login

def login():
    import getpass
    import os
    import time
    import platform
    import hashlib
    import json
    from Crypto.Cipher import AES
    from Crypto.Random import get_random_bytes
    import base64
    import json

    if 'Windows' in platform.system():
        os.system('cls')
    else:
        os.system('clear')

    data = {

}

    secret = get_random_bytes(16)
    cipher = AES.new(secret, AES.MODE_ECB)  # secret is a 16 byte key that you create



    def encrypt_json(cipher, json_data):
        json_string = json.dumps(json_data).encode()
        return base64.b64encode(cipher.encrypt(json_string))


    def decrypt_json(cipher, encrypted_data):
        return cipher.decrypt(base64.b64decode(encrypted_data))

    with open(".users.json", 'rb') as file:
        data = file.read()
        data = json.loads(decrypt_json(cipher, data))

    encrypted = encrypt_json(cipher, json_data)  # encrypt the data
    decrypted = decrypt_json(cipher, encrpyted)

    with open(".users.json", 'wb+') as file:
        file.write(encrypted)

# here is the part to choose login or add new user or exit

    choice1 = False
    choice2 = False
    choice3 = False
    choice4 = False

    while not choice1:
        print('Choose an option:')
        print('[1]login')
        print('[2]add user')
        print('[3]exit')
        choice = input('enter the number here: ')

        if choice == '1':
            choice1 = True
        elif choice == '2':
# adding new user and getting passwords and name (isnt fixed 100%)
                if 'Windows' in platform.system():
                    os.system('cls')
                else:
                    os.system('clear')
                new_usr = input('enter new username: ')
                new_usr_pass = getpass.getpass('enter new password: ')
                new_usr_pass2 = getpass.getpass('re-enter new password: ')

                while not choice2:

                    if len(new_usr_pass) >= 8:
                        choice2 = True
                        choice3 = True
                    else:
                        if 'Windows' in platform.system():
                            os.system('cls')
                        else:
                            os.system('clear')
                    print('password is to short you need at least 8 digits')
                    time.sleep(2.5)
                    new_usr_pass = getpass.getpass('enter new password: ')
                    new_usr_pass2 = getpass.getpass('re-enter new password: ')

                    new_usr_pass_encode = new_usr_pass.encode()
                    new_usr_pass2_encode = new_usr_pass2.encode()
                    new_usr_pass_hash = hashlib.sha3_512(new_usr_pass_encode).hexdigest()
                    new_usr_pass2_hash = hashlib.sha3_512(new_usr_pass2_encode).hexdigest()

                    while not choice3:
                        if new_usr_pass_hash == new_usr_pass2_hash:
                            choice3 = True
                        else:
                            print('passwords DON´T match')
                            time.sleep(1)
                            if 'Windows' in platform.system():
                                os.system('cls')
                            else:
                                os.system('clear')
                            new_usr_pass = getpass.getpass('enter new password: ')
                            new_usr_pass2 = getpass.getpass('re-enter new password: ')

                        while not choice4:

                            if len(new_usr_pass) >= 7:
                                choice4 = True
                            else:
                                if 'Windows' in platform.system():
                                    os.system('cls')
                                else:
                                    os.system('clear')
                                print('password is to short you need at least 8 digits')
                                time.sleep(2.5)
                                new_usr_pass = getpass.getpass('enter new password: ')
                                new_usr_pass2 = getpass.getpass('re-enter new password: ')

                        new_usr_pass_encode = new_usr_pass.encode()
                        new_usr_pass2_encode = new_usr_pass2.encode()
                        new_usr_pass_hash = hashlib.sha3_512(new_usr_pass_encode).hexdigest()
                        new_usr_pass2_hash = hashlib.sha3_512(new_usr_pass2_encode).hexdigest()

                    if new_usr not in usname:
                        encrypt_json()
                        usname[new_usr] = new_usr_pass_hash
                    else:
                        if 'Windows' in platform.system():
                            os.system('cls')
                        else:
                            os.system('clear')

                        print('user is allready existing')
                        time.sleep(2)

                        if 'Windows' in platform.system():
                            os.system('cls')
                        else:
                            os.system('clear')

                        exit()


                    if 'Windows' in platform.system():
                        os.system('cls')
                    else:
                        os.system('clear')

                    print('succesfully added new user!')
                    time.sleep(2)

                    if 'Windows' in platform.system():
                        os.system('cls')
                    else:
                        os.system('clear')
        elif choice == '3':
            shutdown()

    # login stuff

    if 'Windows' in platform.system():
        os.system('cls')
    else:
        os.system('clear')

    username = input('enter username: ')
    pword= usname.get(username.encode(), None)

    if not pword:
        print("Incorrect credentials")
        exit()

    if username in usname:
        right_usn = True
    else:
        print('Wrong username!')
        right_usn = False
        time.sleep(1)
        if 'Windows' in platform.system():
            os.system('cls')
        else:
            os.system('clear')

    if right_usn == True:
        pass
    else:
        username = input('re-enter username: ')
        pword= usname.get(username, None)

        if not pword:
            print("Incorrect credentials")
            exit()

        if username in usname:
            pass
        else:
            print('Wrong username again!')
            time.sleep(1)
            if 'Windows' in platform.system():
                os.system('cls')
            else:
                os.system('clear')
            shutdown()

    password = getpass.getpass('enter password: ')
    password_encode = password.encode()
    password_hash = hashlib.sha3_512(password_encode).hexdigest()

    if password_hash == pword:
        pass
    else:
        if 'Windows' in platform.system():
            os.system('cls')
        else:
            os.system('clear')
        print('Wrong password!')
        time.sleep(1)
        shutdown()
    return