from datetime import date

from utils import get_billing_period


def test_get_billing_period():
    assert get_billing_period(billing_day=29, year=2025, month=2) == (
        date(2025, 2, 28),
        date(2025, 3, 28),
    )

    assert get_billing_period(billing_day=31, year=2025, month=2) == (
        date(2025, 2, 28),
        date(2025, 3, 30),
    )

    # Leap year
    assert get_billing_period(billing_day=29, year=2028, month=2) == (
        date(2028, 2, 29),
        date(2028, 3, 28),
    )

    assert get_billing_period(billing_day=28, year=2025, month=2) == (
        date(2025, 2, 28),
        date(2025, 3, 27),
    )

    assert get_billing_period(billing_day=5, year=2025, month=12) == (
        date(2025, 12, 5),
        date(2026, 1, 4),
    )