"""Tests for the independent physical-line alignment overlay."""

import pytest

from linkerhand_calibration.alignment_view import (
    summarize_alignment_measurements,
)


def _measurement(angle: float, offset: float, y: float) -> dict:
    return {
        "line_xyxy_px": [0.0, y, 100.0, y - angle * 100.0],
        "angle_rad": angle,
        "vertical_offset_px": offset,
    }


def test_line_summary_smooths_only_physical_line_measurements() -> None:
    """The overlay smooths scene lines without any Tag orientation input."""
    result = summarize_alignment_measurements(
        [
            _measurement(-0.02, -4.0, 80.0),
            None,
            _measurement(0.00, 0.0, 82.0),
            _measurement(0.02, 4.0, 84.0),
        ]
    )

    assert result is not None
    assert result["angle_rad"] == pytest.approx(0.0)
    assert result["vertical_offset_px"] == pytest.approx(0.0)
    assert result["line_xyxy_px"] == pytest.approx([0.0, 82.0, 100.0, 82.0])
    assert result["detected_frames"] == 3
    assert result["window_frames"] == 4


def test_line_summary_returns_none_without_scene_line() -> None:
    """No blue line is fabricated when the scene has no valid long edge."""
    assert summarize_alignment_measurements([None, None]) is None