// Clawmates service worker (§16 PWA). Hand-rolled on purpose: ~50 lines we
// fully control beats a build-tool plugin. Strategy:
//   /api/**            -> NEVER touched (approvals + SSE must be live)
//   /_next/static/**   -> cache-first (content-hashed, immutable)
//   navigations        -> network-first, cache fallback for offline shell
const STATIC_CACHE = "tc-static-v2";
const PAGE_CACHE = "tc-pages-v2";

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

self.addEventListener("activate", (event) => {
  event.waitUntil(
    (async () => {
      const keep = [STATIC_CACHE, PAGE_CACHE];
      for (const key of await caches.keys()) {
        if (!keep.includes(key)) await caches.delete(key);
      }
      await self.clients.claim();
    })(),
  );
});

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

  if (url.pathname.startsWith("/_next/static/")) {
    event.respondWith(
      (async () => {
        const cache = await caches.open(STATIC_CACHE);
        const hit = await cache.match(event.request);
        if (hit) return hit;
        const response = await fetch(event.request);
        if (response.ok) cache.put(event.request, response.clone());
        return response;
      })(),
    );
    return;
  }

  if (event.request.mode === "navigate") {
    event.respondWith(
      (async () => {
        const cache = await caches.open(PAGE_CACHE);
        try {
          const response = await fetch(event.request);
          if (response.ok) cache.put(event.request, response.clone());
          return response;
        } catch {
          const hit = await cache.match(event.request);
          if (hit) return hit;
          throw new Error("offline and not cached");
        }
      })(),
    );
  }
});