From 121a33c515b0ecc28591818f086abdda1f053c85 Mon Sep 17 00:00:00 2001
From: jijjhddd <148630633+jijjhddd@users.noreply.github.com>
Date: Sun, 26 Jul 2026 15:14:00 +0800
Subject: [PATCH] Add service worker with caching and fetch handling

Implement a service worker with caching strategies for static assets and API requests.
---
 sw.js | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 sw.js

diff --git a/sw.js b/sw.js
new file mode 100644
index 0000000..2b3da4f
--- /dev/null
+++ b/sw.js
@@ -0,0 +1,114 @@
+// sw.js - 改进版 Service Worker，实现合理的缓存策略
+
+const CACHE_VERSION = 'v3';
+const CACHE_NAME = `blackhole-sim-${CACHE_VERSION}`;
+
+// 需要预缓存的静态资源列表
+const STATIC_ASSETS = [
+    '/',
+    '/index.html',
+    '/code/CSS/style.css',
+    '/code/CSS/panel.css',
+    '/dist/bundle.js',
+    '/code/HTML/panel.html',
+    '/icons/icon-192.svg',
+    '/icons/icon-512.svg',
+    '/manifest.json'
+];
+
+// 安装阶段：预缓存静态资源
+self.addEventListener('install', event => {
+    event.waitUntil(
+        caches.open(CACHE_NAME)
+            .then(cache => {
+                console.log('[SW] 预缓存静态资源');
+                return cache.addAll(STATIC_ASSETS)
+                    .catch(err => {
+                        console.error('[SW] 预缓存失败:', err);
+                        // 即使部分失败也继续，但记录错误
+                    });
+            })
+            .then(() => self.skipWaiting())
+    );
+});
+
+// 激活阶段：清理旧缓存
+self.addEventListener('activate', event => {
+    event.waitUntil(
+        caches.keys()
+            .then(keys => {
+                const deletePromises = keys
+                    .filter(key => key !== CACHE_NAME)
+                    .map(key => caches.delete(key));
+                return Promise.all(deletePromises);
+            })
+            .then(() => {
+                console.log('[SW] 新缓存已激活，旧缓存已清理');
+                return self.clients.claim();
+            })
+    );
+});
+
+// 请求拦截：实现缓存优先策略（静态资源）和网络优先（API）
+self.addEventListener('fetch', event => {
+    const url = new URL(event.request.url);
+
+    // 如果是 API 请求，使用网络优先，不缓存
+    if (url.pathname.startsWith('/api/')) {
+        event.respondWith(
+            fetch(event.request)
+                .catch(() => {
+                    // API 请求失败时返回简单的错误响应
+                    return new Response(JSON.stringify({ error: '网络错误' }), {
+                        status: 503,
+                        headers: { 'Content-Type': 'application/json' }
+                    });
+                })
+        );
+        return;
+    }
+
+    // 如果是静态资源（CSS, JS, 图标等），使用缓存优先策略
+    const isStatic = /\.(css|js|svg|png|jpg|jpeg|gif|webp|woff|woff2|ttf|eot)$/.test(url.pathname);
+    // 或者是 HTML 页面
+    const isHtml = url.pathname === '/' || url.pathname === '/index.html';
+
+    if (isStatic || isHtml) {
+        event.respondWith(
+            caches.match(event.request)
+                .then(cachedResponse => {
+                    if (cachedResponse) {
+                        // 缓存命中，返回缓存
+                        return cachedResponse;
+                    }
+                    // 否则发起网络请求并缓存结果
+                    return fetch(event.request)
+                        .then(response => {
+                            // 只缓存成功的响应
+                            if (!response || response.status !== 200) {
+                                return response;
+                            }
+                            const responseToCache = response.clone();
+                            caches.open(CACHE_NAME)
+                                .then(cache => {
+                                    cache.put(event.request, responseToCache);
+                                })
+                                .catch(err => console.warn('[SW] 缓存写入失败:', err));
+                            return response;
+                        })
+                        .catch(() => {
+                            // 如果网络请求也失败，且是 HTML 请求，返回离线页面
+                            if (isHtml) {
+                                return caches.match('/index.html');
+                            }
+                            // 其他资源无法返回
+                            return new Response('资源不可用', { status: 503 });
+                        });
+                })
+        );
+        return;
+    }
+
+    // 其他请求（如音频、视频等）直接走网络，不缓存
+    event.respondWith(fetch(event.request));
+});