fix undo/redo handling

src/Koogle.Web/Components/Game/GameInputPanel.razor

@@ -163,6 +163,7 @@
     private int? _selectedNumber;
     private bool _hasModifiedPins;
     private ThrowPanelState? _beforeThrowState;
+    private int _lastKnownThrowCounter;
 
     private bool IsInteractive => GameState.Value.IsGameActive && !GameState.Value.IsLoading;
 
@@ -172,15 +173,30 @@
         GameState.StateChanged += OnGameStateChanged;
         // Store initial state for before/after comparison
         CaptureBeforeThrowState();
+        _lastKnownThrowCounter = GameState.Value.ThrowPanel.TotalThrowCounter;
     }
 
     private void OnGameStateChanged(object? sender, EventArgs e)
     {
-        // After throw is processed and pins are reset, capture new before state
-        if (!_hasModifiedPins)
+        var currentCounter = GameState.Value.ThrowPanel.TotalThrowCounter;
+
+        // Detect external state changes (Undo/Redo/SignalR) by comparing throw counter
+        // If counter changed externally, reset local state and capture new before state
+        if (currentCounter != _lastKnownThrowCounter)
         {
+            _hasModifiedPins = false;
+            _selectedNumber = null;
+            CaptureBeforeThrowState();
+            _lastKnownThrowCounter = currentCounter;
+        }
+        else if (!_hasModifiedPins)
+        {
+            // Normal state change (e.g., after throw processed), capture new before state
             CaptureBeforeThrowState();
         }
+
+        // Force re-render to update child components (ThrowPanel, PinPanel, etc.)
+        InvokeAsync(StateHasChanged);
     }
 
     private void CaptureBeforeThrowState()
@@ -201,7 +217,7 @@
         var currentStatus = GetPinStatus(pinNumber);
 
         // In Decrease mode, fallen pins cannot be reset to standing
-        if (GameState.Value.ThrowPanel.ThrowMode == ThrowMode.Decrease && currentStatus == PinStatus.Fallen)
+        if (GameState.Value.ThrowPanel.ThrowMode == ThrowMode.Decrease && currentStatus == PinStatus.Disabled)
         {
             return;
         }

src/Koogle.Web/Store/GameState/GameEffects.cs

@@ -467,6 +467,14 @@ public class GameEffects
     [EffectMethod]
     public Task HandleUndoThrowSuccess(UndoThrowSuccessAction action, IDispatcher dispatcher)
     {
+        //var stateAfterReducer = _gameState.Value;
+        //_logger.LogInformation(
+        //    "UNDO SUCCESS: State after reducer - pins fallen={Fallen}, total={Total}, UndoStack={UndoCount}, RedoStack={RedoCount}",
+        //    stateAfterReducer.ThrowPanel.CountFallenPins(),
+        //    stateAfterReducer.ThrowPanel.TotalThrowCounter,
+        //    stateAfterReducer.UndoStack.Count,
+        //    stateAfterReducer.RedoStack.Count);
+
         // Save after undo as well
         _saveDebounceTimer?.Dispose();
         _saveDebounceTimer = new Timer(
@@ -495,9 +503,12 @@ public class GameEffects
 
         var lastSnapshot = state.UndoStack[^1];
 
-        _logger.LogDebug(
-            "Undoing throw. Stack size before: {StackSize}, Restoring to throw counter: {ThrowCounter}",
+        _logger.LogInformation(
+            "UNDO: Stack={StackSize}, Current pins fallen={CurrentFallen}, Snapshot pins fallen={SnapshotFallen}, Current total={CurrentTotal}, Snapshot total={SnapshotTotal}",
             state.UndoStack.Count,
+            state.ThrowPanel.CountFallenPins(),
+            lastSnapshot.ThrowPanel.CountFallenPins(),
+            state.ThrowPanel.TotalThrowCounter,
             lastSnapshot.ThrowPanel.TotalThrowCounter);
 
         dispatcher.Dispatch(new UndoThrowSuccessAction(

src/Koogle.Web/Store/GameState/GameReducers.cs

@@ -1,5 +1,7 @@
 using System.Collections.Immutable;
+using System.Text.Json;
 using Fluxor;
+using Koogle.Application.Games;
 using Koogle.Domain.Enums;
 
 namespace Koogle.Web.Store.GameState;
@@ -191,11 +193,14 @@ public static class GameReducers
     public static GameState OnRecordThrow(GameState state, RecordThrowAction action)
     {
         // Create snapshot of current state before throw is processed
+        // Deep clone GameModel to avoid reference sharing issues
+        object? clonedGameModel = CloneGameModel(state.GameModel);
+
         var snapshot = new GameSnapshot
         {
             ThrowPanel = state.ThrowPanel,
             Participants = state.Participants,
-            GameModel = state.GameModel
+            GameModel = clonedGameModel
         };
 
         return state with
@@ -322,12 +327,12 @@ public static class GameReducers
     [ReducerMethod]
     public static GameState OnUndoThrowSuccess(GameState state, UndoThrowSuccessAction action)
     {
-        // Create snapshot of current state for redo
+        // Create snapshot of current state for redo (deep clone GameModel)
         var currentSnapshot = new GameSnapshot
         {
             ThrowPanel = state.ThrowPanel,
             Participants = state.Participants,
-            GameModel = state.GameModel
+            GameModel = CloneGameModel(state.GameModel)
         };
 
         // Remove the last snapshot from undo stack
@@ -364,12 +369,12 @@ public static class GameReducers
     [ReducerMethod]
     public static GameState OnRedoThrowSuccess(GameState state, RedoThrowSuccessAction action)
     {
-        // Create snapshot of current state for undo
+        // Create snapshot of current state for undo (deep clone GameModel)
         var currentSnapshot = new GameSnapshot
         {
             ThrowPanel = state.ThrowPanel,
             Participants = state.Participants,
-            GameModel = state.GameModel
+            GameModel = CloneGameModel(state.GameModel)
         };
 
         // Remove the last snapshot from redo stack
@@ -508,4 +513,18 @@ public static class GameReducers
         {
             GameModel = action.GameModel
         };
+
+    // Helper Methods
+
+    /// <summary>
+    /// Deep clones a GameModel using JSON serialization.
+    /// </summary>
+    private static object? CloneGameModel(object? gameModel)
+    {
+        if (gameModel == null)
+            return null;
+
+        var json = JsonSerializer.Serialize(gameModel, gameModel.GetType(), GameModelFactory.JsonSerializerOptions);
+        return JsonSerializer.Deserialize(json, gameModel.GetType(), GameModelFactory.JsonSerializerOptions);
+    }
 }