1/** * 随机图 API - 腾讯云 EdgeOne 大满贯版 * 特性：直连七牛云目录、极速内存缓存、边缘代理(零跨域、非302) */
 2// ==========================================// 1. 核心配置区// ==========================================const CONFIG = {  AK: "AK密钥",  SK: "SK密钥",  BUCKET: "七牛云存储空间名称",  DOMAIN: "最好填写套一层CDN的，EO的域名", // 你的图床 CDN 域名
 3  PC_PREFIX: "blog/bg/",  MOBILE_PREFIX: "blog/bg-m/"};
 4// ==========================================// 2. 全局内存缓存// ==========================================let pcImages = [];let mobileImages = [];let lastCheckTime = 0;const CACHE_TTL = 3 * 60 * 1000; // 3 分钟缓存
 5addEventListener('fetch', event => {  event.respondWith(handleRequest(event.request))});
 6// ==========================================// 3. 密码学：生成七牛云鉴权 Token// ==========================================async function generateQiniuToken(path) {  const signingStr = `${path}\n`;  const encoder = new TextEncoder();  const key = await crypto.subtle.importKey(    'raw', encoder.encode(CONFIG.SK),    { name: 'HMAC', hash: 'SHA-1' }, false, ['sign']  );  const signature = await crypto.subtle.sign('HMAC', key, encoder.encode(signingStr));  const base64 = btoa(String.fromCharCode(...new Uint8Array(signature)));  const encodedSign = base64.replace(/\+/g, '-').replace(/\//g, '_');  return `QBox ${CONFIG.AK}:${encodedSign}`;}
 7// ==========================================// 4. 抓取七牛云真实文件列表// ==========================================async function fetchImagesFromQiniu(prefix) {  try {    const apiPath = `/list?bucket=${CONFIG.BUCKET}&prefix=${prefix}&limit=1000`;    const apiHost = 'rsf.qiniuapi.com';    const token = await generateQiniuToken(apiPath);
 8    const response = await fetch(`https://${apiHost}${apiPath}`, {      headers: {        'Authorization': token,        'Content-Type': 'application/x-www-form-urlencoded'      }    });
 9    if (!response.ok) return [];
10    const data = await response.json();    if (!data.items) return [];
11    return data.items      .filter(item => item.mimeType && item.mimeType.startsWith('image/'))      .map(item => `${CONFIG.DOMAIN}/${item.key}`);
12  } catch (error) {    console.error(`拉取目录 ${prefix} 失败:`, error);    return [];  }}
13// ==========================================// 5. 代理获取图片并注入跨域头 (核心新增逻辑)// ==========================================async function proxyImage(imageUrl) {  try {    // 边缘节点出面去你的 CDN 拿图    const response = await fetch(imageUrl, {      headers: {        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) EdgeOne-Proxy"      }    });
14    if (response.ok) {      // 拿到图片后，重写响应头，强行允许跨域      const newHeaders = new Headers(response.headers);      newHeaders.set("Access-Control-Allow-Origin", "*");      newHeaders.set("Cache-Control", "no-cache"); // 告诉浏览器不要缓存当前API链接，以免下次拿不到新图
15      // 返回 200 状态码和真实图片数据流      return new Response(response.body, {        status: 200,        headers: newHeaders      });    }
16    // 如果图片代理失败，降级回 302 重定向    return Response.redirect(imageUrl, 302);  } catch (e) {    // 网络异常，降级回 302 重定向    return Response.redirect(imageUrl, 302);  }}
17// ==========================================// 6. 主路由逻辑// ==========================================async function handleRequest(request) {  const url = new URL(request.url);  const route = url.pathname;
18  // 初始化或更新缓存  if (Date.now() - lastCheckTime > CACHE_TTL || pcImages.length === 0 || mobileImages.length === 0) {    try {      const [newPc, newMobile] = await Promise.all([        fetchImagesFromQiniu(CONFIG.PC_PREFIX),        fetchImagesFromQiniu(CONFIG.MOBILE_PREFIX)      ]);
19      if (newPc.length > 0) pcImages = newPc;      if (newMobile.length > 0) mobileImages = newMobile;      lastCheckTime = Date.now();    } catch (e) {      console.error("更新列表失败，暂时使用旧缓存");    }  }
20  // --- 处理电脑壁纸 ---  if (route === '/api') {    if (pcImages.length === 0) return new Response("初始化中...", {status: 503});    const randomImg = pcImages[Math.floor(Math.random() * pcImages.length)];    // 调用代理函数，直接返回图片流    return await proxyImage(randomImg);  }
21  // --- 处理手机壁纸 ---  if (route === '/m-api') {    if (mobileImages.length === 0) return new Response("初始化中...", {status: 503});    const randomImg = mobileImages[Math.floor(Math.random() * mobileImages.length)];    // 调用代理函数，直接返回图片流    return await proxyImage(randomImg);  }
22  return new Response("API 正常运行。电脑壁纸请访问 /api，手机壁纸请访问 /m-api", {    status: 200,    headers: { "Content-Type": "text/html;charset=UTF-8" }  });}