/* gen.c -- Generate pseudorandom numbers.

Copyright 1999, 2000, 2002 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 3 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.  If not, see http://www.gnu.org/licenses/.  */

/* Examples:

  $ gen 10
10 integers 0 <= X < 2^32 generated by mpz_urandomb()

  $ gen -f mpf_urandomb 10
10 real numbers 0 <= X < 1

  $ gen -z 127 10
10 integers 0 <= X < 2^127

  $ gen -f mpf_urandomb -x .9,1 10
10 real numbers 0 <= X < .9

  $ gen -s 1 10
10 integers, sequence seeded with 1

*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>
#include <time.h>
#include <string.h>

#if !HAVE_DECL_OPTARG
extern char *optarg;
extern int optind, opterr;
#endif

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

int main (argc, argv)
     int argc;
     char *argv[];
{
  const char usage[] =
    "usage: gen [-bhpq] [-a n] [-c a,c,m2exp] [-C a,c,m] [-f func] [-g alg] [-m n] [-s n] " \
    "[-x f,t] [-z n] [n]\n" \
    "  n        number of random numbers to generate\n" \
    "  -a n     ASCII output in radix n (default, with n=10)\n" \
    "  -b       binary output\n" \
    "  -c a,c,m2exp use supplied LC scheme\n" \
    "  -f func  random function, one of\n" \
    "           mpz_urandomb (default), mpz_urandomm, mpf_urandomb, rand, random\n" \
    "  -g alg   algorithm, one of mt (default), lc\n" \
    "  -h       print this text and exit\n" \
    "  -m n     maximum size of generated number plus 1 (0<= X < n) for mpz_urandomm\n" \
    "  -p       print used seed on stderr\n" \
    "  -q       quiet, no output\n" \
    "  -s n     initial seed (default: output from time(3))\n" \
    "  -x f,t   exclude all numbers f <= x <= t\n" \
    "  -z n     size in bits of generated numbers (0<= X <2^n) (default 32)\n" \
    "";

  unsigned long int f;
  unsigned long int n = 0;
  unsigned long int seed;
  unsigned long int m2exp = 0;
  unsigned int size = 32;
  int seed_from_user = 0;
  int ascout = 1, binout = 0, printseed = 0;
  int output_radix = 10;
  int lc_scheme_from_user = 0;
  int quiet_flag = 0;
  mpz_t z_seed;
  mpz_t z1;
  mpf_t f1;
  gmp_randstate_t rstate;
  int c, i;
  double drand;
  long lrand;
  int do_exclude = 0;
  mpf_t f_xf, f_xt;		/* numbers to exclude from sequence */
  char *str_xf, *str_xt;	/* numbers to exclude from sequence */
  char *str_a, *str_adder, *str_m;
  mpz_t z_a, z_m, z_mmax;
  unsigned long int ul_adder;

  enum
  {
    RFUNC_mpz_urandomb = 0,
    RFUNC_mpz_urandomm,
    RFUNC_mpf_urandomb,
    RFUNC_rand,
    RFUNC_random,
  } rfunc = RFUNC_mpz_urandomb;
  char *rfunc_str[] =  { "mpz_urandomb", "mpz_urandomm", "mpf_urandomb",
			 "rand", "random" };
  enum
  {
    RNG_MT = 0,
    RNG_LC
  };
  gmp_randalg_t ralg = RNG_MT;
  /* Texts for the algorithms.  The index of each must match the
     corresponding algorithm in the enum above.  */
  char *ralg_str[] = { "mt", "lc" };

  mpf_init (f_xf);
  mpf_init (f_xt);
  mpf_init (f1);
  mpz_init (z1);
  mpz_init (z_seed);
  mpz_init_set_ui (z_mmax, 0);


  while ((c = getopt (argc, argv, "a:bc:f:g:hm:n:pqs:z:x:")) != -1)
    switch (c)
      {
      case 'a':
	ascout = 1;
	binout = 0;
	output_radix = atoi (optarg);
	break;

      case 'b':
	ascout = 0;
	binout = 1;
	break;

      case 'c':			/* User supplied LC scheme: a,c,m2exp */
	if (NULL == (str_a = strtok (optarg, ","))
	    || NULL == (str_adder = strtok (NULL, ","))
	    || NULL == (str_m = strtok (NULL, ",")))
	  {
	    fprintf (stderr, "gen: bad LC scheme parameters: %s\n", optarg);
	    exit (1);
	  }
#ifdef HAVE_STRTOUL
	ul_adder = strtoul (str_adder, NULL, 0);
#elif HAVE_STRTOL
	ul_adder = (unsigned long int) strtol (str_adder, NULL, 0);
#else
	ul_adder = (unsigned long int) atoi (str_adder);
#endif

	if (mpz_init_set_str (z_a, str_a, 0))
	  {
	    fprintf (stderr, "gen: bad LC scheme parameter `a': %s\n", str_a);
	    exit (1);
	  }
	if (ULONG_MAX == ul_adder)
	  {
	    fprintf (stderr, "gen: bad LC scheme parameter `c': %s\n",
		     str_adder);
	    exit (1);
	  }
	m2exp = atol (str_m);

	lc_scheme_from_user = 1;
	break;


      case 'f':
	rfunc = -1;
	for (f = 0; f < sizeof (rfunc_str) / sizeof (*rfunc_str); f++)
	    if (!strcmp (optarg, rfunc_str[f]))
	      {
		rfunc = f;
		break;
	      }
	if (rfunc == -1)
	  {
	    fputs (usage, stderr);
	    exit (1);
	  }
	break;

      case 'g':			/* algorithm */
	ralg = -1;
	for (f = 0; f < sizeof (ralg_str) / sizeof (*ralg_str); f++)
	    if (!strcmp (optarg, ralg_str[f]))
	      {
		ralg = f;
		break;
	      }
	if (ralg == -1)
	  {
	    fputs (usage, stderr);
	    exit (1);
	  }
	break;

      case 'm':			/* max for mpz_urandomm() */
	if (mpz_set_str (z_mmax, optarg, 0))
	  {
	    fprintf (stderr, "gen: bad max value: %s\n", optarg);
	    exit (1);
	  }
	break;

      case 'p':			/* print seed on stderr */
	printseed = 1;
	break;

      case 'q':			/* quiet */
	quiet_flag = 1;
	break;

      case 's':			/* user provided seed */
	if (mpz_set_str (z_seed, optarg, 0))
	  {
	    fprintf (stderr, "gen: bad seed argument %s\n", optarg);
	    exit (1);
	  }
	seed_from_user = 1;
	break;

      case 'z':
	size = atoi (optarg);
	if (size < 1)
	  {
	    fprintf (stderr, "gen: bad size argument (-z %u)\n", size);
	    exit (1);
	  }
	break;

      case 'x':			/* Exclude. from,to */
	str_xf = optarg;
	str_xt = strchr (optarg, ',');
	if (NULL == str_xt)
	  {
	    fprintf (stderr, "gen: bad exclusion parameters: %s\n", optarg);
	    exit (1);
	  }
	*str_xt++ = '\0';
	do_exclude = 1;
	break;

      case 'h':
      case '?':
      default:
	fputs (usage, stderr);
	exit (1);
      }
  argc -= optind;
  argv += optind;

  if (! seed_from_user)
    mpz_set_ui (z_seed, (unsigned long int) time (NULL));
  seed = mpz_get_ui (z_seed);
  if (printseed)
    {
      fprintf (stderr, "gen: seed used: ");
      mpz_out_str (stderr, output_radix, z_seed);
      fprintf (stderr, "\n");
    }

  mpf_set_prec (f1, size);

  /* init random state and plant seed */
  switch (rfunc)
    {
    case RFUNC_mpf_urandomb:
#if 0
      /* Don't init a too small generator.  */
      size = PREC (f1) * GMP_LIMB_BITS;
      /* Fall through.  */
#endif
    case RFUNC_mpz_urandomb:
    case RFUNC_mpz_urandomm:
      switch (ralg)
	{
	case RNG_MT:
	  gmp_randinit_mt (rstate);
	  break;

	case RNG_LC:
	  if (! lc_scheme_from_user)
	    gmp_randinit_lc_2exp_size (rstate, MIN (128, size));
	  else
	    gmp_randinit_lc_2exp (rstate, z_a, ul_adder, m2exp);
	  break;

	default:
	  fprintf (stderr, "gen: unsupported algorithm\n");
	  exit (1);
	}

      gmp_randseed (rstate, z_seed);
      break;

    case RFUNC_rand:
      srand (seed);
      break;

    case RFUNC_random:
#ifdef __FreeBSD__		/* FIXME */
      if (seed_from_user)
	srandom (seed);
      else
	srandomdev ();
#else
      fprintf (stderr, "gen: unsupported algorithm\n");
#endif
      break;

    default:
      fprintf (stderr, "gen: random function not implemented\n");
      exit (1);
    }

  /* set up excludes */
  if (do_exclude)
    switch (rfunc)
      {
      case RFUNC_mpf_urandomb:

	if (mpf_set_str (f_xf, str_xf, 10) ||
	    mpf_set_str (f_xt, str_xt, 10))
	  {
	    fprintf (stderr, "gen: bad exclusion-from (\"%s\") " \
		     "or exclusion-to (\"%s\") string.  no exclusion done.\n",
		     str_xf, str_xt);
	    do_exclude = 0;
	  }
	break;

      default:
	fprintf (stderr, "gen: exclusion not implemented for chosen " \
		 "randomization function.  all numbers included in sequence.\n");
      }

  /* generate and print */
  if (argc > 0)
    {
#if HAVE_STRTOUL
      n = strtoul (argv[0], (char **) NULL, 10);
#elif HAVE_STRTOL
      n = (unsigned long int) strtol (argv[0], (char **) NULL, 10);
#else
      n = (unsigned long int) atoi (argv[0]);
#endif
    }

  for (f = 0; n == 0 || f < n; f++)
    {
      switch (rfunc)
	{
	case RFUNC_mpz_urandomb:
	  mpz_urandomb (z1, rstate, size);
	  if (quiet_flag)
	    break;
	  if (binout)
	    {
	      /*fwrite ((unsigned int *) z1->_mp_d, 4, 1, stdout);*/
	      fprintf (stderr, "gen: binary output for mpz_urandom* is broken\n");
	      exit (1);
	    }
	  else
	    {
	      mpz_out_str (stdout, output_radix, z1);
	      puts ("");
	    }
	  break;

	case RFUNC_mpz_urandomm:
	  mpz_urandomm (z1, rstate, z_mmax);
	  if (quiet_flag)
	    break;
	  if (binout)
	    {
	      /*fwrite ((unsigned int *) z1->_mp_d, 4, 1, stdout);*/
	      fprintf (stderr, "gen: binary output for mpz_urandom* is broken\n");
	      exit (1);
	    }
	  else
	    {
	      mpz_out_str (stdout, output_radix, z1);
	      puts ("");
	    }
	  break;

	case RFUNC_mpf_urandomb:
	  mpf_urandomb (f1, rstate, size);
	  if (do_exclude)
	    if (mpf_cmp (f1, f_xf) >= 0 && mpf_cmp (f1, f_xt) <= 0)
		break;
	  if (quiet_flag)
	    break;
	  if (binout)
	    {
	      fprintf (stderr, "gen: binary output for floating point numbers "\
		       "not implemented\n");
	      exit (1);
	    }
	  else
	    {
	      mpf_out_str (stdout, output_radix, 0, f1);
	      puts ("");
	    }
	  break;

	case RFUNC_rand:
	  i = rand ();
#ifdef FLOAT_OUTPUT
	  if (i)
	    drand = (double) i / (double) RAND_MAX;
	  else
	    drand = 0.0;
	  if (quiet_flag)
	    break;
	  if (binout)
	    fwrite (&drand, sizeof (drand), 1, stdout);
	  else
	    printf ("%e\n", drand);
#else
	  if (quiet_flag)
	    break;
	  if (binout)
	    fwrite (&i, sizeof (i), 1, stdout);
	  else
	    printf ("%d\n", i);
#endif
	  break;

	case RFUNC_random:
	  lrand = random ();
	  if (lrand)
	    drand = (double) lrand / (double) 0x7fffffff;
	  else
	    drand = 0;
	  if (quiet_flag)
	    break;
	  if (binout)
	    fwrite (&drand, sizeof (drand), 1, stdout);
	  else
	    printf ("%e\n", drand);
	  break;

	default:
	  fprintf (stderr, "gen: random function not implemented\n");
	  exit (1);
	}

    }

  /* clean up */
  switch (rfunc)
    {
    case RFUNC_mpz_urandomb:
    case RFUNC_mpf_urandomb:
      gmp_randclear (rstate);
      break;
    default:
      break;
    }
  mpf_clear (f1);
  mpf_clear (f_xf);
  mpf_clear (f_xt);
  mpz_clear (z1);
  mpz_clear (z_seed);

  return 0;
}

static void *debug_dummyz = mpz_dump;
static void *debug_dummyf = mpf_dump;