#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <libgen.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "cmds.h"
#include "libbcache.h"
#include "linux/bcache-ioctl.h"
#include "opts.h"
#include "tools-util.h"

/* This code belongs under show_fs */
#if 0

struct bcache_dev {
	unsigned	nr;
	const char	*name;

	unsigned	has_metadata;
	unsigned	has_data;
	const char	*state;
	unsigned	tier;

	u64		bucket_size;
	u64		first_bucket;
	u64		nbuckets;

	/* XXX: dirty != used, it doesn't count metadata */
	u64		bytes_dirty;
};

static struct bcache_dev fill_dev(const char *dev_name, unsigned nr, int dir)
{
	return (struct bcache_dev) {
		.nr		= nr,
		.name		= dev_name,

		.has_metadata	= read_file_u64(dir, "has_metadata"),
		.has_data	= read_file_u64(dir, "has_data"),
		.state		= read_file_str(dir, "state"),
		.tier		= read_file_u64(dir, "tier"),

		.bucket_size	= read_file_u64(dir, "bucket_size_bytes"),
		.first_bucket	= read_file_u64(dir, "first_bucket"),
		.nbuckets	= read_file_u64(dir, "nbuckets"),
		.bytes_dirty	= read_file_u64(dir, "dirty_bytes"),
	};
}

static void show_dev(struct bcache_dev *dev)
{
	u64 capacity = (dev->nbuckets - dev->first_bucket) *
		dev->bucket_size;
	/*
	 * XXX: show fragmentation information, cached/dirty information
	 */

	printf("Device %u (/dev/%s):\n"
	       "    Has metadata:\t%u\n"
	       "    Has dirty data:\t%u\n"
	       "    State:\t\t%s\n"
	       "    Tier:\t\t%u\n"
	       "    Size:\t\t%llu\n"
	       "    Used:\t\t%llu\n"
	       "    Free:\t\t%llu\n"
	       "    Use%%:\t\t%llu\n",
	       dev->nr, dev->name,
	       dev->has_metadata,
	       dev->has_data,
	       dev->state,
	       dev->tier,
	       capacity,
	       dev->bytes_dirty,
	       capacity - dev->bytes_dirty,
	       (dev->bytes_dirty * 100) / capacity);
}

int cmd_device_show(int argc, char *argv[])
{
	int human_readable = 0;
	NihOption opts[] = {
	//	{ int shortoption, char *longoption, char *help, NihOptionGroup, char *argname, void *value, NihOptionSetter}

		{ 'h',	"human-readable",		N_("print sizes in powers of 1024 (e.g., 1023M)"),
			NULL, NULL,	&human_readable,	NULL},
		NIH_OPTION_LAST
	};
	char **args = bch_nih_init(argc, argv, opts);

	if (argc != 2)
		die("Please supply a single device");

	struct bcache_handle fs = bcache_fs_open(argv[1]);
	struct dirent *entry;

	struct bcache_dev devices[256];
	unsigned i, j, nr_devices = 0, nr_active_tiers = 0;

	unsigned tiers[BCH_TIER_MAX]; /* number of devices in each tier */
	memset(tiers, 0, sizeof(tiers));

	while ((entry = readdir(fs.sysfs))) {
		unsigned nr;
		int pos = 0;

		sscanf(entry->d_name, "cache%u%n", &nr, &pos);
		if (pos != strlen(entry->d_name))
			continue;

		char link[PATH_MAX];
		if (readlinkat(dirfd(fs.sysfs), entry->d_name,
			       link, sizeof(link)) < 0)
			die("readlink error: %s\n", strerror(errno));

		char *dev_name = basename(dirname(link));

		int fd = xopenat(dirfd(fs.sysfs), entry->d_name, O_RDONLY);

		devices[nr_devices] = fill_dev(strdup(dev_name), nr, fd);
		tiers[devices[nr_devices].tier]++;
		nr_devices++;

		close(fd);
	}

	for (i = 0; i < BCH_TIER_MAX; i++)
		if (tiers[i])
			nr_active_tiers++;

	/* Print out devices sorted by tier: */
	bool first = true;

	for (i = 0; i < BCH_TIER_MAX; i++) {
		if (!tiers[i])
			continue;

		if (nr_active_tiers > 1) {
			if (!first)
				printf("\n");
			first = false;
			printf("Tier %u:\n\n", i);
		}

		for (j = 0; j < nr_devices; j++) {
			if (devices[j].tier != i)
				continue;

			if (!first)
				printf("\n");
			first = false;
			show_dev(&devices[j]);
		}
	}

	return 0;
}
#endif

static void disk_ioctl(const char *fs, const char *dev, int cmd, int flags)
{
	struct bch_ioctl_disk i = { .flags = flags, .dev = (__u64) dev, };

	xioctl(bcache_fs_open(fs).ioctl_fd, cmd, &i);
}

static void device_add_usage(void)
{
	puts("bcache device add - add a device to an existing filesystem\n"
	     "Usage: bcache device add [OPTION]... filesystem device\n"
	     "\n"
	     "Options:\n"
	     "      --fs_size=size          Size of filesystem on device\n"
	     "      --bucket=size           Bucket size\n"
	     "      --discard               Enable discards\n"
	     "  -t, --tier=#                Higher tier (e.g. 1) indicates slower devices\n"
	     "  -f, --force                 Use device even if it appears to already be formatted\n"
	     "  -h, --help                  Display this help and exit\n"
	     "\n"
	     "Report bugs to <linux-bcache@vger.kernel.org>");
}

int cmd_device_add(int argc, char *argv[])
{
	static const struct option longopts[] = {
		{ "fs_size",		required_argument,	NULL, 'S' },
		{ "bucket",		required_argument,	NULL, 'B' },
		{ "discard",		no_argument,		NULL, 'D' },
		{ "tier",		required_argument,	NULL, 't' },
		{ "force",		no_argument,		NULL, 'f' },
		{ NULL }
	};
	struct format_opts format_opts = format_opts_default();
	struct dev_opts dev_opts = { 0 };
	bool force = false;
	int opt;

	while ((opt = getopt_long(argc, argv, "t:fh",
				  longopts, NULL)) != -1)
		switch (opt) {
		case 'S':
			if (bch_strtoull_h(optarg, &dev_opts.size))
				die("invalid filesystem size");

			dev_opts.size >>= 9;
			break;
		case 'B':
			dev_opts.bucket_size =
				hatoi_validate(optarg, "bucket size");
			break;
		case 'D':
			dev_opts.discard = true;
			break;
		case 't':
			if (kstrtouint(optarg, 10, &dev_opts.tier) ||
			    dev_opts.tier >= BCH_TIER_MAX)
				die("invalid tier");
			break;
		case 'f':
			force = true;
			break;
		case 'h':
			device_add_usage();
			exit(EXIT_SUCCESS);
		}

	if (argc - optind != 2)
		die("Please supply a filesystem and a device to add");

	struct bcache_handle fs = bcache_fs_open(argv[optind]);

	dev_opts.path = argv[optind + 1];
	dev_opts.fd = open_for_format(dev_opts.path, force);

	format_opts.block_size	=
		read_file_u64(fs.sysfs_fd, "block_size_bytes") >> 9;
	format_opts.btree_node_size =
		read_file_u64(fs.sysfs_fd, "btree_node_size_bytes") >> 9;

	struct bch_sb *sb = bcache_format(format_opts, &dev_opts, 1);
	free(sb);
	fsync(dev_opts.fd);
	close(dev_opts.fd);

	struct bch_ioctl_disk i = { .dev = (__u64) dev_opts.path, };

	xioctl(fs.ioctl_fd, BCH_IOCTL_DISK_ADD, &i);
	return 0;
}

static void device_remove_usage(void)
{
	puts("bcache device_remove - remove a device from a filesystem\n"
	     "Usage: bcache device remove filesystem device\n"
	     "\n"
	     "Options:\n"
	     "  -f, --force		    Force removal, even if some data\n"
	     "                              couldn't be migrated\n"
	     "      --force-metadata	    Force removal, even if some metadata\n"
	     "                              couldn't be migrated\n"
	     "  -h, --help                  display this help and exit\n"
	     "Report bugs to <linux-bcache@vger.kernel.org>");
	exit(EXIT_SUCCESS);
}

int cmd_device_remove(int argc, char *argv[])
{
	static const struct option longopts[] = {
		{ "force",		0, NULL, 'f' },
		{ "force-metadata",	0, NULL, 'F' },
		{ "help",		0, NULL, 'h' },
		{ NULL }
	};
	int opt, flags = 0;

	while ((opt = getopt_long(argc, argv, "fh", longopts, NULL)) != -1)
		switch (opt) {
		case 'f':
			flags |= BCH_FORCE_IF_DATA_LOST;
			break;
		case 'F':
			flags |= BCH_FORCE_IF_METADATA_LOST;
			break;
		case 'h':
			device_remove_usage();
		}

	if (argc - optind != 2)
		die("Please supply a filesystem and at least one device to remove");

	disk_ioctl(argv[optind], argv[optind + 1],
		   BCH_IOCTL_DISK_REMOVE, flags);
	return 0;
}

static void device_online_usage(void)
{
	puts("bcache device online - readd a device to a running filesystem\n"
	     "Usage: bcache device online [OPTION]... filesystem device\n"
	     "\n"
	     "Options:\n"
	     "  -h, --help                  Display this help and exit\n"
	     "\n"
	     "Report bugs to <linux-bcache@vger.kernel.org>");
}

int cmd_device_online(int argc, char *argv[])
{
	int opt;

	while ((opt = getopt(argc, argv, "h")) != -1)
		switch (opt) {
		case 'h':
			device_online_usage();
			exit(EXIT_SUCCESS);
		}

	if (argc - optind != 2)
		die("Please supply a filesystem and a device");

	disk_ioctl(argv[optind], argv[optind + 1], BCH_IOCTL_DISK_ONLINE, 0);
	return 0;
}

static void device_offline_usage(void)
{
	puts("bcache device offline - take a device offline, without removing it\n"
	     "Usage: bcache device offline [OPTION]... filesystem device\n"
	     "\n"
	     "Options:\n"
	     "  -f, --force		    Force, if data redundancy will be degraded\n"
	     "  -h, --help                  Display this help and exit\n"
	     "\n"
	     "Report bugs to <linux-bcache@vger.kernel.org>");
}

int cmd_device_offline(int argc, char *argv[])
{
	static const struct option longopts[] = {
		{ "force",		0, NULL, 'f' },
		{ NULL }
	};
	int opt, flags = 0;

	while ((opt = getopt_long(argc, argv, "fh",
				  longopts, NULL)) != -1)
		switch (opt) {
		case 'f':
			flags |= BCH_FORCE_IF_DEGRADED;
			break;
		case 'h':
			device_offline_usage();
			exit(EXIT_SUCCESS);
		}

	if (argc - optind != 2)
		die("Please supply a filesystem and a device");

	disk_ioctl(argv[optind], argv[optind + 1],
		   BCH_IOCTL_DISK_OFFLINE, flags);
	return 0;
}

static void device_evacuate_usage(void)
{
	puts("bcache device evacuate - move data off of a given device\n"
	     "Usage: bcache device evacuate [OPTION]... filesystem device\n"
	     "\n"
	     "Options:\n"
	     "  -h, --help                  Display this help and exit\n"
	     "\n"
	     "Report bugs to <linux-bcache@vger.kernel.org>");
}

int cmd_device_evacuate(int argc, char *argv[])
{
	int opt;

	while ((opt = getopt(argc, argv, "h")) != -1)
		switch (opt) {
		case 'h':
			device_evacuate_usage();
			exit(EXIT_SUCCESS);
		}

	if (argc - optind != 2)
		die("Please supply a filesystem and a device");

	disk_ioctl(argv[optind], argv[optind + 1], BCH_IOCTL_DISK_EVACUATE, 0);
	return 0;
}

static void device_set_state_usage(void)
{
	puts("bcache device set-state\n"
	     "Usage: bcache device set-state filesystem device new-state\n"
	     "\n"
	     "Options:\n"
	     "  -f, --force		    Force, if data redundancy will be degraded\n"
	     "  -h, --help                  display this help and exit\n"
	     "Report bugs to <linux-bcache@vger.kernel.org>");
	exit(EXIT_SUCCESS);
}

int cmd_device_set_state(int argc, char *argv[])
{
	static const struct option longopts[] = {
		{ "force",			0, NULL, 'f' },
		{ "help",			0, NULL, 'h' },
		{ NULL }
	};
	int opt, flags = 0;

	while ((opt = getopt_long(argc, argv, "fh", longopts, NULL)) != -1)
		switch (opt) {
		case 'f':
			flags |= BCH_FORCE_IF_DEGRADED;
			break;
		case 'h':
			device_set_state_usage();
		}

	if (argc - optind != 3)
		die("Please supply a filesystem, device and state");

	struct bcache_handle fs = bcache_fs_open(argv[optind]);

	struct bch_ioctl_disk_set_state i = {
		.flags		= flags,
		.dev		= (__u64) argv[optind + 1],
		.new_state	= read_string_list_or_die(argv[optind + 2],
						bch_dev_state, "device state"),
	};

	xioctl(fs.ioctl_fd, BCH_IOCTL_DISK_SET_STATE, &i);
	return 0;
}