## Password Program v2 ##
## ~~ FEATURES ~~ ##
## Allows Users to Login!
## Allows users to create unlimited accounts.
## Uses Text documents to store user data.
## Forms of verification to protect users data from being over written.
## Password checking.
## Forces user to create a complex password.

import getpass
import time
import linecache

def attemptLogin(username, password):
    try:
        correctPassword = str(linecache.getline(username + ".txt", 1)).rstrip()

    except IOError:
        return "Failed to find account!"

    # Assume the account exists so far
    if password == correctPassword:
        return True
    else:
        return False

def createAccount(username, password, confirmPass):
    if password != confirmPass:
        return False
    else:
        try:
            file = open(username + '.txt', 'r')
            return False

        except IOError:
            file = open(username + '.txt', 'w')
            file.write(Password)
            file.close()
            return True

def changePass(username, oldPassword, newPassword, newPasswordConfirm):
    if oldPassword == newPassword or newPassword != newPasswordConfirm:
        return False

    try:
        correctPassword = str(linecache.getline(username + ".txt", 1)).rstrip()
    except IOError:
        return False

    # Shows account exits
    # Validates new password

    if any(x.isdigit() for x in newPassword) == True and newPassword.upper() != newPassword and newPassword.lower() != newPassword and len(newPassword) >= 8 and oldPassword == str(linecache.getline(username + ".txt", 1)).rstrip():
        # Just checked has number(s), has lower case, has upper case and has a length greater than 8, and their old password is correct.
        file = open(username + '.txt', 'w')
        file.write(newPassword)
        file.close()
        return True

    else:
        return False

while True:
    selectOption = input("Select option: Attempt Login (L), Create Account (C), Change Password (P): ")

    if selectOption == 'L':
        userName = input("Username: ")
        password = getpass.getpass('Password: ')
        if attemptLogin(userName, password) == True:
            print("Login Successful!")
        else:
            print("Login Failed")

    elif selectOption == 'C':
        userName = input("Username: ")
        password = getpass.getpass('Password: ')
        confirmPassword = getpass.getpass('Confirm Password: ')
        if createAccount(userName, password, confirmPassword):
            print('Account Creation Successful!')
        else:
            print('Failed to create account!')

    elif selectOption == 'P':
        userName = input("Username: ")
        password = getpass.getpass('Old Password: ')
        newPassword = getpass.getpass('New Password: ')
        confirmPassword = getpass.getpass('Confirm New Password: ')

        if changePass(userName, password, newPassword, confirmPassword) == True:
            print('Password Successfully Changed!')
        else:
            print("Failed to change password!")

    else:
        print("Invalid Option!")