/*
 * sample_rand - test the libcalc random number generator
 *
 * Copyright (C) 1999-2007,2021-2023,2026  Landon Curt Noll
 *
 * Calc is open software; you can redistribute it and/or modify it under
 * the terms of the version 2.1 of the GNU Lesser General Public License
 * as published by the Free Software Foundation.
 *
 * Calc 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.
 *
 * A copy of version 2.1 of the GNU Lesser General Public License is
 * distributed with calc under the filename COPYING-LGPL.  You should have
 * received a copy with calc; if not, write to Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Under source code control:   1997/04/19 22:46:49
 * File existed as early as:    1997
 *
 * chongo <was here> /\oo/\     http://www.isthe.com/chongo/
 * Share and enjoy!  :-)        http://www.isthe.com/chongo/tech/comp/calc/
 */

/*
 * usage:
 *      test_random [[bits] seed_string]
 *
 *      seed_string     something for which we can seed (def: default seed)
 *      bits            number of bits to generate
 */

/*
 * important <system> header includes
 */
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>

/*
 * calc local src includes
 */
#include "value.h"
#include "calc.h"
#include "lib_util.h"
#include "attribute.h"
#include "errtbl.h"

#include "banned.h" /* include after all other includes */

#define DEF_CNT 128 /* default number of bits to generate */

extern char *program; /* our name */

int
main(int argc, char **argv)
{
    RANDOM *prev_state; /* previous random number state */
    ZVALUE seed;        /* seed for Blum-Blum-Shub */
    ZVALUE random_val;  /* random number produced */
    long cnt;           /* number of bits to generate */
    char *hexstr;       /* random number as hex string */

    /*
     * parse args
     */
    program = argv[0];
    switch (argc) {
    case 3:
        seed = convstr2z(argv[2]);
        cnt = strtol(argv[1], NULL, 0);
        break;
    case 2:
        seed = _zero_; /* use the default seed */
        cnt = strtol(argv[1], NULL, 0);
        break;
    case 1:
        seed = _zero_; /* use the default seed */
        cnt = DEF_CNT;
        break;
    default:
        fprintf(stderr, "usage: %s [[bits] seed_string]\n", program);
        exit(1);
    }
    if (cnt <= 0) {
        fprintf(stderr, "%s: cnt:%d must be > 0\n", program, (int)cnt);
        exit(2);
    }
    printf("seed= 0x%s\n", convz2hex(seed));

    /*
     * libcalc setup
     */
    libcalc_call_me_first();

    /*
     * seed the generator
     */
    prev_state = zsrandom2(seed, _ten_);
    if (prev_state == NULL) {
        math_error("previous random state is NULL");
        not_reached();
    }

    /*
     * generate random bits
     */
    zrandom(cnt, &random_val);

    /*
     * convert into hex string
     */
    hexstr = convz2hex(random_val);
    printf("random= 0x%s\n", hexstr);

    /*
     * all done
     */
    /* exit(0); */
    return 0;
}
