import { describe, expect, it, beforeAll } from 'vitest';

import { setCryptoBackend } from './backend';
import { makeWasmTestBackend } from './testBackend';
import { generateUserKeyPair, sealUserKey, openUserKey, KDF_PRESET } from './userKey';

beforeAll(async () => { setCryptoBackend(await makeWasmTestBackend()); });

describe('userKey', () => {
  it('generates a 32-byte X25519 keypair', async () => {
    const kp = await generateUserKeyPair();
    expect(kp.publicKey).toHaveLength(32);
    expect(kp.privateKey).toHaveLength(32);
  });

  it('seals and opens a private key with the same PIN', async () => {
    const kp = await generateUserKeyPair();
    const sealed = await sealUserKey({ privateKey: kp.privateKey, pin: '123456' });
    const opened = await openUserKey({
      sealed: sealed.sealedPrivateKey,
      pin: '123456',
      salt: sealed.salt,
      kdfParams: sealed.kdfParams,
    });
    expect(Array.from(opened)).toEqual(Array.from(kp.privateKey));
  });

  it('throws when opening with the wrong PIN', async () => {
    const kp = await generateUserKeyPair();
    const sealed = await sealUserKey({ privateKey: kp.privateKey, pin: '123456' });
    await expect(
      openUserKey({ sealed: sealed.sealedPrivateKey, pin: '654321', salt: sealed.salt, kdfParams: sealed.kdfParams }),
    ).rejects.toThrow();
  });

  it('throws when opening with the wrong salt', async () => {
    const kp = await generateUserKeyPair();
    const sealed = await sealUserKey({ privateKey: kp.privateKey, pin: '123456' });
    const wrongSalt = new Uint8Array(sealed.salt.length); wrongSalt.fill(7);
    await expect(
      openUserKey({ sealed: sealed.sealedPrivateKey, pin: '123456', salt: wrongSalt, kdfParams: sealed.kdfParams }),
    ).rejects.toThrow();
  });

  it('emits the documented KDF preset', async () => {
    const kp = await generateUserKeyPair();
    const sealed = await sealUserKey({ privateKey: kp.privateKey, pin: '123456' });
    expect(sealed.kdfParams.algo).toBe('argon2id');
    expect(sealed.kdfParams.preset).toBe(KDF_PRESET);
  });
});