# 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/>.


class Usecase:
    def __init__(self, file, style=None, attributes=None):
        """Edits the attributes of an IfcPresentationItem

        For more information about the attributes and data types of an
        IfcPresentationItem, consult the IFC documentation.

        The IfcPresentationItem is expected to be one of IfcSurfaceStyleShading,
        IfcSurfaceStyleRendering, IfcSurfaceStyleWithTextures,
        IfcSurfaceStyleLighting, IfcSurfaceStyleReflectance, or
        IfcExternallyDefinedSurfaceStyle.

        To represent a colour, a nested dictionary should be used. See the
        example below.

        :param style: The IfcPresentationStyle entity you want to edit
        :type style: ifcopenshell.entity_instance.entity_instance
        :param attributes: a dictionary of attribute names and values.
        :type attributes: dict, optional
        :return: None
        :rtype: None

        Example:

        .. code:: python

            # Create a new surface style
            style = ifcopenshell.api.run("style.add_style", model)

            # Create a blank rendering style.
            rendering = ifcopenshell.api.run("style.add_surface_style", model,
                style=style, ifc_class="IfcSurfaceStyleRendering")

            # Edit the attributes of the rendering style.
            ifcopenshell.api.run("style.edit_surface_style", model,
                style=rendering, attributes={
                    # A surface colour and transparency is still supplied for
                    # viewport display only. This will supersede the shading
                    # presentation item.
                    "SurfaceColour": { "Name": None, "Red": 1.0, "Green": 0.8, "Blue": 0.8 },
                    "Transparency": 0., # 0 is opaque, 1 is transparent

                    # NOTDEFINED is assumed to be a PHYSICAL (PBR) lighting
                    # model. In IFC4X3, you may choose PHYSICAL directly.
                    "ReflectanceMethod": "NOTDEFINED",

                    # For PBR shading, you may specify these parameters:
                    "DiffuseColour": { "Name": None, "Red": 0.9, "Green": 0.8, "Blue": 0.8 },
                    "SpecularColour": 0.1, # Metallic factor
                    "SpecularHighlight": {"SpecularRoughness": 0.5}, # Roughness factor
                })
        """
        self.file = file
        self.settings = {"style": style, "attributes": attributes or {}}

    def execute(self):
        for key, value in self.settings["attributes"].items():
            if key == "SurfaceColour":
                self.edit_surface_colour(value)
            elif key == "SpecularHighlight":
                self.edit_specular_highlight(value)
            elif self.is_colour_or_factor(key):
                self.edit_colour_or_factor(key, value)
            else:
                setattr(self.settings["style"], key, value)

    def edit_surface_colour(self, value):
        if not self.settings["style"].SurfaceColour:
            self.settings["style"].SurfaceColour = self.file.createIfcColourRgb(
                value.get("Name", None), value["Red"], value["Green"], value["Blue"]
            )
        self.settings["style"].SurfaceColour[0] = value.get("Name", None)
        self.settings["style"].SurfaceColour[1] = value["Red"]
        self.settings["style"].SurfaceColour[2] = value["Green"]
        self.settings["style"].SurfaceColour[3] = value["Blue"]

    def is_colour_or_factor(self, name):
        return name in [
            "DiffuseColour",
            "TransmissionColour",
            "DiffuseTransmissionColour",
            "ReflectionColour",
            "SpecularColour",
        ]

    def edit_colour_or_factor(self, name, value):
        if isinstance(value, dict):
            attribute = getattr(self.settings["style"], name)
            if not attribute or not attribute.is_a("IfcColourRgb"):
                colour = self.file.createIfcColourRgb(None, 0, 0, 0)
                setattr(self.settings["style"], name, colour)
                attribute = getattr(self.settings["style"], name)
            attribute[1] = value["Red"]
            attribute[2] = value["Green"]
            attribute[3] = value["Blue"]
        else:
            existing_value = getattr(self.settings["style"], name)
            if existing_value and existing_value.id():
                self.file.remove(existing_value)
            setattr(self.settings["style"], name, self.file.createIfcNormalisedRatioMeasure(value))

    def edit_specular_highlight(self, value):
        if value is None:
            self.settings["style"].SpecularHighlight = None
        elif value.get("IfcSpecularExponent", None):
            self.settings["style"].SpecularHighlight = self.file.createIfcSpecularExponent(value["IfcSpecularExponent"])
        elif value.get("IfcSpecularRoughness", None):
            self.settings["style"].SpecularHighlight = self.file.createIfcSpecularRoughness(
                value["IfcSpecularRoughness"]
            )