const mockRedis = { set: jest.fn(), eval: jest.fn() };
jest.mock("../../app/config/redisClient", () => mockRedis);
const { generateOtp, otpHash, createLoginChallenge, verifyLoginChallenge } = require("../../app/services/auth/otp.service");

describe("login OTP service", () => {
  beforeEach(() => jest.clearAllMocks());
  test("generates six numeric digits cryptographically", () => expect(generateOtp()).toMatch(/^\d{6}$/));
  test("stores only an OTP hash with TTL", async () => {
    const result = await createLoginChallenge({ userId: "usr-1", rememberMe: true, context: {} });
    const stored = JSON.parse(mockRedis.set.mock.calls[0][1]);
    expect(stored.otpHash).toHaveLength(64);
    expect(stored.otp).toBeUndefined();
    expect(mockRedis.set.mock.calls[0]).toEqual(expect.arrayContaining(["EX", 900]));
    expect(result.otp).toMatch(/^\d{6}$/);
    expect(stored.otpHash).toBe(otpHash(result.challengeId, result.otp));
  });
  test("maps invalid, exhausted, and expired challenges to a generic failure", async () => {
    for (const code of [-1, -2, -3]) {
      mockRedis.eval.mockResolvedValueOnce([code]);
      await expect(verifyLoginChallenge("00000000-0000-4000-8000-000000000000", "000000")).rejects.toMatchObject({ code: "INVALID_OTP", status: 401 });
    }
  });
});