# -*- coding: utf-8 -*-
from __future__ import absolute_import

from zope.sqlalchemy import ZopeTransactionExtension
from sqlalchemy.orm import scoped_session, sessionmaker

# from sqlalchemy import MetaData
from sqlalchemy.ext.declarative import declarative_base

# Global session manager: DBSession() returns the Thread-local
# session object appropriate for the current web request.
maker = sessionmaker(
    autoflush=True, autocommit=False, extension=ZopeTransactionExtension()
)
DBSession = scoped_session(maker)

# Base class for all of our model classes: By default, the data model is
# defined with SQLAlchemy's declarative extension, but if you need more
# control, you can switch to the traditional method.
DeclarativeBase = declarative_base()

# There are two convenient ways for you to spare some typing.
# You can have a query property on all your model classes by doing this:
DeclarativeBase.query = DBSession.query_property()
DeclarativeBase.get = classmethod(lambda cls, ident: cls.query.get(ident))
# Or you can use a session-aware mapper as it was used in TurboGears 1:
# DeclarativeBase = declarative_base(mapper=DBSession.mapper)