from .math_rational_rational import rational
from .math_rational_types import Rational
from .math_round_div import RoundingMode, round_div


def rational_to_integer(r: Rational, mode: RoundingMode) -> int:
    """The integer a fraction rounds to, under an explicit rounding mode.

    This is the point where an exact rate becomes minor units, so the policy
    is the caller's to state.
    """
    n = rational(r.numerator, r.denominator)
    return round_div(n.numerator, n.denominator, mode)