try:

            users_group_member = cls()

            users_group_member.user = user

            users_group_member.users_group = users_group

            Session.add(users_group_member)

            Session.commit()

            return users_group_member

        except:

            log.error(traceback.format_exc())

            Session.rollback()

            raise

class Repository(Base, BaseModel):

    __tablename__ = 'repositories'

    __table_args__ = (UniqueConstraint('repo_name'), {'extend_existing':True},)

    repo_id = Column("repo_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    repo_name = Column("repo_name", String(length=255, convert_unicode=False, assert_unicode=None), nullable=False, unique=True, default=None)

    clone_uri = Column("clone_uri", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=False, default=None)

    repo_type = Column("repo_type", String(length=255, convert_unicode=False, assert_unicode=None), nullable=False, unique=False, default='hg')

    user_id = Column("user_id", Integer(), ForeignKey('users.user_id'), nullable=False, unique=False, default=None)

    private = Column("private", Boolean(), nullable=True, unique=None, default=None)

    enable_statistics = Column("statistics", Boolean(), nullable=True, unique=None, default=True)

    enable_downloads = Column("downloads", Boolean(), nullable=True, unique=None, default=True)

    description = Column("description", String(length=10000, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    created_on = Column('created_on', DateTime(timezone=False), nullable=True, unique=None, default=datetime.datetime.now)

    fork_id = Column("fork_id", Integer(), ForeignKey('repositories.repo_id'), nullable=True, unique=False, default=None)

    group_id = Column("group_id", Integer(), ForeignKey('groups.group_id'), nullable=True, unique=False, default=None)

    user = relationship('User')

    fork = relationship('Repository', remote_side=repo_id)

    group = relationship('Group')

    repo_to_perm = relationship('RepoToPerm', cascade='all', order_by='RepoToPerm.repo_to_perm_id')

    users_group_to_perm = relationship('UsersGroupRepoToPerm', cascade='all')

    stats = relationship('Statistics', cascade='all', uselist=False)

    followers = relationship('UserFollowing', primaryjoin='UserFollowing.follows_repo_id==Repository.repo_id', cascade='all')

    logs = relationship('UserLog', cascade='all')

    def __repr__(self):

        return "<%s('%s:%s')>" % (self.__class__.__name__,

                                  self.repo_id, self.repo_name)

    @classmethod

    def by_repo_name(cls, repo_name):

        q = cls.query().filter(cls.repo_name == repo_name)

        q = q.options(joinedload(Repository.fork))\

            .options(joinedload(Repository.user))\

            .options(joinedload(Repository.group))\

        return q.one()

    @classmethod

    def get_repo_forks(cls, repo_id):

        return cls.query().filter(Repository.fork_id == repo_id)

    @classmethod

    def base_path(cls):

        """

        Returns base path when all repos are stored

        :param cls:

        """

        q = Session.query(RhodeCodeUi).filter(RhodeCodeUi.ui_key == '/')

        q.options(FromCache("sql_cache_short", "repository_repo_path"))

        return q.one().ui_value

    @property

    def just_name(self):

        return self.repo_name.split(os.sep)[-1]

    @property

    def groups_with_parents(self):

        groups = []

        if self.group is None:

            return groups

        cur_gr = self.group

        groups.insert(0, cur_gr)

        while 1:

            gr = getattr(cur_gr, 'parent_group', None)

            cur_gr = cur_gr.parent_group

            if gr is None:

                break

            groups.insert(0, gr)

        return groups

    @property

    def groups_and_repo(self):

    @property

    def repositories(self):

        return Repository.query().filter(Repository.group == self)

    @property

    def repositories_recursive_count(self):

        cnt = self.repositories.count()

        def children_count(group):

            cnt = 0

            for child in group.children:

                cnt += child.repositories.count()

                cnt += children_count(child)

            return cnt

        return cnt + children_count(self)

class Permission(Base, BaseModel):

    __tablename__ = 'permissions'

    __table_args__ = {'extend_existing':True}

    permission_id = Column("permission_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    permission_name = Column("permission_name", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    permission_longname = Column("permission_longname", String(length=255, convert_unicode=False, assert_unicode=None), nullable=True, unique=None, default=None)

    def __repr__(self):

        return "<%s('%s:%s')>" % (self.__class__.__name__,

                                  self.permission_id, self.permission_name)

    @classmethod

    def get_by_key(cls, key):

        return cls.query().filter(cls.permission_name == key).scalar()

    @classmethod

    def get_by_name(cls, name):

        return cls.query().filter(cls.permission_name == name).one()

class RepoToPerm(Base, BaseModel):

    __tablename__ = 'repo_to_perm'

    __table_args__ = (UniqueConstraint('user_id', 'repository_id'), {'extend_existing':True})

    repo_to_perm_id = Column("repo_to_perm_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    user_id = Column("user_id", Integer(), ForeignKey('users.user_id'), nullable=False, unique=None, default=None)

    permission_id = Column("permission_id", Integer(), ForeignKey('permissions.permission_id'), nullable=False, unique=None, default=None)

    repository_id = Column("repository_id", Integer(), ForeignKey('repositories.repo_id'), nullable=False, unique=None, default=None)

    user = relationship('User')

    permission = relationship('Permission')

    repository = relationship('Repository')

class UserToPerm(Base, BaseModel):

    __tablename__ = 'user_to_perm'

    __table_args__ = (UniqueConstraint('user_id', 'permission_id'), {'extend_existing':True})

    user_to_perm_id = Column("user_to_perm_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    user_id = Column("user_id", Integer(), ForeignKey('users.user_id'), nullable=False, unique=None, default=None)

    permission_id = Column("permission_id", Integer(), ForeignKey('permissions.permission_id'), nullable=False, unique=None, default=None)

    user = relationship('User')

    permission = relationship('Permission')

    @classmethod

    def has_perm(cls, user_id, perm):

        if not isinstance(perm, Permission):

            raise Exception('perm needs to be an instance of Permission class')

        return cls.query().filter(cls.user_id == user_id)\

            .filter(cls.permission == perm).scalar() is not None

    @classmethod

    def grant_perm(cls, user_id, perm):

        if not isinstance(perm, Permission):

            raise Exception('perm needs to be an instance of Permission class')

        new = cls()

        new.user_id = user_id

        new.permission = perm

        try:

            Session.add(new)

            Session.commit()

        except:

            Session.rollback()

    @classmethod

    def revoke_perm(cls, user_id, perm):

        if not isinstance(perm, Permission):

            raise Exception('perm needs to be an instance of Permission class')

        try:

            cls.query().filter(cls.user_id == user_id)\

                .filter(cls.permission == perm).delete()

            Session.commit()

        except:

            Session.rollback()

class UsersGroupRepoToPerm(Base, BaseModel):

    __tablename__ = 'users_group_repo_to_perm'

    __table_args__ = (UniqueConstraint('repository_id', 'users_group_id', 'permission_id'), {'extend_existing':True})