/**
 * Service Worker：仅做最小化的安装支持与静态壳缓存。
 * - 静态资源（HTML/CSS/JS/图标）走"网络优先、失败回缓存"，保证新版本及时生效
 * - /api/tts 不拦截，直接透传网络
 */
const CACHE = "fj-shell-v1";
const SHELL = ["/", "/index.html", "/style.css?v=18", "/app.js?v=15", "/icon.svg", "/icon-180.png", "/icon-192.png", "/icon-512.png", "/manifest.json"];

self.addEventListener("install", (e) => {
  e.waitUntil(caches.open(CACHE).then((c) => c.addAll(SHELL)).then(() => self.skipWaiting()));
});

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

self.addEventListener("fetch", (e) => {
  const url = new URL(e.request.url);
  if (e.request.method !== "GET" || url.pathname.startsWith("/api/")) return;
  e.respondWith(
    fetch(e.request)
      .then((resp) => {
        if (resp.ok) {
          const clone = resp.clone();
          caches.open(CACHE).then((c) => c.put(e.request, clone));
        }
        return resp;
      })
      .catch(() => caches.match(e.request))
  );
});