"""博弈分析计算引擎"""


def net_position(long_pos: int, short_pos: int) -> int:
    """净持仓 = 多单 - 空单。正=净多, 负=净空"""
    return long_pos - short_pos


def net_pnl(net_pos: int, avg_cost: float, current_price: float) -> float:
    """净盈亏 = 净持仓 × (现价 - 成本均价) × 20"""
    return net_pos * (current_price - avg_cost) * 20


def cost_delta(old_cost: float, new_cost: float) -> float:
    """成本变化 = 新均价 - 旧均价"""
    return round(new_cost - old_cost, 2)


def format_pnl(pnl_yuan: float) -> str:
    """格式化盈亏为亿/万"""
    yi = abs(pnl_yuan) / 1e8
    if yi >= 0.01:
        sign = "+" if pnl_yuan >= 0 else "-"
        return f"{sign}{yi:.2f}亿"
    wan = abs(pnl_yuan) / 1e4
    return f"{'+' if pnl_yuan >= 0 else '-'}{wan:.1f}万"