/*
 * UNG's Not GNU
 * 
 * Copyright (c) 2011, Jakob Kaivo <jakob@kaivo.net>
 * 
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */

#define _XOPEN_SOURCE 700
#include <ftw.h>
#include <grp.h>
#include <limits.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#define NOFOLLOW	0
#define FOLLOWARGV	1
#define FOLLOWALL	2

static int recursive = 0;
static int links = FOLLOWARGV;
static uid_t newowner = -1;
static gid_t newgroup = -1;

int _chown(const char *);

int nftw_chown(const char *p, const struct stat *sb, int typeflag,
	       struct FTW *f)
{
	(void)sb; (void)typeflag; (void)f;
	return _chown(p);
}

int _chown(const char *p)
{
	struct stat st;
	if (lstat(p, &st) != 0) {
		perror(p);
		return 1;
	}
	// FIXME: about symlinks....
	// if (links == NOFOLLOW
	// lchown (p, newowner, newgroup) 
	if (chown(p, newowner, newgroup) != 0) {
		perror(p);
	}
	return 0;
}

static void chown_parse(const char *ug)
{
	char *colon = strchr(ug, ':');
	if (colon == NULL) {
		struct passwd *pwd = getpwnam(ug);
		if (pwd == NULL)
			exit(1);
		newowner = pwd->pw_uid;
	} else {
		struct passwd *pwd;
		struct group *grp;
		char user[NAME_MAX];
		strcpy(user, ug);
		user[strlen(ug) - strlen(colon)] = '\0';
		pwd = getpwnam(user);
		grp = getgrnam(&colon[1]);
		if (pwd == NULL || grp == NULL) {
			exit(1);
		}
		newowner = pwd->pw_uid;
		newgroup = grp->gr_gid;
	}
}

int do_chown(char *path, int recurse, int howlinks, uid_t uid, gid_t gid)
{
	recursive = recurse;
	links = howlinks;
	newowner = uid;
	newgroup = gid;
	// FIXME: This is where to recurse and handle the difference betwixt links types
	return _chown(path);
}

int main(int argc, char *argv[])
{
	int c;
	while ((c = getopt(argc, argv, ":hHLPR")) != -1) {
		switch (c) {
		case 'h':
			if (recursive)
				return 1;
			recursive = -1;
			links = NOFOLLOW;
			break;
		case 'H':
			links = FOLLOWARGV;
			break;
		case 'L':
			links = FOLLOWALL;
			break;
		case 'P':
			links = NOFOLLOW;
			break;
		case 'R':
			if (recursive == -1)
				return 1;
			recursive = 1;
			break;
		default:
			return 1;
		}
	}

	if (optind >= argc - 1) {
		return 1;
	}

	chown_parse(argv[optind++]);

	while (optind < argc) {
		do_chown(argv[optind], recursive, links, newowner, newgroup);
		optind++;
	}

	return 0;
}