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

from itertools import izip_longest
import string
from binascii import hexlify
from math import log
from random import randint
import io
import argparse
import sys

# global variables

# TODO: create dirty hack to work with 3 capacity during specification
cap         = 1
capacity    = cap*2
maxInt      = 2**(cap*8) - 1
rewriteBin  = True
bin         = "bin"

print "MaxINT: %s" % maxInt
#maxInt = int(maxInt)
cap = int(cap)

# amount of address cells
N           = 4
# amount of data cells
D_count     = 8


# 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 or True:
            # we have valid capacity of our integer.
            # now check the max number to given capacity, else raise an Exception
            if numb > maxInt:
                raise ValueError("Integer %s not filling in %s bytes capacity, Max INT: %s" %
                                                            (numb, capacity, maxInt))

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

    return out

# return normalized data from convert function
def unconvert(numb):
    # using this hack to avoid bug with zero
    h = hexlify(numb)
#    print h
    if not "0"*cap == h:
        h = h.lstrip("0")

    return int(h, 16)

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

# Code to provide working lab =)

def _writeDefaultData2Bin():
    fd = open(bin, "wb")
    # using it for code less
    cv = convert

    fd.write(cv(N))
    for i in xrange(1, N+1):
        fd.write(cv(i))


    for i in xrange(0, D_count):
        rnd = randint(0, maxInt)
#        print rnd
        fd.write(cv(rnd))

    fd.close()


def showBinContent():
    fd = open(bin, "rb")

    # use it for less code
    uc = unconvert
    # getting amount of addresses
    binN = fd.read(cap)
    binN = unconvert(binN)

    # list for storing already read data
    addresses = []
    data = []


    for i in xrange(0,N):
        addresses.append(uc(fd.read(cap)))


    for i in xrange(0, D_count):
        data.append(uc(fd.read(cap)))

    print "Addresses:"
    print addresses
    print "Data:"
    print data

    fd.close()


def InteractWithUser():
#    _writeDefaultData2Bin()
#    showBinContent()
#    _movingLoader()

    while True:
        print "Bin file contains:"
        showBinContent()
        new_rnd = raw_input("Do you want to generate new random data?(y) Or write personally?(w)\n")
        if not new_rnd == "y" and not  new_rnd == "w":
            break
        elif new_rnd == "y":
            _writeDefaultData2Bin()
        elif new_rnd == "w":
            _userEditing()
            break



def _movingLoader():
    moveon = 2
    fd = io.open(bin, "r+b")
    uc = unconvert
    cv = convert

#    fd.seek(cap+cap*N+cap*(1-1))

#    data = uc(fd.read(cap))
#    print "Updating Data: %s" % data
#    data += 10
#    print "New Data: %s" % data

    # moving back
#    fd.seek(-cap, 1)

#    fd.write(convert(data))

    adds = list()

    N = fd.read(cap)
    N = uc(N)

    posAd   = cap
    posData = cap+(cap*N)

    fd.seek(posAd)

    for i in xrange(1,N+1):
        adds.append(uc(fd.read(cap)))


    print adds

    fd.seek(posData)
    n = 1
    for a in adds:
        vl = uc(fd.read(cap))
        if n in adds:
            fd.seek(-cap, 1)
            fd.write(cv(vl+moveon))

        n+=1



    fd.close()




if __name__ == "__main__":
#    InteractWithUser()
#    _userEditing()
#    print unconvert(convert(1))
#    _writeDefaultData2Bin()
#    showBinContent()

    showBinContent()
    print ""

    _movingLoader()
    print ""
    showBinContent()
    exit(0)
    if len(sys.argv) == 3:
        if sys.argv[1] == "-m":
            try:
                move = int(sys.argv[2])
                print move
            except:
                print "Unexpected error"
        else:
            print "Error in args"

    else:
        print "No such args"