		event.respondWith(
			fetch(req)
				.then((res) => {
					const copy = res.clone();
					caches
						.open(CACHE)
						.then((c) => c.put(req, copy))
						.catch(() => {});
					return res;
				})
				.catch(() => caches.match(req).then((hit) => hit || caches.match("/"))),
		);
	}
});