from collections.abc import Iterator

from sqlalchemy import create_engine
from sqlalchemy.orm import DeclarativeBase, Session, sessionmaker

from app.config import settings

engine = create_engine(
    settings.database_url,
    pool_pre_ping=True,   # tote Verbindungen nach DB-Neustart erkennen
    pool_recycle=1800,    # unter MariaDBs wait_timeout bleiben
    future=True,
)

SessionLocal = sessionmaker(bind=engine, autoflush=False, expire_on_commit=False)


class Base(DeclarativeBase):
    pass


def get_db() -> Iterator[Session]:
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()