/**
 * Trading Studio PWA Service Worker
 * 缓存应用壳，支持离线打开已访问页面；API 请求始终走网络。
 */
const CACHE_NAME = "trading-studio-v1";
const SHELL = ["/", "/manifest.webmanifest"];

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

  // API / 文件上传 / Gradio 动态接口不走缓存
  if (
    request.method !== "GET" ||
    url.pathname.startsWith("/gradio_api") ||
    url.pathname.startsWith("/file=") ||
    url.pathname.startsWith("/upload") ||
    url.pathname.includes("call")
  ) {
    return;
  }

  event.respondWith(
    fetch(request)
      .then((response) => {
        if (response.ok && url.origin === self.location.origin) {
          const clone = response.clone();
          caches.open(CACHE_NAME).then((cache) => cache.put(request, clone));
        }
        return response;
      })
      .catch(() => caches.match(request).then((r) => r || caches.match("/")))
  );
});