#!/usr/bin/env python3

from math import sqrt

from ..geometry import Vector

from .mesh import Material, MeshPart

Vertex = Vector
Normal = Vertex
TexCoord = Vertex

class FaceVertex:
    def __init__(self, vertex = None, tex_coord = None, normal = None):
        self.vertex = vertex
        self.tex_coord = tex_coord
        self.normal = normal

    def from_array(self, arr):
        self.vertex  = int(arr[0]) if len(arr) > 0 else None

        try:
            self.tex_coord = int(arr[1]) if len(arr) > 1 else None
        except:
            self.tex_coord = None

        try:
            self.normal  = int(arr[2]) if len(arr) > 2 else None
        except:
            self.normal = None

        return self

class Face:
    def __init__(self, a = None, b = None, c = None, material = None):
        self.a = a
        self.b = b
        self.c = c
        self.material = material

    # Expects array of array
    def from_array(self, arr):
        self.a = FaceVertex().from_array(arr[0])
        self.b = FaceVertex().from_array(arr[1])
        self.c = FaceVertex().from_array(arr[2])
        return self

class ModelParser:

    def __init__(self):
        self.vertices = []
        self.normals = []
        self.tex_coords = []
        self.parts = []
        self.current_part = None
        self.bounding_box = BoundingBox()
        self.center_and_scale = True
        self.vertex_vbo = None
        self.tex_coord_vbo = None
        self.normal_vbo = None
        self.path = None

    def init_textures(self):
        for part in self.parts:
            part.init_texture()

    def add_vertex(self, vertex):
        self.vertices.append(vertex)
        self.bounding_box.add(vertex)

    def add_tex_coord(self, tex_coord):
        self.tex_coords.append(tex_coord)

    def add_normal(self, normal):
        self.normals.append(normal)

    def add_face(self, face):
        if self.current_part is None or face.material != self.current_part.material:
            self.current_part = MeshPart(self)
            self.current_part.material = face.material
            self.parts.append(self.current_part)

        self.current_part.add_face(face)

    def parse_line(self, string):
        pass

    def parse_file(self, path):
        self.path = path
        with open(path) as f:
            for line in f.readlines():
                line = line.rstrip()
                self.parse_line(line)

    def draw(self):
        import OpenGL.GL as gl

        if self.center_and_scale:
            center = self.bounding_box.get_center()
            scale = self.bounding_box.get_scale() / 2
            gl.glPushMatrix()
            gl.glScalef(1/scale, 1/scale, 1/scale)
            gl.glTranslatef(-center.x, -center.y, -center.z)

        for part in self.parts:
            part.draw()

        if self.center_and_scale:
            gl.glPopMatrix()

    def generate_vbos(self):
        for part in self.parts:
            part.generate_vbos()

    def generate_vertex_normals(self):

        self.normals = [Normal() for i in self.vertices]

        for part in self.parts:
            for face in part.faces:
                v1 = Vertex.from_points(self.vertices[face.a.vertex], self.vertices[face.b.vertex])
                v2 = Vertex.from_points(self.vertices[face.a.vertex], self.vertices[face.c.vertex])
                cross = Vertex.cross_product(v1, v2)
                self.normals[face.a.vertex] += cross
                self.normals[face.b.vertex] += cross
                self.normals[face.c.vertex] += cross

        for normal in self.normals:
            normal.normalize()

        for part in self.parts:
            for face in part.faces:
                face.a.normal = face.a.vertex
                face.b.normal = face.b.vertex
                face.c.normal = face.c.vertex

    def generate_face_normals(self):

        self.normals = [Normal() for i in sum(list(map(lambda x: len(x), self.faces)))]

        for (index, face) in enumerate(sum(self.faces, [])):

            v1 = Vertex.from_points(self.vertices[face.a.vertex], self.vertices[face.b.vertex])
            v2 = Vertex.from_points(self.vertices[face.a.vertex], self.vertices[face.c.vertex])
            cross = Vertex.cross_product(v1, v2)
            cross.normalize()
            self.normals[index] = cross

            face.a.normal = index
            face.b.normal = index
            face.c.normal = index


class BoundingBox:
    def __init__(self):
        self.min_x = +float('inf')
        self.min_y = +float('inf')
        self.min_z = +float('inf')

        self.max_x = -float('inf')
        self.max_y = -float('inf')
        self.max_z = -float('inf')

    def add(self, vertex):
        self.min_x = min(self.min_x, vertex.x)
        self.min_y = min(self.min_y, vertex.y)
        self.min_z = min(self.min_z, vertex.z)

        self.max_x = max(self.max_x, vertex.x)
        self.max_y = max(self.max_y, vertex.y)
        self.max_z = max(self.max_z, vertex.z)

    def __str__(self):
        return "[{},{}],[{},{}],[{},{}]".format(
            self.min_x,
            self.min_y,
            self.min_z,
            self.max_x,
            self.max_y,
            self.max_z)

    def get_center(self):
        return Vertex(
            (self.min_x + self.max_x) / 2,
            (self.min_y + self.max_y) / 2,
            (self.min_z + self.max_z) / 2)

    def get_scale(self):
        return max(
            abs(self.max_x - self.min_x),
            abs(self.max_y - self.min_y),
            abs(self.max_z - self.min_z))


class Exporter:
    def __init__(self, model):
        self.model = model