from __future__ import annotations

from app.config import settings

# Шаг корректировки/ввода веса вспомогательных (прибавка и снижение).
ACCESSORY_STEP_KG = 0.5


def weight_step_for(exercise_name: str | None = None, *, kind: str | None = None) -> float:
    """Жим — блины (config). Вспомогательные — 0.5 кг."""
    if kind == "bench" or (exercise_name == "Жим"):
        return settings.plate_step_kg
    if kind in ("accessory", "failure"):
        return ACCESSORY_STEP_KG
    if exercise_name:
        return ACCESSORY_STEP_KG
    return settings.plate_step_kg


def round_to_plate(weight_kg: float, step: float | None = None) -> float:
    step = step if step is not None else settings.plate_step_kg
    if weight_kg <= 0:
        return 0.0
    return round(round(weight_kg / step) * step, 2)


def round_exercise_weight(weight_kg: float, exercise_name: str, *, kind: str | None = None) -> float:
    return round_to_plate(weight_kg, weight_step_for(exercise_name, kind=kind))


def bench_weight(one_rm_kg: float, percent: float) -> float:
    """Жим: округление как раньше — по plate_step_kg (1.25)."""
    return round_to_plate(one_rm_kg * (percent / 100.0), settings.plate_step_kg)