#!/usr/bin/env python3

import sys
import ctypes
import argparse
import os
import math

import pygame as pg
import pygame.locals as pgl
import OpenGL.GL as gl
import OpenGL.GLU as glu

from d3.model.tools import load_model
from d3.geometry import Vector
from d3.controls import TrackBallControls, OrbitControls
from d3.camera import Camera
from d3.shader import DefaultShader

WINDOW_WIDTH = 1024
WINDOW_HEIGHT = 768

def main(args):

    if (args.from_up is None) != (args.to_up is None):
        raise Exception("from-up and to-up args should be both present or both absent")

    up_conversion = None
    if args.from_up is not None:
        up_conversion = (args.from_up, args.to_up)


    camera = Camera(Vector(0,0,5), Vector(0,0,0))
    controls = OrbitControls()

    pg.init()
    display = (WINDOW_WIDTH, WINDOW_HEIGHT)
    pg.display.set_mode(display, pgl.DOUBLEBUF | pgl.OPENGL)
    pg.display.set_caption('Model-Converter')

    # OpenGL init
    gl.glMatrixMode(gl.GL_PROJECTION)
    gl.glLoadIdentity()
    glu.gluPerspective(45, (WINDOW_WIDTH / WINDOW_HEIGHT), 0.1, 50.0)

    gl.glBlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE_MINUS_SRC_ALPHA)
    gl.glEnable(gl.GL_DEPTH_TEST)
    gl.glEnable(gl.GL_CULL_FACE)
    gl.glEnable(gl.GL_BLEND)
    gl.glClearColor(0, 0, 0, 0)

    running = True

    # Load and parse the model
    model = load_model(args.input, up_conversion)

    # Initializes OpenGL textures
    model.init_textures()

    # Compute normals if not already computed
    if len(model.normals) == 0:
        model.generate_vertex_normals()

    # Generate vbos for smooth rendering
    model.generate_vbos()

    shader = DefaultShader()

    while running:
        for event in pg.event.get():
            if event.type == pg.QUIT:
                pg.quit()
                quit()
            elif event.type == pg.KEYUP:
                if event.key == pg.K_ESCAPE:
                    pg.quit()
                    quit()
            elif event.type == pg.MOUSEBUTTONDOWN:
                if event.button == 1:
                    pg.mouse.get_rel()

        # Update physics
        controls.update()

        gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
        gl.glMatrixMode(gl.GL_MODELVIEW)
        gl.glLoadIdentity()

        camera.look()

        gl.glPushMatrix()
        controls.apply()
        shader.bind()
        model.draw()
        shader.unbind()
        gl.glPopMatrix()

        gl.glFlush()
        pg.display.flip()

        # Sleep
        pg.time.wait(10)


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.set_defaults(func=main)
    parser.add_argument('-v', '--version', action='version', version='1.0')
    parser.add_argument('-i', '--input', metavar='input', default=None, help='Input model')
    parser.add_argument('-fu', '--from-up', metavar='fup', default=None,
                        help="Initial up vector")
    parser.add_argument('-tu', '--to-up', metavar='fup', default=None,
                        help="Output up vector")

    args = parser.parse_args()
    args.func(args)