// Cross-implementation gate for the BINARY crypto path — encryptBytes /
// decryptBytes, the raw `iv||ct||tag` bytes attachments upload and download as
// (no base64, no JSON). The native client opens the same blobs (LChatCore's
// GroupKey.decryptBytes, via BlobImageLoader); drift here means photos decrypt
// on one platform and not the other. Pinned two ways:
//
//   1. a fresh encryptBytes → decryptBytes round-trips in JS, and
//   2. the committed fixture (LChatCore's Tests/…/Fixtures/attachment-bytes-vector.json)
//      still decrypts to the expected bytes — the SAME fixture the Swift test
//      (`swift test` in ios/LChatCore, AttachmentBytesVectorTests) consumes.
//
// If (2) fails, regenerate with --emit and update LChatCore in the same change.
import { readFileSync, writeFileSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { dirname, join } from "node:path";
import { generateKey, importKey, encryptBytes, decryptBytes, bytesToB64url, b64urlToBytes } from "../web/static/crypto.js";

const here = dirname(fileURLToPath(import.meta.url));
const fixturePath = join(
  here, "..", "ios", "LChatCore", "Tests", "LChatCoreTests", "Fixtures", "attachment-bytes-vector.json"
);

// Every byte value once — catches any encoding/sign slip in either language.
function knownBytes() {
  const raw = new Uint8Array(256);
  for (let i = 0; i < 256; i++) raw[i] = i;
  return raw;
}

function assert(cond, msg) {
  if (!cond) {
    console.error("FAIL:", msg);
    process.exit(1);
  }
}

// `node test/blobbytes.test.mjs --emit` regenerates the committed fixture (the
// encrypt uses a fresh IV, so the fixture must be frozen, not recomputed).
async function emit() {
  const { key, b64 } = await generateKey();
  const blob = await encryptBytes(key, knownBytes());
  const fixture = {
    _comment:
      "Attachment-bytes test vector (binary iv||ct||tag path). Generated by " +
      "test/blobbytes.test.mjs from web/static/crypto.js. LChatCore's " +
      "AttachmentBytesVectorTests opens blobB64url's raw bytes with keyB64 via " +
      "GroupKey.decryptBytes and must get plaintextB64url's bytes back — the " +
      "gate for native attachment/avatar decryption. " +
      "Regenerate with: node test/blobbytes.test.mjs --emit",
    keyB64: b64,
    blobB64url: bytesToB64url(blob),
    plaintextB64url: bytesToB64url(knownBytes()),
  };
  writeFileSync(fixturePath, JSON.stringify(fixture, null, 2) + "\n");
  console.log("wrote", fixturePath);
}

async function test() {
  // (1) crypto.js self-consistency on the binary path.
  const { key } = await generateKey();
  const round = await decryptBytes(key, await encryptBytes(key, knownBytes()));
  assert(bytesToB64url(round) === bytesToB64url(knownBytes()), "fresh encryptBytes/decryptBytes round-trips");

  // (2) the committed fixture (shared with the Swift test) still decrypts.
  const fx = JSON.parse(readFileSync(fixturePath, "utf8"));
  const got = await decryptBytes(await importKey(fx.keyB64), b64urlToBytes(fx.blobB64url));
  assert(bytesToB64url(got) === fx.plaintextB64url, "committed fixture decrypts to expected bytes");

  console.log("blobbytes.test.mjs OK");
}

if (process.argv.includes("--emit")) await emit();
else await test();