#!/usr/bin/env python2
# -*- coding: utf-8 -*-

from itertools import izip_longest
import string
from binascii import hexlify
from math import log

# global variables

# TODO: create dirty hack to work with 3 capacity during specification
capacity = 2


# end global variables

def convert(numb):
    # getting HEX represent, in string, to use it when writing into binary file
    hexNumb = '{0:x}'.format(numb)
    out = ""

    # analyze input number, and compute
    if not capacity == 0:
        # checking power of two
        if log(capacity, 2) % 1 == 0.0:
            # we have valid capacity of our integer.
            # now check the max number to given capacity, else raise an Exception
            if numb >= (2**(capacity*8)):
                raise BaseException("Integer %s not filling in %s bytes capacity, Max INT: %s" %
                                                            (numb, capacity, 2**(capacity*8)))

            # starting pushing to output
            for i in _grouper(2, hexNumb.zfill(capacity), 0):
                # performing modification of izip_longest to string
                i = string.join(i, "")
                out += chr(int(i, 16))
                # using statement below when i want a generator
                # yield chr(int(i, 16))

    return out

def unconvert(numb):
    return int(hexlify(numb), 16)

fd = open("bin", "wb")

def _grouper(n, iterable, fillvalue=None):
    "grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx"
    args = [iter(iterable)] * n
    return izip_longest(fillvalue=fillvalue, *args)

def convert2bin(intStr):
    return '{0:x}'.format( intStr )


def comment():
    num = 3405848999

    print convert2bin(num).zfill(8)

    for i in _grouper(2, convert2bin(num).zfill(8), 0):
        i = string.join(i, "")
        print i
        fd.write(chr(int(i, 16)))

    fd.close()

    fd = open("bin", "rb")
    read = fd.read()
    print read

    print int(hexlify(read), 16)

if __name__ == "__main__":
    print unconvert(convert(6553))
#    print convert(65536)