/*
 * UNG's Not GNU
 *
 * Copyright (c) 2023, Jakob Kaivo <jkk@ung.org>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#define _XOPEN_SOURCE 700
#include <errno.h>
#include <locale.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/statvfs.h>
#include <unistd.h>

static enum { POSIX, TOTAL } output = POSIX;
static unsigned int blocksize = 512;

static int df(const char *path)
{
	struct statvfs fs;
	if (statvfs(path, &fs) != 0) {
		perror(path);
		return 1;
	}

	const char *name = path;
	const char *root = path;
	printf("%-10s %11ju %11ju %11ju %7ju%% %s\n",
		name,
		fs.f_blocks,
		fs.f_blocks - fs.f_bfree,
		fs.f_bfree,
		((fs.f_blocks - fs.f_bfree) * 100 / fs.f_blocks),
		root);
	return 0;
}

int main(int argc, char *argv[])
{
	setlocale(LC_ALL, "");


	int c;
	while ((c = getopt(argc, argv, "kPt")) != -1) {
		switch(c) {
		case 'k':	/** Use 1024-byte blocks **/
			blocksize = 1024;
			break;

		case 'P':
			output = POSIX;
			break;

		case 't':
			output = TOTAL;
			break;

		default:
			return 1;
		}
	}

	if (output == POSIX) {
		printf("Filesystem %4u-blocks        Used   Available Capacity Mounted on\n", blocksize);
	} else {
		/* print some other header */
	}

	int ret = 0;
	do {
		ret |= df(argv[optind++]);
	} while (optind < argc);
	return ret;
}