/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1996 - 2002 FreeBSD Project
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Paul Borman at Krystal Technologies.
 *
 * 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. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <limits.h>
#include <locale.h>
#include <paths.h>                      /* for _PATH_LOCALE */
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "collate.h"
#include "lmonetary.h"                  /* for __monetary_load_locale() */
#include "lnumeric.h"                   /* for __numeric_load_locale() */
#include "lmessages.h"                  /* for __messages_load_locale() */
#include "setlocale.h"
#include "ldpart.h"
#include "../stdtime/timelocal.h"       /* for __time_load_locale() */

/*
 * Category names for getenv()
 */
static const char categories[_LC_LAST][12] = {
        "LC_ALL",
        "LC_COLLATE",
        "LC_CTYPE",
        "LC_MONETARY",
        "LC_NUMERIC",
        "LC_TIME",
        "LC_MESSAGES",
};

/*
 * Current locales for each category
 */
static char current_categories[_LC_LAST][ENCODING_LEN + 1] = {
        "C",
        "C",
        "C",
        "C",
        "C",
        "C",
        "C",
};

/*
 * Path to locale storage directory
 */
char   *_PathLocale;

/*
 * The locales we are going to try and load
 */
static char new_categories[_LC_LAST][ENCODING_LEN + 1];
static char saved_categories[_LC_LAST][ENCODING_LEN + 1];

static char current_locale_string[_LC_LAST * (ENCODING_LEN + 1/*"/"*/ + 1)];

static char *currentlocale(void);
static char *loadlocale(int);
const char *__get_locale_env(int);

char *
setlocale(int category, const char *locale)
{
        int i, j, len, saverr;
        const char *env, *r;

        if (category < LC_ALL || category >= _LC_LAST) {
                errno = EINVAL;
                return (NULL);
        }
        if (locale == NULL)
                return (category != LC_ALL ?
                    current_categories[category] : currentlocale());

        /*
         * Default to the current locale for everything.
         */
        for (i = 1; i < _LC_LAST; ++i)
                (void)strcpy(new_categories[i], current_categories[i]);

        /*
         * Now go fill up new_categories from the locale argument
         */
        if (!*locale) {
                if (category == LC_ALL) {
                        for (i = 1; i < _LC_LAST; ++i) {
                                env = __get_locale_env(i);
                                if (strlen(env) > ENCODING_LEN) {
                                        errno = EINVAL;
                                        return (NULL);
                                }
                                (void)strcpy(new_categories[i], env);
                        }
                } else {
                        env = __get_locale_env(category);
                        if (strlen(env) > ENCODING_LEN) {
                                errno = EINVAL;
                                return (NULL);
                        }
                        (void)strcpy(new_categories[category], env);
                }
        } else if (category != LC_ALL) {
                if (strlen(locale) > ENCODING_LEN) {
                        errno = EINVAL;
                        return (NULL);
                }
                (void)strcpy(new_categories[category], locale);
        } else {
                if ((r = strchr(locale, '/')) == NULL) {
                        if (strlen(locale) > ENCODING_LEN) {
                                errno = EINVAL;
                                return (NULL);
                        }
                        for (i = 1; i < _LC_LAST; ++i)
                                (void)strcpy(new_categories[i], locale);
                } else {
                        for (i = 1; r[1] == '/'; ++r)
                                ;
                        if (!r[1]) {
                                errno = EINVAL;
                                return (NULL);  /* Hmm, just slashes... */
                        }
                        do {
                                if (i == _LC_LAST)
                                        break;  /* Too many slashes... */
                                if ((len = r - locale) > ENCODING_LEN) {
                                        errno = EINVAL;
                                        return (NULL);
                                }
                                (void)strlcpy(new_categories[i], locale,
                                    len + 1);
                                i++;
                                while (*r == '/')
                                        r++;
                                locale = r;
                                while (*r && *r != '/')
                                        r++;
                        } while (*locale);
                        while (i < _LC_LAST) {
                                (void)strcpy(new_categories[i],
                                    new_categories[i - 1]);
                                i++;
                        }
                }
        }

        if (category != LC_ALL)
                return (loadlocale(category));

        for (i = 1; i < _LC_LAST; ++i) {
                (void)strcpy(saved_categories[i], current_categories[i]);
                if (loadlocale(i) == NULL) {
                        saverr = errno;
                        for (j = 1; j < i; j++) {
                                (void)strcpy(new_categories[j],
                                    saved_categories[j]);
                                if (loadlocale(j) == NULL) {
                                        (void)strcpy(new_categories[j], "C");
                                        (void)loadlocale(j);
                                }
                        }
                        errno = saverr;
                        return (NULL);
                }
        }
        return (currentlocale());
}

static char *
currentlocale(void)
{
        int i;

        (void)strcpy(current_locale_string, current_categories[1]);

        for (i = 2; i < _LC_LAST; ++i)
                if (strcmp(current_categories[1], current_categories[i])) {
                        for (i = 2; i < _LC_LAST; ++i) {
                                (void)strcat(current_locale_string, "/");
                                (void)strcat(current_locale_string,
                                    current_categories[i]);
                        }
                        break;
                }
        return (current_locale_string);
}

static char *
loadlocale(int category)
{
        char *new = new_categories[category];
        char *old = current_categories[category];
        int (*func) (const char *);
        int saved_errno;

        if ((new[0] == '.' &&
            (new[1] == '\0' || (new[1] == '.' && new[2] == '\0'))) ||
            strchr(new, '/') != NULL) {
                errno = EINVAL;
                return (NULL);
        }
        saved_errno = errno;
        errno = __detect_path_locale();
        if (errno != 0)
                return (NULL);
        errno = saved_errno;

        switch (category) {
        case LC_CTYPE:
                func = __wrap_setrunelocale;
                break;
        case LC_COLLATE:
                func = __collate_load_tables;
                break;
        case LC_TIME:
                func = __time_load_locale;
                break;
        case LC_NUMERIC:
                func = __numeric_load_locale;
                break;
        case LC_MONETARY:
                func = __monetary_load_locale;
                break;
        case LC_MESSAGES:
                func = __messages_load_locale;
                break;
        default:
                errno = EINVAL;
                return (NULL);
        }

        if (strcmp(new, old) == 0)
                return (old);

        if (func(new) != _LDP_ERROR) {
                (void)strcpy(old, new);
                (void)strcpy(__xlocale_global_locale.components[category-1]->locale, new);
                return (old);
        }

        return (NULL);
}

const char *
__get_locale_env(int category)
{
        const char *env;

        /* 1. check LC_ALL. */
        env = getenv(categories[0]);

        /* 2. check LC_* */
        if (env == NULL || !*env)
                env = getenv(categories[category]);

        /* 3. check LANG */
        if (env == NULL || !*env)
                env = getenv("LANG");

        /* 4. if none is set, fall to "C" */
        if (env == NULL || !*env)
                env = "C";

        return (env);
}

/*
 * Detect locale storage location and store its value to _PathLocale variable
 */
int
__detect_path_locale(void)
{
        if (_PathLocale == NULL) {
                char *p = secure_getenv("PATH_LOCALE");

                if (p != NULL) {
                        if (strlen(p) + 1/*"/"*/ + ENCODING_LEN +
                            1/*"/"*/ + CATEGORY_LEN >= PATH_MAX)
                                return (ENAMETOOLONG);
                        _PathLocale = strdup(p);
                        if (_PathLocale == NULL)
                                return (errno == 0 ? ENOMEM : errno);
                } else
                        _PathLocale = _PATH_LOCALE;
        }
        return (0);
}