from __future__ import annotations

from dataclasses import dataclass, field

from engine.config import DEFAULT_KEYBINDINGS, KeyBindings

# Keys a rebind capture should never accept - they're the menu's own navigation/escape keys,
# so binding a game action to one of them would make the controls menu itself unusable.
RESERVED_CAPTURE_KEYS = {"Escape", "ArrowUp", "ArrowDown", "Enter"}


@dataclass
class ControlsMenu:
    """Pure interaction state for the "configure controls" screen: list every bindable action,
    navigate up/down, and rebind the highlighted action's primary key to whatever key is
    pressed next. Reads/writes through the same KeyBindings the game itself uses (engine/
    config.py) - a rebind takes effect immediately (live) and can be written back to disk via
    save(). No rendering here - same boundary as the rest of engine/ui.py.
    """

    keybindings: KeyBindings
    actions: list[str] = field(default_factory=lambda: list(DEFAULT_KEYBINDINGS))
    selected_index: int = 0
    awaiting_key: bool = False

    def move(self, delta: int) -> None:
        self.selected_index = (self.selected_index + delta) % len(self.actions)

    def selected_action(self) -> str:
        return self.actions[self.selected_index]

    def begin_rebind(self) -> None:
        self.awaiting_key = True

    def cancel_rebind(self) -> None:
        self.awaiting_key = False

    def capture_key(self, key: str) -> bool:
        """Feeds the next raw keypress into the pending rebind, if one is in progress (see
        begin_rebind). Returns whether it was actually applied - a reserved menu key is ignored
        (capture mode stays open so the player can try again) rather than rebinding onto it.
        """
        if not self.awaiting_key:
            return False
        if key in RESERVED_CAPTURE_KEYS:
            return False
        self.keybindings.rebind(self.selected_action(), key)
        self.awaiting_key = False
        return True

    def save(self, path) -> None:
        self.keybindings.save(path)