# Libraries

from xlsxwriter.workbook import Workbook
from openpyxl import load_workbook
import random as ran

# Variables

counter = 0

# Excel tools

filepath = "encrypt.xlsx"
wb = load_workbook(filepath)
ws = wb.active

workbook = Workbook('encrypt.xlsx')
worksheet = workbook.add_worksheet()


# Encrypt and Decrypt functions

def encrypt(key, msg):
    encryped = []
    for i, c in enumerate(msg):
        key_c = ord(key[i % len(key)])
        msg_c = ord(c)
        encryped.append(chr((msg_c + key_c) % 127))
    return ''.join(encryped)


def decrypt(key, encryped):
    msg = []
    for i, c in enumerate(encryped):
        key_c = ord(key[i % len(key)])
        enc_c = ord(c)
        msg.append(chr((enc_c - key_c) % 127))
    return ''.join(msg)


# If there is no message made then this will make you input one.

if ws['A3'].value is None:
    msg = input("Please input your message.\n")
    worksheet.write('A3', str(msg))

message = str(ws['A3'].value)

# Creates Keys if none are made.

if ws['A1'].value is None:
    print("Creating new Keys...")

    # Inputs the texts into the said cells

    worksheet.write('A1', "Private Key")
    worksheet.write('B1', "Public Key")

    # Randomly generates the key.

    key = str(ran.randint(498572983475, 19287348917248938247))

    # Splits the key in half for the private and public key.

    privateKey = key[:len(key) // 2]
    publicKey = key[len(key) // 2:]

    # Inputs the keys into the said cells.

    worksheet.write('A2', str(privateKey))
    worksheet.write('B2', str(publicKey))

    # Closes/Saves the excel document.

    workbook.close()

    print("Finished.")

# Key Variable

privateKey = str(ws['A2'].value)
publicKey = str(ws['B2'].value)

tempKey = privateKey + publicKey

fullKey = tempKey.replace(" ", "")

encMsg = encrypt(fullKey, message)

# Entering key section

while counter < 3:
    tried = input("Input the keys:\n")
    if tried == fullKey:
        counter = 3
    counter = counter + 1

# If succeeded in inputting the key.

if tried == fullKey:
    print("Here his the message:\n", decrypt(fullKey, encMsg))

# If failed to get the key right.

if tried != fullKey:
    print("Invalid input.")

# Stops the CMD prompt from closing down when code is done.

input()

# Made by Shadow/Tyler