from __future__ import annotations

from datetime import UTC, datetime

import pytest

from vuln_scan.core.time import Clock, FixedClock


def test_clock_now_returns_utc_datetime() -> None:
    now = Clock().now()

    assert isinstance(now, datetime)
    assert now.tzinfo is UTC


@pytest.mark.parametrize(
    "fixed_dt",
    [
        pytest.param(datetime(2026, 3, 25, 12, 30, tzinfo=UTC), id="future-date"),
        pytest.param(datetime(2024, 1, 1, 0, 0, tzinfo=UTC), id="past-date"),
    ],
)
def test_fixed_clock_returns_stable_exact_datetime(fixed_dt: datetime) -> None:
    clock = FixedClock(fixed_dt)

    assert clock.now() == fixed_dt
    assert clock.now() == clock.now()