/*
** Zabbix
** Copyright (C) 2001-2014 Zabbix SIA
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
**/

#include "common.h"
#include "sysinfo.h"
#include "zbxjson.h"

static int	get_fs_size_stat(const char *fs, zbx_uint64_t *total, zbx_uint64_t *free,
		zbx_uint64_t *used, double *pfree, double *pused)
{
#ifdef HAVE_SYS_STATVFS_H
#	define ZBX_STATFS	statvfs
#	define ZBX_BSIZE	f_frsize
#else
#	define ZBX_STATFS	statfs
#	define ZBX_BSIZE	f_bsize
#endif
	struct ZBX_STATFS	s;

	assert(fs);

	if (0 != ZBX_STATFS(fs, &s))
		return SYSINFO_RET_FAIL;

	if (total)
		*total = (zbx_uint64_t)s.f_blocks * s.ZBX_BSIZE;
	if (free)
		*free = (zbx_uint64_t)s.f_bavail * s.ZBX_BSIZE;
	if (used)
		*used = (zbx_uint64_t)(s.f_blocks - s.f_bfree) * s.ZBX_BSIZE;
	if (pfree)
	{
		if (0 != s.f_blocks - s.f_bfree + s.f_bavail)
			*pfree = (double)(100.0 * s.f_bavail) /
					(s.f_blocks - s.f_bfree + s.f_bavail);
		else
			*pfree = 0;
	}
	if (pused)
	{
		if (0 != s.f_blocks - s.f_bfree + s.f_bavail)
			*pused = 100.0 - (double)(100.0 * s.f_bavail) /
					(s.f_blocks - s.f_bfree + s.f_bavail);
		else
			*pused = 0;
	}

	return SYSINFO_RET_OK;
}

static int	VFS_FS_USED(const char *fs, AGENT_RESULT *result)
{
	zbx_uint64_t	value = 0;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, NULL, NULL, &value, NULL, NULL))
		return SYSINFO_RET_FAIL;

	SET_UI64_RESULT(result, value);

	return SYSINFO_RET_OK;
}

static int	VFS_FS_FREE(const char *fs, AGENT_RESULT *result)
{
	zbx_uint64_t	value = 0;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, NULL, &value, NULL, NULL, NULL))
		return SYSINFO_RET_FAIL;

	SET_UI64_RESULT(result, value);

	return SYSINFO_RET_OK;
}

static int	VFS_FS_TOTAL(const char *fs, AGENT_RESULT *result)
{
	zbx_uint64_t	value = 0;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, &value, NULL, NULL, NULL, NULL))
		return SYSINFO_RET_FAIL;

	SET_UI64_RESULT(result, value);

	return SYSINFO_RET_OK;

}

static int	VFS_FS_PFREE(const char *fs, AGENT_RESULT *result)
{
	double	value = 0;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, NULL, NULL, NULL, &value, NULL))
		return SYSINFO_RET_FAIL;

	SET_DBL_RESULT(result, value);

	return SYSINFO_RET_OK;
}

static int	VFS_FS_PUSED(const char *fs, AGENT_RESULT *result)
{
	double	value = 0;

	if (SYSINFO_RET_OK != get_fs_size_stat(fs, NULL, NULL, NULL, NULL, &value))
		return SYSINFO_RET_FAIL;

	SET_DBL_RESULT(result, value);

	return SYSINFO_RET_OK;
}

int	VFS_FS_SIZE(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	char	*fsname, *mode;
	int	ret = SYSINFO_RET_FAIL;

	if (2 < request->nparam)
		return SYSINFO_RET_FAIL;

	fsname = get_rparam(request, 0);
	mode = get_rparam(request, 1);

	if (NULL == fsname || '\0' == *fsname)
		return SYSINFO_RET_FAIL;

	if (NULL == mode || '\0' == *mode || 0 == strcmp(mode, "total"))
		ret = VFS_FS_TOTAL(fsname, result);
	else if (0 == strcmp(mode, "free"))
		ret = VFS_FS_FREE(fsname, result);
	else if (0 == strcmp(mode, "pfree"))
		ret = VFS_FS_PFREE(fsname, result);
	else if (0 == strcmp(mode, "used"))
		ret = VFS_FS_USED(fsname, result);
	else if (0 == strcmp(mode, "pused"))
		ret = VFS_FS_PUSED(fsname, result);
	else
		ret = SYSINFO_RET_FAIL;

	return SYSINFO_RET_FAIL;
}

int	VFS_FS_DISCOVERY(AGENT_REQUEST *request, AGENT_RESULT *result)
{
	int		ret = SYSINFO_RET_FAIL;
	struct mntent	*mt;
	FILE		*f;
	struct zbx_json	j;

	zbx_json_init(&j, ZBX_JSON_STAT_BUF_LEN);

	zbx_json_addarray(&j, ZBX_PROTO_TAG_DATA);

	/* opening the mounted filesystems file */
	if (NULL != (f = setmntent(MNT_MNTTAB, "r")))
	{
		/* fill mnttab structure from file */
		while (NULL != (mt = getmntent(f)))
		{
			zbx_json_addobject(&j, NULL);
			zbx_json_addstring(&j, "{#FSNAME}", mt->mnt_dir, ZBX_JSON_TYPE_STRING);
			zbx_json_addstring(&j, "{#FSTYPE}", mt->mnt_type, ZBX_JSON_TYPE_STRING);
			zbx_json_close(&j);
		}

		endmntent(f);

		ret = SYSINFO_RET_OK;
	}

	zbx_json_close(&j);

	SET_STR_RESULT(result, zbx_strdup(NULL, j.buffer));

	zbx_json_free(&j);

	return ret;
}
