# 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/>.

from math import cos, sin
from typing import Optional, Union

import ifcopenshell.util.element
import ifcopenshell.util.unit
from ifcopenshell.util.data import Clipping


def add_slab_representation(
    file: ifcopenshell.file,
    context: ifcopenshell.entity_instance,
    depth: float = 0.2,
    # TODO: document remaining args.
    direction_sense: str = "POSITIVE",
    offset: float = 0.0,
    x_angle: float = 0.0,
    clippings: Optional[list[Union[Clipping, ifcopenshell.entity_instance]]] = None,
    polyline: Optional[list[tuple[float, float]]] = None,
) -> ifcopenshell.entity_instance:
    """
    Add a geometric representation for a slab.

    :param context: The IfcGeometricRepresentationContext for the representation,
        only Model/Body/MODEL_VIEW type of representations are currently supported.
    :param depth: The slab depth, in meters.
    :param x_angle: The slope angle along the slab's X-axis, in radians.
    :param clippings: List of planes that define clipping half space solids.
        Clippings can be `Clipping` objects or dictionaries of arguments for `Clipping.parse`.
    :return: IfcShapeRepresentation.

    Example:

    .. code:: python

        context = ifcopenshell.util.representation.get_context(ifc_file, "Model", "Body", "MODEL_VIEW")
        clippings = [ifcopenshell.util.data.Clipping(location=(0.0, 0.0, 0.1), normal=(0.0, 0.0, 1.0),)]
        representation = ifcopenshell.api.geometry.add_slab_representation(ifc_file, context, depth=0.2, clippings=clippings)
        ifcopenshell.api.geometry.assign_representation(ifc_file, product=element, representation=representation)
    """
    usecase = Usecase()
    usecase.file = file
    return usecase.execute(
        context,
        depth,
        direction_sense,
        offset,
        x_angle,
        clippings if clippings is not None else [],
        polyline,
    )


class Usecase:
    file: ifcopenshell.file

    def execute(
        self,
        context: ifcopenshell.entity_instance,
        depth: float,
        direction_sense: str,
        offset: float,
        x_angle: float,
        clippings: list[Union[Clipping, ifcopenshell.entity_instance]],
        polyline: Optional[list[tuple[float, float]]],
    ) -> ifcopenshell.entity_instance:
        self.unit_scale = ifcopenshell.util.unit.calculate_unit_scale(self.file)
        self.clippings = clippings
        self.depth = depth
        self.direction_sense = direction_sense
        self.offset = offset
        self.x_angle = x_angle
        self.polyline = polyline
        return self.file.create_entity(
            "IfcShapeRepresentation",
            context,
            context.ContextIdentifier,
            "Clipping" if self.clippings else "SweptSolid",
            [self.create_item()],
        )

    def create_item(self) -> ifcopenshell.entity_instance:
        size = self.convert_si_to_unit(1)
        points = ((0.0, 0.0), (size, 0.0), (size, size), (0.0, size), (0.0, 0.0))
        if self.polyline:
            points = [
                (self.convert_si_to_unit(p[0]), self.convert_si_to_unit(p[1] * abs(1 / cos(self.x_angle))))
                for p in self.polyline
            ]
        if self.file.schema == "IFC2X3":
            curve = self.file.createIfcPolyline([self.file.createIfcCartesianPoint(p) for p in points])
        else:
            curve = self.file.createIfcIndexedPolyCurve(self.file.createIfcCartesianPointList2D(points))

        if self.x_angle:
            direction_ratios = (0.0, sin(self.x_angle), cos(self.x_angle))
        else:
            direction_ratios = (0.0, 0.0, 1.0)

        offset_direction = direction_ratios  # offset direction doesn't change if direction_sense is negative
        extrusion_direction = self.file.createIfcDirection(direction_ratios)
        if self.direction_sense == "NEGATIVE":
            direction_ratios = tuple(-n for n in direction_ratios)
            extrusion_direction = self.file.createIfcDirection(direction_ratios)

        perpendicular_offset = self.convert_si_to_unit(self.offset) * abs(1 / cos(self.x_angle))
        perpendicular_depth = self.convert_si_to_unit(self.depth) * abs(1 / cos(self.x_angle))
        position = None
        # default position for IFC2X3 where .Position is not optional
        if self.file.schema == "IFC2X3" or self.offset != 0:
            position_vector = (
                offset_direction[0] * perpendicular_offset,
                offset_direction[1] * perpendicular_offset,
                offset_direction[2] * perpendicular_offset,
            )
            position = self.file.createIfcAxis2Placement3D(
                self.file.createIfcCartesianPoint(position_vector),
                self.file.createIfcDirection((0.0, 0.0, 1.0)),
                self.file.createIfcDirection((1.0, 0.0, 0.0)),
            )

        extrusion = self.file.create_entity(
            "IfcExtrudedAreaSolid",
            self.file.createIfcArbitraryClosedProfileDef("AREA", None, curve),
            position,
            extrusion_direction,
            perpendicular_depth,
        )
        if self.clippings:
            return self.apply_clippings(extrusion)
        return extrusion

    def apply_clippings(self, first_operand: ifcopenshell.entity_instance) -> ifcopenshell.entity_instance:
        while self.clippings:
            clipping = self.clippings.pop()
            if isinstance(clipping, ifcopenshell.entity_instance):
                new = ifcopenshell.util.element.copy(self.file, clipping)
                new.FirstOperand = first_operand
                first_operand = new
            else:  # Clipping
                first_operand = clipping.apply(self.file, first_operand, self.unit_scale)
        return first_operand

    def convert_si_to_unit(self, co: float) -> float:
        return co / self.unit_scale
