user_group_to_perm.permission = Permission.get_by_key(default_perm)

        user_group_to_perm.user_group = user_group

        user_group_to_perm.user_id = def_user.user_id

        Session().add(user_group_to_perm)

        return user_group_to_perm

    def _update_permissions(self, user_group, perms_new=None,

                            perms_updates=None):

        from kallithea.lib.auth import HasUserGroupPermissionLevel

        if not perms_new:

            perms_new = []

        if not perms_updates:

            perms_updates = []

        # update permissions

        for member, perm, member_type in perms_updates:

            if member_type == 'user':

                # this updates existing one

                self.grant_user_permission(

                    user_group=user_group, user=member, perm=perm

                )

            else:

                # check if we have permissions to alter this usergroup's access

                if HasUserGroupPermissionLevel('read')(member):

                    self.grant_user_group_permission(

                        target_user_group=user_group, user_group=member, perm=perm

                    )

        # set new permissions

        for member, perm, member_type in perms_new:

            if member_type == 'user':

                self.grant_user_permission(

                    user_group=user_group, user=member, perm=perm

                )

            else:

                # check if we have permissions to alter this usergroup's access

                if HasUserGroupPermissionLevel('read')(member):

                    self.grant_user_group_permission(

                        target_user_group=user_group, user_group=member, perm=perm

                    )

    def get(self, user_group_id, cache=False):

        return UserGroup.get(user_group_id)

    def get_group(self, user_group):

        return UserGroup.guess_instance(user_group)

    def get_by_name(self, name, cache=False, case_insensitive=False):

    def create(self, name, description, owner, active=True, group_data=None):

        try:

            new_user_group = UserGroup()

            new_user_group.owner = User.guess_instance(owner)

            new_user_group.users_group_name = name

            new_user_group.user_group_description = description

            new_user_group.users_group_active = active

            if group_data:

                new_user_group.group_data = group_data

            Session().add(new_user_group)

            self._create_default_perms(new_user_group)

            self.grant_user_permission(user_group=new_user_group,

                                       user=owner, perm='usergroup.admin')

            return new_user_group

        except Exception:

            log.error(traceback.format_exc())

            raise

    def update(self, user_group, form_data):

        try:

            user_group = UserGroup.guess_instance(user_group)

            for k, v in form_data.items():

                if k == 'users_group_members':

                    members_list = []

                    if v:

                        v = [v] if isinstance(v, basestring) else v

                        for u_id in set(v):

                            member = UserGroupMember(user_group.users_group_id, u_id)

                            members_list.append(member)

                            Session().add(member)

                    user_group.members = members_list

                setattr(user_group, k, v)

            # Flush to make db assign users_group_member_id to newly

            # created UserGroupMembers.

            Session().flush()

        except Exception:

            log.error(traceback.format_exc())

            raise

    def delete(self, user_group, force=False):

        """

        Deletes user group, unless force flag is used