feat(runtime): own character selection flow

tests/AcDream.App.Tests/Composition/SessionPlayerCompositionTests.cs

@@ -134,6 +134,30 @@ public sealed class SessionPlayerCompositionTests
             "LiveSessionRuntimeFactory.cs")), StringComparison.Ordinal);
     }
 
+    [Fact]
+    public void GraphicalCompositionPausesOnlyWhenCharacterSelectorIsAbsent()
+    {
+        string phase = File.ReadAllText(Path.Combine(
+            FindRepoRoot(),
+            "src",
+            "AcDream.App",
+            "Composition",
+            "SessionPlayerComposition.cs"));
+
+        Assert.Contains(
+            "AwaitCharacterSelection:",
+            phase,
+            StringComparison.Ordinal);
+        Assert.Contains(
+            "d.Options.LiveCharacterSelector is null",
+            phase,
+            StringComparison.Ordinal);
+        Assert.DoesNotContain(
+            "CharacterList.TrySelectFirstAvailable",
+            phase,
+            StringComparison.Ordinal);
+    }
+
     private sealed class RetryBinding(
         string name,
         List<string> calls,

tests/AcDream.App.Tests/Configuration/RuntimeOptionsSessionConfigTests.cs

@@ -62,7 +62,7 @@ public sealed class RuntimeOptionsSessionConfigTests
     }
 
     [Fact]
-    public void AbsentCharacterSelectorLeavesFirstAvailableFallbackInEffect()
+    public void AbsentCharacterSelectorRemainsNullForGraphicalSelectionFlow()
     {
         var config = new SessionConfiguration { Version = 1 };
         var session = new SessionDescriptor

tests/AcDream.App.Tests/Runtime/CurrentGameRuntimeAdapterTests.cs

@@ -173,6 +173,44 @@ public sealed class CurrentGameRuntimeAdapterTests
                 .ToArray());
     }
 
+    [Fact]
+    public void AdapterBorrowsPreWorldSelectionAndCommandsEnterTheSameRuntimeOwner()
+    {
+        using var harness = new Harness(awaitCharacterSelection: true);
+        RuntimeGenerationToken initial = harness.Runtime.Generation;
+
+        RuntimeSessionStartResult start = harness.Runtime.Session.Start(initial);
+
+        Assert.Equal(
+            RuntimeSessionStartStatus.AwaitingCharacterSelection,
+            start.Status);
+        Assert.Equal(
+            RuntimeCharacterSelectionLifecycle.AwaitingSelection,
+            harness.Runtime.CharacterSelection.Snapshot.Lifecycle);
+        Assert.Equal(2, harness.Runtime.CharacterSelection.Snapshot.RosterCount);
+
+        RuntimeGenerationToken generation = harness.Runtime.Generation;
+        Assert.True(harness.Runtime.CharacterSelectionCommands.Highlight(
+            generation,
+            0x50000001u).Accepted);
+        Assert.True(
+            harness.Runtime.CharacterSelection.Snapshot.Buttons.CanRestore);
+        Assert.Equal(
+            RuntimeCommandStatus.Rejected,
+            harness.Runtime.CharacterSelectionCommands.Enter(generation).Status);
+        Assert.True(harness.Runtime.CharacterSelectionCommands.Highlight(
+            generation,
+            Harness.PlayerGuid).Accepted);
+        Assert.True(harness.Runtime.CharacterSelectionCommands.Enter(
+            generation).Accepted);
+
+        Assert.Equal(RuntimeLifecycleState.InWorld, harness.Runtime.Lifecycle.State);
+        Assert.Equal(
+            RuntimeCharacterSelectionLifecycle.InWorld,
+            harness.Runtime.CharacterSelection.Snapshot.Lifecycle);
+        Assert.Equal(Harness.PlayerGuid, harness.Identity.ServerGuid);
+    }
+
     [Fact]
     public void GenerationGateRejectsStaleCommandsAndStopAcknowledgesTeardown()
     {
@@ -698,7 +736,7 @@ public sealed class CurrentGameRuntimeAdapterTests
         private readonly IDisposable _combatModeBinding;
         private readonly GameRuntime _gameRuntime;
 
-        public Harness()
+        public Harness(bool awaitCharacterSelection = false)
         {
             CombatAttackOperations = new CombatAttackOperationsSlot();
             CombatModeOperations = new RuntimeCombatModeOperationsSlot();
@@ -758,7 +796,11 @@ public sealed class CurrentGameRuntimeAdapterTests
                 new SelectionTransport(() => _session?.IsInWorld == true),
                 new NoopInteractionMovement());
 
-            Host = CreateHost(_session, Commands, Identity);
+            Host = CreateHost(
+                _session,
+                Commands,
+                Identity,
+                awaitCharacterSelection);
             Runtime = new CurrentGameRuntimeAdapter(
                 _gameRuntime,
                 Host,
@@ -873,7 +915,8 @@ public sealed class CurrentGameRuntimeAdapterTests
     private static LiveSessionHost CreateHost(
         LiveSessionController controller,
         RecordingCommandRouting commands,
-        LocalPlayerIdentityState identity)
+        LocalPlayerIdentityState identity,
+        bool awaitCharacterSelection = false)
     {
         Action noop = static () => { };
         var reset = new LiveSessionResetBindings
@@ -925,7 +968,8 @@ public sealed class CurrentGameRuntimeAdapterTests
                 "127.0.0.1",
                 9000,
                 "user",
-                "password"));
+                "password",
+                AwaitCharacterSelection: awaitCharacterSelection));
     }
 
     private static RuntimeOptions LiveOptions()
@@ -1039,6 +1083,10 @@ public sealed class CurrentGameRuntimeAdapterTests
                 true,
                 true);
 
+        public void StartCharacterSelectionReceive(WorldSession session)
+        {
+        }
+
         public void EnterWorld(WorldSession session, int activeCharacterIndex)
         {
         }

tests/AcDream.Core.Net.Tests/WorldSessionCharacterSelectionTests.cs

@@ -0,0 +1,175 @@
+using System.Buffers.Binary;
+using System.Net;
+using System.Reflection;
+using AcDream.Core.Net.Messages;
+using AcDream.Core.Net.Packets;
+
+namespace AcDream.Core.Net.Tests;
+
+public sealed class WorldSessionCharacterSelectionTests
+{
+    private sealed class NullTransport : IWorldSessionTransport
+    {
+        public void Send(ReadOnlySpan<byte> datagram) { }
+        public void Send(IPEndPoint remote, ReadOnlySpan<byte> datagram) { }
+        public int Receive(
+            Span<byte> destination,
+            TimeSpan timeout,
+            out IPEndPoint? from)
+        {
+            from = null;
+            return -1;
+        }
+        public ValueTask<NetReceiveResult> ReceiveAsync(
+            Memory<byte> destination,
+            CancellationToken cancellationToken) =>
+            ValueTask.FromCanceled<NetReceiveResult>(cancellationToken);
+        public void Dispose() { }
+    }
+
+    [Fact]
+    public void CharacterManagementSends_UseRetailQueuesAndExactBodies()
+    {
+        using var session = CreateSession();
+        var sent = new List<(byte[] Body, GameMessageGroup Queue)>();
+        session.GameMessageCapture =
+            (body, queue) => sent.Add((body, queue));
+
+        session.SendDeleteCharacter("Canonical", activeIndex: 3);
+        session.SendRestoreCharacter(0x50000001u);
+
+        Assert.Collection(
+            sent,
+            delete =>
+            {
+                Assert.Equal(GameMessageGroup.LoginQueue, delete.Queue);
+                Assert.Equal(
+                    CharacterDelete.BuildRequestBody("Canonical", 3u),
+                    delete.Body);
+            },
+            restore =>
+            {
+                Assert.Equal(GameMessageGroup.ControlQueue, restore.Queue);
+                Assert.Equal(
+                    CharacterRestore.BuildRequestBody(0x50000001u),
+                    restore.Body);
+            });
+    }
+
+    [Fact]
+    public void UiQueueReplies_DispatchInWireOrderAndRosterRefreshReplacesCharacters()
+    {
+        using var session = CreateSession();
+        var events = new List<string>();
+        session.CharacterListReceived += roster =>
+            events.Add($"roster:{roster.Characters[0].SecondsGreyedOut}");
+        session.CharacterDeleteAcknowledged += () => events.Add("delete");
+        session.CharacterRestoreReceived += restore =>
+            events.Add($"restore:{restore.Guid:X8}");
+        session.CharacterErrorReceived += error =>
+            events.Add($"error:{error.RawErrorCode:X}");
+
+        byte[] packet = BuildPacket(
+            BuildRoster(secondsGreyedOut: 0u),
+            BitConverter.GetBytes(CharacterDelete.Opcode),
+            BuildRestoreResponse(),
+            BuildCharacterError(CharacterError.Code.Delete),
+            BuildRoster(secondsGreyedOut: 1u));
+        InvokeProcessDatagram(session, packet);
+
+        Assert.Equal(
+            [
+                "roster:0",
+                "delete",
+                "restore:50000001",
+                "error:6",
+                "roster:1",
+            ],
+            events);
+        CharacterList.Character current =
+            Assert.Single(session.Characters!.Characters);
+        Assert.Equal(1u, current.SecondsGreyedOut);
+    }
+
+    private static WorldSession CreateSession() =>
+        new(
+            new IPEndPoint(IPAddress.Loopback, 9000),
+            new NullTransport());
+
+    private static byte[] BuildRoster(uint secondsGreyedOut)
+    {
+        var writer = new PacketWriter(96);
+        writer.WriteUInt32(CharacterList.Opcode);
+        writer.WriteUInt32(0u);
+        writer.WriteUInt32(1u);
+        writer.WriteUInt32(0x50000001u);
+        writer.WriteString16L("Character");
+        writer.WriteUInt32(secondsGreyedOut);
+        writer.WriteUInt32(0u);
+        writer.WriteUInt32(11u);
+        writer.WriteString16L("Canonical");
+        writer.WriteUInt32(1u);
+        writer.WriteUInt32(1u);
+        return writer.ToArray();
+    }
+
+    private static byte[] BuildRestoreResponse()
+    {
+        var writer = new PacketWriter(64);
+        writer.WriteUInt32(CharacterRestore.ResponseOpcode);
+        writer.WriteUInt32(1u);
+        writer.WriteUInt32(0x50000001u);
+        writer.WriteString16L("Character");
+        writer.WriteUInt32(0u);
+        return writer.ToArray();
+    }
+
+    private static byte[] BuildCharacterError(CharacterError.Code error)
+    {
+        byte[] body = new byte[8];
+        BinaryPrimitives.WriteUInt32LittleEndian(
+            body,
+            CharacterError.Opcode);
+        BinaryPrimitives.WriteUInt32LittleEndian(
+            body.AsSpan(4),
+            (uint)error);
+        return body;
+    }
+
+    private static byte[] BuildPacket(params byte[][] messages)
+    {
+        int length = messages.Sum(message =>
+            MessageFragmentHeader.Size + message.Length);
+        var fragments = new byte[length];
+        int position = 0;
+        uint sequence = 1u;
+        foreach (byte[] message in messages)
+        {
+            position += GameMessageFragment.WriteSingleFragment(
+                fragments.AsSpan(position),
+                sequence++,
+                GameMessageGroup.UIQueue,
+                message);
+        }
+        return PacketCodec.Encode(
+            new PacketHeader
+            {
+                Sequence = 1u,
+                Flags = PacketHeaderFlags.BlobFragments,
+            },
+            fragments,
+            outboundIsaac: null);
+    }
+
+    private static void InvokeProcessDatagram(
+        WorldSession session,
+        byte[] datagram)
+    {
+        MethodInfo method = typeof(WorldSession).GetMethod(
+            "ProcessDatagram",
+            BindingFlags.NonPublic | BindingFlags.Instance)!;
+        method.Invoke(
+            session,
+            [new ReadOnlyMemory<byte>(datagram), null, true]);
+    }
+}

tests/AcDream.Runtime.Tests/Session/LiveSessionControllerTests.cs

@@ -57,10 +57,13 @@ public sealed class LiveSessionControllerTests
         public bool ThrowOnCreate { get; set; }
         public bool ThrowOnCharacters { get; set; }
         public bool ThrowOnEnterWorld { get; set; }
+        public CharacterError.Parsed? EnterWorldRejection { get; set; }
         public bool ThrowOnTick { get; set; }
         public bool FailDisposeOnce { get; set; }
         public List<WorldSession> Sessions { get; } = [];
         public Dictionary<WorldSession, int> DisposeCounts { get; } = [];
+        public List<(string Account, int ActiveIndex)> DeleteRequests { get; } = [];
+        public List<uint> RestoreRequests { get; } = [];
         public int EnterWorldCount { get; private set; }
         public int TickCount { get; private set; }
 
@@ -98,15 +101,35 @@ public sealed class LiveSessionControllerTests
             return Characters;
         }
 
+        public void StartCharacterSelectionReceive(WorldSession session) =>
+            calls.Add("start-character-selection-receive");
+
         public void EnterWorld(WorldSession session, int activeCharacterIndex)
         {
             calls.Add($"enter:{activeCharacterIndex}");
             EnterWorldCount++;
             OnEnterWorld?.Invoke();
+            if (EnterWorldRejection is { } rejection)
+                throw new CharacterSelectionRejectedException(rejection);
             if (ThrowOnEnterWorld)
                 throw new InvalidOperationException("enter failure");
         }
 
+        public void DeleteCharacter(
+            WorldSession session,
+            string accountName,
+            int activeCharacterIndex)
+        {
+            calls.Add($"delete:{activeCharacterIndex}");
+            DeleteRequests.Add((accountName, activeCharacterIndex));
+        }
+
+        public void RestoreCharacter(WorldSession session, uint characterId)
+        {
+            calls.Add($"restore:{characterId:X8}");
+            RestoreRequests.Add(characterId);
+        }
+
         public void Tick(WorldSession session)
         {
             calls.Add("tick");
@@ -340,6 +363,179 @@ public sealed class LiveSessionControllerTests
         Assert.True(calls.IndexOf("roster") < calls.IndexOf("selected"));
     }
 
+    [Fact]
+    public void Start_GraphicalNoSelectorStopsBeforeEnterWorldThenTypedEnterContinuesSameScope()
+    {
+        var calls = new List<string>();
+        var operations = new TestOperations(calls);
+        var host = new TestHost(calls);
+        var controller = new LiveSessionController(operations);
+
+        LiveSessionStartResult result = controller.Start(
+            LiveOptions(awaitSelection: true),
+            host);
+
+        Assert.Equal(
+            LiveSessionStartStatus.AwaitingCharacterSelection,
+            result.Status);
+        Assert.False(controller.IsInWorld);
+        Assert.NotNull(controller.CurrentSession);
+        Assert.Equal(0, operations.EnterWorldCount);
+        Assert.False(host.CommandBuses[0].Active);
+        RuntimeGenerationToken generation = controller.Generation;
+        Assert.Equal(
+            RuntimeCharacterSelectionLifecycle.AwaitingSelection,
+            controller.CharacterSelection.Snapshot.Lifecycle);
+
+        // Greyed entries remain highlightable but cannot enter.
+        Assert.True(controller.Highlight(generation, 0x50000001u).Accepted);
+        Assert.Equal(
+            RuntimeCommandStatus.Rejected,
+            controller.Enter(generation).Status);
+        Assert.True(controller.Highlight(generation, 0x50000002u).Accepted);
+        Assert.True(controller.Enter(generation).Accepted);
+
+        Assert.True(controller.IsInWorld);
+        Assert.Equal(1, operations.EnterWorldCount);
+        Assert.Contains("enter:1", calls);
+        Assert.True(host.CommandBuses[0].Active);
+        Assert.Same(operations.Sessions[0], controller.CurrentSession);
+    }
+
+    [Fact]
+    public void Start_ExplicitSelectorStillEntersWhenGraphicalPauseFlagIsSet()
+    {
+        var calls = new List<string>();
+        var operations = new TestOperations(calls);
+        var host = new TestHost(calls);
+        var controller = new LiveSessionController(operations);
+
+        LiveSessionStartResult result = controller.Start(
+            LiveOptions(
+                selector: new LiveSessionCharacterSelector(
+                    CharacterId: 0x50000002u),
+                awaitSelection: true),
+            host);
+
+        Assert.Equal(LiveSessionStartStatus.Connected, result.Status);
+        Assert.True(controller.IsInWorld);
+        Assert.Equal(1, operations.EnterWorldCount);
+    }
+
+    [Fact]
+    public void EnterRejection_SurfacesErrorAndKeepsExactPreWorldScopeRetryable()
+    {
+        var calls = new List<string>();
+        var operations = new TestOperations(calls)
+        {
+            EnterWorldRejection = new CharacterError.Parsed(
+                (uint)CharacterError.Code.EnterGameCharacterLocked),
+        };
+        var host = new TestHost(calls);
+        var controller = new LiveSessionController(operations);
+        Assert.Equal(
+            LiveSessionStartStatus.AwaitingCharacterSelection,
+            controller.Start(LiveOptions(awaitSelection: true), host).Status);
+        RuntimeGenerationToken generation = controller.Generation;
+        WorldSession session = controller.CurrentSession!;
+
+        Assert.Equal(
+            RuntimeCommandStatus.Rejected,
+            controller.Enter(generation).Status);
+        Assert.Same(session, controller.CurrentSession);
+        Assert.Equal(generation, controller.Generation);
+        Assert.False(controller.IsInWorld);
+        RuntimeCharacterSelectionSnapshot rejected =
+            controller.CharacterSelection.Snapshot;
+        Assert.Equal(
+            RuntimeCharacterSelectionLifecycle.AwaitingSelection,
+            rejected.Lifecycle);
+        Assert.Equal(
+            CharacterError.Code.EnterGameCharacterLocked,
+            rejected.Error!.Value.Code);
+
+        operations.EnterWorldRejection = null;
+        Assert.True(controller.Enter(generation).Accepted);
+        Assert.True(controller.IsInWorld);
+        Assert.Same(session, controller.CurrentSession);
+    }
+
+    [Fact]
+    public async Task CharacterCommands_UseWireSlotAndRestoreNeverWaitsForReply()
+    {
+        var calls = new List<string>();
+        var operations = new TestOperations(calls);
+        var host = new TestHost(calls);
+        var controller = new LiveSessionController(operations);
+        Assert.Equal(
+            LiveSessionStartStatus.AwaitingCharacterSelection,
+            controller.Start(LiveOptions(awaitSelection: true), host).Status);
+        RuntimeGenerationToken generation = controller.Generation;
+
+        Assert.True(controller.Highlight(generation, 0x50000002u).Accepted);
+        Assert.True(controller.RequestDelete(generation).Accepted);
+        Assert.Equal(0x50000002u,
+            controller.CharacterSelection.Snapshot.PendingDeleteCharacterId);
+        Assert.True(controller.Cancel(generation).Accepted);
+        Assert.True(controller.RequestDelete(generation).Accepted);
+        Assert.True(controller.ConfirmDelete(generation).Accepted);
+        Assert.Equal([("Canonical", 1)], operations.DeleteRequests);
+        Assert.False(controller.CharacterSelection.Snapshot.Buttons.CanEnter);
+        controller.CharacterSelectionState.ApplyDeleteAcknowledged();
+        controller.CharacterSelectionState.ApplyRoster(new LiveSessionRosterReport(
+            "Canonical",
+            11,
+            [
+                new(0x50000001u, "Grey", 10u),
+                new(0x50000002u, "Ready", 1u),
+            ]));
+
+        Assert.True(controller.Highlight(generation, 0x50000001u).Accepted);
+        RuntimeCommandResult restore = await Task.Run(
+                () => controller.Restore(generation))
+            .WaitAsync(TimeSpan.FromSeconds(5));
+        Assert.True(restore.Accepted);
+        Assert.Equal([0x50000001u], operations.RestoreRequests);
+        // ACE may send no response for an unknown guid. The synchronous
+        // command has already returned and does not gate later commands.
+        Assert.True(controller.Highlight(generation, 0x50000002u).Accepted);
+        controller.Tick();
+        Assert.Equal(1, operations.TickCount);
+        Assert.False(controller.IsInWorld);
+    }
+
+    [Fact]
+    public void CharacterCommands_AreGenerationGatedAcrossReconnectAndStop()
+    {
+        var calls = new List<string>();
+        var operations = new TestOperations(calls);
+        var host = new TestHost(calls);
+        var controller = new LiveSessionController(operations);
+        controller.Start(LiveOptions(awaitSelection: true), host);
+        RuntimeGenerationToken first = controller.Generation;
+
+        LiveSessionStartResult reconnect = controller.Reconnect(
+            LiveOptions(awaitSelection: true),
+            host);
+
+        Assert.Equal(
+            LiveSessionStartStatus.AwaitingCharacterSelection,
+            reconnect.Status);
+        Assert.Equal(
+            RuntimeCommandStatus.StaleGeneration,
+            controller.Highlight(first, 0x50000002u).Status);
+        RuntimeGenerationToken second = controller.Generation;
+        Assert.True(controller.Highlight(second, 0x50000002u).Accepted);
+        controller.Stop();
+        Assert.Equal(
+            RuntimeCommandStatus.StaleGeneration,
+            controller.Enter(second).Status);
+        Assert.Equal(
+            RuntimeCharacterSelectionLifecycle.Inactive,
+            controller.CharacterSelection.Snapshot.Lifecycle);
+        Assert.Equal(0, controller.CharacterSelection.Snapshot.RosterCount);
+    }
+
     [Fact]
     public void Start_DisabledAndMissingCredentialsResetButNeverConstructSession()
     {
@@ -1232,7 +1428,8 @@ public sealed class LiveSessionControllerTests
         bool live = true,
         string? user = "user",
         LiveSessionCharacterSelector? selector = null,
-        bool probe = false) =>
+        bool probe = false,
+        bool awaitSelection = false) =>
         new(
             live,
             "127.0.0.1",
@@ -1240,7 +1437,8 @@ public sealed class LiveSessionControllerTests
             user ?? string.Empty,
             "password",
             selector,
-            probe);
+            probe,
+            awaitSelection);
 
     private static CharacterList.Parsed AvailableCharacters() => new(
         0u,

tests/AcDream.Runtime.Tests/Session/RuntimeCharacterSelectionStateTests.cs

@@ -0,0 +1,247 @@
+using AcDream.Core.Net.Messages;
+using AcDream.Runtime;
+using AcDream.Runtime.Session;
+
+namespace AcDream.Runtime.Tests.Session;
+
+public sealed class RuntimeCharacterSelectionStateTests
+{
+    private sealed class Collector : IRuntimeCharacterSelectionVisitor
+    {
+        public List<RuntimeCharacterSelectionEntry> Entries { get; } = [];
+
+        public void Visit(in RuntimeCharacterSelectionEntry character) =>
+            Entries.Add(character);
+    }
+
+    private sealed class Observer(
+        Action<RuntimeCharacterSelectionDelta> onDelta)
+        : IRuntimeCharacterSelectionObserver
+    {
+        public void OnCharacterSelectionChanged(
+            in RuntimeCharacterSelectionDelta delta) =>
+            onDelta(delta);
+    }
+
+    [Fact]
+    public void ApplyRoster_PortsRetailOrderFallbackAndDisabledButtonMatrix()
+    {
+        using var state = new RuntimeCharacterSelectionState();
+        state.Begin(new RuntimeGenerationToken(7));
+
+        state.ApplyRoster(Roster(
+            new(0x50000001u, "Zulu", 1u),
+            new(0x50000002u, "Bravo", 0u),
+            new(0x50000003u, "Alpha", 0u),
+            new(0x50000004u, "Able", 9u)));
+
+        RuntimeCharacterSelectionSnapshot snapshot = state.Snapshot;
+        Assert.Equal(RuntimeCharacterSelectionLifecycle.AwaitingSelection, snapshot.Lifecycle);
+        // Retail falls back in CharacterSet wire order, independently of the
+        // alphabetized display order.
+        Assert.Equal(0x50000002u, snapshot.HighlightedCharacterId);
+        Assert.True(snapshot.Buttons.CanEnter);
+        Assert.True(snapshot.Buttons.CanDelete);
+        Assert.False(snapshot.Buttons.CanRestore);
+        Assert.True(snapshot.Buttons.DeleteVisible);
+        Assert.False(snapshot.Buttons.RestoreVisible);
+
+        var collector = new Collector();
+        state.View.Visit(collector);
+        Assert.Equal(
+            [
+                (0x50000003u, 2, false),
+                (0x50000002u, 1, false),
+                (0x50000004u, 3, true),
+                (0x50000001u, 0, true),
+            ],
+            collector.Entries.Select(entry =>
+                (entry.CharacterId, entry.ActiveIndex, entry.IsPendingDelete)));
+
+        Assert.True(state.TryHighlight(0x50000004u));
+        snapshot = state.Snapshot;
+        Assert.False(snapshot.Buttons.CanEnter);
+        Assert.False(snapshot.Buttons.CanDelete);
+        Assert.True(snapshot.Buttons.CanRestore);
+        Assert.False(snapshot.Buttons.DeleteVisible);
+        Assert.True(snapshot.Buttons.RestoreVisible);
+    }
+
+    [Fact]
+    public void ApplyRoster_PreservesHighlightedGuidAcrossDeleteRefresh()
+    {
+        using var state = new RuntimeCharacterSelectionState();
+        state.Begin(new RuntimeGenerationToken(3));
+        state.ApplyRoster(Roster(
+            new(0x50000001u, "One", 0u),
+            new(0x50000002u, "Two", 0u)));
+        Assert.True(state.TryHighlight(0x50000002u));
+        Assert.True(state.TryRequestDelete(out uint requested));
+        Assert.Equal(0x50000002u, requested);
+        Assert.True(state.TryTakeDeleteConfirmation(
+            out RuntimeCharacterSelectionEntry deleted,
+            out string account));
+        Assert.Equal(1, deleted.ActiveIndex);
+        Assert.Equal("Canonical", account);
+
+        state.ApplyDeleteAcknowledged();
+        Assert.Equal(
+            RuntimeCharacterSelectionOperation.DeleteAcknowledged,
+            state.Snapshot.Operation);
+        state.ApplyRoster(Roster(
+            new(0x50000001u, "One", 0u),
+            new(0x50000002u, "Two", 1u)));
+
+        RuntimeCharacterSelectionSnapshot snapshot = state.Snapshot;
+        Assert.Equal(0x50000002u, snapshot.HighlightedCharacterId);
+        Assert.Equal(RuntimeCharacterSelectionOperation.None, snapshot.Operation);
+        Assert.True(snapshot.Buttons.CanRestore);
+        Assert.False(snapshot.Buttons.CanEnter);
+    }
+
+    [Fact]
+    public void DeleteConfirmation_CancelIsIdempotentlyGenerationLocal()
+    {
+        using var state = new RuntimeCharacterSelectionState();
+        state.Begin(new RuntimeGenerationToken(4));
+        state.ApplyRoster(Roster(
+            new LiveSessionRosterEntry(0x50000001u, "One", 0u)));
+
+        Assert.True(state.TryRequestDelete(out _));
+        Assert.Equal(0x50000001u, state.Snapshot.PendingDeleteCharacterId);
+        Assert.False(state.TryHighlight(0x50000001u));
+        Assert.False(state.BeginEnter(out _));
+        Assert.True(state.Cancel());
+        Assert.Equal(0u, state.Snapshot.PendingDeleteCharacterId);
+        Assert.False(state.Cancel());
+
+        state.Reset(new RuntimeGenerationToken(5));
+        Assert.Equal(RuntimeCharacterSelectionLifecycle.Inactive, state.Snapshot.Lifecycle);
+        Assert.Equal(0, state.Snapshot.RosterCount);
+        Assert.Equal(new RuntimeGenerationToken(5), state.Snapshot.Generation);
+    }
+
+    [Fact]
+    public void Restore_IsFireAndObserveAndSuccessUpdatesTheCanonicalEntry()
+    {
+        using var state = new RuntimeCharacterSelectionState();
+        state.Begin(new RuntimeGenerationToken(11));
+        state.ApplyRoster(Roster(
+            new LiveSessionRosterEntry(0x50000001u, "Grey", 1u)));
+
+        Assert.True(state.TryBeginRestore(out RuntimeCharacterSelectionEntry request));
+        Assert.Equal(0x50000001u, request.CharacterId);
+        Assert.Equal(
+            RuntimeCharacterSelectionOperation.RestoreRequested,
+            state.Snapshot.Operation);
+        // No response is required to keep using the state. ACE's unknown-guid
+        // branch intentionally sends no reply.
+        Assert.True(state.TryHighlight(0x50000001u));
+
+        state.ApplyRestore(new CharacterRestore.Parsed(
+            VerificationFlag: 1u,
+            Guid: 0x50000001u,
+            Name: "Restored",
+            SecondsGreyedOut: 0u));
+
+        Assert.True(state.View.TryGet(0x50000001u, out var restored));
+        Assert.Equal("Restored", restored.Name);
+        Assert.False(restored.IsPendingDelete);
+        Assert.True(state.Snapshot.Buttons.CanEnter);
+        Assert.Equal(
+            RuntimeCharacterSelectionOperation.RestoreSucceeded,
+            state.Snapshot.Operation);
+    }
+
+    [Fact]
+    public void RestoreResponse_FromSupersededRequestCannotCompleteTheCurrentRequest()
+    {
+        using var state = new RuntimeCharacterSelectionState();
+        state.Begin(new RuntimeGenerationToken(12));
+        state.ApplyRoster(Roster(
+            new(0x50000001u, "First", 1u),
+            new(0x50000002u, "Second", 1u)));
+
+        Assert.True(state.TryBeginRestore(out _));
+        Assert.True(state.TryHighlight(0x50000002u));
+        Assert.True(state.TryBeginRestore(out _));
+        state.ApplyRestore(new CharacterRestore.Parsed(
+            1u,
+            0x50000001u,
+            "First",
+            0u));
+
+        Assert.Equal(
+            RuntimeCharacterSelectionOperation.RestoreRequested,
+            state.Snapshot.Operation);
+        Assert.True(state.View.TryGet(0x50000001u, out var first));
+        Assert.True(first.IsPendingDelete);
+    }
+
+    [Fact]
+    public void CharacterErrors_MapKnownAndUnknownButNeverPublishNumErrorsSentinel()
+    {
+        using var state = new RuntimeCharacterSelectionState();
+        state.Begin(new RuntimeGenerationToken(2));
+        state.ApplyRoster(Roster(
+            new LiveSessionRosterEntry(0x50000001u, "One", 0u)));
+        var deltas = new List<RuntimeCharacterSelectionDelta>();
+        using IDisposable subscription = state.View.Subscribe(
+            new Observer(deltas.Add));
+
+        state.ApplyError(new CharacterError.Parsed(
+            (uint)CharacterError.Code.Delete));
+        RuntimeCharacterSelectionError known =
+            Assert.IsType<RuntimeCharacterSelectionError>(state.Snapshot.Error);
+        Assert.Equal(CharacterError.Code.Delete, known.Code);
+        Assert.Contains("delete", known.Message, StringComparison.OrdinalIgnoreCase);
+
+        Assert.True(state.Cancel());
+        state.ApplyError(new CharacterError.Parsed(0xDEADBEEFu));
+        RuntimeCharacterSelectionError unknown =
+            Assert.IsType<RuntimeCharacterSelectionError>(state.Snapshot.Error);
+        Assert.Contains("0xDEADBEEF", unknown.Message, StringComparison.Ordinal);
+
+        long revision = state.Snapshot.Revision;
+        int count = deltas.Count;
+        state.ApplyError(new CharacterError.Parsed(
+            (uint)CharacterError.Code.NumErrors));
+        Assert.Equal(revision, state.Snapshot.Revision);
+        Assert.Equal(count, deltas.Count);
+        Assert.Equal(0xDEADBEEFu, state.Snapshot.Error!.Value.RawCode);
+    }
+
+    [Fact]
+    public void Deltas_AreMonotonicAndReentrantMutationsStayOrdered()
+    {
+        using var state = new RuntimeCharacterSelectionState();
+        state.Begin(new RuntimeGenerationToken(9));
+        var deltas = new List<RuntimeCharacterSelectionDelta>();
+        var observer = new Observer(delta =>
+        {
+            deltas.Add(delta);
+            if (delta.Kind == RuntimeCharacterSelectionDeltaKind.RosterChanged)
+                Assert.True(state.TryHighlight(0x50000002u));
+        });
+        using IDisposable subscription = state.View.Subscribe(observer);
+
+        state.ApplyRoster(Roster(
+            new(0x50000001u, "Ready", 0u),
+            new(0x50000002u, "Grey", 1u)));
+
+        Assert.Equal(
+            [
+                RuntimeCharacterSelectionDeltaKind.RosterChanged,
+                RuntimeCharacterSelectionDeltaKind.HighlightChanged,
+            ],
+            deltas.Select(delta => delta.Kind));
+        Assert.True(deltas[0].Sequence < deltas[1].Sequence);
+        Assert.All(
+            deltas,
+            delta => Assert.Equal(new RuntimeGenerationToken(9), delta.Generation));
+    }
+
+    private static LiveSessionRosterReport Roster(
+        params LiveSessionRosterEntry[] entries) =>
+        new("Canonical", 11, entries);
+}