# pylint: disable=missing-docstring

import pytest

from acpi_backlight.evaluate import evaluate_expression


@pytest.mark.parametrize(('expr_str', 'names', 'expected'), [
    ('0', {}, 0),
    ('0.0', {}, 0),
    ('1.0', {}, 1),
    ('-1', {}, -1),
    ('0.1 + 0.2', {}, 0.3),
    ('0.3 - 0.2', {}, 0.1),
    ('0.2 * 3', {}, 0.6),
    ('0.6 / 3', {}, 0.2),
    ('0.6 / 3 + 0.1', {}, 0.3),
    ('(0.6 - 0.2) / 2', {}, 0.2),
    ('b', {'b': 0.4}, 0.4),
    ('-b', {'b': 0.3}, -0.3),
    ('0.1 + b', {'b': 0.2}, 0.3),
])
def test_evaluate_expression(expr_str, names, expected):
    assert expected == pytest.approx(evaluate_expression(expr_str, names))


@pytest.mark.parametrize('expr_str', [
    'read("/proc/cpuinfo")',
    'os.exit(42)',
    'os.system("echo evil")',
    '0.__class__',
    'None.__class__',
    'eval("1")',
])
def test_evaluate_expression_fail(expr_str):
    with pytest.raises(Exception):
        evaluate_expression(expr_str, {})