from datetime import datetime
from dataclasses import dataclass
from soku import Class, Attribute


def is_int(_, value):  # validator must be callable and return bool or raise exception
    return isinstance(value, int)


def timestamp_to_date(value):
    return datetime.fromtimestamp(value)


def date_to_timestamp(value):
    return int(value.timestamp())


@dataclass
class FullName(Class):
    first_name: str = Attribute(key='firstName')
    last_name: str = Attribute(key='lastName')

    def full_name(self):
        return f'{self.first_name} {self.last_name}'


@dataclass
class Person(Class):
    id: int = Attribute(validate=is_int)
    full_name: FullName = Attribute(key='fullName', attach=FullName)


@dataclass
class User(Person):
    birthday: datetime = Attribute(deserialize=timestamp_to_date, serialize=date_to_timestamp)


if __name__ == '__main__':
    # create instance and serialize
    full_name = FullName('John', 'Smith')
    user = User(12345, full_name, datetime.fromtimestamp(1193875200))
    print(user.serialize())  #  {'id': 12345, 'birthday': 1193875200, 'fullName': {'firstName': 'John', 'lastName': 'Smith'}}


    # deserialize and serialize
    user = User.deserialize({'id': 12345, 'birthday': 1193875200, 'fullName': {'firstName': 'John', 'lastName': 'Smith'}})
    print(user.full_name.full_name())  # John Smith
    print(user.serialize())  # {'id': 12345, 'birthday': 1193875200, 'fullName': {'firstName': 'John', 'lastName': 'Smith'}}

    # validate
    try:
        User.deserialize({'id': '12345', 'birthday': 1193875200, 'fullName': {'firstName': 'John', 'lastName': 'Smith'}})
    except ValueError as exc:
        print(exc)  # Key id validation error.