from .money_amount import Money, assert_same_currency, money


def add_money(a: Money, b: Money) -> Money:
    assert_same_currency(a, b)
    return money(a.minor + b.minor, a.currency)


def subtract_money(a: Money, b: Money) -> Money:
    assert_same_currency(a, b)
    return money(a.minor - b.minor, a.currency)


def negate_money(a: Money) -> Money:
    return money(-a.minor, a.currency)