from typing import Optional

from maya import cmds, mel
from maya.api.OpenMaya import MFnMesh, MSpace, MVector

from ..config.mesh import Mesh as MeshConfig
from ..model.dna import DNA
from ..model.mesh import Mesh as MeshModel
from ..util.maya_util import Maya


class MeshNormals:
    """
    A utility class used for adding normals to a mesh
    """

    @staticmethod
    def add_normals(
        config: MeshConfig,
        dna: DNA,
        data: MeshModel,
        fn_mesh: MFnMesh,
        space: Optional[MSpace] = MSpace.kObject,
    ) -> None:
        """
        Adds normals to the mesh node.

        @type config: MeshConfig
        @param config: Mesh configuration from the DNA.

        @type data: MeshModel
        @param data: An object that stores values that get passed around different methods.

        @type fn_mesh: MFnMesh
        @params fn_mesh: Object used for manipulating maya mesh objects.

        @type space: Optional[space]
        @params space: The maya space used for setting the face vertex normals (defaults to MSpace.kObject)
        """

        data.vertex_normals = dna.get_vertex_normals_for_mesh(config.mesh_index)
        data.dna_vertex_layout_normals = []
        for layout in dna.get_layouts_for_mesh_index(config.mesh_index):
            data.dna_vertex_layout_normals.append(
                dna.get_normal_for_mesh_index_and_layout(config.mesh_index, layout)
            )

        normal_array = []
        face_array = []
        vertex_array = []

        dna_faces = dna.get_faces(config.mesh_index)
        for face_id, vertices_layout_index_array in enumerate(dna_faces):
            for vertex_layout_index in vertices_layout_index_array:
                vertex_normal_raw = data.dna_vertex_layout_normals[vertex_layout_index]
                vertex_normal = MVector(
                    vertex_normal_raw.x, vertex_normal_raw.y, vertex_normal_raw.z
                )
                normal_array.append(vertex_normal)
                face_array.append(face_id)
                vertex_id = data.dna_vertex_layout_positions[vertex_layout_index]
                vertex_array.append(vertex_id)

        fn_mesh.setFaceVertexNormals(normal_array, face_array, vertex_array, space)

        mesh_node = MFnMesh(Maya.get_element(dna.get_mesh_name(config.mesh_index)))
        mesh_node.unlockVertexNormals(range(len(data.dna_vertex_positions)))
        cmds.polySoftEdge(mesh_node.name(), a=180, ch=False)
        mel.eval("BakeAllNonDefHistory;")