/** Read a request body with a hard byte cap; throws { code:'BODY_TOO_LARGE' } past the cap. */
async function readRequestBodyCapped(req, maxBytes) {
  const chunks = [];
  let total = 0;
  for await (const chunk of req) {
    total += chunk.length;
    if (total > maxBytes) {
      const err = new Error('Request body too large');
      err.code = 'BODY_TOO_LARGE';
      throw err;
    }
    chunks.push(chunk);
  }
  return Buffer.concat(chunks);
}

function readRequestBody(req, maxBytes = 1024 * 1024) {
  return new Promise((resolve, reject) => {
    let total = 0;
    const chunks = [];
    req.on('data', (chunk) => {
      total += chunk.length;
      if (total > maxBytes) {
        reject(new Error(`Request body exceeds ${maxBytes} bytes`));
        req.destroy();
        return;
      }
      chunks.push(chunk);
    });
    req.on('end', () => resolve(Buffer.concat(chunks).toString('utf8')));
    req.on('error', reject);
  });
}

export { readRequestBodyCapped, readRequestBody };