/*

 * User language lookup for generic POSIX platforms

 *

 * This file is part of mpv.

 *

 * mpv is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * mpv is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.

 */

#include "misc/language.h"

#include "mpv_talloc.h"

#include <stddef.h>

char **mp_get_user_langs(void)

{

    static const char *const list[] = {

        "LC_ALL",

        "LC_MESSAGES",

        "LANG",

        NULL

    };

    size_t nb = 0;

    char **ret = NULL;

    bool has_c = false;

    // Prefer anything we get from LANGUAGE first

    for (const char *langList = getenv("LANGUAGE"); langList && *langList;) {

        size_t len = strcspn(langList, ":");

        MP_TARRAY_GROW(NULL, ret, nb);

        char *lang = talloc_strndup(ret, langList, len);

        for (int i = 0; i < len; i++) {

            if (lang[i] == '_')

                lang[i] = '-';

        }

        ret[nb++] = lang;

        langList += len;

        while (*langList == ':')

            langList++;

    }

    // Then, the language components of other relevant locale env vars

    for (int i = 0; list[i]; i++) {

        const char *envval = getenv(list[i]);

        if (envval && *envval) {

            size_t len = strcspn(envval, ".@");

            if (!strncmp("C", envval, len)) {

                has_c = true;

                continue;

            }

            MP_TARRAY_GROW(NULL, ret, nb);

            char *lang = talloc_strndup(ret, envval, len);

            for (int j = 0; j < len; j++) {

                if (lang[j] == '_')

                    lang[j] = '-';

            }

            ret[nb++] = lang;

        }

    }

    if (has_c && !nb) {

        MP_TARRAY_GROW(NULL, ret, nb);

        ret[nb++] = talloc_strdup(ret, "en");

    }

    // Null-terminate the list

    MP_TARRAY_APPEND(NULL, ret, nb, NULL);

    return ret;

}