from datetime import datetime, timezone

import pytest

from app.jobs import next_run, validate_cron


def test_cron_validation_accepts_standard_expression():
    validate_cron("0 2 * * *")
    assert next_run("0 2 * * *")


def test_cron_validation_rejects_invalid_expression():
    with pytest.raises(ValueError):
        validate_cron("not a cron")


def test_next_run_interprets_cron_in_configured_timezone():
    base = datetime(2026, 1, 1, 0, 0, tzinfo=timezone.utc)

    assert next_run("0 2 * * *", base=base, timezone_name="Europe/Berlin") == "2026-01-01T01:00:00+00:00"