from random import sample
from string import ascii_letters

from behavioral.memento.concrete_memento import ConcreteMemento
from behavioral.memento.memento import Memento


class Originator:
    """
    The Originator holds some important state that may change over time. It also
    defines a method for saving the state inside a memento and another method
    for restoring the state from it.
    """

    """
    For the sake of simplicity, the originator's state is stored inside a single
    variable.
    """
    _state = None

    def __init__(self, state: str) -> None:
        self._state = state
        print(f"Originator: My initial state is: {self._state}")

    def do_something(self) -> None:
        """
        The Originator's business logic may affect its internal state.
        Therefore, the client should backup the state before launching methods
        of the business logic via the save() method.
        """
        print("Originator: I'm doing something important.")
        self._state = self._generate_random_string(30)
        print(f"Originator: and my state has changed to: {self._state}")

    def _generate_random_string(self, length: int) -> str:
        return "".join(sample(ascii_letters, length))

    def save(self) -> Memento:
        """
        Saves the current state inside a memento.
        """
        return ConcreteMemento(self._state)

    def restore(self, memento: Memento) -> None:
        """
        Restores the Originator's state from a memento object.
        """

        self._state = memento.get_state()

        print(f"Originator: My state has changed to: {self._state}")