/********************************************************************\
 * gnc-locale-utils.c -- locale functions		            *
 * Copyright (C) 2000 Dave Peticolas <dave@krondo.com>              *
 *                                                                  *
 * This program is free software; you can redistribute it and/or    *
 * modify it under the terms of the GNU General Public License as   *
 * published by the Free Software Foundation; either version 2 of   *
 * the License, or (at your option) any later version.              *
 *                                                                  *
 * This program 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 General Public License for more details.                     *
 *                                                                  *
 * You should have received a copy of the GNU General Public License*
 * along with this program; if not, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
 * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
\********************************************************************/

#include "config.h"

#include "gnc-locale-utils.h"

#include <glib.h>
#include <glib/gi18n.h>
#include <stdlib.h> /* for mbstowcs() */

static void
gnc_lconv_set_utf8 (char **p_value, char *default_value)
{
    char *value = *p_value;
    *p_value = NULL;

    if ((value == NULL) || (value[0] == 0))
        value = default_value;

#ifdef G_OS_WIN32
    {
        /* get number of resulting wide characters */
        size_t count = mbstowcs (NULL, value, 0);
        if (count > 0)
        {
            /* malloc and convert */
            wchar_t *wvalue = g_malloc ((count + 1) * sizeof(wchar_t));
            count = mbstowcs (wvalue, value, count + 1);
            if (count > 0)
            {
                *p_value = g_utf16_to_utf8 (wvalue, -1, NULL, NULL, NULL);
            }
            g_free (wvalue);
        }
    }
#else /* !G_OS_WIN32 */
    *p_value = g_locale_to_utf8 (value, -1, NULL, NULL, NULL);
#endif

    if (*p_value == NULL)
    {
        // The g_locale_to_utf8 conversion failed. FIXME: Should we rather
        // use an empty string instead of the default_value? Not sure.
        *p_value = default_value;
    }
}

static void
gnc_lconv_set_char (char *p_value, char default_value)
{
    if ((p_value != NULL) && (*p_value == CHAR_MAX))
        *p_value = default_value;
}

struct lconv *
gnc_localeconv (void)
{
    static struct lconv lc;
    static gboolean lc_set = FALSE;

    if (lc_set)
        return &lc;

    lc = *localeconv();

    gnc_lconv_set_utf8(&lc.decimal_point, ".");
    gnc_lconv_set_utf8(&lc.thousands_sep, ",");
    gnc_lconv_set_utf8(&lc.grouping, "\003");
    gnc_lconv_set_utf8(&lc.int_curr_symbol, "USD ");
    gnc_lconv_set_utf8(&lc.currency_symbol, "$");
    gnc_lconv_set_utf8(&lc.mon_decimal_point, ".");
    gnc_lconv_set_utf8(&lc.mon_thousands_sep, ",");
    gnc_lconv_set_utf8(&lc.mon_grouping, "\003");
    gnc_lconv_set_utf8(&lc.negative_sign, "-");
    gnc_lconv_set_utf8(&lc.positive_sign, "");

    gnc_lconv_set_char(&lc.frac_digits, 2);
    gnc_lconv_set_char(&lc.int_frac_digits, 2);
    gnc_lconv_set_char(&lc.p_cs_precedes, 1);
    gnc_lconv_set_char(&lc.p_sep_by_space, 0);
    gnc_lconv_set_char(&lc.n_cs_precedes, 1);
    gnc_lconv_set_char(&lc.n_sep_by_space, 0);
    gnc_lconv_set_char(&lc.p_sign_posn, 1);
    gnc_lconv_set_char(&lc.n_sign_posn, 1);

    lc_set = TRUE;

    return &lc;
}

const char *
gnc_locale_default_iso_currency_code (void)
{
    static char *code = NULL;
    struct lconv *lc;

    if (code)
        return code;

    lc = gnc_localeconv ();

    code = g_strdup (lc->int_curr_symbol);

    /* The int_curr_symbol includes a space at the end! Note: you
     * can't just change "USD " to "USD" in gnc_localeconv, because
     * that is only used if int_curr_symbol was not defined in the
     * current locale. If it was, it will have the space! */
    g_strstrip (code);

    return code;
}

/* Return the number of decimal places for this locale. */
int
gnc_locale_decimal_places (void)
{
    static gboolean got_it = FALSE;
    static int places;
    struct lconv *lc;

    if (got_it)
        return places;

    lc = gnc_localeconv();
    places = lc->frac_digits;

    /* frac_digits is already initialized by gnc_localeconv, hopefully
     * to a reasonable default. */
    got_it = TRUE;

    return places;
}


static GList *locale_stack = NULL;

void
gnc_push_locale (int category, const char *locale)
{
    char *saved_locale;

    g_return_if_fail (locale != NULL);

# ifdef G_OS_WIN32
    /* On win32, setlocale() doesn't say anything useful. Use
       glib's function instead. */
    saved_locale = g_win32_getlocale();
# else
    saved_locale = g_strdup(setlocale(category, NULL) ?
                            setlocale(category, NULL) : "C");
#endif
    locale_stack = g_list_prepend (locale_stack, saved_locale);
    setlocale (category, locale);
}

void
gnc_pop_locale (int category)
{
    char *saved_locale;
    GList *node;

    g_return_if_fail (locale_stack != NULL);

    node = locale_stack;
    saved_locale = node->data;

    setlocale (category, saved_locale);

    locale_stack = g_list_remove_link (locale_stack, node);
    g_list_free_1 (node);
    g_free (saved_locale);
}