import os
import tempfile
import unittest
from unittest import mock

import services.cache as cache_module


class RefreshableCacheDataVersionTest(unittest.TestCase):
    def setUp(self):
        self.temp_dir = tempfile.TemporaryDirectory()
        self.old_cache_dir = cache_module.CACHE_DIR
        cache_module.CACHE_DIR = self.temp_dir.name

    def tearDown(self):
        cache_module.CACHE_DIR = self.old_cache_dir
        self.temp_dir.cleanup()

    def test_data_version_change_invalidates_memory_and_file_cache(self):
        source = mock.Mock(side_effect=[{'库存': 7642}, {'库存': 7566}])
        cache = cache_module.RefreshableCache(maxsize=1, cache_key='test.inventory')
        wrapped = cache.wrap(source)

        self.assertEqual({'库存': 7642}, wrapped())
        self.assertEqual({'库存': 7642}, wrapped())
        self.assertEqual(1, source.call_count)

        cache_module.bump_data_version()

        self.assertEqual({'库存': 7566}, wrapped())
        self.assertEqual(2, source.call_count)

    def test_refresh_all_caches_publishes_new_data_version(self):
        before = cache_module._data_version_signature()
        cache_module.refresh_all_caches()
        after = cache_module._data_version_signature()

        self.assertIsNotNone(after)
        self.assertNotEqual(before, after)
        self.assertTrue(os.path.exists(
            os.path.join(self.temp_dir.name, cache_module.DATA_VERSION_FILE)))


if __name__ == '__main__':
    unittest.main()