# --- Tests for standard rotations (Happy Path) ---
import math

import pytest
from _pytest.python_api import approx

from src.matrixmania.compute import rot_3D


# --- HELPER FUNCTION ---
def assert_matrices_3x3_close(m1, m2, abs_tol=1e-9):
    """
    Helper function to compare two 3x3 matrices element-wise
    using math.isclose for float comparison.
    """
    assert len(m1) == 3 and all(len(row) == 3 for row in m1), "Matrix 1 is not 3x3"
    assert len(m2) == 3 and all(len(row) == 3 for row in m2), "Matrix 2 is not 3x3"

    for i in range(3):
        for j in range(3):
            assert math.isclose(m1[i][j], m2[i][j], abs_tol=abs_tol), \
                   f"Mismatch at [{i}][{j}]: {m1[i][j]} != {m2[i][j]}"
# --- END HELPER FUNCTION ---


def test_90_deg_rotation_x_axis():
    """Tests a 90-degree (pi/2) rotation around the X-axis."""
    # cos(pi/2) = 0, sin(pi/2) = 1
    # Expected: [[1, 0, 0], [0, 0, -1], [0, 1, 0]]
    expected = [[1.0, 0.0, 0.0], [0.0, 0.0, -1.0], [0.0, 1.0, 0.0]]
    assert_matrices_3x3_close(rot_3D(math.pi / 2, "x"), expected)


def test_90_deg_rotation_y_axis():
    """Tests a 90-degree (pi/2) rotation around the Y-axis."""
    # cos(pi/2) = 0, sin(pi/2) = 1
    # Expected: [[0, 0, 1], [0, 1, 0], [-1, 0, 0]]
    expected = [[0.0, 0.0, 1.0], [0.0, 1.0, 0.0], [-1.0, 0.0, 0.0]]
    assert_matrices_3x3_close(rot_3D(math.pi / 2, "y"), expected)


def test_90_deg_rotation_z_axis():
    """Tests a 90-degree (pi/2) rotation around the Z-axis."""
    # cos(pi/2) = 0, sin(pi/2) = 1
    # Expected: [[0, -1, 0], [1, 0, 0], [0, 0, 1]]
    expected = [[0.0, -1.0, 0.0], [1.0, 0.0, 0.0], [0.0, 0.0, 1.0]]
    assert_matrices_3x3_close(rot_3D(math.pi / 2, "z"), expected)


def test_0_radian_rotation():
    """Tests 0-radian rotation for all axes (should return identity matrix)."""
    identity = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]]
    assert_matrices_3x3_close(rot_3D(0, "x"), identity)
    assert_matrices_3x3_close(rot_3D(0.0, "y"), identity)
    assert_matrices_3x3_close(rot_3D(0, "z"), identity)


def test_pi_rotation_y_axis():
    """Tests a 180-degree (pi) rotation around Y."""
    # cos(pi) = -1, sin(pi) = 0
    # Expected: [[-1, 0, 0], [0, 1, 0], [0, 0, -1]]
    expected = [[-1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, -1.0]]
    assert_matrices_3x3_close(rot_3D(math.pi, "y"), expected)


# --- Tests for error handling (Invalid Inputs) ---

def test_error_invalid_axis_string():
    """Tests that a ValueError is raised for an invalid axis string."""
    with pytest.raises(ValueError, match="axis must be either x, y or z"):
        rot_3D(math.pi / 2, "a")


def test_error_invalid_axis_case():
    """Tests that the axis check is case-sensitive."""
    with pytest.raises(ValueError, match="axis must be either x, y or z"):
        rot_3D(math.pi / 2, "X")  # 'X' is not 'x'


def test_error_invalid_axis_type():
    """Tests that a ValueError is raised if the axis is not a string."""
    with pytest.raises(ValueError, match="axis must be a string"):
        rot_3D(math.pi / 2, 1)


def test_error_invalid_angle_type():
    """Tests that a ValueError is raised if the angle is not numeric."""
    with pytest.raises(ValueError, match="instance of a numeric datatype"):
        rot_3D("pi", "x")


def test_error_invalid_angle_type_none():
    """Tests that a ValueError is raised if the angle is None."""
    with pytest.raises(ValueError, match="instance of a numeric datatype"):
        rot_3D(None, "z")