"""Width-independent process application from actual rotational speeds."""

from collections.abc import Iterable
from math import isfinite


def rotational_application_g_m2(
    rotational_speeds_rpm: Iterable[float], specific_discharge_kg_per_rev_m: float,
    line_speed_m_min: float, gate_threshold: float,
) -> float | None:
    speeds = tuple(rotational_speeds_rpm)
    if not speeds or not all(isfinite(value) for value in speeds):
        raise ValueError("rotational speeds must be non-empty and finite")
    if not isfinite(specific_discharge_kg_per_rev_m) or specific_discharge_kg_per_rev_m <= 0:
        raise ValueError("specific discharge must be finite and positive")
    if not isfinite(gate_threshold) or gate_threshold <= 0:
        raise ValueError("speed gate threshold must be finite and positive")
    if not isfinite(line_speed_m_min):
        raise ValueError("line speed must be finite")
    if line_speed_m_min <= gate_threshold:
        return None
    value = sum(speeds) * specific_discharge_kg_per_rev_m * 1000 / line_speed_m_min
    if not isfinite(value):
        raise ValueError("derived application must be finite")
    return value