// EXIF Scanner — Service Worker
// Cache-first for static assets, network-first for API.
const CACHE = "exif-cache-v1";
const STATIC = ["/", "/static/"];

self.addEventListener("install", (e) => {
  self.skipWaiting();
  e.waitUntil(
    caches.open(CACHE).then((c) => c.addAll(["/", "/static/index.html"]))
  );
});

self.addEventListener("activate", (e) => {
  e.waitUntil(clients.claim());
});

self.addEventListener("fetch", (e) => {
  const url = new URL(e.request.url);
  // API calls: network-first
  if (url.pathname.startsWith("/api/")) {
    e.respondWith(
      fetch(e.request).catch(() => {
        return new Response(
          JSON.stringify({ offline: true, error: "No network connection" }),
          { status: 503, headers: { "Content-Type": "application/json" } }
        );
      })
    );
    return;
  }
  // Static assets: cache-first
  e.respondWith(
    caches.match(e.request).then((r) => r || fetch(e.request))
  );
});

// Background Sync
self.addEventListener("sync", (e) => {
  if (e.tag === "sync-photos") {
    e.waitUntil(syncPhotos());
  }
});

async function syncPhotos() {
  const clients = await self.clients.matchAll();
  for (const client of clients) {
    client.postMessage({ type: "SYNC_TRIGGERED" });
  }
}