/*
 * Copyright (c) 2013 Manuele Conti
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup df
 * @brief Df utility.
 * @{
 */
/**
 * @file
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <getopt.h>
#include <sys/statfs.h>
#include <errno.h>
#include <adt/list.h>
#include <vfs/vfs.h>

#define NAME  "df"

#define HEADER_TABLE "Filesystem     512-blocks           Used      Available Used% Mounted on"

#define PERCENTAGE(x, tot) ((unsigned long long) (100L * (x) / (tot)))  
#define FSBK_TO_BK(x, fsbk, bk) \
	(((fsbk) != 0 && (fsbk) < (bk)) ? \
		(unsigned long long) ((x) / ((bk) / (fsbk))) : \
		(unsigned long long) ((x) * ((fsbk) / (bk))))

static void print_statfs(struct statfs *, char *, char *);
static void print_usage(void);

int main(int argc, char *argv[])
{
	int optres, errflg = 0;
	struct statfs st;
	
	/******************************************/
	/*   Parse command line options...        */
	/******************************************/
	while ((optres = getopt(argc, argv, ":hi")) != -1) {
		switch(optres) {
		case 'h':
			break;

		case 'i':
			break;
    
		case ':':       
			fprintf(stderr, "Option -%c requires an operand\n", optopt);
			errflg++;
			break;

		case '?':
			fprintf(stderr, "Unrecognized option: -%c\n", optopt);
			errflg++;
			break;

		default:
			fprintf(stderr, "Unknown error while parsing command line options.");
			errflg++;
			break;
		}
	}

	if (optind > argc) {
		fprintf(stderr, "Too many input parameter\n");
		errflg++;
	}
	
	if (errflg) {
		print_usage();
		return 1;
	}
	
	LIST_INITIALIZE(mtab_list);
	get_mtab_list(&mtab_list);
	printf("%s\n", HEADER_TABLE);
	list_foreach(mtab_list, cur) {
		mtab_ent_t *mtab_ent = list_get_instance(cur, mtab_ent_t,
		    link);
		statfs(mtab_ent->mp, &st);
		print_statfs(&st, mtab_ent->fs_name, mtab_ent->mp);
	}
	putchar('\n');	
	return 0;
}

static void print_statfs(struct statfs *st, char *name, char *mountpoint)
{
	printf("%10s", name);
	printf(" %14llu %14llu %14llu %4llu%% %s\n", 
		FSBK_TO_BK(st->f_blocks, st->f_bsize, 512),                              /* Blocks     */
		FSBK_TO_BK(st->f_blocks - st->f_bfree, st->f_bsize, 512),                /* Used       */
		FSBK_TO_BK(st->f_bfree, st->f_bsize, 512),                               /* Available  */
		(st->f_blocks)?PERCENTAGE(st->f_blocks - st->f_bfree, st->f_blocks):0L,  /* Used%      */
		mountpoint                                                               /* Mounted on */
	);
}

static void print_usage(void)
{
  printf("syntax: %s [-h] [-i]\n", NAME);
  printf("  h : \"Human-readable\" output.\n");  
  printf("  i : Include statistics on the number of free inodes. \n");
  printf("\n");
}

/** @}
 */