from PyQt5.QtCore import QTimer
from PyQt5.QtWidgets import QOpenGLWidget
from OpenGL.GL import *
from OpenGL.GLU import *

class GLWidget(QOpenGLWidget):
  def __init__(self, parent=None):
    super().__init__(parent)
    self.xRot = 20.0
    self.yRot = 30.0
    self.zRot = 0.0
    self.rotation_speed = 2.0
    self.timer = QTimer(self)
    self.timer.timeout.connect(self.updateRotation)

  def initializeGL(self):
    version = glGetString(GL_VERSION)
    print("GL version:", version)
    glClearColor(0.1, 0.1, 0.1, 1.0)
    glEnable(GL_DEPTH_TEST)
    glShadeModel(GL_SMOOTH)
    glEnable(GL_COLOR_MATERIAL)
    glEnable(GL_LIGHTING)
    glEnable(GL_LIGHT0)
    light_position = [4.0, 4.0, 8.0, 1.0]
    glLightfv(GL_LIGHT0, GL_POSITION, light_position)

  def resizeGL(self, w, h):
    if h == 0:
      h = 1
    glViewport(0, 0, w, h)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glLoadIdentity()
    gluPerspective(45.0, float(w) / float(h), 0.1, 100.0)
    glMatrixMode(GL_MODELVIEW)

  def paintGL(self):
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glLoadIdentity()
    glTranslatef(0.0, 0.0, -7.0)
    glRotatef(self.xRot, 1.0, 0.0, 0.0)
    glRotatef(self.yRot, 0.0, 1.0, 0.0)
    glRotatef(self.zRot, 0.0, 0.0, 1.0)
    self.drawCube()

  def drawCube(self):
    glBegin(GL_QUADS)
    # Front (red)
    glColor3f(1.0, 0.0, 0.0)
    glVertex3f(-1.0, -1.0,    1.0)
    glVertex3f( 1.0, -1.0,    1.0)
    glVertex3f( 1.0,    1.0,    1.0)
    glVertex3f(-1.0,    1.0,    1.0)
    # Back (green)
    glColor3f(0.0, 1.0, 0.0)
    glVertex3f(-1.0, -1.0, -1.0)
    glVertex3f(-1.0,    1.0, -1.0)
    glVertex3f( 1.0,    1.0, -1.0)
    glVertex3f( 1.0, -1.0, -1.0)
    # Top (blue)
    glColor3f(0.0, 0.0, 1.0)
    glVertex3f(-1.0,    1.0, -1.0)
    glVertex3f(-1.0,    1.0,    1.0)
    glVertex3f( 1.0,    1.0,    1.0)
    glVertex3f( 1.0,    1.0, -1.0)
    # Bottom (yellow)
    glColor3f(1.0, 1.0, 0.0)
    glVertex3f(-1.0, -1.0, -1.0)
    glVertex3f( 1.0, -1.0, -1.0)
    glVertex3f( 1.0, -1.0,    1.0)
    glVertex3f(-1.0, -1.0,    1.0)
    # Right (magenta)
    glColor3f(1.0, 0.0, 1.0)
    glVertex3f( 1.0, -1.0, -1.0)
    glVertex3f( 1.0,    1.0, -1.0)
    glVertex3f( 1.0,    1.0,    1.0)
    glVertex3f( 1.0, -1.0,    1.0)
    # Left (cyan)
    glColor3f(0.0, 1.0, 1.0)
    glVertex3f(-1.0, -1.0, -1.0)
    glVertex3f(-1.0, -1.0,    1.0)
    glVertex3f(-1.0,    1.0,    1.0)
    glVertex3f(-1.0,    1.0, -1.0)
    glEnd()

  def startRotation(self):
    if not self.timer.isActive():
      self.timer.start(30)

  def stopRotation(self):
    if self.timer.isActive():
      self.timer.stop()

  def resetView(self):
    self.xRot = 20.0
    self.yRot = 30.0
    self.zRot = 0.0
    self.update()

  def updateRotation(self):
    self.xRot += self.rotation_speed
    self.yRot += self.rotation_speed * 0.8
    self.zRot += self.rotation_speed * 0.5
    self.update()