from datetime import datetime
from typing import Tuple


def get_time_or_now(time):
    return time if time is not None else datetime.now()


def parse_optional_time(time):
    return None if time is None else datetime.fromisoformat(time)


class RegistrationCode:
    def __init__(self,
                 code: str,
                 creation_time: datetime = None,
                 expiration_time: datetime = None,
                 usages: int = 0,
                 max_usages: int = 1):
        self.code = code
        self.creation_time = get_time_or_now(creation_time)
        self.expiration_time = expiration_time
        self.usages = usages
        self.max_usages = max_usages

    @staticmethod
    def from_db(db_registration_code: Tuple) -> 'RegistrationCode':
        return RegistrationCode(
            db_registration_code[0],
            datetime.fromisoformat(db_registration_code[1]),
            parse_optional_time(db_registration_code[2]),
            db_registration_code[3],
            db_registration_code[4]
        )

    def is_expired(self):
        return self.expiration_time is not None and self.expiration_time < datetime.now()

    def has_available_uses(self):
        return self.usages < self.max_usages


class RegisteredUser:
    def __init__(self,
                 registration_code: str,
                 username: str,
                 registered_user_id: str,
                 registered_time: datetime = None):
        self.registration_code = registration_code
        self.username = username
        self.registered_user_id = registered_user_id
        self.registered_time = get_time_or_now(registered_time)

    @staticmethod
    def from_db(db_registered_user: Tuple) -> 'RegisteredUser':
        return RegisteredUser(
            db_registered_user[0],
            db_registered_user[1],
            db_registered_user[3],
            datetime.fromisoformat(db_registered_user[2])
        )