# classes.py
import random

BARD      = "Bard"
BARBARIAN = "Barbarian"
FIGHTER   = "Fighter"
WIZARD    = "Wizard"
DRUID     = "Druid"
CLERIC    = "Cleric"
WARLOCK   = "Warlock"
MONK      = "Monk"
PALADIN   = "Paladin"
ROGUE     = "Rogue"
RANGER    = "Ranger"
SORCERER = "Sorcerer"
COMMONER  = "Commoner"

CLASSES = [BARD, BARBARIAN, FIGHTER, WIZARD, DRUID, CLERIC,
           WARLOCK, MONK, PALADIN, ROGUE, RANGER, SORCERER]

CLASSES_CHANCE = [2, 8, 26, 7, 4, 18, 2, 2, 6, 17, 6, 2]

DEFAULT_COMMONER_CHANCE = 0.90  # 90% мира — простолюдины

def get_random_class(
    allowed_classes: list[str] | None = None,
    commoner_chance: float = DEFAULT_COMMONER_CHANCE,
) -> str:
    """
    Двухуровневый выбор класса.

    allowed_classes:
        None или [] → все классы, включая Commoner
        ["Fighter", "Rogue"] → только боевые из списка, Commoner исключён
        ["Commoner"] → всегда Commoner
        ["Fighter", "Commoner"] → Fighter или Commoner

    commoner_chance:
        Вероятность выпадения Commoner (если он допустим). Default 0.90.
    """
    all_allowed = not allowed_classes  # [] или None → все

    commoner_allowed = all_allowed or (COMMONER in allowed_classes)
    combat_pool = (
        {cls: chance for cls, chance in zip(CLASSES, CLASSES_CHANCE)}
        if all_allowed
        else {cls: chance for cls, chance in zip(CLASSES, CLASSES_CHANCE)
              if cls in allowed_classes}
    )

    has_combat  = bool(combat_pool)
    has_commoner = commoner_allowed

    # Крайние случаи
    if has_commoner and not has_combat:
        return COMMONER
    if has_combat and not has_commoner:
        return _pick_from_combat(combat_pool)

    # Общий случай: оба варианта допустимы
    if random.random() < commoner_chance:
        return COMMONER
    return _pick_from_combat(combat_pool)


def _pick_from_combat(pool: dict[str, float]) -> str:
    """Взвешенный выбор из пула боевых классов."""
    total = sum(pool.values())
    r = random.random() * total
    cumulative = 0.0
    for cls, chance in pool.items():
        cumulative += chance
        if r < cumulative:
            return cls
    return list(pool.keys())[-1]