''' cool Ceasar cypher encryptor/decryptor '''
# made by Jeremy Carder Apr. 15, 2018


try:
	import pyperclip
except ModuleNotFoundError:
	pass

import random


mode = ''
alphabet = "abcdefghijklmnopqrstuvwxyz"
output = []


def cryptor(encrypt):
	global output

	for letter in message:
		if letter == ".":
			output.append(".")
		elif letter == ",":
			output.append("")
		elif letter == " ":
			output.append(" ")
		else:
			if encrypt:
				comb = alphabet.index(letter) + int(shift)
			else:
				comb = alphabet.index(letter) - int(shift)

			if comb > 25:
				comb -= 26

			output.append(alphabet[comb])


	print(shift, "".join(output), "\n")

	if encrypt:
		try:
			pyperclip.copy("".join(output))
			print("(copied to clipboard)")
		except:
			print("Install the 'pyperclip' Python module to automatically copy encoded message to clipboard.")

	output = []


print("Press 'q' to quit.")

while mode != 'q':

	mode = input("\nEnter 'e' to encrypt or 'd' to decrypt: ")

	if mode != 'q':
		message = input("Message: ").lower()
		shift = input("Shift (random is default): ")

	if mode == 'e':

		if shift == "":
			shift = random.randint(0, 26)
		cryptor(True)

	else:

		if shift == "":
			for shift in range(0, 26):
				cryptor(False)
		else:
			cryptor(False)