from pathlib import Path

import pytest

from engine.character import BodyPart, Character
from engine.defs import DefRegistry

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_two_healthy_legs_give_full_base_speed(registry):
    character = make_human(registry)
    assert character.effective_speed(30.0, registry) == pytest.approx(30.0)


def test_missing_one_leg_halves_speed(registry):
    character = make_human(registry, body_parts=[BodyPart("left_leg", "human_left_leg", removed=True)])
    assert character.effective_speed(30.0, registry) == pytest.approx(15.0)


def test_missing_both_legs_gives_zero_speed(registry):
    character = make_human(
        registry,
        body_parts=[
            BodyPart("left_leg", "human_left_leg", removed=True),
            BodyPart("right_leg", "human_right_leg", removed=True),
        ],
    )
    assert character.effective_speed(30.0, registry) == 0.0


def test_damaged_leg_contributes_proportionally_to_integrity(registry):
    character = make_human(registry, body_parts=[BodyPart("left_leg", "human_left_leg", integrity=50.0)])
    # left leg contributes 0.5 * 0.5 = 0.25, right leg contributes 0.5 -> total 0.75
    assert character.effective_speed(30.0, registry) == pytest.approx(30.0 * 0.75)


def test_bionic_leg_replacement_is_faster_than_a_normal_leg(registry):
    normal = make_human(registry)
    bionic = make_human(registry, body_parts=[BodyPart("left_leg", "bionic_leg")])

    normal_speed = normal.effective_speed(30.0, registry)
    bionic_speed = bionic.effective_speed(30.0, registry)
    assert bionic_speed > normal_speed
    # 0.5 (right leg) + 1.2 (bionic left leg) = 1.7
    assert bionic_speed == pytest.approx(30.0 * 1.7)


def test_non_leg_parts_do_not_affect_speed(registry):
    character = make_human(registry, body_parts=[BodyPart("head", "human_head", removed=True)])
    assert character.effective_speed(30.0, registry) == pytest.approx(30.0)