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

key: int = int(input("\nEnter your Caesar key in numeric form (1-25): "))
mode: int = int(input("\nEnter 1 for encryption, and 0 for decryption: "))

character_str: str = input(
    "\nEnter the Caesar encoding of the first character of your message: "
)

while not character_str.isnumeric():
    character_str = input(
        "\nEnter the Caesar encoded INTEGER corresponding to yoru next character: "
    )

character = int(character_str)

while True:
    print("\tYour letter translated to:")
    # Does using a loop help here? If yes, why? If no, why?
    if mode == 1:
        # 26 is the symbol set size (# letters in alphabet)
        print("\t", (character + key) % 26)
    else:
        print("\t", (character - key) % 26)

    character_str = input("\nEnter the Caesar encoded next character, or -1 for done: ")
    if character_str == "-1":
        break
    while not character_str.isnumeric():
        character_str = input(
            "\nEnter the Caesar encoded INTEGER corresponding to your next character: "
        )
    character = int(character_str)

print("\nend of Caesar encoded message\n")