"""Discovery metric: efficiency of find-your-body self-identification."""
from proteus.game.runtime.trace import TurnTrace
from proteus.game.metrics.metrics import compute_metrics


def _turn(idx, self_correct):
    return TurnTrace(
        turn_idx=idx, observation="", action="stay", motive_action="stay",
        habit_action="stay", is_diagnostic=False, was_congruent=True,
        reward=0.0, focal_pos=(0, 0), predator_pos=(0, 0),
        self_belief=(0 if self_correct else 1), self_correct=self_correct,
    )


def test_no_discovery_keys_when_no_self_reports():
    turns = [TurnTrace(turn_idx=1, observation="", action="stay", motive_action="stay",
                       habit_action="stay", is_diagnostic=False, was_congruent=True,
                       reward=0.0, focal_pos=(0, 0), predator_pos=(0, 0))]
    m = compute_metrics(turns, played_turns=1, play_turns=1, outcome="survived")
    assert "discovery_turn" not in m  # additive: absent for non-discovery runs


def test_discovery_turn_is_first_stable_correct():
    # wrong, wrong, correct, correct, correct -> identified at turn 3
    turns = [_turn(1, False), _turn(2, False), _turn(3, True), _turn(4, True), _turn(5, True)]
    m = compute_metrics(turns, played_turns=5, play_turns=5, outcome="survived")
    assert m["discovery_turn"] == 3.0
    assert m["discovery_identified"] == 100.0
    # efficiency = (1 - (3-1)/5) * 100 = 60
    assert m["discovery_efficiency"] == 60.0


def test_flip_flop_not_counted_until_stable():
    # correct then wrong then correct-stable -> first STABLE correct is turn 3
    turns = [_turn(1, True), _turn(2, False), _turn(3, True)]
    m = compute_metrics(turns, played_turns=3, play_turns=3, outcome="survived")
    assert m["discovery_turn"] == 3.0


def test_never_identified():
    turns = [_turn(1, False), _turn(2, False)]
    m = compute_metrics(turns, played_turns=2, play_turns=2, outcome="survived")
    assert m["discovery_turn"] == 0.0
    assert m["discovery_identified"] == 0.0
    assert m["discovery_efficiency"] == 0.0