// 利用api.nsmao.net实现的bing接口
const API_KEY = "ajdlfklahweufbrffbhjefjfsmd,shj" // 自行申请API
const CACHE_TTL = 36000 // 10 小时

export default {
  async fetch(request, env, ctx) {
    const { pathname } = new URL(request.url)

    // 首页说明
    if (pathname === "/") {
      return new Response(
        "🚀 本服务用于代理并缓存 https://api.nsmao.net 的图片接口，保护密钥不泄露。\n" +
        "当前支持：/api/360bz 与 /api/bing 接口，图片将自动缓存10小时以减少请求压力。",
        {
          status: 200,
          headers: { "Content-Type": "text/plain; charset=utf-8" }
        }
      )
    }

    // 360bz 图片接口
    if (pathname === "/api/360bz") {
      return await cachedProxyImage(
        "360bz",
        "https://api.nsmao.net/api/360bz/query",
        { key: API_KEY },
        "url",
        ctx
      )
    }

    // bing 图片接口
    if (pathname === "/api/bing") {
      return await cachedProxyImage(
        "bing",
        "https://api.nsmao.net/api/bing/query",
        { key: API_KEY, type: "json" },
        "image_url",
        ctx
      )
    }

    return new Response("Not found", { status: 404 })
  }
}

async function cachedProxyImage(
  cacheKey,
  apiUrl,
  queryParams,
  imageField,
  ctx
) {
  const cache = caches.default
  const cacheRequest = new Request(`https://cache.nsmao/${cacheKey}`)
  const cached = await cache.match(cacheRequest)

  if (cached) {
    const cachedWithHeader = new Response(cached.body, cached)
    cachedWithHeader.headers.set("X-Cache-Status", "HIT")
    return cachedWithHeader
  }

  // 构造真实请求 URL
  const url = new URL(apiUrl)
  Object.entries(queryParams).forEach(([k, v]) => url.searchParams.set(k, v))

  const headers = {
    "Accept": "application/json",
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36",
    "Referer": "https://www.google.com/",
    "Accept-Language": "zh-CN,zh;q=0.9,en;q=0.8"
  }

  // 请求 nsmao 接口
  const apiResp = await fetch(url.toString(), { method: "GET", headers })
  if (!apiResp.ok) {
    return new Response("Failed to fetch API", { status: 502 })
  }

  const json = await apiResp.json()
  const imageUrl = json?.data?.[imageField]

  if (!imageUrl) {
    return new Response("Image URL not found in API response", { status: 500 })
  }

  // 请求图片
  const imageResp = await fetch(imageUrl, {
    headers: {
      ...headers,
      "Accept": "image/*"
    }
  })

  const contentType = imageResp.headers.get("content-type") || "image/jpeg"
  const response = new Response(imageResp.body, {
    headers: {
      "Content-Type": contentType,
      "Cache-Control": `public, max-age=${CACHE_TTL}`,
      "X-Cache-Status": "MISS"
    }
  })

  // 后台写入缓存
  ctx.waitUntil(cache.put(cacheRequest, response.clone()))
  return response
}