"""期权买一流动性：张数 × ctMult 是否覆盖名义 ETH。"""

from __future__ import annotations


def contracts_for_eth(qty_eth: float, ct_mult: float) -> float:
    m = float(ct_mult) if ct_mult and ct_mult > 0 else 0.01
    return float(qty_eth) / m


def eth_from_contracts(contracts: float, ct_mult: float) -> float:
    m = float(ct_mult) if ct_mult and ct_mult > 0 else 0.01
    return float(contracts) * m


def bid_covers_eth(*, bid_sz_contracts: float | None, ct_mult: float, need_eth: float) -> bool:
    if bid_sz_contracts is None or bid_sz_contracts <= 0:
        return False
    return eth_from_contracts(bid_sz_contracts, ct_mult) + 1e-12 >= float(need_eth)