import math

import pytest

from matrixmania.compute import matmul, rot_2D, rot_3D


def assert_matrix(actual: list[list[float]], expected: list[list[float]]) -> None:
    """Compares two matrices element‑wise with a float tolerance."""
    assert len(actual) == len(expected)
    for actual_row, expected_row in zip(actual, expected, strict=True):
        assert actual_row == pytest.approx(expected_row)


def test_rot_2D_identity() -> None:
    assert_matrix(rot_2D(0.0), [[1.0, 0.0], [0.0, 1.0]])


def test_rot_3D_x_90_degrees() -> None:
    matrix = rot_3D(math.pi / 2, "x")
    assert_matrix(matrix, [[1.0, 0.0, 0.0], [0.0, 0.0, -1.0], [0.0, 1.0, 0.0]])


def test_rot_3D_y_90_degrees() -> None:
    matrix = rot_3D(math.pi / 2, "y")
    assert_matrix(matrix, [[0.0, 0.0, 1.0], [0.0, 1.0, 0.0], [-1.0, 0.0, 0.0]])


def test_rot_3D_z_90_degrees() -> None:
    matrix = rot_3D(math.pi / 2, "z")
    assert_matrix(matrix, [[0.0, -1.0, 0.0], [1.0, 0.0, 0.0], [0.0, 0.0, 1.0]])


def test_rot_3D_zero_angle_is_identity() -> None:
    identity = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]]
    for axis in ("x", "y", "z"):
        assert_matrix(rot_3D(0.0, axis), identity)


def test_rot_3D_rotates_vector() -> None:
    rotated = matmul(rot_3D(math.pi / 2, "z"), [[1.0], [0.0], [0.0]])
    assert_matrix(rotated, [[0.0], [1.0], [0.0]])


def test_rot_3D_invalid_axis() -> None:
    for axis in ("w", "", "X", 1, None):
        with pytest.raises(ValueError):
            rot_3D(1.0, axis)


def test_rot_3D_invalid_angle() -> None:
    with pytest.raises(ValueError):
        rot_3D("not a number", "z")