fix test and add doc

tests/unit/test_analytics_service.py

@@ -72,16 +72,16 @@ async def test_get_download_stats_with_data(
     analytics_service, mock_db
 ):
     """Test download statistics with download data."""
-    # Mock downloads
+    # Mock downloads - updated to use actual model fields
     download1 = MagicMock()
     download1.status = "completed"
-    download1.size_bytes = 1024 * 1024 * 100  # 100 MB
-    download1.duration_seconds = 60
+    download1.total_bytes = 1024 * 1024 * 100  # 100 MB
+    download1.download_speed = 1024 * 1024 * 10  # 10 MB/s
 
     download2 = MagicMock()
     download2.status = "failed"
-    download2.size_bytes = 0
-    download2.duration_seconds = 0
+    download2.total_bytes = 0
+    download2.download_speed = None
 
     mock_db.execute = AsyncMock(return_value=MagicMock(
         scalars=MagicMock(return_value=MagicMock(all=MagicMock(
@@ -120,12 +120,15 @@ async def test_get_series_popularity_with_data(
     analytics_service, mock_db
 ):
     """Test series popularity with data."""
-    row = MagicMock()
-    row.series_name = "Test Anime"
-    row.download_count = 5
-    row.total_size = 1024 * 1024 * 500
-    row.last_download = datetime.now()
-    row.successful = 4
+    # Mock returns tuples:
+    # (series_name, download_count, total_size, last_download, successful)
+    row = (
+        "Test Anime",
+        5,
+        1024 * 1024 * 500,
+        datetime.now(),
+        4
+    )
 
     mock_db.execute = AsyncMock(return_value=MagicMock(
         all=MagicMock(return_value=[row])