import numpy as np
import pytest

from proteus.game.agents import VanillaAgent
from proteus.game.engine.difficulty import Difficulty
from proteus.game.scenarios.base import get_scenario
from proteus.providers import FakeProvider
from proteus.game.runtime.session import SessionRunner
from proteus.game.viz import FrameStep, TraceReconstructionError, reconstruct


def _make_trace(seed=42, turns=5, action="ACTION: up"):
    agent = VanillaAgent(FakeProvider([action]))
    return SessionRunner(
        "template", agent, seed=seed, play_turns=turns, use_probe=False,
    ).run()


def test_reconstruct_frame_count_matches_cut_plus_play():
    trace = _make_trace()
    steps = reconstruct(trace)
    cut_len = get_scenario("template")().cut_length(Difficulty.EASY)
    # initial Cut frame + cut_len Cut steps + one frame per played turn.
    assert len(steps) == (cut_len + 1) + len(trace.turns)
    assert all(isinstance(s, FrameStep) for s in steps)
    assert isinstance(steps[0].frame, np.ndarray)


def test_reconstruct_phases_and_terminal_flag():
    trace = _make_trace()
    steps = reconstruct(trace)
    assert steps[0].meta.phase == "cut"
    assert steps[-1].meta.phase == "play"
    # The final frame carries the session outcome iff the game actually ended.
    if trace.outcome in ("eliminated", "survived") and (
        len(trace.turns) < 5 or trace.outcome == "survived"
    ):
        assert steps[-1].meta.terminal == trace.outcome


def test_reconstruct_carries_turn_metadata():
    trace = _make_trace()
    steps = reconstruct(trace)
    play = [s for s in steps if s.meta.phase == "play"]
    assert len(play) == len(trace.turns)
    first = play[0].meta
    assert first.turn_idx == trace.turns[0].turn_idx
    assert first.action == trace.turns[0].action
    assert first.motive_action == trace.turns[0].motive_action
    assert first.habit_action == trace.turns[0].habit_action


def test_reconstruct_raises_on_corrupt_positions():
    trace = _make_trace()
    bad_turn = trace.turns[0].model_copy(update={"focal_pos": (99, 99)})
    corrupt = trace.model_copy(update={"turns": [bad_turn] + list(trace.turns[1:])})
    with pytest.raises(TraceReconstructionError):
        reconstruct(corrupt)


def test_reconstruct_raises_on_corrupt_cut_frame():
    trace = _make_trace()
    corrupt = trace.model_copy(
        update={"cut_frames": ["GARBAGE"] + list(trace.cut_frames[1:])}
    )
    with pytest.raises(TraceReconstructionError):
        reconstruct(corrupt)