refactor(net): cut GameWindow over to session owner

src/AcDream.App/Net/LiveSessionLifecycleHost.cs

@@ -0,0 +1,65 @@
+using AcDream.Core.Net;
+
+namespace AcDream.App.Net;
+
+internal sealed record LiveSessionLifecycleBindings(
+    Func<WorldSession, LiveSessionBinding> Bind,
+    Action Reset,
+    Action<string, int, string> Connecting,
+    Action Connected,
+    Action<LiveSessionCharacterSelection> Selected,
+    Action<LiveSessionCharacterSelection> Entered);
+
+/// <summary>
+/// Focused adapter between the session lifetime owner and App composition.
+/// It tracks only the exact borrowed session attached to the host; domain and
+/// presentation state remain behind the supplied lifecycle callbacks.
+/// </summary>
+internal sealed class LiveSessionLifecycleHost : ILiveSessionLifecycleHost
+{
+    private readonly LiveSessionLifecycleBindings _bindings;
+    private WorldSession? _boundSession;
+
+    public LiveSessionLifecycleHost(LiveSessionLifecycleBindings bindings)
+    {
+        _bindings = bindings ?? throw new ArgumentNullException(nameof(bindings));
+        ArgumentNullException.ThrowIfNull(bindings.Bind);
+        ArgumentNullException.ThrowIfNull(bindings.Reset);
+        ArgumentNullException.ThrowIfNull(bindings.Connecting);
+        ArgumentNullException.ThrowIfNull(bindings.Connected);
+        ArgumentNullException.ThrowIfNull(bindings.Selected);
+        ArgumentNullException.ThrowIfNull(bindings.Entered);
+    }
+
+    public LiveSessionBinding BindSession(WorldSession session)
+    {
+        ArgumentNullException.ThrowIfNull(session);
+        if (_boundSession is not null)
+            throw new InvalidOperationException("A live session is already attached to this host.");
+
+        LiveSessionBinding binding = _bindings.Bind(session);
+        _boundSession = session;
+        return binding;
+    }
+
+    public void ResetSessionState() => _bindings.Reset();
+
+    public void ReportConnecting(string host, int port, string user) =>
+        _bindings.Connecting(host, port, user);
+
+    public void ReportConnected() => _bindings.Connected();
+
+    public void ApplySelectedCharacter(LiveSessionCharacterSelection selection) =>
+        _bindings.Selected(selection);
+
+    public void ApplyEnteredWorld(LiveSessionCharacterSelection selection) =>
+        _bindings.Entered(selection);
+
+    public void DetachSession(WorldSession session)
+    {
+        if (!ReferenceEquals(_boundSession, session))
+            throw new InvalidOperationException(
+                "The live-session controller attempted to detach a session that is not bound.");
+        _boundSession = null;
+    }
+}