/*      $NetBSD: type_regex.c,v 1.8 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_regex.c,v 1.8 2021/04/13 13:13:04 christos Exp $");

#include <stdlib.h>
#include <sys/types.h>
#include <regex.h>
#include "form.h"
#include "internals.h"

/*
 * The regex type handling.
 */

typedef struct 
{
        regex_t compiled;
        unsigned references;
} regex_args;

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

        new = malloc(sizeof(*new));

        if (new != NULL) {
                new->references = 1;
                expression = va_arg(*args, char *);
                if ((regcomp(&new->compiled, expression,
                             (REG_EXTENDED | REG_NOSUB | REG_NEWLINE))) != 0) {
                        free(new);
                        return NULL;
                }
        }

        return (void *) new;
}

/*
 * Copy the regex argument structure.
 */
static char *
copy_regex_args(char *args)
{
        ((regex_args *) (void *) args)->references++;
        
        return (void *) args;
}

/*
 * Free the allocated storage associated with the type arguments.
 */
static void
free_regex_args(char *args)
{
        if (args != NULL) {
                ((regex_args *) (void *) args)->references--;
                if (((regex_args *) (void *) args)->references == 0)
                        free(args);
        }
}

/*
 * Check the contents of the field buffer match the regex.
 */
static int
regex_check_field(FIELD *field, char *args)
{
        if ((args != NULL) &&
            (regexec(&((regex_args *) (void *) field->args)->compiled,
                   args, (size_t) 0, NULL, 0) == 0))
                return TRUE;

        return FALSE;
}

static FIELDTYPE builtin_regex = {
        _TYPE_HAS_ARGS | _TYPE_IS_BUILTIN,  /* flags */
        0,                                  /* refcount */
        NULL,                               /* link */
        create_regex_args,                  /* make_args */
        copy_regex_args,                    /* copy_args */
        free_regex_args,                    /* free_args */
        regex_check_field,                  /* field_check */
        NULL,                               /* char_check */
        NULL,                               /* next_choice */
        NULL                                /* prev_choice */
};

FIELDTYPE *TYPE_REGEXP = &builtin_regex;