from pathlib import Path

import pytest

from engine.defs import DefRegistry
from engine.entity import EntityPosition
from engine.inventory import Inventory
from engine.item import ItemInstance
from engine.map import Map
from engine.tile import Tile, TileLayerInstance
from engine.world import World
from resources.logic.pickup import drop_item, try_pickup

DEFS_DIR = Path(__file__).resolve().parent.parent / "resources" / "defs"


@pytest.fixture()
def registry():
    return DefRegistry.load(DEFS_DIR)


def make_world(registry):
    field = Map("field", 5, 5, 1)
    for x in range(5):
        for y in range(5):
            field.set_tile(x, y, 0, Tile(flooring=TileLayerInstance("grass")))
    world = World(registry=registry)
    world.add_map(field)
    return world


def make_human(registry, **kwargs):
    from engine.character import Character

    return Character(
        species_id="human", default_body_parts=registry.new_default_body_parts("human"), **kwargs
    )


# --- try_pickup -----------------------------------------------------------------------------


def test_pickup_moves_a_ground_item_into_inventory(registry):
    world = make_world(registry)
    human = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    human.inventory = Inventory(4, 4)
    world.add_entity(human)
    world.drop_item_at("field", 2, 2, 0, ItemInstance("item-1", "bandage"))

    picked = try_pickup(human, world, registry)

    assert picked == 1
    assert {p.item.item_id for p in human.inventory.items()} == {"item-1"}
    assert world.ground_items_at("field", 2, 2, 0) == []


def test_pickup_picks_up_everything_that_fits(registry):
    world = make_world(registry)
    human = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    human.inventory = Inventory(4, 4)
    world.add_entity(human)
    world.drop_item_at("field", 2, 2, 0, ItemInstance("item-1", "bandage"))
    world.drop_item_at("field", 2, 2, 0, ItemInstance("item-2", "sealant"))

    picked = try_pickup(human, world, registry)

    assert picked == 2
    assert world.ground_items_at("field", 2, 2, 0) == []


def test_pickup_leaves_items_that_do_not_fit(registry):
    world = make_world(registry)
    human = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    human.inventory = Inventory(1, 1)  # room for exactly one 1x1 item
    world.add_entity(human)
    world.drop_item_at("field", 2, 2, 0, ItemInstance("item-1", "bandage"))
    world.drop_item_at("field", 2, 2, 0, ItemInstance("item-2", "sealant"))

    picked = try_pickup(human, world, registry)

    assert picked == 1
    remaining = world.ground_items_at("field", 2, 2, 0)
    assert len(remaining) == 1


def test_pickup_only_affects_the_characters_own_tile(registry):
    world = make_world(registry)
    human = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    human.inventory = Inventory(4, 4)
    world.add_entity(human)
    world.drop_item_at("field", 3, 3, 0, ItemInstance("item-1", "bandage"))

    assert try_pickup(human, world, registry) == 0
    assert world.ground_items_at("field", 3, 3, 0) != []


def test_pickup_is_a_no_op_without_an_inventory(registry):
    world = make_world(registry)
    human = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    world.add_entity(human)
    world.drop_item_at("field", 2, 2, 0, ItemInstance("item-1", "bandage"))

    assert try_pickup(human, world, registry) == 0
    assert world.ground_items_at("field", 2, 2, 0) != []


# --- drop_item -------------------------------------------------------------------------------


def test_drop_item_moves_it_from_inventory_to_the_ground(registry):
    world = make_world(registry)
    human = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    human.inventory = Inventory(4, 4)
    item = ItemInstance("item-1", "bandage")
    human.inventory.place(item, registry.get_item_def("bandage"), 0, 0)
    world.add_entity(human)

    assert drop_item(human, world, "item-1", "bandage", human.inventory, registry) is True
    assert human.inventory.items() == []
    assert world.ground_items_at("field", 2, 2, 0) == [item]


def test_drop_item_returns_false_if_not_actually_in_inventory(registry):
    world = make_world(registry)
    human = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    human.inventory = Inventory(4, 4)
    world.add_entity(human)

    assert drop_item(human, world, "no-such-item", "bandage", human.inventory, registry) is False
    assert world.ground_items_at("field", 2, 2, 0) == []


def test_drop_item_is_a_no_op_without_an_inventory(registry):
    world = make_world(registry)
    human = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    world.add_entity(human)

    assert drop_item(human, world, "item-1", "bandage", human.inventory, registry) is False