from contextlib import contextmanager
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

from fpsweeper import config

# fingerprint_capture db
fpc_engine = create_engine(config.FPC_DB_URL, **config.DB_ENGINE_SETTINGS)
fpc_session = sessionmaker(bind=fpc_engine, expire_on_commit=False)

# art_relations db
ar_engine = create_engine(config.AR_DB_URL, **config.DB_ENGINE_SETTINGS)
ar_session = sessionmaker(bind=ar_engine, expire_on_commit=False)

# direct_delivery db
dd_engine = create_engine(config.DD_DB_URL, **config.DB_ENGINE_SETTINGS)
dd_session = sessionmaker(bind=dd_engine, expire_on_commit=False)


@contextmanager
def db_session_scope(db_session):
    """Context manager for db session
    """

    session = db_session()
    try:
        yield session
        session.commit()
    except:
        session.rollback()
        raise
    finally:
        session.close()