from __future__ import annotations

from engine.character import Character
from engine.defs import DefRegistry
from engine.world import World


def try_pickup(character: Character, world: World, registry: DefRegistry) -> int:
    """Picks up every ground item at `character`'s current tile that fits somewhere in their
    inventory, leaving behind whatever doesn't (no free slot, or no inventory at all). Returns
    how many items were actually picked up.
    """
    if character.position is None or character.inventory is None:
        return 0
    pos = character.position
    picked = 0
    for item in world.ground_items_at(pos.map_id, pos.x, pos.y, pos.z):
        item_def = registry.get_item_def(item.def_id)
        slot = character.inventory.find_first_fit(item_def)
        if slot is None:
            continue
        if character.inventory.place(item, item_def, *slot):
            world.remove_ground_item(pos.map_id, pos.x, pos.y, pos.z, item.item_id)
            picked += 1
    return picked


def drop_item(
    character: Character, world: World, item_id: str, def_id: str, inventory, registry: DefRegistry
) -> bool:
    """Removes `item_id` from `inventory` (the character's own base inventory, or a worn
    container's granted inventory - see CharacterMenu.resolve_open_inventory) and places it on
    the ground at `character`'s current position - the logic half of "drag it out of an open
    inventory card to drop" (see engine/render/menu_draw.py for the drag hit-testing, main.py
    for wiring the release event). Returns whether it actually happened (False if there's no
    such item in `inventory`, or no inventory/position to work with at all).
    """
    if character.position is None or inventory is None:
        return False
    item_def = registry.get_item_def(def_id)
    removed = inventory.remove(item_id, item_def)
    if removed is None:
        return False
    pos = character.position
    world.drop_item_at(pos.map_id, pos.x, pos.y, pos.z, removed)
    return True