/* See LICENSE file for copyright and license details. */
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <limits.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "fs.h"
#include "util.h"

static int   hflag = 0;
static uid_t uid = -1;
static gid_t gid = -1;
static int   ret = 0;

static void
chownpwgr(int dirfd, const char *name, struct stat *st, void *data, struct recursor *r)
{
	int flags = 0;

	if ((r->maxdepth == 0 && r->follow == 'P') || (r->follow == 'H' && r->depth) || (hflag && !(r->depth)))
		flags |= AT_SYMLINK_NOFOLLOW;

	if (fchownat(dirfd, name, uid, gid, flags) < 0) {
		weprintf("chown %s:", r->path);
		ret = 1;
	} else if (S_ISDIR(st->st_mode)) {
		recurse(dirfd, name, NULL, r);
	}
}

static void
usage(void)
{
	eprintf("usage: %s [-h] [-R [-H | -L | -P]] owner[:[group]] file ...\n"
	        "       %s [-h] [-R [-H | -L | -P]] :group file ...\n",
	        argv0, argv0);
}

int
main(int argc, char *argv[])
{
	struct group *gr;
	struct passwd *pw;
	struct recursor r = { .fn = chownpwgr, .maxdepth = 1, .follow = 'P' };
	char *owner, *group;

	ARGBEGIN {
	case 'h':
		hflag = 1;
		break;
	case 'r':
	case 'R':
		r.maxdepth = 0;
		break;
	case 'H':
	case 'L':
	case 'P':
		r.follow = ARGC();
		break;
	default:
		usage();
	} ARGEND

	if (argc < 2)
		usage();

	owner = argv[0];
	if ((group = strchr(owner, ':')))
		*group++ = '\0';

	if (owner && *owner) {
		errno = 0;
		pw = getpwnam(owner);
		if (pw) {
			uid = pw->pw_uid;
		} else {
			if (errno)
				eprintf("getpwnam %s:", owner);
			uid = estrtonum(owner, 0, UINT_MAX);
		}
	}
	if (group && *group) {
		errno = 0;
		gr = getgrnam(group);
		if (gr) {
			gid = gr->gr_gid;
		} else {
			if (errno)
				eprintf("getgrnam %s:", group);
			gid = estrtonum(group, 0, UINT_MAX);
		}
	}
	if (uid == (uid_t)-1 && gid == (gid_t)-1)
		usage();

	for (argc--, argv++; *argv; argc--, argv++)
		recurse(AT_FDCWD, *argv, NULL, &r);

	return ret || recurse_status;
}