/*
 *   Copyright (c) International Business Machines Corp., 2000-2002
 *
 *   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
 */

#include <linux/fs.h>
#include <linux/slab.h>
#include "jfs_types.h"
#include "jfs_filsys.h"
#include "jfs_unicode.h"
#include "jfs_debug.h"

/*
 * NAME:	jfs_strfromUCS()
 *
 * FUNCTION:	Convert little-endian unicode string to character string
 *
 */
int jfs_strfromUCS_le(char *to, const wchar_t * from,	/* LITTLE ENDIAN */
		      int len, struct nls_table *codepage)
{
	int i;
	int outlen = 0;

	for (i = 0; (i < len) && from[i]; i++) {
		int charlen;
		charlen =
		    codepage->uni2char(le16_to_cpu(from[i]), &to[outlen],
				       NLS_MAX_CHARSET_SIZE);
		if (charlen > 0) {
			outlen += charlen;
		} else {
			to[outlen++] = '?';
		}
	}
	to[outlen] = 0;
	return outlen;
}

/*
 * NAME:	jfs_strtoUCS()
 *
 * FUNCTION:	Convert character string to unicode string
 *
 */
static int jfs_strtoUCS(wchar_t * to, const char *from, int len,
		struct nls_table *codepage)
{
	int charlen;
	int i;

	for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
		charlen = codepage->char2uni(from, len, &to[i]);
		if (charlen < 1) {
			jfs_err("jfs_strtoUCS: char2uni returned %d.", charlen);
			jfs_err("charset = %s, char = 0x%x",
				codepage->charset, (unsigned char) *from);
			return charlen;
		}
	}

	to[i] = 0;
	return i;
}

/*
 * NAME:	get_UCSname()
 *
 * FUNCTION:	Allocate and translate to unicode string
 *
 */
int get_UCSname(struct component_name * uniName, struct dentry *dentry,
		struct nls_table *nls_tab)
{
	int length = dentry->d_name.len;

	if (length > JFS_NAME_MAX)
		return -ENAMETOOLONG;

	uniName->name =
	    kmalloc((length + 1) * sizeof(wchar_t), GFP_NOFS);

	if (uniName->name == NULL)
		return -ENOSPC;

	uniName->namlen = jfs_strtoUCS(uniName->name, dentry->d_name.name,
				       length, nls_tab);

	if (uniName->namlen < 0) {
		kfree(uniName->name);
		return uniName->namlen;
	}

	return 0;
}