/*      $NetBSD: type_enum.c,v 1.13 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_enum.c,v 1.13 2021/04/13 13:13:04 christos Exp $");

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

/*
 * Prototypes.
 */
static int
trim_blanks(char *field);

/*
 * The enum type handling.
 */

typedef struct 
{
        char **choices;
        unsigned num_choices;
        bool ignore_case;
        bool exact;
} enum_args;

/*
 * Find the first non-blank character at the end of a field, return the
 * index of that character.
 */
static int
trim_blanks(char *field)
{
        int i;

        i = (int) strlen(field);
        if (i > 0)
                i--;
        else
                return 0;
        
        while ((i > 0) && isblank((unsigned char)field[i]))
                i--;
        
        return i;
}

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

        new = malloc(sizeof(*new));
        if (new == NULL)
                return NULL;

        new->choices = va_arg(*args, char **);
        new->ignore_case = (va_arg(*args, int)) ? TRUE : FALSE;
        new->exact = (va_arg(*args, int)) ? TRUE : FALSE;

        _formi_dbg_printf("%s: ignore_case %d, no_blanks %d\n", __func__,
            new->ignore_case, new->exact);
        
          /* count the choices we have */
        choices = new->choices;
        new->num_choices = 0;
        while (*choices != NULL) {
                _formi_dbg_printf("%s: choice[%u] = \'%s\'\n", __func__,
                    new->num_choices, new->choices[new->num_choices]);
                new->num_choices++;
                choices++;
        }
        _formi_dbg_printf("%s: have %u choices\n", __func__,
            new->num_choices);

        return (void *) new;
}

/*
 * Copy the enum argument structure.
 */
static char *
copy_enum_args(char *args)
{
        enum_args *new;

        new = malloc(sizeof(*new));

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

        return (void *) new;
}

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

/*
 * Attempt to match the string in this to the choices given.  Returns
 * TRUE if match found otherwise FALSE.
 * 
 */
static bool
match_enum(char **choices, unsigned num_choices, bool ignore_case,
           bool exact, char *this, unsigned *match_num)
{
        unsigned i, start, end, enum_start, blen, elen, enum_end;
        bool cur_match;

        start = _formi_skip_blanks(this, 0);
        end = trim_blanks(this);

        if (end >= start)
                blen = (unsigned) (strlen(&this[start])
                                   - strlen(&this[end]) + 1);
        else
                blen = 0;

        _formi_dbg_printf("%s: start %u, blen %u\n", __func__, start, blen);
        for (i = 0; i < num_choices; i++) {
                enum_start = _formi_skip_blanks(choices[i], 0);
                enum_end = trim_blanks(choices[i]);

                if (enum_end >= enum_start)
                        elen = (unsigned) (strlen(&choices[i][enum_start])
                                - strlen(&choices[i][enum_end]) + 1);
                else
                        elen = 0;
                
                _formi_dbg_printf("%s: checking choice \'%s\'\n", __func__,
                        choices[i]);
                _formi_dbg_printf("%s: enum_start %u, elen %u\n", __func__,
                        enum_start, elen);
                
                  /* don't bother if we are after an exact match
                   * and the test length is not equal to the enum
                   * in question - it will never match.
                   */
                if ((exact == TRUE) && (blen != elen))
                        continue;

                  /*
                   * If the test length is longer than the enum
                   * length then there is no chance of a match
                   * so we skip.
                   */
                if ((exact != TRUE) && (blen > elen))
                        continue;
                
                if (ignore_case)
                        cur_match = (strncasecmp(&choices[i][enum_start],
                                                 &this[start],
                                                 (size_t)blen) == 0) ?
                                TRUE : FALSE;
                else
                        cur_match = (strncmp(&choices[i][enum_start],
                                             &this[start],
                                             (size_t) blen) == 0) ?
                                TRUE : FALSE;

                _formi_dbg_printf("%s: curmatch is %s\n", __func__,
                        (cur_match == TRUE)? "TRUE" : "FALSE");
                
                if (cur_match == TRUE) {
                        *match_num = i;
                        return TRUE;
                }

        }

        _formi_dbg_printf("%s: no match found\n", __func__);
        return FALSE;
}

/*
 * Check the contents of the field buffer match one of the enum strings only.
 */
static int
enum_check_field(FIELD *field, char *args)
{
        enum_args *ta;
        unsigned match_num;

        if (args == NULL)
                return FALSE;
        
        ta = (enum_args *) (void *) field->args;
        
        if (match_enum(ta->choices, ta->num_choices, ta->ignore_case,
                       ta->exact, args, &match_num) == TRUE) {
                _formi_dbg_printf("%s: We matched, match_num %u\n", __func__,
                    match_num);
                _formi_dbg_printf("%s: buffer is \'%s\'\n", __func__,
                    ta->choices[match_num]);
                set_field_buffer(field, 0, ta->choices[match_num]);
                return TRUE;
        }

        return FALSE;
}

/*
 * Get the next enum in the list of choices.
 */
static int
next_enum(FIELD *field, char *args)
{
        enum_args *ta;
        unsigned cur_choice;

        if (args == NULL)
                return FALSE;
        
        ta = (enum_args *) (void *) field->args;

        _formi_dbg_printf("%s: attempt to match \'%s\'\n", __func__, args);

        if (match_enum(ta->choices, ta->num_choices, ta->ignore_case,
                       ta->exact, args, &cur_choice) == FALSE) {
                _formi_dbg_printf("%s: match failed\n", __func__);
                return FALSE;
        }
        
        _formi_dbg_printf("%s: cur_choice is %u\n", __func__, cur_choice);
        
        cur_choice++;
        
        if (cur_choice >= ta->num_choices)
                cur_choice = 0;

        _formi_dbg_printf("%s: cur_choice is %u on exit\n", __func__,
            cur_choice);
        
        set_field_buffer(field, 0, ta->choices[cur_choice]);
        return TRUE;
}

/*
 * Get the previous enum in the list of choices.
 */
static int
prev_enum(FIELD *field, char *args)
{
        enum_args *ta;
        unsigned cur_choice;

        if (args == NULL)
                return FALSE;
        
        ta = (enum_args *) (void *) field->args;
        
        _formi_dbg_printf("%s: attempt to match \'%s\'\n", __func__, args);

        if (match_enum(ta->choices, ta->num_choices, ta->ignore_case,
                       ta->exact, args, &cur_choice) == FALSE) {
                _formi_dbg_printf("%s: match failed\n", __func__);
                return FALSE;
        }

        _formi_dbg_printf("%s: cur_choice is %u\n", __func__, cur_choice);
        if (cur_choice == 0)
                cur_choice = ta->num_choices - 1;
        else
                cur_choice--;
        
        _formi_dbg_printf("%s: cur_choice is %u on exit\n",
            __func__, cur_choice);

        set_field_buffer(field, 0, ta->choices[cur_choice]);
        return TRUE;
}


static FIELDTYPE builtin_enum = {
        _TYPE_HAS_ARGS | _TYPE_IS_BUILTIN,  /* flags */
        0,                                  /* refcount */
        NULL,                               /* link */
        create_enum_args,                  /* make_args */
        copy_enum_args,                    /* copy_args */
        free_enum_args,                    /* free_args */
        enum_check_field,                  /* field_check */
        NULL,                              /* char_check */
        next_enum,                         /* next_choice */
        prev_enum                          /* prev_choice */
};

FIELDTYPE *TYPE_ENUM = &builtin_enum;