refactor: 推进后端分层架构治理

tests/test_download_task_service.py

@@ -0,0 +1,52 @@
+"""下载任务应用服务测试。"""
+
+from types import SimpleNamespace
+
+from app.application.download.tasks import DownloadTaskService
+
+
+def test_download_task_service_enriches_history_and_controls_task():
+    """下载任务查询应附加历史媒体信息，控制方法只转发规范参数。"""
+    torrent = SimpleNamespace(hash="hash", media=None)
+    history = SimpleNamespace(
+        media_source="tmdb",
+        media_id="123",
+        type="电影",
+        title="测试电影",
+        seasons=[1],
+        episodes=[2],
+        poster="poster",
+        image="backdrop",
+        torrent_site="站点",
+        userid=1,
+        username="alice",
+    )
+    calls = []
+    service = DownloadTaskService(
+        list_torrents=lambda **kwargs: [torrent],
+        get_history_by_hashes=lambda hashes: {hashes[0]: history},
+        start_torrents=lambda **kwargs: calls.append(("start", kwargs)) or True,
+        stop_torrents=lambda **kwargs: calls.append(("stop", kwargs)) or True,
+        remove_torrents=lambda **kwargs: calls.append(("remove", kwargs)) or True,
+    )
+
+    assert service.downloading("qb") == [torrent]
+    assert torrent.media["media_id"] == "123"
+    assert torrent.username == "alice"
+    assert service.set_downloading("hash", "start", "qb") is True
+    assert service.set_downloading("hash", "stop", "qb") is True
+    assert service.remove_downloading("hash", "qb") is True
+    assert [call[0] for call in calls] == ["start", "stop", "remove"]
+
+
+def test_download_task_service_rejects_unknown_operation():
+    """未知操作保持旧的 False 返回语义。"""
+    service = DownloadTaskService(
+        list_torrents=lambda **_kwargs: [],
+        get_history_by_hashes=lambda _hashes: {},
+        start_torrents=lambda **_kwargs: True,
+        stop_torrents=lambda **_kwargs: True,
+        remove_torrents=lambda **_kwargs: True,
+    )
+
+    assert service.set_downloading("hash", "pause") is False