from engine.item import ItemInstance
from engine.world import World


def make_world():
    return World()


def test_ground_items_at_is_empty_by_default():
    world = make_world()
    assert world.ground_items_at("field", 3, 4, 0) == []


def test_drop_item_at_makes_it_visible_at_that_tile():
    world = make_world()
    item = ItemInstance("item-1", "bandage")
    world.drop_item_at("field", 3, 4, 0, item)
    assert world.ground_items_at("field", 3, 4, 0) == [item]


def test_drop_item_at_floors_fractional_coordinates():
    world = make_world()
    item = ItemInstance("item-1", "bandage")
    world.drop_item_at("field", 3.9, 4.2, 0.0, item)
    assert world.ground_items_at("field", 3, 4, 0) == [item]


def test_multiple_items_can_stack_on_the_same_tile():
    world = make_world()
    a = ItemInstance("item-1", "bandage")
    b = ItemInstance("item-2", "sealant")
    world.drop_item_at("field", 3, 4, 0, a)
    world.drop_item_at("field", 3, 4, 0, b)
    assert world.ground_items_at("field", 3, 4, 0) == [a, b]


def test_different_tiles_are_independent():
    world = make_world()
    item = ItemInstance("item-1", "bandage")
    world.drop_item_at("field", 3, 4, 0, item)
    assert world.ground_items_at("field", 3, 5, 0) == []
    assert world.ground_items_at("other_map", 3, 4, 0) == []


def test_remove_ground_item_removes_and_returns_the_matching_item():
    world = make_world()
    a = ItemInstance("item-1", "bandage")
    b = ItemInstance("item-2", "sealant")
    world.drop_item_at("field", 3, 4, 0, a)
    world.drop_item_at("field", 3, 4, 0, b)

    removed = world.remove_ground_item("field", 3, 4, 0, "item-1")
    assert removed is a
    assert world.ground_items_at("field", 3, 4, 0) == [b]


def test_remove_ground_item_returns_none_when_not_found():
    world = make_world()
    world.drop_item_at("field", 3, 4, 0, ItemInstance("item-1", "bandage"))
    assert world.remove_ground_item("field", 3, 4, 0, "no-such-id") is None


def test_remove_last_item_cleans_up_the_empty_tile_entry():
    world = make_world()
    world.drop_item_at("field", 3, 4, 0, ItemInstance("item-1", "bandage"))
    world.remove_ground_item("field", 3, 4, 0, "item-1")
    assert ("field", 3, 4, 0) not in world.ground_items