/*      $NetBSD: type_alnum.c,v 1.12 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 <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
#include "form.h"
#include "internals.h"

/*
 * The alpha-numeric type handling.
 */

typedef struct 
{
        unsigned width;
} alnum_args;

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

        new = malloc(sizeof(*new));

        if (new != NULL)
                new->width = va_arg(*args, int);

        return (void *)new;
}

/*
 * Copy the alnum argument structure.
 */
static char *
copy_alnum_args(char *args)
{
        alnum_args *new;

        new = malloc(sizeof(*new));

        if (new != NULL)
                new->width = ((alnum_args *) (void *)args)->width;

        return (void *)new;
}

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

/*
 * Check the contents of the field buffer are alphanumeric only.
 */
static int
alnum_check_field(FIELD *field, char *args)
{
        int width, start, cur, end;
        char *buf, *new;

        width = ((alnum_args *) (void *) field->args)->width;
        buf = args;
        start = 0;

        if (buf == NULL)
                return FALSE;
        
          /* skip leading white space */
        while ((buf[start] != '\0')
               && ((buf[start] == ' ') || (buf[start] == '\t')))
                start++;

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

          /* find the end of the non-whitespace stuff */
        cur = start;
        while(isalnum((unsigned char)buf[cur]))
                cur++;

          /* no good if it exceeds the width */
        if ((cur - start) > width)
                return FALSE;

        end = 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;

        if ((new = malloc(sizeof(*new) * (end - start + 1))) == NULL)
                return FALSE;

        if ((end - start) >= 1) {
                strncpy(new, &buf[start], (size_t) (end - start - 1));
                new[end] = '\0';
        } else
                new[0]= '\0';
                
        set_field_buffer(field, 0, new);
        free(new);
        
          /* otherwise all was ok */
        return TRUE;
}

/*
 * Check the given character is alpha-numeric, return TRUE if it is.
 */
static int
alnum_check_char(/* ARGSUSED1 */ int c, char *args)
{
        return (isalnum(c) ? TRUE : FALSE);
}

static FIELDTYPE builtin_alnum = {
        _TYPE_HAS_ARGS | _TYPE_IS_BUILTIN,  /* flags */
        0,                                  /* refcount */
        NULL,                               /* link */
        create_alnum_args,                  /* make_args */
        copy_alnum_args,                    /* copy_args */
        free_alnum_args,                    /* free_args */
        alnum_check_field,                  /* field_check */
        alnum_check_char,                   /* char_check */
        NULL,                               /* next_choice */
        NULL                                /* prev_choice */
};

FIELDTYPE *TYPE_ALNUM = &builtin_alnum;