# IfcOpenShell - IFC toolkit and geometry engine
# Copyright (C) 2022 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/>.


def get_system_elements(system):
    results = []
    for rel in system.IsGroupedBy:
        results.extend(rel.RelatedObjects)
    return results


def get_element_systems(element):
    results = []
    for rel in element.HasAssignments:
        if rel.is_a("IfcRelAssignsToGroup") and rel.RelatingGroup.is_a() in [
            "IfcSystem",
            "IfcDistributionSystem",
            "IfcBuildingSystem",
        ]:
            results.append(rel.RelatingGroup)
    return results


def get_ports(element):
    results = []
    for rel in getattr(element, "IsNestedBy", []) or []:
        results.extend([o for o in rel.RelatedObjects if o.is_a("IfcDistributionPort")])
    for rel in element.HasPorts or []:
        results.append(rel.RelatingPort)
    return results


def get_connected_port(port):
    for rel in port.ConnectedTo:
        return rel.RelatedPort
    for rel in port.ConnectedFrom:
        return rel.RelatingPort


def get_connected_to(element):
    # Note: this code is for IFC2X3. IFC4 has a different approach.
    results = []
    for rel in element.HasPorts:
        for rel2 in rel.RelatingPort.ConnectedTo:
            results.extend([r.RelatedElement for r in rel2.RelatedPort.ContainedIn if r.RelatedElement != element])
    return results


def get_connected_from(element):
    # Note: this code is for IFC2X3. IFC4 has a different approach.
    results = []
    for rel in element.HasPorts:
        for rel2 in rel.RelatingPort.ConnectedFrom:
            results.extend([r.RelatedElement for r in rel2.RelatingPort.ContainedIn if r.RelatedElement != element])
    return results