/*
 * The Rubik's cube.
 *
 * Sed - april 1999 / december 2003.
 *
 * This program is in the public domain.
 *--------------------
 * The wait event function, or how to show the superiority of select in face of threads shit.
 */

#include "event.h"

#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <X11/Xlib.h>

#include "screen.h"
#include "cube.h"

int can_mix(int fd)
{
  fd_set w;
  struct timeval t;

  FD_ZERO(&w);

  t.tv_sec=0;
  t.tv_usec=0;

  FD_SET(fd, &w);

  select(fd+1, 0, &w, 0, &t);

  return FD_ISSET(fd, &w);
}

/* return -1 of error, and what it has to, read it */
int wait_event(SCREEN *s, CUBE *c)
{
  fd_set r, w;
  struct timeval t; /* , u; */
  int ret;
  XEvent ev;

  FD_ZERO(&r);
  FD_ZERO(&w);

  t.tv_sec=0;
  t.tv_usec=0; /* 50*1000; */

  if (XCheckMaskEvent(s->d, -1L, &ev)!=False) {
    XPutBackEvent(s->d, &ev);
    return SCREEN_EVENT;
  }

  FD_SET(ConnectionNumber(s->d), &r);

  if (c->anim)
    while((ret=select(FD_SETSIZE, &r, &w, 0, &t))==-1) {
      if (errno!=EINTR) {
	perror("select");
	return -1;
      }
    }
  else
    while((ret=select(FD_SETSIZE, &r, &w, 0, (struct timeval *)0))==-1) {
      if (errno!=EINTR) {
	perror("select");
	return -1;
      }
    }

  if (!ret) {
    return CUBE_EVENT;
  }
  ret=0;

  if (FD_ISSET(ConnectionNumber(s->d), &r))
    ret|=SCREEN_EVENT;
  else { /* I have to do this XCheckMaskEvent because X functions might already have taken
	  * away from the socket some events, that I may see too late, producing
	  * bad results for the player.
	  */
    if (XCheckMaskEvent(s->d, -1L, &ev)!=False) {
      ret |= SCREEN_EVENT;
      XPutBackEvent(s->d, &ev);
    }
  }

  return ret;
}