#!/usr/bin/python3
# -*- coding: utf-8 -*-

# Transposition Cipher Test
# https://www.nostarch.com/crackingcodes (BSD Licensed)

import random, sys, transpositionEncrypt, transpositionDecrypt


def main() -> None:
    random.seed(42)  # set the random "seed" to a static value
    for i in range(20):  # run 20 tests
        # Generate random messages to test.
        # The message will have a random length:
        message = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" * random.randint(4, 40)
        # Convert the message string to a list to shuffle it.
        message_array = list(message)
        random.shuffle(message_array)
        message = "".join(message_array)  # convert list to string
        print('Test #%s: "%s..."' % (i + 1, message[:50]))
        # Check all possible keys for each message.
        for key in range(1, int(len(message) / 2)):
            encrypted = transpositionEncrypt.encryptMessage(key, message)
            print(encrypted)
            decrypted = transpositionDecrypt.decryptMessage(key, encrypted)
            # If the decryption doesn't match the original message, display
            # an error message and quit.
            if message != decrypted and message != encrypted:
                print("Mismatch with key %s and message %s." % (key, message))
                print("Decrypted as: " + decrypted)
                sys.exit()
    print("Transposition cipher test passed.")


# If transpositionTest.py is run (instead of imported as a module) call
# the main() function.
if __name__ == "__main__":
    main()