from .money_amount import Money, assert_same_currency


def compare_money(a: Money, b: Money) -> int:
    """-1, 0 or 1, comparing two amounts of the same currency.

    Refuses mixed currencies: which of GBP 10 and EUR 10 is larger depends on a
    rate, and a comparison that ignores the currency sorts a list into nonsense.
    """
    assert_same_currency(a, b)
    return -1 if a.minor < b.minor else 1 if a.minor > b.minor else 0