"""Разбор периода для analytics."""

from __future__ import annotations

from datetime import date, datetime, timedelta
from typing import Optional, Tuple


def parse_iso_date(value: Optional[str]) -> Optional[date]:
    if not value:
        return None
    try:
        return date.fromisoformat(str(value).strip()[:10])
    except ValueError:
        return None


def resolve_date_bounds(
    date_from: Optional[str],
    date_to: Optional[str],
) -> Tuple[datetime, datetime]:
    """Включительно date_from … date_to (конец дня date_to)."""
    today = date.today()
    start_d = parse_iso_date(date_from) or today
    end_d = parse_iso_date(date_to) or start_d
    if end_d < start_d:
        start_d, end_d = end_d, start_d
    start_dt = datetime.combine(start_d, datetime.min.time())
    end_dt = datetime.combine(end_d, datetime.max.time())
    return start_dt, end_dt


def iter_dates_in_range(start_d: date, end_d: date):
    cur = start_d
    while cur <= end_d:
        yield cur
        cur += timedelta(days=1)