import numpy as np

from repro_beyond_model_ranking.experiment import (
    forecast_linear_trend,
    forecast_persistence,
    forecast_seasonal,
    make_windows,
)


def test_make_windows_respects_interval_and_shapes():
    values = np.arange(40, dtype=float).reshape(20, 2)

    history, future, starts = make_windows(
        values,
        seq_len=4,
        pred_len=3,
        first_target=8,
        last_target=15,
        stride=2,
    )

    assert history.shape == (3, 4, 2)
    assert future.shape == (3, 3, 2)
    assert starts.tolist() == [8, 10, 12]
    np.testing.assert_array_equal(history[0, :, 0], [8, 10, 12, 14])
    np.testing.assert_array_equal(future[0, :, 0], [16, 18, 20])


def test_forecasters_return_multi_horizon_predictions():
    history = np.array(
        [
            [[1.0], [2.0], [3.0], [4.0]],
            [[2.0], [4.0], [6.0], [8.0]],
        ]
    )

    persistence = forecast_persistence(history, pred_len=3)
    seasonal = forecast_seasonal(history, pred_len=3, period=2)
    trend = forecast_linear_trend(history, pred_len=3, fit_length=4)

    assert persistence.shape == (2, 3, 1)
    np.testing.assert_allclose(persistence[0, :, 0], [4.0, 4.0, 4.0])
    np.testing.assert_allclose(seasonal[0, :, 0], [3.0, 4.0, 3.0])
    np.testing.assert_allclose(trend[0, :, 0], [5.0, 6.0, 7.0])