/*
 * bd-test.c
 * Copyright (C) 2010  Krzysztof Mazur <krzysiek@podlesie.net>
 *
 * 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 Fundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <getopt.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <malloc.h>
#include <inttypes.h>
#include <string.h>

static char *device = NULL;

#define SECTOR_SIZE	4096
#define SECTORS		1024

static unsigned char mirror[SECTORS * SECTOR_SIZE];
	
static int fd;

static void show_info(void)
{
	fprintf(stderr, "lsbd-fsck "PACKAGE_VERSION"\n"
			"Copyright (C) 2011  "
			"Krzysztof Mazur <krzysiek@podlesie.net>\n\n");
}

static void show_usage(char *name)
{
	show_info();
	fprintf(stderr,	"usage: %s [options] (file)\n"
			"Options:\n"
			"  -b, --start		set partition start\n"
			"  -h, --help		show this help\n"
			"  -p, --partition	partition number\n"
			"  -s, --size		set partition size\n"
			"  -m, --mirror		use mirroring\n"
			"  -V, --version		show version\n",
			(name == NULL) ? "lsbd-fsck" : name);
	exit(0);
}

static void parse_command_line(int argc, char **args)
{
	int c;
	int option_index = 0;
	static struct option long_options[] = {
		{"help", 0, 0, 'h'},
		{"version", 0, 0, 'V'},
		{0, 0, 0, 0},
	};
	
	while (1) {
		c = getopt_long(argc, args, "hV", long_options,
				&option_index);
		if (c == -1)
			break;
		switch (c) {
		case 'h':
			show_usage(args[0]);
			break;
		case 'V':
			exit(0);
			break;
		default:
			fprintf(stderr, "Unknown option.\n");
			exit(1);
		}
	}

	if (optind < argc) {
		device = args[optind++];
	}
}

static void swrite(unsigned long id, void *buf)
{
	lseek(fd, id * SECTOR_SIZE, SEEK_SET);
	write(fd, buf, SECTOR_SIZE);
	memcpy(mirror + id * SECTOR_SIZE, buf, SECTOR_SIZE);
}

static void sread(unsigned long id, void *buf)
{
	lseek(fd, id * SECTOR_SIZE, SEEK_SET);
	read(fd, buf, SECTOR_SIZE);
	if (memcmp(mirror + id * SECTOR_SIZE, buf, SECTOR_SIZE))
		fprintf(stderr, "sector %ld: read error\n", id);
}

int write_zeros(void)
{
	unsigned int i;
	unsigned char buf[SECTOR_SIZE];

	memset(buf, 0, sizeof(buf));
	for (i = 0; i < SECTORS; i++) {
		swrite(i, buf);
		sread(i, buf);
	}
	for (i = 0; i < SECTORS; i++)
		sread(i, buf);
	return 0;
}

int write_random(void)
{
	unsigned int i;
	unsigned char buf[SECTOR_SIZE];
	unsigned long s;

	for (i = 0; i < 1000000; i++) {
		if (i % 1000 == 999) {
			fprintf(stderr, ".");
		}

		s = (unsigned long) (SECTORS * drand48());
		if (s >= SECTORS)
			s = SECTORS - 1;

		sread(s, buf);
	
		memset(buf, 0, sizeof(buf));
		buf[0] = (i >>  0) & 0xff;
		buf[1] = (i >>  8) & 0xff;
		buf[2] = (i >> 16) & 0xff;
		buf[3] = (i >> 24) & 0xff;

		swrite(s, buf);
		sread(s, buf);
	}
	for (i = 0; i < SECTORS; i++)
		sread(i, buf);
	return 0;
}

int main(int argc, char **argv)
{
	parse_command_line(argc, argv);
	if (device == NULL) {
		fprintf(stderr, "error: device option is required\n");
		exit(EXIT_FAILURE);
	}

	fd = open(device, O_RDWR);
	if (fd == -1) {
		perror("open");
		exit(EXIT_FAILURE);
	}

	write_zeros();
	write_random();

	exit(EXIT_SUCCESS);
}