created_by_user = relationship('User')

    notifications_to_users = relationship('UserNotification', lazy='joined',

                                          cascade="all, delete, delete-orphan")

    @property

    def recipients(self):

        return [x.user for x in UserNotification.query()\

                .filter(UserNotification.notification == self).all()]

    @classmethod

    def create(cls, created_by, subject, body, recipients, type_=None):

        if type_ is None:

            type_ = Notification.TYPE_MESSAGE

        notification = cls()

        notification.created_by_user = created_by

        notification.subject = subject

        notification.body = body

        notification.type_ = type_

        notification.created_on = datetime.datetime.now()

        for u in recipients:

            assoc = UserNotification()

            assoc.notification = notification

            u.notifications.append(assoc)

        Session.add(notification)

        return notification

    @property

    def description(self):

        from rhodecode.model.notification import NotificationModel

        return NotificationModel().make_description(self)

class UserNotification(Base, BaseModel):

    __tablename__ = 'user_to_notification'

    __table_args__ = (

        UniqueConstraint('user_id', 'notification_id'),

        {'extend_existing': True}

    )

    user_id = Column('user_id', Integer(), ForeignKey('users.user_id'), primary_key=True)

    notification_id = Column("notification_id", Integer(), ForeignKey('notifications.notification_id'), primary_key=True)

    read = Column('read', Boolean, default=False)

    sent_on = Column('sent_on', DateTime(timezone=False), nullable=True, unique=None)

    user = relationship('User', lazy="joined")

    notification = relationship('Notification', lazy="joined",

    def mark_as_read(self):

        self.read = True

        Session.add(self)

class DbMigrateVersion(Base, BaseModel):

    __tablename__ = 'db_migrate_version'

    __table_args__ = {'extend_existing': True}

    repository_id = Column('repository_id', String(250), primary_key=True)

    repository_path = Column('repository_path', Text)

    version = Column('version', Integer)