🛠️ 后端中转站 (Proxy) 完整源码公示

为了消除疑虑，以下是部署在服务器上的完整代码。你可以看到它没有任何数据库存储或日志记录的操作。

// 文件：netlify/functions/proxy.js
const axios = require('axios');

exports.handler = async function(event, context) {
  // 1. 获取前端传来的目标 URL
  const targetUrl = event.queryStringParameters.url;

  if (!targetUrl) {
    return {
      statusCode: 400,
      body: JSON.stringify({ error: '没有提供目标URL' }),
    };
  }

  try {
    const decodedUrl = decodeURIComponent(targetUrl);

    // 2. 准备请求头 (只透传必要的认证信息，不记录日志)
    const headersToSend = {
        'User-Agent': 'Mozilla/5.0 ... Chrome/118.0.0.0 Safari/537.36'
    };

    const lowerCaseHeaders = Object.keys(event.headers).reduce((acc, key) => {
        acc[key.toLowerCase()] = event.headers[key];
        return acc;
    }, {});

    if (lowerCaseHeaders['authorization']) {
      headersToSend['Authorization'] = lowerCaseHeaders['authorization'];
    }
    
    if (lowerCaseHeaders['x-requested-with']) {
      headersToSend['X-Requested-With'] = lowerCaseHeaders['x-requested-with'];
      headersToSend['Referer'] = 'https://music.163.com/';
    }
    
    if (event.httpMethod.toUpperCase() !== 'GET' && event.body) {
        headersToSend['Content-Type'] = 'application/json';
    }

    // 3. 准备请求体 (Body)
    let requestData;
    try {
        if (event.body) {
            requestData = JSON.parse(event.body);
        }
    } catch (e) {
        requestData = event.body;
    }

    // 4. 发起请求 (使用 axios 转发)
    const response = await axios({
      method: event.httpMethod,
      url: decodedUrl,
      headers: headersToSend,
      data: requestData,
    });

    // 5. 返回结果给前端
    return {
      statusCode: 200,
      headers: {
        'Access-Control-Allow-Origin': '*',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(response.data),
    };

  } catch (error) {
    const errorResponse = error.response ? error.response.data : { proxy_error: error.message };
    
    return {
      statusCode: error.response ? error.response.status : 500,
      body: JSON.stringify({ 
        error: "代理请求失败",
        details: errorResponse,
        target_url: decodeURIComponent(targetUrl) 
      }),
    };
  }
};