from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, declarative_base
from app_core.config.settings import AppSettings

settings = AppSettings()

if not settings.database_url:
    raise RuntimeError(
        "Database configuration missing. Set DATABASE_URL or DB_HOST/DB_PORT/DB_NAME/DB_USER/DB_PASSWORD in a .env file at the project root."
    )

engine = create_engine(settings.database_url, pool_pre_ping=True, future=True, echo=settings.db_echo)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine, future=True)
Base = declarative_base()

def get_db_session():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()