/**
 * ntfslabel - Part of the Linux-NTFS project.
 *
 * Copyright (c) 2002 Matthew J. Fanto
 * Copyright (c) 2002-2005 Anton Altaparmakov
 * Copyright (c) 2002-2003 Richard Russon
 *
 * This utility will display/change the label on an NTFS partition.
 *
 * 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 (in the main directory of the Linux-NTFS
 * distribution in the file COPYING); if not, write to the Free Software
 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "config.h"

#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif

#include "debug.h"
#include "mft.h"
#include "utils.h"
/* #include "version.h" */
#include "logging.h"

static const char *EXEC_NAME = "ntfslabel";

static struct options {
	char	*device;	/* Device/File to work with */
	char	*label;		/* Set the label to this */
	int	 quiet;		/* Less output */
	int	 verbose;	/* Extra output */
	int	 force;		/* Override common sense */
	int	 noaction;	/* Do not write to disk */
} opts;

/**
 * version - Print version information about the program
 *
 * Print a copyright statement and a brief description of the program.
 *
 * Return:  none
 */
static void version(void)
{
	ntfs_log_info("\n%s v%s (libntfs-3g) - Display, or set, the label for an "
			"NTFS Volume.\n\n", EXEC_NAME, VERSION);
	ntfs_log_info("Copyright (c)\n");
	ntfs_log_info("    2002      Matthew J. Fanto\n");
	ntfs_log_info("    2002-2005 Anton Altaparmakov\n");
	ntfs_log_info("    2002-2003 Richard Russon\n");
	ntfs_log_info("\n%s\n%s%s\n", ntfs_gpl, ntfs_bugs, ntfs_home);
}

/**
 * usage - Print a list of the parameters to the program
 *
 * Print a list of the parameters and options for the program.
 *
 * Return:  none
 */
static void usage(void)
{
	ntfs_log_info("\nUsage: %s [options] device [label]\n"
	       "    -n, --no-action    Do not write to disk\n"
	       "    -f, --force        Use less caution\n"
	       "    -q, --quiet        Less output\n"
	       "    -v, --verbose      More output\n"
	       "    -V, --version      Display version information\n"
	       "    -h, --help         Display this help\n\n",
	       EXEC_NAME);
	ntfs_log_info("%s%s\n", ntfs_bugs, ntfs_home);
}

/**
 * parse_options - Read and validate the programs command line
 *
 * Read the command line, verify the syntax and parse the options.
 * This function is very long, but quite simple.
 *
 * Return:  1 Success
 *	    0 Error, one or more problems
 */
static int parse_options(int argc, char *argv[])
{
	static const char *sopt = "-fh?nqvV";
	static const struct option lopt[] = {
		{ "force",	 no_argument,		NULL, 'f' },
		{ "help",	 no_argument,		NULL, 'h' },
		{ "no-action",	 no_argument,		NULL, 'n' },
		{ "quiet",	 no_argument,		NULL, 'q' },
		{ "verbose",	 no_argument,		NULL, 'v' },
		{ "version",	 no_argument,		NULL, 'V' },
		{ NULL, 0, NULL, 0 },
	};

	int c = -1;
	int err  = 0;
	int ver  = 0;
	int help = 0;
	int levels = 0;

	opterr = 0; /* We'll handle the errors, thank you. */

	while ((c = getopt_long(argc, argv, sopt, lopt, NULL)) != -1) {
		switch (c) {
		case 1:	/* A non-option argument */
			if (!err && !opts.device)
				opts.device = argv[optind-1];
			else if (!err && !opts.label)
				opts.label = argv[optind-1];
			else
				err++;
			break;
		case 'f':
			opts.force++;
			break;
		case 'h':
		case '?':
			if (strncmp (argv[optind-1], "--log-", 6) == 0) {
				if (!ntfs_log_parse_option (argv[optind-1]))
					err++;
				break;
			}
			help++;
			break;
		case 'n':
			opts.noaction++;
			break;
		case 'q':
			opts.quiet++;
			ntfs_log_clear_levels(NTFS_LOG_LEVEL_QUIET);
			break;
		case 'v':
			opts.verbose++;
			ntfs_log_set_levels(NTFS_LOG_LEVEL_VERBOSE);
			break;
		case 'V':
			ver++;
			break;
		default:
			ntfs_log_error("Unknown option '%s'.\n", argv[optind-1]);
			err++;
			break;
		}
	}

	/* Make sure we're in sync with the log levels */
	levels = ntfs_log_get_levels();
	if (levels & NTFS_LOG_LEVEL_VERBOSE)
		opts.verbose++;
	if (!(levels & NTFS_LOG_LEVEL_QUIET))
		opts.quiet++;

	if (help || ver) {
		opts.quiet = 0;
	} else {
		if (opts.device == NULL) {
			if (argc > 1)
				ntfs_log_error("You must specify a device.\n");
			err++;
		}

		if (opts.quiet && opts.verbose) {
			ntfs_log_error("You may not use --quiet and --verbose at "
					"the same time.\n");
			err++;
		}
	}

	if (ver)
		version();
	if (help || err)
		usage();

	return (!err && !help && !ver);
}


/**
 * print_label - display the current label of a mounted ntfs partition.
 * @dev:	device to read the label from
 * @mnt_flags:	mount flags of the device or 0 if not mounted
 * @mnt_point:	mount point of the device or NULL
 *
 * Print the label of the device @dev.
 */
static int print_label(ntfs_volume *vol, unsigned long mnt_flags)
{
	int result = 0;
	//XXX significant?
	if ((mnt_flags & (NTFS_MF_MOUNTED | NTFS_MF_READONLY)) ==
			NTFS_MF_MOUNTED) {
		ntfs_log_error("%s is mounted read-write, results may be "
			"unreliable.\n", opts.device);
		result = 1;
	}

	ntfs_log_info("%s\n", vol->vol_name);
	return result;
}

/**
 * resize_resident_attribute_value - resize a resident attribute
 * @m:		mft record containing attribute to resize
 * @a:		attribute record (inside @m) which to resize
 * @new_vsize:	the new attribute value size to resize the attribute to
 *
 * Return 0 on success and -1 with errno = ENOSPC if not enough space in the
 * mft record.
 */
static int resize_resident_attribute_value(MFT_RECORD *m, ATTR_RECORD *a,
		const u32 new_vsize)
{
	int new_alen, new_muse;

	/* New attribute length and mft record bytes used. */
	new_alen = (le16_to_cpu(a->value_offset) + new_vsize + 7) & ~7;
	new_muse = le32_to_cpu(m->bytes_in_use) - le32_to_cpu(a->length) +
			new_alen;
	/* Check for sufficient space. */
	if ((u32)new_muse > le32_to_cpu(m->bytes_allocated)) {
		errno = ENOSPC;
		return -1;
	}
	/* Move attributes behind @a to their new location. */
	memmove((char*)a + new_alen, (char*)a + le32_to_cpu(a->length),
			le32_to_cpu(m->bytes_in_use) - ((char*)a - (char*)m) -
			le32_to_cpu(a->length));
	/* Adjust @m to reflect change in used space. */
	m->bytes_in_use = cpu_to_le32(new_muse);
	/* Adjust @a to reflect new value size. */
	a->length = cpu_to_le32(new_alen);
	a->value_length = cpu_to_le32(new_vsize);
	return 0;
}

/**
 * change_label - change the current label on a device
 * @dev:	device to change the label on
 * @mnt_flags:	mount flags of the device or 0 if not mounted
 * @mnt_point:	mount point of the device or NULL
 * @label:	the new label
 *
 * Change the label on the device @dev to @label.
 */
static int change_label(ntfs_volume *vol, unsigned long mnt_flags, char *label, BOOL force)
{
	ntfs_attr_search_ctx *ctx;
	ntfschar *new_label = NULL;
	ATTR_RECORD *a;
	int label_len;
	int result = 0;

	//XXX significant?
	if (mnt_flags & NTFS_MF_MOUNTED) {
		/* If not the root fs or mounted read/write, refuse change. */
		if (!(mnt_flags & NTFS_MF_ISROOT) ||
				!(mnt_flags & NTFS_MF_READONLY)) {
			if (!force) {
				ntfs_log_error("Refusing to change label on "
						"read-%s mounted device %s.\n",
						mnt_flags & NTFS_MF_READONLY ?
						"only" : "write", opts.device);
				return 1;
			}
		}
	}
	ctx = ntfs_attr_get_search_ctx(vol->vol_ni, NULL);
	if (!ctx) {
		ntfs_log_perror("Failed to get attribute search context");
		goto err_out;
	}
	if (ntfs_attr_lookup(AT_VOLUME_NAME, AT_UNNAMED, 0, CASE_SENSITIVE,
			0, NULL, 0, ctx)) {
		if (errno != ENOENT) {
			ntfs_log_perror("Lookup of $VOLUME_NAME attribute failed");
			goto err_out;
		}
		/* The volume name attribute does not exist.  Need to add it. */
		a = NULL;
	} else {
		a = ctx->attr;
		if (a->non_resident) {
			ntfs_log_error("Error: Attribute $VOLUME_NAME must be "
					"resident.\n");
			goto err_out;
		}
	}
	label_len = ntfs_mbstoucs_libntfscompat(label, &new_label, 0);
	if (label_len == -1) {
		ntfs_log_perror("Unable to convert label string to Unicode");
		goto err_out;
	}
	label_len *= sizeof(ntfschar);
	if (label_len > 0x100) {
		ntfs_log_error("New label is too long. Maximum %u characters "
				"allowed. Truncating excess characters.\n",
				(unsigned)(0x100 / sizeof(ntfschar)));
		label_len = 0x100;
		new_label[label_len / sizeof(ntfschar)] = const_cpu_to_le16(0);
	}
	if (a) {
		if (resize_resident_attribute_value(ctx->mrec, a, label_len)) {
			ntfs_log_perror("Error resizing resident attribute");
			goto err_out;
		}
	} else {
		/* sizeof(resident attribute record header) == 24 */
		int asize = (24 + label_len + 7) & ~7;
		u32 biu = le32_to_cpu(ctx->mrec->bytes_in_use);
		if (biu + asize > le32_to_cpu(ctx->mrec->bytes_allocated)) {
			errno = ENOSPC;
			ntfs_log_perror("Error adding resident attribute");
			goto err_out;
		}
		a = ctx->attr;
		memmove((u8*)a + asize, a, biu - ((u8*)a - (u8*)ctx->mrec));
		ctx->mrec->bytes_in_use = cpu_to_le32(biu + asize);
		a->type = AT_VOLUME_NAME;
		a->length = cpu_to_le32(asize);
		a->non_resident = 0;
		a->name_length = 0;
		a->name_offset = cpu_to_le16(24);
		a->flags = cpu_to_le16(0);
		a->instance = ctx->mrec->next_attr_instance;
		ctx->mrec->next_attr_instance = cpu_to_le16((le16_to_cpu(
				ctx->mrec->next_attr_instance) + 1) & 0xffff);
		a->value_length = cpu_to_le32(label_len);
		a->value_offset = a->name_offset;
		a->resident_flags = 0;
		a->reservedR = 0;
	}
	memcpy((u8*)a + le16_to_cpu(a->value_offset), new_label, label_len);
	if (!opts.noaction && ntfs_inode_sync(vol->vol_ni)) {
		ntfs_log_perror("Error writing MFT Record to disk");
		goto err_out;
	}
	result = 0;
err_out:
	free(new_label);
	if (ctx)
		ntfs_attr_put_search_ctx(ctx);
	return result;
}

/**
 * main - Begin here
 *
 * Start from here.
 *
 * Return:  0  Success, the program worked
 *	    1  Error, something went wrong
 */
int main(int argc, char **argv)
{
	unsigned long mnt_flags = 0;
	int result = 0;
	ntfs_volume *vol;

	ntfs_log_set_handler(ntfs_log_handler_outerr);

	if (!parse_options(argc, argv))
		return 1;

	utils_set_locale();

	if (!opts.label)
		opts.noaction++;

	vol = utils_mount_volume(opts.device,
			(opts.noaction ? MS_RDONLY : 0) |
			(opts.force ? MS_RECOVER : 0));
	if (!vol)
		return 1;

	if (opts.label)
		result = change_label(vol, mnt_flags, opts.label, opts.force);
	else
		result = print_label(vol, mnt_flags);

	ntfs_umount(vol, FALSE);
	return result;
}

