"""Tests for the Manager object for FileCheckers."""
import errno

import mock
import pytest

from flake8 import checker


def style_guide_mock(**kwargs):
    """Create a mock StyleGuide object."""
    kwargs.setdefault('diff', False)
    kwargs.setdefault('jobs', '4')
    style_guide = mock.Mock()
    style_guide.options = mock.Mock(**kwargs)
    return style_guide


def test_oserrors_cause_serial_fall_back():
    """Verify that OSErrors will cause the Manager to fallback to serial."""
    err = OSError(errno.ENOSPC, 'Ominous message about spaceeeeee')
    style_guide = style_guide_mock()
    with mock.patch('multiprocessing.Queue', side_effect=err):
        manager = checker.Manager(style_guide, [], [])
    assert manager.using_multiprocessing is False


def test_oserrors_are_reraised():
    """Verify that OSErrors will cause the Manager to fallback to serial."""
    err = OSError(errno.EAGAIN, 'Ominous message')
    style_guide = style_guide_mock()
    with mock.patch('multiprocessing.Queue', side_effect=err):
        with pytest.raises(OSError):
            checker.Manager(style_guide, [], [])


def test_multiprocessing_is_disabled():
    """Verify not being able to import multiprocessing forces jobs to 0."""
    style_guide = style_guide_mock()
    with mock.patch('flake8.checker.multiprocessing', None):
        manager = checker.Manager(style_guide, [], [])
        assert manager.jobs == 0


def test_make_checkers():
    """Verify that we create a list of FileChecker instances."""
    style_guide = style_guide_mock()
    files = ['file1', 'file2']
    with mock.patch('flake8.checker.multiprocessing', None):
        manager = checker.Manager(style_guide, files, [])

    with mock.patch('flake8.utils.filenames_from') as filenames_from:
        filenames_from.side_effect = [['file1'], ['file2']]
        with mock.patch('flake8.utils.fnmatch', return_value=True):
            with mock.patch('flake8.processor.FileProcessor'):
                manager.make_checkers()

    for file_checker in manager.checkers:
        assert file_checker.filename in files