/*
 *
 * Copyright  1990-2006 Sun Microsystems, Inc. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 only, as published by the Free Software Foundation.
 *
 * 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 version 2 for more details (a copy is
 * included at /legal/license.txt).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this work; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
 * Clara, CA 95054 or visit www.sun.com if you need additional
 * information or have any questions.
 */

#include "wrappers.h"

#define UTF8 "UTF-8"

static iconv_t
open_iconv(const char* to, const char* from) {
    iconv_t ic = iconv_open(to, from);
    if (ic == (iconv_t)-1) {
        if (errno == EINVAL) {
            /* There is a bug in some versions of Solaris in which
             * nl_langinfo() returns a string beginning with ISO, but you
             * have to remove the ISO before calling open_iconv.
             */
            if (strncmp(from, "ISO", 3) == 0) {
                /* Try again, but with the ISO in front of the "from" */
                return open_iconv(to, from + 3);
            } else if (strncmp(to, "ISO", 3) == 0) {
                /* Try again, but with the ISO in front of the "to" */
                return open_iconv(to + 3, from);
            } else {
                fprintf(stderr, "%s to %s not supported on this platform\n",
                        from, to);
            }
        } else {
            perror("iconv_open error: ");
        }
        exit(1);
    }
    return ic;
}

static char*
get_langinfo_codeset()
{
    static char *name = NULL;

    if (name == NULL) {
        name = nl_langinfo(CODESET);
        if (name == NULL || strlen(name) == 0) {
            name = "ISO8859-1";
        }
    }
    return name;
}

int native2utf8(const char* from, char* to, int buflen) {
    int ret;
    size_t ileft, oleft;
    char *langinfo_codeset = get_langinfo_codeset();
    iconv_t ic;
    if (strncmp(langinfo_codeset, UTF8, 5) == 0) {
        /* don't invoke 'iconv' functions to do the
         * conversion if it's already in UTF-8 encoding
         */
        memcpy(to, from, buflen);
        return 0;
    }

    ic = open_iconv(UTF8, get_langinfo_codeset());
    memset(to, 0, buflen);
    ileft = strlen(from);
    oleft = buflen;

    ret = iconv(ic, &from, &ileft, &to, &oleft);
    if (ret == (size_t)-1) {
        fprintf(stderr, "native2utf8:Failed to convert (err=%d)\n", ret);
        exit(1);
    }
    iconv_close(ic);

    return buflen-oleft;
}

int utf2native(const char* from, char* to, int buflen) {
    int ret;
    size_t ileft, oleft;

    char *langinfo_codeset = get_langinfo_codeset();
    iconv_t ic;

    if (strncmp(langinfo_codeset, UTF8, 5) == 0) {
        /* Don't do the conversion if it's
         * already in UTF-8 encoding
         * Copy over the 'from' to 'to'.
         */
        memcpy(to, from, buflen);
        return 0;
    }

    ic = open_iconv(get_langinfo_codeset(), UTF8);
    memset(to, 0, buflen);
    ileft = strlen(from);
    oleft = buflen;

    ret = iconv(ic, &from, &ileft, &to, &oleft);
    if (ret == (size_t)-1) {
        fprintf(stderr, "utf2native:Failed to convert (err=%d)\n", ret);
        exit(1);
    }
    iconv_close(ic);

    return buflen-oleft;
}