from threading import Event
from unittest import TestCase, mock

from mycroft.util.download import (download, _running_downloads,
                                   _get_download_tmp)
from mycroft.util.file_utils import get_temp_path

TEST_URL = 'http://example.com/mycroft-test.tar.gz'
TEST_DEST = get_temp_path('file.tar.gz')


@mock.patch('mycroft.util.download.subprocess')
@mock.patch('mycroft.util.download.os')
class TestDownload(TestCase):
    def setUp(self):
        """Remove any cached instance."""
        for key in list(_running_downloads.keys()):
            _running_downloads.pop(key)

    def test_download_basic(self, mock_os, mock_subprocess):
        """Test the basic download call."""
        mock_subprocess.call.return_value = 0

        downloader = download(url=TEST_URL,
                              dest=TEST_DEST)
        downloader.join()
        mock_subprocess.call.assert_called_once_with(['wget', '-c', TEST_URL,
                                                      '-O',
                                                      TEST_DEST + '.part',
                                                      '--tries=20',
                                                      '--read-timeout=5'])
        self.assertTrue(downloader.done)

    def test_download_with_header(self, mock_os, mock_subprocess):
        """Test download with specific header."""
        mock_subprocess.call.return_value = 0

        test_hdr = 'TEST_HEADER'
        downloader = download(url=TEST_URL,
                              dest=TEST_DEST,
                              header=test_hdr)
        downloader.join()

        self.assertTrue(downloader.done)
        mock_subprocess.call.assert_called_once_with(['wget', '-c', TEST_URL,
                                                      '-O',
                                                      TEST_DEST + '.part',
                                                      '--tries=20',
                                                      '--read-timeout=5',
                                                      '--header=' + test_hdr])

    def test_download_callback(self, mock_os, mock_subprocess):
        """Check that callback function is called with correct destination."""
        mock_subprocess.call.return_value = 0
        action_called_with = None

        def action(dest):
            nonlocal action_called_with
            action_called_with = dest

        downloader = download(url=TEST_URL,
                              dest=TEST_DEST,
                              complete_action=action)
        downloader.join()

        self.assertTrue(downloader.done)
        self.assertEqual(action_called_with, TEST_DEST)

    def test_download_cache(self, mock_os, mock_subprocess):
        """Make sure that a cached download is used if exists."""

        transfer_done = Event()

        def wget_call(*args, **kwargs):
            nonlocal transfer_done
            transfer_done.wait()
            return 0

        downloader = download(url=TEST_URL,
                              dest=TEST_DEST)
        downloader2 = download(url=TEST_URL,
                               dest=TEST_DEST)
        # When called with the same args a cached download in progress should
        # be returned instead of a new one.
        self.assertTrue(downloader is downloader2)
        transfer_done.set()
        downloader.join()


@mock.patch('mycroft.util.download.glob')
class TestGetTemp(TestCase):
    def test_no_existing(self, mock_glob):
        mock_glob.return_value = []
        dest = get_temp_path('test')
        self.assertEqual(_get_download_tmp(dest), dest + '.part')

    def test_existing(self, mock_glob):
        mock_glob.return_value = [get_temp_path('test.part')]
        dest = get_temp_path('test')
        self.assertEqual(_get_download_tmp(dest), dest + '.part.1')

    def test_multiple_existing(self, mock_glob):
        mock_glob.return_value = [get_temp_path('test.part'),
                                  get_temp_path('test.part.1'),
                                  get_temp_path('test.part.2')]

        dest = get_temp_path('test')
        self.assertEqual(_get_download_tmp(dest), dest + '.part.3')