import { readFileSync } from "node:fs";
import { HKDF } from "@stablelib/hkdf";
import { SHA256 } from "@stablelib/sha256";
import { expect, it } from "vitest";

type Vector = {
  masterKeyHex: string;
  entryId: string;
  nonceHex: string;
  plaintext: string;
  envelopeBase64: string;
};

const vector = JSON.parse(
  readFileSync("fixtures/golden/sync-entry-envelope-v1.json", "utf8"),
) as Vector;
const fromHex = (hex: string) =>
  Uint8Array.from(hex.match(/../g)!.map((byte) => Number.parseInt(byte, 16)));

it("matches the cross-client sync-entry-v1 envelope vector", async () => {
  const info = new TextEncoder().encode(`${vector.entryId}\0sync-entry-v1`);
  const rawKey = new HKDF(
    SHA256,
    fromHex(vector.masterKeyHex),
    new Uint8Array(0),
    info,
  ).expand(32);
  const nonce = fromHex(vector.nonceHex);
  const additionalData = new TextEncoder().encode("peach-sync-entry-v1");
  const plaintext = new TextEncoder().encode(vector.plaintext);
  const key = await crypto.subtle.importKey(
    "raw",
    rawKey.buffer as ArrayBuffer,
    "AES-GCM",
    false,
    ["encrypt"],
  );
  const ciphertext = new Uint8Array(await crypto.subtle.encrypt(
    {
      name: "AES-GCM",
      iv: nonce.buffer as ArrayBuffer,
      additionalData: additionalData.buffer as ArrayBuffer,
      tagLength: 128,
    },
    key,
    plaintext.buffer as ArrayBuffer,
  ));
  const envelope = new Uint8Array(12 + ciphertext.length);
  envelope.set(nonce);
  envelope.set(ciphertext, 12);

  expect(Buffer.from(envelope).toString("base64")).toBe(vector.envelopeBase64);
});