from __future__ import annotations

from datetime import datetime, timedelta, timezone

try:
    from zoneinfo import ZoneInfo
except ImportError:  # pragma: no cover
    ZoneInfo = None  # type: ignore[assignment]


CHINA_TZ = ZoneInfo("Asia/Shanghai") if ZoneInfo else timezone(timedelta(hours=8))


def china_now() -> datetime:
    return datetime.now(CHINA_TZ)


def china_now_string() -> str:
    return china_now().strftime("%Y-%m-%d %H:%M:%S")


def china_from_timestamp_string(value: float) -> str:
    return datetime.fromtimestamp(value, CHINA_TZ).strftime("%Y-%m-%d %H:%M:%S")


def china_date_from_timestamp_string(value: float) -> str:
    return datetime.fromtimestamp(value, CHINA_TZ).strftime("%Y-%m-%d")