from pathlib import Path

import pytest

from engine.character import BodyPart, Character
from engine.defs import DefRegistry
from engine.entity import EntityPosition
from engine.map import Map
from engine.tile import Tile, TileLayerInstance
from engine.world import World

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


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


def make_human(registry, **kwargs) -> Character:
    return Character(species_id="human", default_body_parts=registry.new_default_body_parts("human"), **kwargs)


def test_species_def_carries_sample_abilities(registry):
    species = registry.get_species_def("human")
    ability_ids = {a.id for a in species.abilities}
    assert ability_ids == {"leap", "melee_attack", "ranged_attack", "time_warp_sphere"}
    leap = next(a for a in species.abilities if a.id == "leap")
    assert leap.required_slots == ("left_leg", "right_leg")


def test_can_perform_ability_true_when_required_parts_present(registry):
    character = make_human(registry)
    assert character.can_perform_ability("leap", registry) is True


def test_can_perform_ability_false_when_a_required_part_is_missing(registry):
    character = make_human(registry, body_parts=[BodyPart("left_leg", "human_left_leg", removed=True)])
    assert character.can_perform_ability("leap", registry) is False


def test_can_perform_ability_false_for_unknown_ability(registry):
    character = make_human(registry)
    assert character.can_perform_ability("fly", registry) is False


def test_can_perform_ability_false_without_species(registry):
    character = Character()
    assert character.can_perform_ability("leap", registry) is False


def test_world_try_leap_gated_by_missing_legs(registry):
    field = Map("field", 10, 10, 1)
    for x in range(10):
        for y in range(10):
            field.set_tile(x, y, 0, Tile(flooring=TileLayerInstance("grass")))
    world = World(registry=registry)
    world.add_map(field)

    legless = make_human(
        registry,
        position=EntityPosition("field", 2, 2, 0),
        body_parts=[BodyPart("left_leg", "human_left_leg", removed=True)],
    )
    assert world.try_leap(legless, 1, 0, 0) is False
    assert (legless.position.x, legless.position.y) == (2, 2)  # unchanged


def test_world_try_leap_allowed_with_both_legs(registry):
    field = Map("field", 10, 10, 1)
    for x in range(10):
        for y in range(10):
            field.set_tile(x, y, 0, Tile(flooring=TileLayerInstance("grass")))
    world = World(registry=registry)
    world.add_map(field)

    healthy = make_human(registry, position=EntityPosition("field", 2, 2, 0))
    assert world.try_leap(healthy, 1, 0, 0) is True
    assert (healthy.position.x, healthy.position.y) == (4, 2)