const CACHE_NAME = "wtr-shell-v3";
const SHELL = ["/", "/offline", "/manifest.json", "/icons/icon.svg", "/icons/maskable.svg", "/icons/icon-192.png", "/icons/icon-512.png", "/icons/maskable-512.png"];

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

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

self.addEventListener("fetch", (event) => {
  if (event.request.method !== "GET") return;
  const url = new URL(event.request.url);
  if (url.pathname.startsWith("/api/imgw/") || url.pathname === "/api/imgw-current" || url.pathname === "/api/forecast") {
    event.respondWith(
      fetch(event.request)
        .then((response) => {
          const copy = response.clone();
          caches.open(CACHE_NAME).then((cache) => cache.put(event.request, copy));
          return response;
        })
        .catch(() => caches.match(event.request)),
    );
    return;
  }
  if (event.request.mode === "navigate") {
    event.respondWith(fetch(event.request).catch(() => caches.match(event.request).then((response) => response || caches.match("/offline"))));
  }
});