fix(jellyfin): preserve virtual playlist context

allstarr.Tests/Protocols/JellyfinControllerSearchLimitTests.cs

@@ -60,15 +60,17 @@ public class JellyfinControllerSearchLimitTests
     }
 
     [Theory]
-    [InlineData(22, 20, 0, 20, 0, 0)]
-    [InlineData(22, 2, 20, 20, 0, 18)]
-    [InlineData(22, 0, 40, 20, 18, 20)]
-    [InlineData(0, 0, 0, 20, 0, 20)]
+    [InlineData(22, 20, 0, 20, 22, 0, 0)]
+    [InlineData(22, 2, 20, 20, 22, 0, 18)]
+    [InlineData(22, 0, 40, 20, 22, 18, 20)]
+    [InlineData(0, 0, 0, 20, 0, 0, 20)]
+    [InlineData(24, 2, 0, 200, 2, 0, 198)]
     public void VirtualPlaylistPage_FollowsBackendRowsWithoutBreakingPaging(
         int backendTotal,
         int backendReturned,
         int startIndex,
         int limit,
+        int expectedBackendTotal,
         int expectedStart,
         int expectedTake)
     {
@@ -76,9 +78,10 @@ public class JellyfinControllerSearchLimitTests
             "GetVirtualPlaylistPage",
             BindingFlags.Static | BindingFlags.NonPublic);
 
-        var result = ((int Start, int Take))method!.Invoke(
+        var result = ((int BackendTotal, int Start, int Take))method!.Invoke(
             null, [backendTotal, backendReturned, startIndex, limit])!;
 
+        Assert.Equal(expectedBackendTotal, result.BackendTotal);
         Assert.Equal(expectedStart, result.Start);
         Assert.Equal(expectedTake, result.Take);
     }

allstarr.Tests/Protocols/ProtocolRouteFixtureTests.cs

@@ -2235,7 +2235,7 @@ public sealed class ProtocolRouteFixtureTests
         Assert.All(playlist.RootElement.GetProperty("Items").EnumerateArray(),
             item => Assert.False(string.IsNullOrWhiteSpace(item.GetProperty("Id").GetString())));
         var first = playlist.RootElement.GetProperty("Items")[0];
-        Assert.False(first.TryGetProperty("ParentId", out _));
+        Assert.Equal(nativeId, first.GetProperty("ParentId").GetString());
         Assert.Equal("source-a", first.GetProperty("MediaSources")[0].GetProperty("Id").GetString());
         Assert.Equal(
             "every-field",
@@ -2381,13 +2381,14 @@ public sealed class ProtocolRouteFixtureTests
         var actual = JsonNode.Parse(
             tracks.RootElement.GetProperty("Items")[0].GetRawText())!.AsObject();
         var expected = JsonNode.Parse(originalItem)!.AsObject();
+        expected["ParentId"] = virtualId;
         expected["PlaylistItemId"] = "local-song-a";
 
         Assert.True(
             JsonNode.DeepEquals(expected, actual),
             $"Expected full source DTO with playlist overlays.\nExpected: {expected}\nActual: {actual}");
         Assert.Equal("Original Track", actual["Name"]!.GetValue<string>());
-        Assert.Equal("original-parent", actual["ParentId"]!.GetValue<string>());
+        Assert.Equal(virtualId, actual["ParentId"]!.GetValue<string>());
         Assert.False(actual["ProviderIds"]!.AsObject().ContainsKey("AllstarrSource"));
         Assert.Equal("local-song-a", actual["Id"]!.GetValue<string>());
         Assert.Equal("local-song-a", actual["PlaylistItemId"]!.GetValue<string>());

allstarr.Tests/Protocols/VirtualPlaylistProtocolAdapterTests.cs

@@ -43,7 +43,8 @@ public sealed class VirtualPlaylistProtocolAdapterTests
         Assert.Empty(unresolved.GetProperty("MediaSources").EnumerateArray());
         Assert.Equal("apple-music",
             unresolved.GetProperty("ProviderIds").GetProperty("AllstarrSource").GetString());
-        Assert.All(items.EnumerateArray(), item => Assert.False(item.TryGetProperty("ParentId", out _)));
+        Assert.All(items.EnumerateArray(), item =>
+            Assert.Equal(ProtocolId, item.GetProperty("ParentId").GetString()));
         Assert.All(items.EnumerateArray(), item =>
         {
             var id = item.GetProperty("Id").GetString();

allstarr/Controllers/JellyfinController.Search.cs

@@ -1090,12 +1090,12 @@ public partial class JellyfinController
         foreach (var playlist in appendable.Skip(virtualPage.Start).Take(virtualPage.Take))
             items.Add(JsonSerializer.SerializeToNode(
                 _virtualPlaylistProtocolAdapter.ToItem(playlist)));
-        root["TotalRecordCount"] = backendTotal + appendable.Length;
+        root["TotalRecordCount"] = virtualPage.BackendTotal + appendable.Length;
         root["StartIndex"] = startIndex;
         return Content(root.ToJsonString(), "application/json");
     }
 
-    private static (int Start, int Take) GetVirtualPlaylistPage(
+    private static (int BackendTotal, int Start, int Take) GetVirtualPlaylistPage(
         int backendTotal,
         int backendReturned,
         int startIndex,
@@ -1103,9 +1103,13 @@ public partial class JellyfinController
     {
         var requestedLimit = Math.Max(0, limit);
         var backendEnd = startIndex + backendReturned;
-        return backendEnd < backendTotal || backendReturned >= requestedLimit
-            ? (0, 0)
-            : (Math.Max(0, backendEnd - backendTotal), requestedLimit - backendReturned);
+        var effectiveBackendTotal = backendReturned < requestedLimit
+            ? Math.Min(backendTotal, backendEnd)
+            : backendTotal;
+        return backendEnd < effectiveBackendTotal || backendReturned >= requestedLimit
+            ? (effectiveBackendTotal, 0, 0)
+            : (effectiveBackendTotal, Math.Max(0, backendEnd - effectiveBackendTotal),
+                requestedLimit - backendReturned);
     }
 
     #endregion

allstarr/Core/Protocols/Jellyfin/JellyfinVirtualPlaylistProtocolAdapter.cs

@@ -314,6 +314,7 @@ public sealed class JellyfinVirtualPlaylistProtocolAdapter(
                 }
             }
 
+            item["ParentId"] = responsePlaylistId;
             item["PlaylistItemId"] = track.NativePlaylistEntryId ?? track.BackendItemId;
             return item;
         }).ToArray();