#!/usr/bin/python2

# import os for statvfs
import os


# reading a file
def fileparser(path):
    file = open(path, "r")
    result = file.read()
    file.close()
    return result

#file = open("/proc/partitions", "r")
#parts = file.read()
#file.close()
#file = open("/proc/mounts", "r")
#mounts = file.read()
#file.close()

# reading needed files
parts = fileparser("/proc/partitions")
mounts = fileparser("/proc/mounts") #bug.. what if uuids are in /proc/mounts

partitions = []
blocks = []
# getting all local partitions (regardless if mounted or not)
# and blocks from /proc/partitions and write it to lists
for line in parts.split("\n"):
    if line and "name" not in line and "sr0" not in line:
        if line.split()[2] != "1":
            partitions.append("/dev/" + line.split()[3])
            blocks.append(line.split()[2])


hold="nothing"
holdblocks = 0
blockcount = 0
counter = 0
partsnew = []
blocksnew = []
# detect disk like /dev/sda itself and
# filter it from partitions and blocks list
for part in partitions:
    if hold in part:
        blockcount = blockcount + int(blocks[counter])
        partsnew.append(part)
        blocksnew.append(blocks[counter])
    else:
        hold = part
        holdblocks = blocks[counter]
        blockcount = 0
    counter += 1


# moving back to old var name
# too lazy to rename everything below
partitions = partsnew
blocks = blocksnew

# getting mounted partitions and their mountpoints
mountpoints = []
mountparts = []
for item in partitions:
    for line in mounts.split("\n"):
        if line and item in line:
            mountpoints.append(line.split()[1])
            mountparts.append(item)
            break

# output for debugging
print "debug output:"
print "availible partitions: %s\nblocks: %s\nmounted partitions: %s\nmountpoints: %s" %(partitions, blocks, mountparts, mountpoints)
print "" #linebreak


# given paths(mountpoints)
#path=("/boot", "/", "/dev/sda6")
path = mountpoints

print "mountpoints\tfree megabytes"
print "------------------------------"

# getting usage information and print it to stdout
for mountpoint in path:
    #check if given path is a mountpoint
    if os.path.ismount(mountpoint):
        #create statvfs object
        fs = os.statvfs(mountpoint)
        #calculate free megabytes
        freembytes = fs.f_bavail * fs.f_bsize / 1024**2.0
        #output
        print "%s\t\t%.1f MB" %(mountpoint, freembytes)
    else:
        print "error: given path (%s) is not a mountpoint" %(mountpoint)


# end of file