"""Base screen module - shared interface for all game screens."""

class BaseScreen:
    """Abstract base class defining the interface for all game screens.

    Subclasses override :meth:`process_event`, :meth:`update`, and :meth:`draw`
    to implement screen-specific behaviour. UI elements added to ``self.elements``
    are shown and hidden automatically when the screen is switched.

    Attributes:
        game (Game): The central game instance.
        elements (list): pygame_gui elements managed by this screen.
    """

    def __init__(self, game):
        self.game = game
        self.elements = []

    def process_event(self, event):
        """Handle a single pygame event.

        Args:
            event (pygame.event.Event): The event to process.
        """

    def update(self, dt):
        """Update screen state for the current frame.

        Args:
            dt (float): Time elapsed since the last frame in seconds.
        """

    def draw(self, surface):
        """Draw the screen onto the given surface.

        Args:
            surface (pygame.Surface): Target surface to draw onto.
        """

    def show(self):
        """Make all UI elements on this screen visible."""
        for element in self.elements:
            element.show()

    def hide(self):
        """Hide all UI elements on this screen."""
        for element in self.elements:
            element.hide()