sw.js

const CACHE_NAME = 'year-progress-v3';
const ASSETS_TO_CACHE = [
  '/',
  '/index.html',
  '/config.js',
  '/site.webmanifest',
  '/favicon.ico',
  '/img/favicon-16x16.png',
  '/img/favicon-32x32.png',
  '/img/apple-touch-icon.png',
  '/img/android-chrome-192x192.png',
  '/img/android-chrome-512x512.png'
];

// 安装 SW 并缓存资源
self.addEventListener('install', (event) => {
  event.waitUntil(
    caches.open(CACHE_NAME).then((cache) => {
      console.log('SW: Caching assets');
      return cache.addAll(ASSETS_TO_CACHE);
    })
  );
});

// 激活 SW 并清理旧缓存
self.addEventListener('activate', (event) => {
  event.waitUntil(
    caches.keys().then((cacheNames) => {
      return Promise.all(
        cacheNames.map((cache) => {
          if (cache !== CACHE_NAME) {
            console.log('SW: Clearing old cache');
            return caches.delete(cache);
          }
        })
      );
    })
  );
});

// 拦截请求：缓存优先策略
self.addEventListener('fetch', (event) => {
  event.respondWith(
    caches.match(event.request).then((response) => {
      // 如果缓存中有，直接返回
      if (response) {
        return response;
      }
      // 否则从网络请求
      return fetch(event.request);
    })
  );
});