/*      $NetBSD: type_numeric.c,v 1.10 2021/04/13 13:13:04 christos Exp $       */

/*-
 * Copyright (c) 1998-1999 Brett Lymn
 *                         (blymn@baea.com.au, brett_lymn@yahoo.com.au)
 * All rights reserved.
 *
 * This code has been donated to The NetBSD Foundation by the Author.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: type_numeric.c,v 1.10 2021/04/13 13:13:04 christos Exp $");

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "form.h"
#include "internals.h"

/*
 * The numeric type handling.
 */

typedef struct 
{
        unsigned precision;
        double min;
        double max;
} numeric_args;

/*
 * Create the numeric arguments structure from the given args.  Return NULL
 * if the call fails, otherwise return a pointer to the structure allocated.
 */
static char *
create_numeric_args(va_list *args)
{
        numeric_args *new;

        new = malloc(sizeof(*new));

        if (new != NULL) {
                new->precision = va_arg(*args, unsigned);
                new->min = va_arg(*args, double);
                new->max = va_arg(*args, double);
        }

        return (void *) new;
}

/*
 * Copy the numeric argument structure.
 */
static char *
copy_numeric_args(char *args)
{
        numeric_args *new;

        new = malloc(sizeof(*new));

        if (new != NULL)
                memcpy(new, args, sizeof(*args));

        return (void *) new;
}

/*
 * Free the allocated storage associated with the type arguments.
 */
static void
free_numeric_args(char *args)
{
        if (args != NULL)
                free(args);
}

/*
 * Check the contents of the field buffer are numeric only.  A valid
 * number is of the form nnnn[.mmmmm][Ee[+-]ddd]
 */
static int
numeric_check_field(FIELD *field, char *args)
{
        int cur;
        double number, max, min;
        int precision;
        char *buf, *new_buf;

        if (args == NULL)
                return FALSE;
        
        precision = ((numeric_args *) (void *) field->args)->precision;
        min = ((numeric_args *) (void *) field->args)->min;
        max = ((numeric_args *) (void *) field->args)->max;
        
        buf = args;
        cur = 0;

          /* skip leading white space */
        while ((buf[cur] != '\0')
               && ((buf[cur] == ' ') || (buf[cur] == '\t')))
                cur++;

          /* no good if we have hit the end */
        if (buf[cur] == '\0')
                return FALSE;

          /* find the end of the digits but allow a leading + or - sign, and
           * a decimal point.
           */
        if ((buf[cur] == '-') || (buf[cur] == '+'))
                cur++;
        
        while(isdigit((unsigned char)buf[cur]))
                cur++;

          /* if not at end of string then check for decimal... */
        if (buf[cur] == '.') {
                cur++;
                /* check for more digits now.... */
                while (buf[cur] && isdigit((unsigned char)buf[cur]))
                        cur++;
        }
        
          /* check for an exponent */
        if ((buf[cur] == 'E') || (buf[cur] == 'e')) {
                cur++;
                if (buf[cur] == '\0')
                        return FALSE;
                        
                  /* allow a + or a - for exponent */
                if ((buf[cur] == '+') || (buf[cur] == '-'))
                        cur++;

                if (buf[cur] == '\0')
                        return FALSE;
                        
                  /* we expect a digit now */
                if (!isdigit((unsigned char)buf[cur]))
                        return FALSE;
                        
                  /* skip digits for the final time */
                while(isdigit((unsigned char)buf[cur]))
                        cur++;
        }
                        
          /* check there is only trailing whitespace */
        while ((buf[cur] != '\0')
               && ((buf[cur] == ' ') || (buf[cur] == '\t')))
                cur++;

          /* no good if we are not at the end of the string */
        if (buf[cur] != '\0')
                return FALSE;

          /* convert and range check the number...*/
        number = atof(buf);
        if ((min < max) && ((number < min) || (number > max)))
                return FALSE;

        if (asprintf(&new_buf, "%.*f", precision, number) < 0)
                return FALSE;

          /* re-set the field buffer to be the reformatted numeric */
        set_field_buffer(field, 0, new_buf);

        free(new_buf);
        
          /* otherwise all was ok */
        return TRUE;
}

/*
 * Check the given character is numeric, return TRUE if it is.
 */
static int
numeric_check_char(/* ARGSUSED1 */ int c, char *args)
{
        return ((isdigit(c) || (c == '-') || (c == '+')
                 || (c == '.') || (c == 'e') || (c == 'E')) ? TRUE : FALSE);
}

static FIELDTYPE builtin_numeric = {
        _TYPE_HAS_ARGS | _TYPE_IS_BUILTIN,  /* flags */
        0,                                  /* refcount */
        NULL,                               /* link */
        create_numeric_args,                  /* make_args */
        copy_numeric_args,                    /* copy_args */
        free_numeric_args,                    /* free_args */
        numeric_check_field,                  /* field_check */
        numeric_check_char,                   /* char_check */
        NULL,                               /* next_choice */
        NULL                                /* prev_choice */
};

FIELDTYPE *TYPE_NUMERIC = &builtin_numeric;