import { ServiceError } from "./service-error";

export const jsonBodyLimit = 2 * 1024 * 1024;

export async function jsonBody(request: Pick<Request, "body">) {
  const reader = request.body?.getReader();
  if (!reader) throw new ServiceError("JSON request required", 400);
  const chunks: Uint8Array[] = [];
  let size = 0;
  while (true) {
    const { done, value } = await reader.read();
    if (done) break;
    size += value.byteLength;
    if (size > jsonBodyLimit) {
      await reader.cancel();
      throw new ServiceError("Request too large", 413);
    }
    chunks.push(value);
  }
  return JSON.parse(Buffer.concat(chunks).toString("utf8"));
}