"""B03 카드 미리보기 — 노선 좌표열 솎기(2026-09-04)."""

from B03_FileInput.B03_FileInput_Engine_Shapefile import _thin_preview_path


def test_thin_keeps_endpoints_and_cap() -> None:
    part = [(float(i), float(i * 2)) for i in range(5000)]
    preview = _thin_preview_path([part], limit=200)
    assert len(preview) == 1
    points = preview[0]
    # 상한(+ 끝점 보정 1)을 넘지 않는다.
    assert len(points) <= 201
    assert points[0] == [0.0, 0.0]
    assert points[-1] == [4999.0, 9998.0]


def test_thin_handles_multipart_and_empty() -> None:
    assert _thin_preview_path([]) == []
    assert _thin_preview_path([[]]) == []
    preview = _thin_preview_path([[(0.0, 0.0), (1.0, 1.0)], [(5.0, 5.0), (6.0, 6.0)]], limit=200)
    assert preview == [[[0.0, 0.0], [1.0, 1.0]], [[5.0, 5.0], [6.0, 6.0]]]