const CACHE_VERSION = "v2";
const CACHE_NAME = `fleetledger-${CACHE_VERSION}`;
const ASSETS = [
  "/",
  "/static/style.css",
  "/static/icon-192.png",
  "/static/icon-512.png",
  "/static/manifest.webmanifest",
];

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

self.addEventListener("activate", (event) => {
  event.waitUntil(
    caches.keys().then((keys) =>
      Promise.all(
        keys
          .filter((key) => key.startsWith("fleetledger-") && key !== CACHE_NAME)
          .map((key) => caches.delete(key))
      )
    )
  );
});

async function networkFirst(request) {
  try {
    const response = await fetch(request);
    const cache = await caches.open(CACHE_NAME);
    cache.put(request, response.clone());
    return response;
  } catch (err) {
    const cached = await caches.match(request);
    if (cached) {
      return cached;
    }
    return caches.match("/");
  }
}

async function cacheFirst(request) {
  const cached = await caches.match(request);
  if (cached) {
    return cached;
  }
  const response = await fetch(request);
  const cache = await caches.open(CACHE_NAME);
  cache.put(request, response.clone());
  return response;
}

self.addEventListener("fetch", (event) => {
  if (event.request.method !== "GET") {
    return;
  }

  const url = new URL(event.request.url);

  // Navigation requests: network first, fallback to cache
  if (event.request.mode === "navigate") {
    event.respondWith(networkFirst(event.request));
    return;
  }

  // Same-origin static assets: cache first
  if (url.origin === self.location.origin) {
    event.respondWith(cacheFirst(event.request));
  }
});