"""Periodic sweep of expired auth_sessions rows.

get_current_user (app/deps.py) already rejects expired sessions on read, but
never deletes them — left alone, auth_sessions grows forever. The lifespan
in app/main.py runs delete_expired_sessions on a timer to keep the table
bounded.
"""

from datetime import datetime, timezone

from sqlalchemy import delete
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.auth_session import AuthSession


async def delete_expired_sessions(db: AsyncSession) -> int:
    """Deletes expired auth_sessions rows. Returns the number deleted."""
    result = await db.execute(
        delete(AuthSession).where(AuthSession.expires_at < datetime.now(timezone.utc))
    )
    await db.commit()
    return result.rowcount