from datetime import datetime, timedelta, timezone
from zoneinfo import ZoneInfo

EASTERN = ZoneInfo("America/New_York")
SHOW_DAY_DEFAULT = 2  # Wednesday (Monday=0)
SHOW_HOUR_DEFAULT = 22


def get_show_week(
    now_utc: datetime,
    show_day: int = SHOW_DAY_DEFAULT,
    show_hour: int = SHOW_HOUR_DEFAULT,
) -> tuple[datetime, datetime]:
    """Return (week_start_utc, week_end_utc) for the show week containing now_utc.

    The week starts at show_day at show_hour Eastern Time and runs for 7 days.
    """
    now_et = now_utc.astimezone(EASTERN)

    days_since_show_day = (now_et.weekday() - show_day) % 7
    candidate_date = now_et.date() - timedelta(days=days_since_show_day)
    candidate = datetime(
        candidate_date.year,
        candidate_date.month,
        candidate_date.day,
        show_hour,
        0,
        0,
        tzinfo=EASTERN,
    )

    if candidate > now_et:
        candidate -= timedelta(days=7)

    week_start_utc = candidate.astimezone(timezone.utc).replace(tzinfo=timezone.utc)
    week_end_utc = (candidate + timedelta(days=7)).astimezone(timezone.utc).replace(tzinfo=timezone.utc)

    return week_start_utc, week_end_utc