# IfcOpenShell - IFC toolkit and geometry engine
# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
#
# This file is part of IfcOpenShell.
#
# IfcOpenShell is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# IfcOpenShell is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.

from typing import Union

import ifcopenshell
import ifcopenshell.api.group


def assign_structural_analysis_model(
    file: ifcopenshell.file,
    products: list[ifcopenshell.entity_instance],
    structural_analysis_model: ifcopenshell.entity_instance,
) -> Union[ifcopenshell.entity_instance, None]:
    """Assigns a load or structural member to an analysis model

    :param products: The structural elements that is part of the analysis.
    :param structural_analysis_model: The IfcStructuralAnalysisModel that
        the structural element is related to.
    :return: The IfcRelAssignsToGroup relationship
    """
    return ifcopenshell.api.group.assign_group(file, products, structural_analysis_model)
