#include <X11/keysym.h>
#include <GL/gl.h>
#include <GL/glx.h>

#include <WINGs/WINGs.h>
#include <WINGs/WINGsP.h>
#include <stdio.h>

#define CONTENTH  300
#define CONTENTW  300
#define CONTENTMARGIN 30


struct couple {
  WMWindow *window;
  WMFrame *frame;
} datacouple;


float red  = 252.0/256, green  =  88.0/256, blue  = 16.0/256;
float redb = 252.0/256, greenb = 242.0/256, blueb = 80.0/256;

int Attr[] = {
  GLX_RGBA,
  GLX_RED_SIZE, 8,
  GLX_GREEN_SIZE, 8,
  GLX_BLUE_SIZE, 8,
  GLX_DEPTH_SIZE, 16,
  GLX_DOUBLEBUFFER,
  None
};
Display *display;
float alpha = 0;

void init(void) 
{
  GLfloat ambientLight[] = { 0.2f, 0.2f, 0.2f, 1.0f };
  GLfloat diffuseLight[] = { 0.8f, 0.8f, 0.8f, 1.0f };
  GLfloat specularLight[] = { 0.5f, 0.5f, 0.5f, 1.0f };
  GLfloat position[]  = { 2.0f, -0.1f, 2.0f, 1.0f };
  GLfloat position2[] = { -2.0f, -0.26f, -4.0f, 1.0f };

  glClearColor(256.0/256, 256.0/256, 256.0/256, 0.0);
  glPolygonMode(GL_FRONT, GL_FILL);
  glPolygonMode(GL_BACK, GL_FILL);
  glEnable(GL_DEPTH_TEST);
  glShadeModel(GL_SMOOTH);

  glEnable(GL_LIGHTING);
  glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientLight);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuseLight);
  //glLightfv(GL_LIGHT0, GL_SPECULAR, specularLight);
  glMateriali(GL_FRONT, GL_SHININESS, 98);
  glLightfv(GL_LIGHT0, GL_POSITION, position2);
  //glLightfv(GL_LIGHT1, GL_POSITION, position2);

  glEnable(GL_LIGHT0);
  //glEnable(GL_LIGHT1);
  glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
  //glColorMaterial(GL_FRONT, GL_SPECULAR);
  glEnable(GL_COLOR_MATERIAL);
  glShadeModel(GL_SMOOTH);
  glCullFace(GL_BACK);
  glEnable(GL_CULL_FACE);

  glEnable(GL_POLYGON_SMOOTH);
  /*glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA_SATURATE, GL_ONE);
  //glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  glHint(GL_POLYGON_SMOOTH_HINT,GL_NICEST);*/
}

void normvector(float a, float aa, float aaa,
                float b, float bb, float bbb,
                float c, float cc, float ccc,
                float *result)
{
  float v1[3], v2[3], tmp;

  v1[0] = (b-a); v1[1] = (bb-aa); v1[2] = (bbb-aaa);
  v2[0] = (b-c); v2[1] = (bb-cc); v2[2] = (bbb-ccc);

  result[0] = (v1[1] * v2[2] - v1[2] * v2[1]);
  result[1] = (v1[2] * v2[0] - v1[0] * v2[2]);
  result[2] = (v1[0] * v2[1] - v1[1] * v2[0]);

  tmp = sqrt(result[0] * result[0] + result[1] * result[1] + result[2] * result[2]);
  result[0] /= tmp;
  result[1] /= tmp;
  result[2] /= tmp;
}


void redraw(XEvent * v, void *xw)
{
  Window win;
  float z[3];

  win = *(Window *)xw;

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  glShadeModel(GL_SMOOTH);

  glRotatef(alpha, 0, 1, 0);

  glBegin(GL_TRIANGLES);

  glColor3f(redb, greenb, blueb);
  normvector(-0.85f, 0.0f, 0.0f, 0.0f, 0.0f, 0.85f, 0.0f, 0.6f, 0.0f, z);
  glNormal3fv(z);
  glVertex3f(-0.85f, 0.0f, 0.0f);
  glVertex3f(0.0f, 0.0f, 0.85f);
  glVertex3f(0.0f, 0.6f, 0.0f);

  normvector(0.0f,  0.0f,0.85f, 0.85f, 0.0f, 0.0f, 0.0f, 0.60f,0.0f, z);
  glNormal3fv(z);
  glVertex3f(0.0f, 0.0f, 0.85f);
  glVertex3f(0.85f, 0.0f, 0.0f);
  glVertex3f(0.0f, 0.6f, 0.0f);

  glColor3f(red, green, blue);
  normvector(0.85f, 0.0f, 0.0f, 0.0f, 0.0f, -0.85f, 0.0f, 0.6f, 0.0f, z);
  glNormal3fv(z);
  glVertex3f(0.85f, 0.0f, 0.0f);
  glVertex3f(0.0f, 0.0f, -0.85f);
  glVertex3f(0.0f, 0.6f, 0.0f);

  normvector(0.0f, 0.0f, -0.85f, -0.85f, 0.0f, 0.0f, 0.0f, 0.6f, 0.0f, z);
  glNormal3fv(z);
  glVertex3f(0.0f, 0.0f, -0.85f);
  glVertex3f(-0.85f, 0.0f, 0.0f);
  glVertex3f(0.0f, 0.6f, 0.0f);

  glColor3f(redb, greenb, blueb);
  normvector(-0.85f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f, 0.85f, z);
  glNormal3fv(z);
  glVertex3f(-0.85f, 0.0f, 0.0f);
  glVertex3f(0.0f, -1.0f, 0.0f);
  glVertex3f(0.0f, 0.0f, 0.85f);
 
  normvector(0.0f, 0.0f, 0.85f, 0.0f, -1.0f, 0.0f,0.85f, 0.0f, 0.0f, z);
  glNormal3fv(z);
  glVertex3f(0.0f, 0.0f, 0.85f);
  glVertex3f(0.0f, -1.0f, 0.0f);
  glVertex3f(0.85f, 0.0f, 0.0f);

  glColor3f(red, green, blue);
  normvector(0.85f, 0.0f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0, -0.85f, z);
  glNormal3fv(z);
  glVertex3f(0.85f, 0.0f, 0.0f);
  glVertex3f(0.0f,-1.0f, 0.0f);
  glVertex3f(0.0f, 0.0f, -0.85f);

  normvector(0.0f, 0.0f, -0.85f, 0.0f, -1.0f, 0.0f, -0.85f, 0.0f, 0.0f, z);
  glNormal3fv(z);
  glVertex3f(0.0f, 0.0f, -0.85f);
  glVertex3f(0.0f, -1.0f, 0.0f);
  glVertex3f(-0.85f, 0.0f, 0.0f);
      
  glEnd();

  glPopMatrix();
  glXSwapBuffers(display, win);
}

setsize(unsigned int width, unsigned int height)
{
  glViewport(0, 0, width, height);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
  glMatrixMode(GL_MODELVIEW);
}

void DoRotate(void *self, void *xwindow)
{
  XEvent event;
  int i = 0;

  alpha += 15;
  if (alpha > 360) alpha = alpha - 360;

  redraw(NULL, (Window *)xwindow);
}

void redo(XEvent * event, void *xw)
{
  switch (event->type) {
  case Expose:
    if (event->xexpose.count != 0) break;
    redraw(event, &event->xexpose.window);
    break;

  case ConfigureNotify:
    setsize(event->xconfigure.width, event->xconfigure.height); // assuming there will be an expose afterwards
    break;
  }
}

void closeAll(WMWidget *self, void *data)
{
  WMDestroyWidget(self);
  exit(0);
}

static void resizeHandler(void *data, WMNotification *notif)
{
  struct couple *tmp;
  WMSize size;

  tmp = (struct couple *) data;
  size = WMGetViewSize(WMWidgetView(tmp->window));
  WMResizeWidget(tmp->frame, size.width - 2*CONTENTMARGIN, size.height - 2*CONTENTMARGIN);
}

void getargs(int argc, char **argv)
{
  if (argc > 3) {
    redb   = red   = (float)atoi(argv[1]) / 256;
    greenb = green = (float)atoi(argv[2]) / 256;
    blueb  = blue  = (float)atoi(argv[3]) / 256;
  }
  if (argc > 6) {
    redb   = (float)atoi(argv[4]) / 256;
    greenb = (float)atoi(argv[5]) / 256;
    blueb  = (float)atoi(argv[6]) / 256;
  }
}

int main(int argc, char **argv)
{
  WMFrame *glframe;
  WMScreen *screen;
  WMWindow *window;
  WMButton *Button;

  /*    Xlib and glX variables    */
  Window 	win;
  XVisualInfo	*xvVisualInfo;
  Colormap	cmColorMap;
  XSetWindowAttributes 	winAttr;
  GLXContext       glXContext;

  getargs(argc, argv);
  WMInitializeApplication("GLWindow", &argc, argv);
  display = XOpenDisplay("");
  screen = WMCreateScreen(display, DefaultScreen(display));

  if(!glXQueryExtension(display, NULL, NULL)) {
    werror("X server does not have GLX\n");
    return 0;
  }

  window = WMCreateWindow(screen, "Main");
  WMResizeWidget(window, CONTENTW + 2*CONTENTMARGIN, CONTENTH + 2*CONTENTMARGIN*CONTENTH/CONTENTW);
  WMSetWindowAspectRatio(window, CONTENTW, CONTENTH, CONTENTW, CONTENTH);
  WMSetWindowCloseAction(window, closeAll, NULL);
  WMSetWindowTitle(window, "GL Frame");
  WMRealizeWidget(window);
  datacouple.window = window;
  WMSetViewNotifySizeChanges(WMWidgetView(window), True);
  WMAddNotificationObserver(resizeHandler, &datacouple, WMViewSizeDidChangeNotification, WMWidgetView(window));

  glframe = WMCreateFrame(window);
  datacouple.frame = glframe;
  WMResizeWidget(glframe, CONTENTW, CONTENTH);
  WMMoveWidget(glframe, CONTENTMARGIN, CONTENTMARGIN);
  WMRealizeWidget(glframe);

  Button = WMCreateButton(window, WBTMomentaryPush);
  WMSetButtonAction(Button, DoRotate, &win);
  WMSetButtonText(Button, "Turn");
  WMMoveWidget(Button, CONTENTMARGIN, 2);
  WMRealizeWidget(Button);
  WMMapWidget(Button);

  /*  get the frame's X window value  */
  win = W_VIEW_DRAWABLE(WMWidgetView(glframe));
  WMCreateEventHandler(WMWidgetView(glframe), ExposureMask | StructureNotifyMask, redo, &win);

  xvVisualInfo = glXChooseVisual(display, DefaultScreen(display), Attr);
  if (xvVisualInfo == NULL) {
    werror("glX could not find a suitable visual\n");
    return 0;
  }

  cmColorMap = XCreateColormap(display, RootWindow(display, DefaultScreen(display)), xvVisualInfo->visual, AllocNone);

  winAttr.colormap = cmColorMap;
  winAttr.border_pixel = 0;
  winAttr.background_pixel = 0;
  winAttr.event_mask = ExposureMask | ButtonPressMask | StructureNotifyMask | KeyPressMask;

  XChangeWindowAttributes(display, win, CWBorderPixel | CWColormap | CWEventMask, &winAttr);
  glXContext = glXCreateContext(display, xvVisualInfo, None, True);
  if(!glXContext) {
    werror("glX cannot create rendering context\n");
    return 0;
  }

  glXMakeCurrent(display, win, glXContext);

  WMMapWidget(glframe);
  init();
  setsize(CONTENTW, CONTENTH);
  WMMapWidget(window);

  WMScreenMainLoop(screen);

  return 0;
}