# 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/>.

import ifcopenshell
import ifcopenshell.api.owner
import ifcopenshell.util.element


def unassign_control(
    file: ifcopenshell.file,
    relating_control: ifcopenshell.entity_instance,
    related_objects: list[ifcopenshell.entity_instance],
) -> None:
    """Unassigns a planning control or constraint to an object

    :param relating_control: The IfcControl entity that is creating the
        control or constraint
    :param related_objects: The list IfcObjectDefinitions that is being controlled
    :return: None

    Example:

    .. code:: python

        # Let's relate a cost item and a product
        wall = ifcopenshell.api.root.create_entity(model, ifc_class="IfcWall")
        schedule = ifcopenshell.api.cost.add_cost_schedule(model)
        cost_item = ifcopenshell.api.cost.add_cost_item(model,
            cost_schedule=schedule)
        ifcopenshell.api.control.assign_control(model,
            relating_control=cost_item, related_objects=[wall])

        # And now let's change our mind
        ifcopenshell.api.control.unassign_control(model,
            relating_control=cost_item, related_objects=[wall])
    """
    related_objects_set = set(related_objects)
    control_assignments = set(relating_control.Controls)
    rels = set(rel for obj in related_objects_set for rel in obj.HasAssignments if rel in control_assignments)

    for rel in rels:
        related_objects_new = set(rel.RelatedObjects) - related_objects_set
        if related_objects_new:
            rel.RelatedObjects = list(related_objects_new)
            ifcopenshell.api.owner.update_owner_history(file, element=rel)
        else:
            history = rel.OwnerHistory
            file.remove(rel)
            if history:
                ifcopenshell.util.element.remove_deep2(file, history)