Sys log

"""

    Log in system with a feature of changing username and password

"""

import os
import json


def input_func(part):        # 2, the user will be inputting here the choice of what he want to do.
    if part == 1:            # part 1 == while not logged in | part 2 == while logged in.
        while True:
            choice = input("""Input the number of your choice:
            1. Sing up
            2. Login
            7. Exit\n""")
            try:
                choice = int(choice)

            except ValueError:
                print('Input the number of your choice')

            if choice in [1, 2, 7]:
                break

            else:
                print('Invalid number')

        return choice

    if part == 2:
        while True:
            choice2 = input("""Input the number of your choice:
            3. Change password
            4. Change username
            5. Logout
            7. Exit\n""")
            try:
                choice2 = int(choice2)

            except ValueError:
                print('Input the number of your choice')

            if choice2 in [3, 4, 5, 7]:
                break

            else:
                print('Invalid number')

        return choice2


def sign_up_system():    # 2, function that responsible for the signing up.
    user_name = input('Input Username: ')
    password = input('Input password: ')
    storage_info[user_name] = password

    with open('logins.json', 'w') as j:
        json.dump(storage_info, j)
    print('''Registered!
    Username: {}
    Password: {}
    '''.format(user_name, password))


def change_pass(user_name):       # 3, function that changes your pass.
    new_pass = input('Type your new password: ')
    print('Your new password is: {}'.format(new_pass))
    storage_info[user_name] = new_pass
    with open('logins.json', 'w') as j:
        json.dump(storage_info, j)


def change_usrname(old_user_name):    # 4, function that changes your user name.
    new_username = input('Type your new username: ')
    print('Your new username is: {}'.format(new_username))
    storage_info[new_username] = storage_info.pop(old_user_name)
    with open('logins.json', 'w') as j:
        json.dump(storage_info, j)


def check_login(username, password):
    if storage_info[username] == password:
        return True
    else:
        return False


def main():              # The main function that includes everything and runs the program.
    print("Hi welcome to the Login system\n")

    with open('logins.json', 'r')as j:
        global storage_info
        storage_info = json.load(j)

    done = False
    while not done:

        logged_in = False
        while not logged_in:

            choice = input_func(1)

            if choice == 1:  # Sign up
                sign_up_system()

            elif choice == 2:
                logging_in = False
                while not logging_in:  # Log in checks checks if the user and pass are valid or not.
                    log_in_user_name = input('Username: \n')
                    log_in_user_pass = input('Password: ')
                    logging_in = check_login(log_in_user_name, log_in_user_pass)

                    if logging_in is False:
                        'Invalid username or password'

                    elif logging_in is True:
                        print('Hi {}, You are logged in!\n'.format(log_in_user_name))
                        logged_in = True

            elif choice == 7:  # Exit
                raise SystemExit(0)

        while logged_in:

                choice2 = input_func(2)  # input function part 2

                if choice2 == 3:  # change password
                    change_pass(log_in_user_name)

                elif choice2 == 4:  # Change username
                    change_usrname(log_in_user_name)

                elif choice2 == 5:  # Logout
                    logged_in = False

                elif choice2 == 7:  # Exit
                    raise SystemExit(0)


if __name__ == '__main__':
    main()