/**
 * v1.17.1 — server-side helpers for the structured lab-result store.
 *
 * The AES-256-GCM ↔ `Bytes` codec for `LabResult.noteEncrypted`. The
 * free-text note is the only sensitive column on the model; it shares the
 * `encrypt()` string format (`"<keyId>.<base64>"`) every other `*Encrypted`
 * column uses, encoded as UTF-8 bytes.
 *
 * There is one decrypt here and it throws. A fail-soft twin used to sit
 * beside it for bulk reads; the list DTO never carries the note (it reports
 * `hasNote` only) and the export now writes a visible marker instead of a
 * null, so nothing was left that wanted a silent one.
 */
import { Buffer } from "node:buffer";

import { decrypt, encrypt } from "@/lib/crypto";

/** Encrypt a UTF-8 note into the `Bytes` payload the schema stores. */
export function encryptNoteToBytes(plaintext: string): Uint8Array<ArrayBuffer> {
  const ciphertext = encrypt(plaintext);
  const encoded = Buffer.from(ciphertext, "utf8");
  // Prisma `Bytes` maps to `Uint8Array<ArrayBuffer>`; allocate a fresh
  // ArrayBuffer-backed view so the structural type stays stable.
  const out = new Uint8Array(new ArrayBuffer(encoded.byteLength));
  out.set(encoded);
  return out;
}

/** Decrypt a stored `Bytes` note back to plaintext. Throws on a bad key id. */
export function decryptNoteFromBytes(buf: Uint8Array): string {
  return decrypt(Buffer.from(buf).toString("utf8"));
}