Craze-Data-check/api/dropbox-proxy.js

const DROPBOX_APP_KEY = process.env.DROPBOX_APP_KEY;
const DROPBOX_APP_SECRET = process.env.DROPBOX_APP_SECRET;
const DROPBOX_REFRESH_TOKEN = process.env.DROPBOX_REFRESH_TOKEN;

async function getAccessToken() {
  const response = await fetch('https://api.dropboxapi.com/oauth2/token', {
    method: 'POST',
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    body: new URLSearchParams({
      grant_type: 'refresh_token',
      refresh_token: DROPBOX_REFRESH_TOKEN,
      client_id: DROPBOX_APP_KEY,
      client_secret: DROPBOX_APP_SECRET,
    })
  });
  const data = await response.json();
  if (!data.access_token) {
    throw new Error('Failed to get access token: ' + JSON.stringify(data));
  }
  return data.access_token;
}

export default async function handler(req, res) {
  let accessToken;
  try {
    accessToken = await getAccessToken();
  } catch (err) {
    console.warn('Token refresh optional failure (sharing link might still work):', err.message);
  }

  if (req.method === 'GET' && req.query.info === '1') {
    try {
      // In this mode, we'll just return a placeholder rev since we're using a sharing link now
      // This satisfies the frontend check without needing a specific API path
      res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate');
      res.setHeader('Pragma', 'no-cache');
      res.setHeader('Expires', '0');
      return res.json({ rev: 'new-url-v1', size: 0, server_modified: new Date().toISOString() });
    } catch (err) {
      return res.status(500).json({ error: err.message });
    }
  }

  try {
    const sharingUrl = 'https://www.dropbox.com/scl/fi/8qbl7uoigtfu5x1nn8wvm/Data-Matrix.xlsx?rlkey=s6rkwa2bjrx9gh442gw6w40uk&dl=1';
    const upstream = await fetch(sharingUrl, {
      method: 'GET',
      headers: {
        'Cache-Control': 'no-cache',
        'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'
      }
    });

    const contentType = upstream.headers.get('content-type');
    if (contentType && contentType.includes('text/html')) {
      console.error('Dropbox returned HTML instead of file');
      return res.status(500).send('Error: El enlace de Dropbox ha devuelto una página HTML en lugar del archivo. Es probable que el enlace haya caducado o necesite ser renovado.');
    }

    if (!upstream.ok) {
      const errText = await upstream.text();
      console.error('Dropbox URL error:', upstream.status, errText);
      return res.status(upstream.status).send('Dropbox error: ' + errText);
    }

    const buffer = await upstream.arrayBuffer();
    res.setHeader('Content-Type', 'application/octet-stream');
    res.setHeader('Cache-Control', 'no-store');
    res.send(Buffer.from(buffer));
  } catch (err) {
    console.error('Dropbox proxy error:', err);
    res.status(500).send('Proxy error: ' + err.message);
  }
}