/*
 * i18n.c -
 * $Id: i18n.c,v 1.26.4.12 2008-03-06 15:38:09 opengl2772 Exp $
 * 
 * Copyright (C) 1997-1999 Satoru Takabayashi All rights reserved.
 * Copyright (C) 2000-2008 Namazu Project All rights reserved.
 * This is free software with ABSOLUTELY NO WARRANTY.
 * 
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA
 * 
 * 
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif
#ifdef HAVE_SUPPORT_H
#  include "support.h"
#endif

#include <stdio.h>
#ifdef HAVE_STDLIB_H
#  include <stdlib.h>
#endif

#ifdef HAVE_STRING_H
#  include <string.h>
#else
#  include <strings.h>
#endif

#ifdef HAVE_LOCALE_H
#  include <locale.h>
#endif

#include "libnamazu.h"
#include "util.h"
#include "i18n.h"

/*
 *
 * Private functions
 *
 */

static const char *guess_category_value ( const char *categoryname );
static char *get_lang_by_category ( const char *categoryname );
static int _purification_lang( char *lang, size_t n );


/* The following is (partly) taken from the gettext package.
   Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.  */

static const char *
guess_category_value (const char *categoryname)
{
    const char *retval;

    if (!strcmp(categoryname, "LC_MESSAGES")) {

	/* The highest priority value is the `LANGUAGE' environment
	   variable.  This is a GNU extension.  */
	retval = getenv ("LANGUAGE");
	if (retval != NULL && retval[0] != '\0')
	    return retval;
    }

    /* `LANGUAGE' is not set.  So we have to proceed with the POSIX
       methods of looking to `LC_ALL', `LC_xxx', and `LANG'.  On some
       systems this can be done by the `setlocale' function itself.  */

    /* Setting of LC_ALL overwrites all other.  */
    retval = getenv ("LC_ALL");  
    if (retval != NULL && retval[0] != '\0')
	return retval;

    /* Next comes the name of the desired category.  */
    retval = getenv (categoryname);
    if (retval != NULL && retval[0] != '\0')
	return retval;

    /* Last possibility is the LANG environment variable.  */
    retval = getenv ("LANG");
    if (retval != NULL && retval[0] != '\0')
	return retval;

    return NULL;
}

static char *
get_lang_by_category(const char *categoryname) 
{
    static char lang[BUFSIZE] = "";
    char *value;

    value = (char *)guess_category_value(categoryname);
    if (value == NULL) {
        return "C";
    } else {
        strncpy(lang, value, BUFSIZE - 1);
        lang[BUFSIZE - 1] = '\0';
        _purification_lang(lang, BUFSIZE);
        if (lang[0] == '\0') {
            return "C";
        }
        return lang;
    }
}

/*
 *
 * Public functions
 *
 */

char *
nmz_set_lang(const char *value)
{
    static char lang[BUFSIZE] = "";
    const char* env;

    strncpy(lang, value, BUFSIZE - 1);
    _purification_lang(lang, BUFSIZE);

    env = guess_category_value("LC_MESSAGES");
    if (env == NULL && *lang != '\0') {
#ifdef HAVE_SETENV
	setenv("LANG", lang, 1);
#else
# ifdef HAVE_PUTENV
	{
	    static char *store = NULL;

	    if (store != NULL)
		free(store);
	    store = (char *)malloc(strlen(lang) + 6); /* do *not* free */
	    if (store == NULL)
		return NULL; /* FIXME: should be fatal error */
	    strcpy(store, "LANG=");
	    strcat(store, lang);
	    putenv(store);
	}
# endif
#endif
    }

#ifdef HAVE_SETLOCALE
    /* Set locale via LC_ALL.  */
    setlocale (LC_ALL, "");
#endif

    return (char *)lang;
}

char *
nmz_get_lang(void)
{
    return get_lang_by_category("LC_MESSAGES");
}

char *
nmz_get_lang_ctype(void)
{
    return get_lang_by_category("LC_CTYPE");
}

/*
 * Choose suffix of message files such as ".ja_JP", ".ja", "", etc.
 * lang
 */
enum nmz_stat
nmz_choose_msgfile_suffix(const char *pfname,  char *lang_suffix)
{
    FILE *fp;
    size_t baselen;
    char fname[BUFSIZE] = "";
    char suffix[BUFSIZE] = "";

    strncpy(fname, pfname, BUFSIZE - 1);
    baselen = strlen(fname);
    strncat(fname, ".", BUFSIZE - strlen(fname) - 1);
    nmz_delete_since_path_delimitation(suffix, nmz_get_lang(), BUFSIZE);
    strncat(fname, suffix, BUFSIZE - strlen(fname) - 1);

    /* 
     * Trial example:
     * 1. NMZ.tips.ja_JP.ISO-2022-JP
     * 2. NMZ.tips.ja_JP
     * 3. NMZ.tips.ja
     * 4. NMZ.tips
     */

    do {
	int i;

	fp = fopen(fname, "rb");
	if (fp != NULL) { /* fopen success */
	    nmz_debug_printf("choose_msgfile: %s open SUCCESS.\n", fname);
	    fclose(fp);
	    strcpy(lang_suffix, fname + baselen); /* it shouldn't be flood  */
	    return SUCCESS;
	}
	nmz_debug_printf("choose_msgfile: %s open failed.\n", fname);

	for (i = (int)strlen(fname) - 1; i >= 0; i--) {
	    if (fname[i] == '.' ||
		fname[i] == '_')
	    {
		fname[i] = '\0';
		break;
	    }
	}
	if (strlen(fname) < baselen) {
	    break;
	}
    } while (1);
    return FAILURE;
}

/*
 *   purification language.
 *     [A-Za-z][A-Za-z0-9_,+@\-\.=]*
 *     (ex. ja_JP.eucJP, ja_JP.SJIS, C)
 */
static int _purification_lang(char *lang, size_t n)
{
    char *p;

    p = lang;

    /*   [A-Za-z][A-Za-z0-9_,+@\-\.=]*   */
    if ((*p >= 'A' && *p <= 'Z') || (*p >= 'a' && *p <= 'z')) {
        p++;
        while(*p) {
            if ((*p >= 'A' && *p <= 'Z') || (*p >= 'a' && *p <= 'z')
            || (*p >= '0' && *p <= '9')
            || *p == '_' || *p == ',' || *p == '+' || *p == '@' 
            || *p == '-' || *p == '.' || *p == '='
            ) {
            } else {
                *p = '\0';
                break;
            }
            p++;
        }
    } else {
        *p = '\0';
    }

    return 1;
}