"""报销模块日期范围工具（从 bx-backend 迁移）。"""
from __future__ import annotations

from datetime import datetime, timedelta


def current_month_bounds(now: datetime | None = None) -> tuple[datetime, datetime]:
    """当前自然月 [month_start, next_month_start)。"""
    if now is None:
        now = datetime.now()
    month_start = now.replace(day=1, hour=0, minute=0, second=0, microsecond=0)
    if now.month == 12:
        month_end = datetime(now.year + 1, 1, 1)
    else:
        month_end = datetime(now.year, now.month + 1, 1)
    return month_start, month_end


def parse_create_time_day_bounds(apply_date: str | None) -> tuple[datetime, datetime] | None:
    if not apply_date or not str(apply_date).strip():
        return None
    try:
        day_start = datetime.strptime(str(apply_date).strip(), "%Y-%m-%d")
        return day_start, day_start + timedelta(days=1)
    except ValueError:
        return None