from datetime import date, datetime, time, timedelta

from sqlalchemy.orm import Session

from ..core.datetime import utc_now
from ..models.models import AttendanceCheckoutSource, AttendanceSession


def duration_seconds(start: datetime, end: datetime) -> int:
    return max(0, int((end - start).total_seconds()))


def close_stale_attendance_sessions(
    db: Session,
    cutoff_date: date | None = None,
    checkout_hour: int = 17,
) -> int:
    cutoff = cutoff_date or date.today()
    cutoff_at = datetime.combine(cutoff, time.min)
    sessions = (
        db.query(AttendanceSession)
        .filter(
            AttendanceSession.is_open == True,
            AttendanceSession.checked_in_at < cutoff_at,
        )
        .all()
    )

    now = utc_now()
    for session in sessions:
        checkout_at = datetime.combine(session.checked_in_at.date(), time(hour=checkout_hour))
        if checkout_at < session.checked_in_at:
            checkout_at = session.checked_in_at + timedelta(minutes=1)
        session.checked_out_at = checkout_at
        session.checkout_source = AttendanceCheckoutSource.SYSTEM
        session.system_flag_reason = "User did not check out before midnight; checkout time was system-set."
        session.duration_seconds = duration_seconds(session.checked_in_at, checkout_at)
        session.is_open = False
        session.updated_at = now

    db.commit()
    return len(sessions)