const CACHE_NAME = "checkflow-v2";
const STATIC_ASSETS = ["/manifest.json", "/icons/icon.svg"];

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

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

self.addEventListener("fetch", (event) => {
  const { request } = event;
  const url = new URL(request.url);

  // Only handle http/https GET requests to the same origin
  if (request.method !== "GET" || !url.protocol.startsWith("http") || url.origin !== self.location.origin) {
    return;
  }

  // Network-first for API & navigation routes to avoid stale/failed page loads
  if (url.pathname.startsWith("/api") || request.mode === "navigate") {
    event.respondWith(
      fetch(request).catch(() => {
        if (url.pathname.startsWith("/api")) {
          return new Response(JSON.stringify({ error: "Offline or service unavailable" }), {
            headers: { "Content-Type": "application/json" },
          });
        }
        return caches.match(request).then((cached) => cached || Response.error());
      })
    );
    return;
  }

  // Cache-first for static assets with safe network fallback
  event.respondWith(
    caches.match(request).then((cached) => {
      if (cached) return cached;
      return fetch(request).then((response) => {
        if (response && response.status === 200 && response.type === "basic") {
          const clone = response.clone();
          caches.open(CACHE_NAME).then((cache) => cache.put(request, clone)).catch(() => {});
        }
        return response;
      }).catch(() => Response.error());
    })
  );
});