from collections.abc import Generator

from sqlalchemy import create_engine
from sqlalchemy.orm import declarative_base, sessionmaker

from app.config import settings


if not settings.database_url:
    raise RuntimeError("DATABASE_URL is not set")

engine = create_engine(
    settings.database_url,
    pool_pre_ping=True,
)

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

Base = declarative_base()


def get_db() -> Generator:
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()