merge {dudecon:Human-Undo}: Fix for SebLague#305

Author: VitorA29

Chess-Challenge/src/Framework/Application/Core/ChallengeController.cs

@@ -8,6 +8,7 @@
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Collections.Generic;
 using static ChessChallenge.Application.Settings;
 using static ChessChallenge.Application.ConsoleHelper;
 
@@ -84,6 +85,22 @@ public ChallengeController()
             StartNewGame(PlayerType.Human, PlayerType.MyBot);
         }
 
+        public void UndoMoves(uint numToUndo)
+        {
+            List<Move> allMoves = board.AllGameMoves;
+            numToUndo = Math.Min((uint)allMoves.Count, numToUndo);
+
+            for (int i = 0; i < numToUndo; i++)
+            {
+                Move moveToUndo = allMoves.Last();
+                board.UndoMove(moveToUndo, false);
+            }
+
+            var lastMove = (allMoves.Count == 0) ? new Move(0) : allMoves.Last() ;
+            boardUI.UpdatePosition(board, lastMove);
+            NotifyTurnToMove();
+        }
+
         public void StartNewGame(PlayerType whiteType, PlayerType blackType)
         {
             // End any ongoing game
@@ -180,6 +197,12 @@ void NotifyTurnToMove()
             {
                 PlayerToMove.Human.SetPosition(FenUtility.CurrentFen(board));
                 PlayerToMove.Human.NotifyTurnToMove();
+
+                if (PlayerNotOnMove.IsHuman)
+                {
+                    // for the case of a human vs human match when a manual undo fires
+                    PlayerNotOnMove.Human.CancelTurnToMove();
+                }
             }
             else
             {

Chess-Challenge/src/Framework/Application/Players/HumanPlayer.cs

@@ -28,6 +28,11 @@ public void NotifyTurnToMove()
         {
             isTurnToMove = true;
         }
+        
+        public void CancelTurnToMove()
+        {
+            isTurnToMove = false;
+        }
 
         public void SetPosition(string fen)
         {

Chess-Challenge/src/Framework/Application/UI/MenuUI.cs

@@ -9,12 +9,31 @@ public static class MenuUI
     {
         public static void DrawButtons(ChallengeController controller)
         {
-            Vector2 buttonPos = UIHelper.Scale(new Vector2(260, 210));
+            Vector2 buttonPos = UIHelper.Scale(new Vector2(260, 144));
             Vector2 buttonSize = UIHelper.Scale(new Vector2(260, 55));
             float spacing = buttonSize.Y * 1.2f;
             float breakSpacing = spacing * 0.6f;
 
+            // Undo Button
+            if (controller.PlayerWhite.IsHuman || controller.PlayerBlack.IsHuman)
+            {
+                var undoNum = (controller.PlayerWhite.IsBot || controller.PlayerBlack.IsBot) ? 2 : 1 ;
+                if (NextButtonInRow("Undo Move", ref buttonPos, spacing, buttonSize))
+                {
+                    controller.UndoMoves((uint)undoNum);
+                }
+            } else {
+                buttonPos = UIHelper.Scale(new Vector2(260, 210));
+            }
+            
+
             // Game Buttons
+            buttonPos.Y += breakSpacing;
+
+            if (NextButtonInRow("Human vs Human", ref buttonPos, spacing, buttonSize))
+            {
+                controller.StartNewGame(ChallengeController.PlayerType.Human, ChallengeController.PlayerType.Human);
+            }
             if (NextButtonInRow("Human vs MyBot", ref buttonPos, spacing, buttonSize))
             {
                 var whiteType = controller.HumanWasWhiteLastGame ? ChallengeController.PlayerType.MyBot : ChallengeController.PlayerType.Human;