worker.js

export default {
  async fetch(request, env) {
    const allowHeaders = {
      "Access-Control-Allow-Origin": "*",
      "Access-Control-Allow-Methods": "POST, OPTIONS",
      "Access-Control-Allow-Headers": "Authorization, Content-Type",
    };

    if (request.method === "OPTIONS") {
      return new Response(null, { status: 204, headers: allowHeaders });
    }

    if (request.method !== "POST") {
      return new Response("Method Not Allowed", { status: 405, headers: allowHeaders });
    }

    try {
      const url = env.API_URL || "https://dashscope.aliyuncs.com/compatible-mode/v1/chat/completions"; // 允许环境变量覆盖默认 API
      const headers = {
        "Authorization": request.headers.get("Authorization"),
        "Content-Type": "application/json",
      };

      let body = await request.text();
      let parsedBody = JSON.parse(body);
      parsedBody.stream = true; // 启用流式传输

      const response = await fetch(url, {
        method: "POST",
        headers,
        body: JSON.stringify(parsedBody),
      });

      if (!response.ok) {
        return new Response(JSON.stringify({ error: "请求失败", status: response.status }), {
          status: response.status,
          headers: { ...allowHeaders, "Content-Type": "application/json" },
        });
      }

      return new Response(response.body, {
        status: 200,
        headers: {
          ...allowHeaders,
          "Content-Type": "text/event-stream",
          "Cache-Control": "no-cache",
          "Connection": "keep-alive",
        },
      });
    } catch (error) {
      return new Response(JSON.stringify({ error: "服务器内部错误", details: error.toString() }), {
        status: 500,
        headers: { ...allowHeaders, "Content-Type": "application/json" },
      });
    }
  },
};