refactor: centralize settings and application services

tests/test_config.py

@@ -5,6 +5,35 @@ from unittest.mock import patch
 from assistant_bot import config
 
 
+class AppSettingsTests(unittest.TestCase):
+    def test_loads_complete_startup_configuration_once(self) -> None:
+        environment = {
+            config.TOKEN_ENV_NAME: "token",
+            config.PASSWORD_ENV_NAME: "secret",
+            config.MODE_ENV_NAME: "local",
+            config.DB_ENV_NAME: "data/test.sqlite3",
+            config.TIMEZONE_ENV_NAME: "UTC",
+            config.WHISPER_LANGUAGE_ENV_NAME: "auto",
+        }
+        with patch(
+            "assistant_bot.config.load_env_file"
+        ) as load_env_file, patch.dict(
+            os.environ,
+            environment,
+            clear=True,
+        ):
+            settings = config.load_app_settings()
+
+        load_env_file.assert_called_once_with()
+        self.assertEqual(settings.bot_token, "token")
+        self.assertEqual(settings.assistant_password, "secret")
+        self.assertEqual(settings.mode, "local")
+        self.assertEqual(settings.db_path, config.PROJECT_ROOT / "data/test.sqlite3")
+        self.assertEqual(settings.timezone.key, "UTC")
+        self.assertIsNone(settings.whisper_language)
+        self.assertIsNone(settings.yandex_cloud_folder)
+
+
 class WhisperConfigTests(unittest.TestCase):
     def test_gpu_int8_defaults(self) -> None:
         variable_names = (