from __future__ import annotations

import configparser
from pathlib import Path

DEFAULT_KEYBINDINGS: dict[str, list[str]] = {
    "move_up": ["w", "ArrowUp"],
    "move_down": ["s", "ArrowDown"],
    "move_left": ["a", "ArrowLeft"],
    "move_right": ["d", "ArrowRight"],
    "leap": ["space"],
    "swim_down": ["Control"],
    "block": ["b"],
    "activate_right_hand": ["mouse_left"],
    "activate_left_hand": ["mouse_right"],
    "activate_right_hand_2": ["shift+mouse_left"],
    "activate_left_hand_2": ["shift+mouse_right"],
    "select_ability_1": ["1"],
    "select_ability_2": ["2"],
    "select_ability_3": ["3"],
    "select_ability_4": ["4"],
    "select_ability_5": ["5"],
    "select_ability_6": ["6"],
    "select_ability_7": ["7"],
    "select_ability_8": ["8"],
    "select_ability_9": ["9"],
    "select_ability_0": ["0"],
    "activate_selected_ability": ["e"],
    "pickup": ["f"],
    "pause": ["Escape"],
    "toggle_character_card": ["c"],
    "cycle_character_tab": ["Tab"],
    "toggle_dev_mode": ["F1"],
    "dev_cycle_spawn": ["F2"],
    "dev_spawn_object": ["F3"],
    "dev_spawn_npc_menu": ["F4"],
}

# Human-friendly config names for keys that don't have a printable representation.
_KEY_ALIASES = {"space": " "}


def _normalize(key: str) -> str:
    return _KEY_ALIASES.get(key, key)


class KeyBindings:
    """Action -> list of keys, loaded from an editable .conf file (arrays, so several keys
    can share one action). Falls back to DEFAULT_KEYBINDINGS for anything the file omits.
    """

    def __init__(self, bindings: dict[str, list[str]]):
        self.bindings = bindings
        self._action_by_key: dict[str, str] = {}
        self._reindex()

    def _reindex(self) -> None:
        self._action_by_key = {}
        for action, keys in self.bindings.items():
            for key in keys:
                self._action_by_key[_normalize(key)] = action

    @classmethod
    def load(cls, path: Path) -> "KeyBindings":
        bindings = {action: list(keys) for action, keys in DEFAULT_KEYBINDINGS.items()}
        if path.exists():
            parser = configparser.ConfigParser()
            parser.read(path)
            for section in parser.sections():
                for action, raw in parser.items(section):
                    keys = [k.strip() for k in raw.split(",") if k.strip()]
                    if keys:
                        bindings[action] = keys
        return cls(bindings)

    def action_for_key(self, key: str) -> str | None:
        return self._action_by_key.get(key)

    def keys_for_action(self, action: str) -> list[str]:
        return self.bindings.get(action, [])

    def rebind(self, action: str, key: str, index: int = 0) -> None:
        """Replaces the key at `index` in `action`'s bound-key list (default: its primary key)
        with `key` - the "configure controls" menu's rebind action (engine/controls_menu.py).
        Steals `key` away from any other action it was already bound to first, so two actions
        can never end up racing for the same input.
        """
        key = _normalize(key)
        for other_action, keys in self.bindings.items():
            if other_action != action and key in keys:
                keys.remove(key)
        keys = self.bindings.setdefault(action, [])
        if index < len(keys):
            keys[index] = key
        else:
            keys.append(key)
        self._reindex()

    def save(self, path: Path) -> None:
        parser = configparser.ConfigParser()
        parser.add_section("actions")
        for action, keys in self.bindings.items():
            parser.set("actions", action, ", ".join(keys))
        path.parent.mkdir(parents=True, exist_ok=True)
        with path.open("w") as handle:
            parser.write(handle)