/* A stupid little spinning wheel designed to make it look like useful work
   is being done.

Copyright 1999, 2000, 2001 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.

The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */

#include "config.h"

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#if HAVE_UNISTD_H
#include <unistd.h>     /* for isatty */
#endif

#include "gmp.h"
#include "gmp-impl.h"

#include "tests.h"


/* "alarm" is not available on mingw32, and the SIGALRM constant is not
   defined.  Don't bother with a spinner in this case.  */
#if ! HAVE_ALARM || ! defined (SIGALRM)
#define alarm(n)          abort()
#define signal(sig,func)  SIG_ERR
#endif


/* An application can update this to get a count printed with the spinner.
   If left at 0, no count is printed. */

unsigned long  spinner_count = 0;


int  spinner_wanted = -1;  /* -1 uninitialized, 1 wanted, 0 not */
int  spinner_tick = 1;     /* 1 ready to print, 0 not */


/*ARGSUSED*/
RETSIGTYPE
spinner_signal (int signum)
{
  spinner_tick = 1;

  if (signal (SIGALRM, spinner_signal) == SIG_ERR)
    {
      printf ("spinner_signal(): Oops, cannot reinstall SIGALRM\n");
      abort ();
    }
  alarm (1);
}


/* Initialize the spinner.

   This is done the first time spinner() is called, so an application
   doesn't need to call this directly.
  
   The spinner is only wanted if the output is a tty.  */

#define SPINNER_WANTED_INIT() \
  if (spinner_wanted < 0) spinner_init ()

void
spinner_init (void)
{
  spinner_wanted = isatty (fileno (stdout));
  if (spinner_wanted == -1)                   
    abort ();                                  

  if (!spinner_wanted)
    return;

  if (signal (SIGALRM, spinner_signal) == SIG_ERR)
    {
      printf ("(no spinner)\r");
      spinner_tick = 0;
      return;
    }
  alarm (1);

  /* unbufferred output so the spinner will show up */
  setbuf (stdout, NULL);
}


void
spinner (void)
{
  static const char  data[] = { '|', '/', '-', '\\' };
  static int         pos = 0;

  char  buf[128];

  SPINNER_WANTED_INIT ();

  if (spinner_tick)
    {
      buf[0] = data[pos];
      pos = (pos + 1) % numberof (data);
      spinner_tick = 0;

      if (spinner_count != 0)
        {
          sprintf (buf+1, " %lu\r", spinner_count);
        }
      else
        {
          buf[1] = '\r';
          buf[2] = '\0';
        }
      fputs (buf, stdout);
    }
}
