"""日历日分组键（开仓时间窗已取消，由期权剩余时长约束）。"""

from __future__ import annotations

from datetime import datetime
from zoneinfo import ZoneInfo

_SH = ZoneInfo("Asia/Shanghai")


def now_sh(now: datetime | None = None) -> datetime:
    return (now or datetime.now(tz=_SH)).astimezone(_SH)


def window_key(now: datetime | None = None) -> str:
    """组号日期键：日历日 YYYYMMDD。"""
    return now_sh(now).strftime("%Y%m%d")


def can_open_new(
    now: datetime | None = None,
    *,
    open_hhmm: str = "16:00",
    stop_hhmm: str = "08:00",
) -> bool:
    """开仓窗已取消，始终允许（仍受期权剩余时长/杠杆筛选）。"""
    return True


def group_date_ymd(now: datetime | None = None) -> str:
    return window_key(now)