import random
import hashlib
import os
from datetime import datetime
import getpass

def pretty_time(t):
    return str(t.date()) + " " + str(t.hour) + "-" + str(t.minute) + "-" + str(t.second)

if not os.path.isfile("input.txt"):
    open("input.txt", "w").write("Write your input here")
    print("Please open the input.txt file")
    exit()

input_text = open("input.txt", "r").read()

username = input("Username : ")
password = getpass.getpass("Password : ")

key = hashlib.sha256( (username + "." + password).encode("utf-8") ).hexdigest()

print("\nInput : ")
print(input_text, "\n")

print("Decode / Encode?")
action = ""
while action != "decode" and action != "encode":
    action = input("Action : ").lower()
    if action != "decode" and action != "encode":
        print("Invalid action")

output = ""
for i in input_text:
    if ord(i) > 31 and ord(i) < 127:
        value = ord(i) - 32
        if action == "encode":
            output += chr((value + int(key, 16)) % 95 + 32)
        elif action == "decode":
            output += chr( (value - int(key, 16)) % 95 + 32 )
        key = hashlib.sha256(key.encode("utf-8")).hexdigest()

save_file = ""
while save_file != "y" and save_file != "n":
    save_file = input("Save output as a file? (Y/N) : ").lower()
    if save_file != "y" and save_file != "n":
        print("Invalid input")

if save_file == "y":
        output_dir = pretty_time(datetime.now()) + ".txt"
        output_file = open(output_dir, "w")
        output_file.write(output)
        print("Output saved at : " + output_dir)
print(output)