from __future__ import annotations

import uuid
from dataclasses import dataclass, field

from engine.character import Character
from engine.defs import DefRegistry
from engine.item import ItemInstance


@dataclass
class DevSpawnMenu:
    """Dev-mode-only cheat tool: cycle through every loaded item def and materialize one
    straight into the player's inventory (first free-fitting slot). Gated off in normal play by
    engine/dev_config.py::DevConfig.enabled - see main.py's dev_spawn_object handling.

    No world floor-item system exists in this engine yet (items only ever live in an Inventory,
    or worn/held on a Character), so "spawning" here means "into inventory", not placing a loose
    item on the ground - that's a bigger feature this doesn't attempt.
    """

    registry: DefRegistry
    item_ids: list[str] = field(default_factory=list)
    selected_index: int = 0

    def __post_init__(self) -> None:
        if not self.item_ids:
            self.item_ids = sorted(self.registry.item_defs)

    def cycle(self, delta: int) -> None:
        if self.item_ids:
            self.selected_index = (self.selected_index + delta) % len(self.item_ids)

    def selected_item_id(self) -> str | None:
        if not self.item_ids:
            return None
        return self.item_ids[self.selected_index]

    def spawn_into(self, character: Character) -> bool:
        """Returns whether it actually fit - a no-op (False) if the character has no inventory
        or the selected item has nowhere left to go.
        """
        item_id = self.selected_item_id()
        if item_id is None or character.inventory is None:
            return False
        item_def = self.registry.get_item_def(item_id)
        slot = character.inventory.find_first_fit(item_def)
        if slot is None:
            return False
        instance = ItemInstance(f"dev-spawn-{uuid.uuid4().hex[:8]}", item_id)
        return character.inventory.place(instance, item_def, *slot)