"""split_sbs 裁切测试（需求说明 §2.3：sbs 单流形态）。"""

import numpy as np
import pytest

from stereo_yolo import split_sbs


def test_split_returns_left_and_right_halves():
    image = np.zeros((4, 10, 3), dtype=np.uint8)
    image[:, :5] = 1
    image[:, 5:] = 2

    left, right = split_sbs(image)

    assert left.shape == (4, 5, 3) and right.shape == (4, 5, 3)
    assert (left == 1).all() and (right == 2).all()


def test_odd_width_rejected():
    with pytest.raises(ValueError, match="宽度须为偶数"):
        split_sbs(np.zeros((4, 9, 3), dtype=np.uint8))


def test_non_image_rejected():
    with pytest.raises(ValueError, match="宽度须为偶数"):
        split_sbs(np.zeros((9,), dtype=np.uint8))