---

from datetime import date, timedelta
from flask import request


def parse_period(default_days: int = 30):
    """Возвращает (date_from, date_to) из query-параметров."""
    today = date.today()
    default_from = today - timedelta(days=default_days)

    df = request.args.get("date_from")
    dt = request.args.get("date_to")

    try:
        date_from = date.fromisoformat(df) if df else default_from
    except ValueError:
        date_from = default_from
    try:
        date_to = date.fromisoformat(dt) if dt else today
    except ValueError:
        date_to = today

    if date_from > date_to:
        date_from, date_to = date_to, date_from
    return date_from, date_to