/*
 * Copyright (c) 2008, Stefan Walter
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *     * Redistributions of source code must retain the above
 *       copyright notice, this list of conditions and the
 *       following disclaimer.
 *     * Redistributions in binary form must reproduce the
 *       above copyright notice, this list of conditions and
 *       the following disclaimer in the documentation and/or
 *       other materials provided with the distribution.
 *     * The names of contributors to this software may not be
 *       used to endorse or promote products derived from this
 *       software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 *
 * CONTRIBUTORS
 *  Stef Walter <stef@memberwebs.com>
 */

#include <sys/types.h>
#include <sys/stat.h>

#include <err.h>
#include <errno.h>
#include <fts.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include "hash.h"

static uint64_t jail_blocks = 0;
static uint64_t jail_files = 0;
static uint64_t jail_bytes = 0;

static hsh_t *jail_inodes = NULL;

static int syslog_facility = 0;

/* For use in the hash table as a value */
#define HAVE ((void*)1)

static void
usage ()
{
	fprintf (stderr, "usage: jail-measure [-l syslog] path ...\n");
	exit (2);
}

static void
emsg (const char *format, ...)
{
	va_list va;
	va_start (va, format);
	if (syslog_facility)
		vsyslog (syslog_facility, format, va);
	vwarnx (format, va);
	va_end (va);
}

static int
check_skip_link (FTSENT *f)
{
	unsigned int inode = f->fts_statp->st_ino;

	if (hsh_get (jail_inodes, (void*)inode, HSH_KEY_DIRECT)) {
		return 1;
 	} else {
		if (!hsh_set (jail_inodes, (void*)inode, HSH_KEY_DIRECT, HAVE)) {
			emsg ("out of memory");
			exit (1);
		}
		return 0;
	}
}

static void
measure_jail (const char *path)
{
	const char *paths[2] = { path, NULL };
	FTS *fts;
	FTSENT *f;

	jail_blocks = 0;
	jail_bytes = 0;
	hsh_clear (jail_inodes);

	fts = fts_open ((char**)paths, FTS_COMFOLLOW | FTS_PHYSICAL | FTS_XDEV, NULL);
	if (fts == NULL) {
		emsg ("couldn't access jail path: %s", path);
		return;
	}

	while ((f = fts_read (fts)) != NULL) {
		switch (f->fts_info) {
		case FTS_D:
			break;
		case FTS_DP:
			jail_blocks += f->fts_statp->st_blocks;
			jail_bytes += f->fts_statp->st_size;
			jail_files++;
			break;
		case FTS_DC:
			break;
		case FTS_DNR:
		case FTS_ERR:
		case FTS_NS:
			if (f->fts_errno != ENOENT)
				emsg ("couldn't access path: %s: %s", f->fts_path, strerror (f->fts_errno));
			break;
		default:
			if (f->fts_statp->st_nlink == 1 || !check_skip_link (f)) {
				jail_blocks += f->fts_statp->st_blocks;
				jail_bytes += f->fts_statp->st_size;
				jail_files++;
			}
			break;
		};
	}

	fts_close (fts);

	printf ("jail-space: %llu %s\n", jail_blocks * 512, path);
	printf ("jail-files: %llu %s\n", jail_files, path);
}

int
main (int argc, char* argv[])
{
	int ch, i;

	/* Parse the arguments nicely */
	while ((ch = getopt (argc, argv, "l:")) != -1) {
		switch(ch) {

		/* Log to syslog */
		case 'l':
			syslog_facility = atoi (optarg);
			break;

		/* Usage information */
		case '?':
		default:
			usage();
			break;
		}
	}

	argc -= optind;
	argv += optind;

	if (argc < 1)
		usage ();

	jail_inodes = hsh_create ();

	for (i = 0; i < argc; ++i)
		measure_jail (argv[i]);

	hsh_free (jail_inodes);

	return 0;
}