/* plugin_common - Routines common to several plugins

 * Copyright (C) 2002-2009  Josh Coalson

 * Copyright (C) 2011-2016  Xiph.Org Foundation

 *

 * Only slightly modified charset.c from:

 *  EasyTAG - Tag editor for MP3 and OGG files

 *  Copyright (C) 1999-2001  Håvard Kvålen <havardk@xmms.org>

 *

 * 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.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#ifdef HAVE_CONFIG_H

#  include <config.h>

#endif

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <errno.h>

#ifdef HAVE_ICONV

#include <iconv.h>

#endif

#ifdef HAVE_LANGINFO_CODESET

#include <langinfo.h>

#endif

#include "charset.h"

/*************

 * Functions *

 *************/

char* FLAC_plugin__charset_get_current (void)

{

	char *charset = getenv("CHARSET");

#ifdef HAVE_LANGINFO_CODESET

	if (!charset)

		charset = nl_langinfo(CODESET);

#endif

	if (!charset)

		charset = "ISO-8859-1";

	return charset;

}

#ifdef HAVE_ICONV

char* FLAC_plugin__charset_convert_string (const char *string, char *from, char *to)

{

	size_t outleft, outsize, length;

	iconv_t cd;

	char *out, *outptr;

	const char *input = string;

	if (!string)

		return NULL;

	length = strlen(string);

	if ((cd = iconv_open(to, from)) == (iconv_t)-1)

	{

#ifdef DEBUG

		fprintf(stderr, "convert_string(): Conversion not supported. Charsets: %s -> %s", from, to);

#endif

		return strdup(string);

	}

	/* Due to a GLIBC bug, round outbuf_size up to a multiple of 4 */

	/* + 1 for nul in case len == 1 */

	outsize = ((length + 3) & ~3) + 1;

	if(outsize < length) /* overflow check */

		return NULL;

	out = malloc(outsize);

	outleft = outsize - 1;

	outptr = out;

retry:

	if (iconv(cd, (char**)&input, &length, &outptr, &outleft) == (size_t)(-1))

	{

		int used;

		switch (errno)

		{

			case E2BIG:

				used = outptr - out;

				if((outsize - 1) * 2 + 1 <= outsize) { /* overflow check */

					free(out);

					return NULL;

				}

				outsize = (outsize - 1) * 2 + 1;

				out = realloc(out, outsize);

				outptr = out + used;

				outleft = outsize - 1 - used;

				goto retry;

			case EINVAL:

				break;

			case EILSEQ:

				/* Invalid sequence, try to get the rest of the string */

				input++;

				length = strlen(input);

				goto retry;

			default:

#ifdef DEBUG

				fprintf(stderr, "convert_string(): Conversion failed. Inputstring: %s; Error: %s", string, strerror(errno));

#endif

				break;

		}

	}

	*outptr = '\0';

	iconv_close(cd);

	return out;

}

#else

char* FLAC_plugin__charset_convert_string (const char *string, char *from, char *to)

{

	(void)from, (void)to;

	if (!string)

		return NULL;

	return strdup(string);

}

#endif

#ifdef HAVE_ICONV

int FLAC_plugin__charset_test_conversion (char *from, char *to)

{

	iconv_t cd;

	if ((cd=iconv_open(to,from)) == (iconv_t)-1)

	{

		/* Conversion not supported */

		return 0;

	}

	iconv_close(cd);

	return 1;

}

#else

int FLAC_plugin__charset_test_conversion (char *from, char *to)

{

	(void)from, (void)to;

	return 1;

}

#endif