database.py

"""Database engine and session management with SQLModel."""
from collections.abc import Generator

from sqlmodel import Session, SQLModel, create_engine

from app.config import settings

# check_same_thread is a SQLite-only quirk; harmless to pass conditionally.
connect_args = (
    {"check_same_thread": False}
    if settings.database_url.startswith("sqlite")
    else {}
)

engine = create_engine(settings.database_url, echo=settings.debug, connect_args=connect_args)


def create_db_and_tables() -> None:
    """Create tables from SQLModel metadata.

    Handy for local dev and tests. For real schema changes over time, use
    Alembic migrations (see docs/05-migrations-alembic.md).
    """
    SQLModel.metadata.create_all(engine)


def get_session() -> Generator[Session, None, None]:
    """FastAPI dependency that yields a database session per request."""
    with Session(engine) as session:
        yield session