accountbook/frontend/pages/api/[...path].js

export default async function handler(req, res) {
  const path = Array.isArray(req.query.path)
    ? req.query.path.join('/')
    : req.query.path;

  if (!path) {
    res.status(400).json({ error: 'Missing API path' });
    return;
  }

  const query = { ...req.query };
  delete query.path;
  const searchParams = new URLSearchParams(query);
  const backendUrl = `http://localhost:3501/api/${path}${searchParams.size ? `?${searchParams}` : ''}`;

  const response = await fetch(backendUrl, {
    method: req.method,
    headers: {
      'Content-Type': 'application/json',
      ...(req.headers.authorization ? { Authorization: req.headers.authorization } : {}),
    },
    body: req.method !== 'GET' && req.method !== 'HEAD' ? JSON.stringify(req.body) : undefined,
  });

  const data = await response.json();
  res.status(response.status).json(data);
}