/**
 * @file utils.c Tar utility functions
 * 
 * $Id: utils.c,v 1.5 2003/01/01 06:22:33 chipx86 Exp $
 *
 * @Copyright (C) 1999-2003 The GNUpdate Project.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 */
#include "tar.h"

/* Octal to Integer */
int
cxTarOctalToInt(const char *oct)
{
	int i;

	sscanf(oct, "%o", &i);

	return i;
}

#if 0
int
tarIoError(TarInfo *info)
{
	int error = errno;  /* fflush() could cause errno to change. */
	
	fflush(stdout);
	fprintf(stderr, "tar.so: %s: %s\n", info->name, strerror(error));

	return -2;
}

int
tarSetModes(TarInfo *info)
{
	struct utimbuf t;

#ifdef HAVE_LCHOWN
	lchown(info->name, info->user_id, info->group_id);
#else
	chown(info->name, info->user_id, info->group_id);
#endif

	chmod(info->name, info->mode & ~S_IFMT);

	t.actime  = time(0);
	t.modtime = info->mod_time;
	utime(info->name, &t);

	return 0;
}

int
tarMkDir(TarInfo *info)
{
	if (mkdir(info->name, info->mode & ~S_IFMT) != 0)
	{
		if (errno == EEXIST)
		{
			struct stat s;

			if (stat(info->name, &s) != 0 || !(s.st_mode & S_IFDIR))
				return tarIoError(info);
		}
		else
			return tarIoError(info);
	}

	tarSetModes(info);

	return 0;
}

int
tarMakeHardlink(TarInfo *info)
{
	if (link(info->link_name, info->name) != 0)
		return tarIoError(info);
	
	tarSetModes(info);

	return 0;
}

int
tarMakeSymlink(TarInfo *info)
{
	if (symlink(info->link_name, info->name) != 0)
		return -2; /* tarIoError(info); ? */
	
	tarSetModes(info);

	return 0;
}

int
tarMakeSpecial(TarInfo *info)
{
	if (mknod(info->name, info->mode, info->device) != 0)
		return -2; /* tarIoError(info); ? */

	tarSetModes(info);

	return 0;
}

int
tarDecodeHeader(char *block, TarInfo *info)
{
	TarHeader     *header = (TarHeader *)block;
	unsigned char *s      = (unsigned char *)block;
	struct passwd *passwd = NULL;
	struct group  *group  = NULL;
	unsigned int   i;
	long           sum;
	long           checksum;

	if (*header->user_name != NULL)
		passwd = getpwnam(header->user_name);

	if (*header->group_name != NULL)
		group = getgrnam(header->group_name);

	info->name       = header->name;
	info->link_name  = header->link_name;
	info->mode       = (mode_t)tarOctalToLong(header->mode,
											  sizeof(header->mode));
	info->size       = (size_t)tarOctalToLong(header->size,
											  sizeof(header->size));
	info->mod_time   = (time_t)tarOctalToLong(header->mod_time,
											  sizeof(header->mod_time));
	info->device     = ((tarOctalToLong(header->major_device,
										sizeof(header->major_device))
						 & 0xFF) << 8) |
	                   (tarOctalToLong(header->minor_device,
									   sizeof(header->minor_device)) & 0xFF);
	checksum         = tarOctalToLong(header->checksum,
									  sizeof(header->checksum));
	info->user_id    = (uid_t)tarOctalToLong(header->user_id,
											 sizeof(header->user_id));
	info->group_id   = (gid_t)tarOctalToLong(header->group_id,
											 sizeof(header->group_id));
	info->type       = (TarFileType)header->link_flag;

	if (passwd != NULL) info->user_id  = passwd->pw_uid;
	if (group  != NULL) info->group_id = group->gr_gid;

	/* Treat checksum field as all blank. */
	sum = ' ' * sizeof(header->checksum);

	for (i = tarChecksumOffset; i > 0; i--)
		sum += *s++;

	s += sizeof(header->checksum);  /* Skip the real checksum field. */

	for (i = (512 - tarChecksumOffset - sizeof(header->checksum)); i > 0; i--)
		sum += *s++;

	return (sum == checksum);
}

int
tarExtractNextFile(TarInfo *info)
{
	/*
	 * If you don't want to extract the file, you must advance the tape
	 * by the file size rounded up to the next 512-byte boundary and
	 * return 0.
	 */

	/* TODO: Make this extract to the correct place! */
	int fd = open(info->name, O_CREAT | O_TRUNC | O_WRONLY,
				  info->mode & ~S_IFMT);
	
	char buffer[512];
}

#endif