#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xcms.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

Display*
getDisplay() {
  /* Get a display to use */
  /* Currently just uses the default display */
  Display *display = XOpenDisplay(NULL);

  if (display == NULL) {
    fprintf(stderr, "Could not open the display! :(\n");
    exit(1);
  }

  return display;
}

XColor*
getColor(Display *display,
         int screen,
         unsigned short red,
         unsigned short green,
         unsigned short blue) {
  /* Return a new XColor structure */
  /* Initialize it with RGB */

  XColor *xcolor = malloc(sizeof (XColor));

  xcolor->red = red;
  xcolor->green = green;
  xcolor->blue = blue;

  xcolor->flags = DoRed | DoGreen | DoBlue;
  XAllocColor(display,
              XDefaultColormap(display, screen),
              xcolor);

  return xcolor;
}

int
main(void) {
  Window window;
  XEvent event;

  Display *display = getDisplay();
  int screen = DefaultScreen(display);
  GC gc = XDefaultGC(display, screen);

  XColor *xcolor = getColor(display, screen, 0xffff, 0xffff, 0xffff);

  window = XCreateSimpleWindow(display,
                               RootWindow(display, screen),
                               10,
                               10,
                               100,
                               100,
                               1,
                               WhitePixel(display, screen),
                               xcolor->pixel);

  XSelectInput(display,
               window,
               ExposureMask | KeyPressMask);

  XMapWindow(display, window);

  int depth = DefaultDepth(display, DefaultScreen(display));

  Pixmap pixmap;
  pixmap = XCreatePixmap(display,
                         window,
                         100,
                         100,
                         depth);

  int factor = 0;

  struct timespec req;
  struct timespec rem;

  req.tv_sec = 0;
  req.tv_nsec = 20000000;

  while (1) {
    /* Event loop that handles events from the X server's event queue */
    /* Will actually block if there are no events */

    XNextEvent(display, &event);
    if (event.type == Expose) {

      XColor *boxcolor = getColor(display, screen, 32000, 0, 32000);

      XSetForeground(display, gc, boxcolor->pixel);

    }

    //if (event.type == KeyPress) {
      //break;
    //}

    for(int x = 0; x < 100; x++) {
      for(int y = 0; y < 100; y++) {
        XDrawPoint(display, pixmap, gc, x, y);
      }
    }

    factor++;

    XClearWindow(display, window);

    XCopyArea(display,
              pixmap,
              window,
              gc,
              0,
              0,
              100,
              100,
              factor,
              factor);

    nanosleep(&req, &rem);

  }

  XCloseDisplay(display);

  return 0;
}