#include <dirent.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/xattr.h>
#include <unistd.h>

#include "libbcachefs/bcachefs_ioctl.h"

#include "cmds.h"
#include "libbcachefs.h"

static void propagate_recurse(int dirfd)
{
	DIR *dir = fdopendir(dirfd);
	struct dirent *d;

	if (!dir) {
		fprintf(stderr, "fdopendir() error: %m\n");
		return;
	}

	while ((errno = 0), (d = readdir(dir))) {
		if (!strcmp(d->d_name, ".") ||
		    !strcmp(d->d_name, ".."))
			continue;

		struct stat st = xfstatat(dirfd, d->d_name,
					  AT_SYMLINK_NOFOLLOW);
		if (S_ISLNK(st.st_mode))
			continue;

		int ret = ioctl(dirfd, BCHFS_IOC_REINHERIT_ATTRS,
			    d->d_name);
		if (ret < 0) {
			fprintf(stderr, "error propagating attributes to %s: %m\n",
				d->d_name);
			continue;
		}

		if (!ret) /* did no work */
			continue;
		if (!S_ISDIR(st.st_mode))
			continue;

		int fd = openat(dirfd, d->d_name, O_RDONLY);
		if (fd < 0) {
			fprintf(stderr, "error opening %s: %m\n", d->d_name);
			continue;
		}
		propagate_recurse(fd);
	}

	if (errno)
		die("readdir error: %m");
	closedir(dir);
}

static void remove_bcachefs_attr(const char *path, const char *full_attr_name)
{
	if (removexattr(path, full_attr_name) != 0) {
		// EINVAL in case bcachefs-tools is newer than kernel
		if (errno != ENODATA && errno != EINVAL) {
			fprintf(stderr, "error removing attribute %s from %s: %m\n",
				full_attr_name, path);
		}
	}
}

static void remove_all_bcachefs_attrs(const char *path)
{
	unsigned i;

	for (i = 0; i < bch2_opts_nr; i++) {
		if (bch2_opt_table[i].flags & OPT_INODE) {
			// Only works on empty directory.
			if (strcmp(bch2_opt_table[i].attr.name, "casefold") == 0)
				continue;

			char *full_name = mprintf("bcachefs.%s", bch2_opt_table[i].attr.name);
			remove_bcachefs_attr(path, full_name);
			free(full_name);
		}
	}
}

static void do_setattr(char *path, struct bch_opt_strs opts, bool remove_all)
{
	unsigned i;

	if (remove_all) {
		remove_all_bcachefs_attrs(path);
	}

	for (i = 0; i < bch2_opts_nr; i++) {
		if (!opts.by_id[i])
			continue;

		char *n = mprintf("bcachefs.%s", bch2_opt_table[i].attr.name);

		if (strcmp(opts.by_id[i], "-") == 0) {
			remove_bcachefs_attr(path, n);
		} else {
			if (setxattr(path, n, opts.by_id[i], strlen(opts.by_id[i]), 0))
				die("setxattr error: %m");
		}

		free(n);
	}

	struct stat st = xstat(path);
	if (!S_ISDIR(st.st_mode))
		return;

	int dirfd = open(path, O_RDONLY);
	if (dirfd < 0)
		die("error opening %s: %m", path);

	propagate_recurse(dirfd);
}

static void setattr_usage(void)
{
	puts("bcachefs set-file-option - set attributes on files in a bcachefs filesystem\n"
	     "Usage: bcachefs set-file-option [OPTION]... <files>\n"
	     "\n"
	     "Options:");

	bch2_opts_usage(OPT_INODE);
	puts("      --remove-all             Remove all file options\n"
	     "                               To remove specific options, use: --option=-\n"
	     "  -h, --help                   Display this help and exit\n"
	     "\n"
	     "Report bugs to <linux-bcachefs@vger.kernel.org>");
	exit(EXIT_SUCCESS);
}

int cmd_setattr(int argc, char *argv[])
{
	unsigned i;
	bool remove_all = false;

	for (i = 1; i < argc; i++) {
		if (strcmp(argv[i], "--help") == 0) {
			setattr_usage();
			exit(EXIT_SUCCESS);
		}
		if (strcmp(argv[i], "-h") == 0) {
			setattr_usage();
			exit(EXIT_SUCCESS);
		}
		if (strcmp(argv[i], "--remove-all") == 0) {
			remove_all = true;
			bch_remove_arg_from_argv(&argc, argv, i);
			i--;
		}
	}

	struct bch_opt_strs opts =
		bch2_cmdline_opts_get(&argc, argv, OPT_INODE);

	for (i = 1; i < argc; i++)
		if (argv[i][0] == '-') {
			printf("invalid option %s\n", argv[i]);
			setattr_usage();
			exit(EXIT_FAILURE);
		}

	if (argc <= 1)
		die("Please supply one or more files");

	for (i = 1; i < argc; i++)
		do_setattr(argv[i], opts, remove_all);
	bch2_opt_strs_free(&opts);

	return 0;
}
