dojo_cate/tests/test_bots.py

"""Bot decisions on the fixture board (positions as in test_engine.py)."""

import random

import pytest
from scripted import fixture_board, make_game, put

from dojo.board import Board, Pos, rotate
from dojo.bots import (
    AGGRESSIVE,
    BALANCED,
    FARMER,
    PROFILES,
    CasualAgent,
    HeuristicAgent,
    Profile,
    RandomAgent,
    own_frame,
    series_probability,
    start_square,
    win_probability,
)
from dojo.engine import Agent, FightView, Game, RandomSource
from dojo.rules import DEFAULT_RULES, Card, RulesConfig

ALLENAMENTO = Pos(0, 5)
FATICA = Pos(3, 6)
TATAMI = Pos(4, 4)
DOJO_ENTRANCE = Pos(5, 7)
DOJO = Pos(6, 7)


def test_win_probability_counts_senshu_and_bonuses() -> None:
    assert win_probability(0, 0) == pytest.approx(21 / 36)
    assert win_probability(2, 0) == pytest.approx(30 / 36)
    assert win_probability(0, 2) == pytest.approx(10 / 36)
    assert win_probability(0, 0, senshu=False) == pytest.approx(15 / 36)


def test_series_probability_is_a_best_of_n() -> None:
    assert series_probability(0.3, 1) == pytest.approx(0.3)
    assert series_probability(0.5, 3) == pytest.approx(0.5)
    assert series_probability(0.6, 3) == pytest.approx(0.6**2 * (3 - 2 * 0.6))


def test_kiai_that_only_ties_the_exam_is_kept_when_ties_go_to_the_defender() -> None:
    game, _, _ = make_game(config=RulesConfig(exam_ties_to_defender=True))
    game.players[0].tecnica = Card.KIAI
    exam = FightView(0, 1, True, 3, 5, played=())

    assert not HeuristicAgent().play_tecnica(game.view(0), exam)
    assert HeuristicAgent().play_tecnica(game.view(0), fight(3, 5))


def test_heuristic_prefers_allenamento_to_fatica() -> None:
    game, _, _ = make_game()

    choice = HeuristicAgent().choose_path(game.view(0), [(FATICA,), (ALLENAMENTO,)])

    assert choice == (ALLENAMENTO,)


def test_heuristic_walks_around_fatica() -> None:
    game, _, _ = make_game()
    put(game, 0, Pos(2, 6), track=3)
    paths = [(FATICA, Pos(3, 7)), (Pos(2, 7), Pos(3, 7))]

    assert HeuristicAgent().choose_path(game.view(0), paths) == paths[1]


def test_heuristic_sees_no_opponent_to_fight_in_round_one() -> None:
    game, _, _ = make_game()
    game.round = 1
    put(game, 0, Pos(4, 3), track=3)
    put(game, 1, TATAMI, track=3)

    # In round 2 the aggressive bot picks the fight (test_profiles_differ_on_an_even_fight).
    # Two plain Tatami tie; the tie goes to the lower square in the bot's frame, (4, 2).
    choice = HeuristicAgent(AGGRESSIVE).choose_path(game.view(0), [(TATAMI,), (Pos(4, 2),)])

    assert choice == (Pos(4, 2),)


def test_bots_start_from_the_same_square_of_every_safe_room() -> None:
    board = fixture_board()

    assert len({own_frame(start_square(board, corner), corner) for corner in range(4)}) == 1


def test_tied_paths_are_chosen_alike_from_every_corner() -> None:
    game, _, _ = make_game(players=4)
    agent = HeuristicAgent(BALANCED)
    chosen = set()
    for seat, player in enumerate(game.players):
        player.position = rotate(Pos(4, 3), player.corner)
        tatami = [(rotate(square, player.corner),) for square in (Pos(5, 3), Pos(3, 3), Pos(4, 2))]
        choice = agent.choose_path(game.view(seat), tatami)
        chosen.add(own_frame(choice[0], player.corner))

    assert chosen == {Pos(3, 3)}


def test_brown_heuristic_takes_the_exam_when_it_can() -> None:
    game, _, _ = make_game()
    put(game, 0, DOJO_ENTRANCE, track=15)

    choice = HeuristicAgent().choose_path(game.view(0), [(ALLENAMENTO,), (DOJO,)])

    assert choice == (DOJO,)


@pytest.mark.parametrize(("profile", "fights"), [(FARMER, False), (AGGRESSIVE, True)])
def test_profiles_differ_on_an_even_fight(profile: Profile, fights: bool) -> None:
    game, _, _ = make_game()
    put(game, 0, Pos(4, 3), track=3)
    put(game, 1, TATAMI, track=3)
    choice = HeuristicAgent(profile).choose_path(game.view(0), [(Pos(5, 3),), (TATAMI,)])

    assert (choice == (TATAMI,)) is fights


def fight(attacker_total: int, defender_total: int) -> FightView:
    return FightView(0, 1, False, attacker_total, defender_total, played=())


@pytest.mark.parametrize(
    ("me", "card", "totals", "plays"),
    [
        (0, Card.KIAI, (3, 5), True),  # 5 ties 5: Senshu gives it to the attacker.
        (0, Card.KIAI, (2, 5), False),  # Kiai cannot turn it: keep it.
        (0, Card.KIAI, (5, 5), False),  # Already winning.
        (1, Card.KIAI, (5, 4), True),  # The defender needs to beat, not tie.
        (1, Card.KIAI, (6, 4), False),
        (0, Card.KAESHI, (1, 6), True),  # Losing: a reroll can only help.
        (1, Card.UKE, (4, 4), True),
    ],
)
def test_heuristic_plays_a_tecnica_only_when_losing(
    me: int, card: Card, totals: tuple[int, int], plays: bool
) -> None:
    game, _, _ = make_game()
    game.players[me].tecnica = card

    assert HeuristicAgent().play_tecnica(game.view(me), fight(*totals)) is plays


def test_heuristic_keeps_the_tecnica_its_profile_ranks_first() -> None:
    game, _, _ = make_game()

    assert HeuristicAgent(BALANCED).keep_tecnica(game.view(0), Card.UKE, Card.KIAI) is Card.KIAI
    assert HeuristicAgent(FARMER).keep_tecnica(game.view(0), Card.UKE, Card.KIAI) is Card.UKE


def test_casual_bot_compares_every_move_when_offered_few() -> None:
    game, _, _ = make_game()

    choice = CasualAgent(random.Random(0)).choose_path(game.view(0), [(FATICA,), (ALLENAMENTO,)])

    assert choice == (ALLENAMENTO,)


def test_casual_bot_compares_only_a_sample_of_many_moves() -> None:
    game, _, _ = make_game()
    paths = [(Pos(4, col),) for col in range(8)]

    choice = CasualAgent(random.Random(3), sample=1).choose_path(game.view(0), paths)

    assert choice == random.Random(3).sample(paths, 1)[0]


def test_casual_bot_needs_a_sample() -> None:
    with pytest.raises(ValueError, match="sample size 0"):
        CasualAgent(random.Random(0), sample=0)


def play(board: Board, config: RulesConfig, seed: int) -> Game:
    rng = random.Random(seed)
    agents: list[Agent] = [HeuristicAgent(p) for p in PROFILES.values()]
    agents.append(RandomAgent(rng))
    game = Game(board, config, agents, RandomSource(seed))
    game.run()
    return game


@pytest.mark.parametrize(
    "config",
    [
        DEFAULT_RULES,
        RulesConfig(exam_ties_to_defender=True, exam_defender_black=True, exam_rounds=3),
    ],
)
def test_bots_play_full_games_reproducibly(board: Board, config: RulesConfig) -> None:
    first, again = play(board, config, seed=7), play(board, config, seed=7)

    assert first.winner is not None
    assert first.events == again.events