"""Test Maths."""

from decimal import Decimal
import math

import pytest

from video.utils import maths


@pytest.mark.parametrize(('n', 'x', 'expected_return'), [
    (0, 0, None),
    (0, 1, None),
    (1, 0, 0),
    (1, 1, 1),
    (2, 0, 0),
    (2, 2, 2),
    (2, 3, 4),
    (2, 4, 4),
    (2, 511, 512),
    (2, 512, 512),
    (2, 513, 512),
    (7, 2, 0),
    (7, 3.49, 0),
    (7, 3.5, 0),
    (7, 8, 7),
    (7, 13.123, 14),
    (2, 405, 404),
])
def test_find_multiple_of_n_nearest_x(n, x, expected_return):
    """Test find_multiple_of_n_nearest_x."""
    assert expected_return == maths.find_multiple_of_n_nearest_x(n, x)


@pytest.mark.parametrize(
    ('n1', 'n2', 'result'), [
        (1, 2, 100),
        (2, 1, -50),
        (1, 0, -100),
        (0, 1, math.inf),
        (0.515, 15.5454, Decimal('2918.524271844660266198500751')),
        (33.2234, 3, Decimal('-90.97021978485043620890832615')),
        (-10, 10, 200),
        (10, -10, -200),
        (-10, -20, -100),
        (10, 10, 0),
        (-10, -10, 0),
    ]
)
def test_percent_change(n1, n2, result):
    """Test percent_change."""
    assert result == maths.percent_change(n1, n2)


@pytest.mark.parametrize(
    ('x1', 'y1', 'x2', 'y2', 'expected_distance'),
    [
        (0, 0, 1, 0, 1),
        (0, 0, 0, 1, 1),
        (0, 0, 1, 1, 1.4142135623730951),
        (1, 2, 3, 4, 2.8284271247461903),
        (-1, -2, -3, -4, 2.8284271247461903),
        (-1, 2, -3, 4, 2.8284271247461903),
    ]
)
def test_euclidean_distance_2d(x1, y1, x2, y2, expected_distance):
    """Test euclidean_distance_2d."""
    assert maths.euclidean_distance_2d(x1, y1, x2, y2) == expected_distance