# Copyright (c) 2015 Ultimaker B.V.
# Copyright (c) 2013 David Braam
# Uranium is released under the terms of the AGPLv3 or higher.

from UM.Mesh.MeshReader import MeshReader
from UM.Mesh.MeshData import MeshData
import os
import struct
from UM.Scene.SceneNode import SceneNode

from UM.Job import Job

class OBJReader(MeshReader):
    def __init__(self):
        super(OBJReader, self).__init__()
        self._supported_extensions = [".obj"]
        
    def read(self, file_name):
        mesh = None
        scene_node = None

        vertex_list = []
        normal_list = []
        uv_list = []
        face_list = []
        scene_node = SceneNode()

        mesh = MeshData()
        scene_node.setMeshData(mesh)
        f = open(file_name, "rt")
        for line in f:
            parts = line.split()
            if len(parts) < 1:
                continue
            if parts[0] == "v":
                vertex_list.append([float(parts[1]), float(parts[3]), -float(parts[2])])
            if parts[0] == "vn":
                normal_list.append([float(parts[1]), float(parts[3]), -float(parts[2])])
            if parts[0] == "vt":
                uv_list.append([float(parts[1]), float(parts[2])])
            if parts[0] == "f":
                parts = [i for i in map(lambda p: p.split("/"), parts)]
                for idx in range(1, len(parts)-2):
                    data = [int(parts[1][0]), int(parts[idx+1][0]), int(parts[idx+2][0])]
                    if len(parts[1]) > 2:
                        data += [int(parts[1][2]), int(parts[idx+1][2]), int(parts[idx+2][2])]

                        if parts[1][1] and parts[idx+1][1] and parts[idx+2][1]:
                            data += [int(parts[1][1]), int(parts[idx+1][1]), int(parts[idx+2][1])]
                    face_list.append(data)
            Job.yieldThread()
        f.close()

        mesh.reserveVertexCount(3 * len(face_list))
        num_vertices = len(vertex_list)
        num_normals = len(normal_list)

        for face in face_list:
            # Substract 1 from index, as obj starts counting at 1 instead of 0
            i = face[0] - 1
            j = face[1] - 1
            k = face[2] - 1

            if len(face) > 3:
                ni = face[3] - 1
                nj = face[4] - 1
                nk = face[5] - 1
            else:
                ni = -1
                nj = -1
                nk = -1

            if len(face) > 6:
                ui = face[6] - 1
                uj = face[7] - 1
                uk = face[8] - 1
            else:
                ui = -1
                uj = -1
                uk = -1

            #TODO: improve this handling, this can cause weird errors
            if i < 0 or i >= num_vertices:
                i = 0
            if j < 0 or j >= num_vertices:
                j = 0
            if k < 0 or k >= num_vertices:
                k = 0
            if(ni != -1 and nj != -1 and nk != -1):
                mesh.addFaceWithNormals(vertex_list[i][0], vertex_list[i][1], vertex_list[i][2], normal_list[ni][0], normal_list[ni][1], normal_list[ni][2], vertex_list[j][0], vertex_list[j][1], vertex_list[j][2], normal_list[nj][0], normal_list[nj][1], normal_list[nj][2], vertex_list[k][0], vertex_list[k][1], vertex_list[k][2],normal_list[nk][0], normal_list[nk][1], normal_list[nk][2])
            else:
                mesh.addFace(vertex_list[i][0], vertex_list[i][1], vertex_list[i][2], vertex_list[j][0], vertex_list[j][1], vertex_list[j][2], vertex_list[k][0], vertex_list[k][1], vertex_list[k][2])

            if ui != -1:
                mesh.setVertexUVCoordinates(mesh.getVertexCount() - 3, uv_list[ui][0], uv_list[ui][1])

            if uj != -1:
                mesh.setVertexUVCoordinates(mesh.getVertexCount() - 2, uv_list[uj][0], uv_list[uj][1])

            if uk != -1:
                mesh.setVertexUVCoordinates(mesh.getVertexCount() - 1, uv_list[uk][0], uv_list[uk][1])

            Job.yieldThread()
        if not mesh.hasNormals():
            mesh.calculateNormals(fast = True)

        return scene_node