#! /usr/bin/python3

import wordsegment
import numpy
import random
import itertools
import binascii 
from Crypto.Util.strxor import strxor

import hw7a

## try hw7a.main() for test examples


## also, see seti.py

## problem 1

# load the bigrams, unigrams, etc.
S = wordsegment.Segmenter()
S.load()

p1 = S.segment("thisisatest")

## problem 2

p2 = "thisisanotherlittlestring"

## use numpy array functions
p2a = numpy.asarray(list(p2))
p2a2 = p2a.reshape([5,5])

## note: this is destructive
def swap_cols(arr, frm, to):
    arr[:,[frm, to]] = arr[:,[to, frm]]

## note: this is destructive
def swap_rows(arr, frm, to):
    arr[[frm, to],:] = arr[[to, frm],:]

#p2ac = swap_cols(p2a2, 1, 2)
#p2ar = swap_rows(p2a2, 1, 2)

p2apc = hw7a.permute_cols(p2a2, [4,3,2,1,0])
p2apr = hw7a.permute_rows(p2a2, [4,3,2,1,0])

p2shuffle = list(range(5))
random.shuffle(p2shuffle)

## for transdecode, can try all possible permutations

p2x = list(range(3))
p2xi = itertools.permutations(p2x)

## or just
p2xip = itertools.permutations(range(3))


## problem 3
## use trial and error with swap functions


## problem 4


## for encodexorbase64(string, key)
## need to adjust key to be same length as string

## convert strings to base64

p4 = b"thisisatest"
p4b64 = binascii.b2a_base64(p4)

## from Crypto module
p4xor = strxor(p4b64,p4b64)
p4againb64 = strxor(p4xor,p4b64)
p4again = binascii.a2b_base64(p4againb64)

# problem 5

## see UNIX shell scripts discussion