#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# @Author: KevinMidboe
# @Date:   2017-01-28 10:54:06
# @Last Modified by:   KevinMidboe
# @Last Modified time: 2017-02-18 11:40:34

# f_avail = free blocks avail to non sudo
# frsize = fundamental file sys byte size
# f_blocks = total number of blocks in the filesystem

from os import statvfs, path
from re import sub

# TODO: Add multiple dirs.

def sizeof(num, suffix='B'):
	for unit in ['','K','M','G','T','P','E','Z']:
		if abs(num) < 1024.0:
			return "%3.1f%s%s" % (num, unit, suffix)
		num /= 1024.0
	return "%.1f%s%s" % (num, 'Y', suffix)

# diskUsage uses statvfs to calculate disk size and availability for given disk
def diskUsage(rootPath=None):
	if rootPath == None: rootPath = '/'
	
	if not path.isdir(rootPath):
		return {"errors": "Directory does not exist."}

	s = statvfs(rootPath)
	byteLeft = s.f_bavail * s.f_frsize
	byteTotal = s.f_blocks * s.f_frsize
	byteUsed = byteTotal-byteLeft
	return { 'left': sizeof(byteLeft), 'used': sizeof(byteUsed), 'total': sizeof(byteTotal) }

if __name__=="__main__":
	print(diskUsage())