"""CPU-only traceback capture checks; no CUDA or GPU test import."""
import importlib.util
from pathlib import Path
from types import SimpleNamespace
import numpy as np

PATH = Path(__file__).resolve().parents[1] / 'validation/multigrid/channel_parity_diagnostic/discover.py'
spec = importlib.util.spec_from_file_location('channel_discovery', PATH)
discovery = importlib.util.module_from_spec(spec)
spec.loader.exec_module(discovery)


def test_captures_exact_original_frame_and_arrays():
    def test_uniform_matched_root():
        cfg = SimpleNamespace(velocity=.025)
        shifted, profile, clamp, damping, block = True, 'parabolic', False, .8, (4, 1)
        expected = np.array([.001], np.float32)
        actual = np.nextafter(expected, np.float32(1))
        np.testing.assert_array_equal(actual, expected)
    try:
        test_uniform_matched_root()
    except AssertionError as exc:
        config, expected, actual = discovery.capture_case(exc)
    assert config['shifted'] == 1 and config['profile'] == 'parabolic'
    assert config['clamp'] == 0 and config['damping'] == .8
    assert config['block'] == [4, 1] and config['steps'] == 8
    np.testing.assert_array_equal(actual, np.nextafter(expected, np.float32(1)))
    assert expected.flags.owndata and actual.flags.owndata


def test_other_assertion_does_not_guess_case():
    def test_uniform_matched_root():
        cfg = SimpleNamespace(velocity=.025)
        shifted, profile, clamp, damping, block = False, 'uniform', True, .5, (20, 24)
        expected = actual = np.array([np.nan], np.float32)
        assert np.isfinite(expected).all()
    try:
        test_uniform_matched_root()
    except AssertionError as exc:
        assert discovery.capture_case(exc) is None


def test_unrelated_array_assertion_does_not_guess_case():
    try:
        np.testing.assert_array_equal([1], [2])
    except AssertionError as exc:
        assert discovery.capture_case(exc) is None