Update difficulty levels in ChessEngine

Added a new difficulty level and adjusted the ranking of the "Unbeatable" level. Changes also include a minor adjustment in the calculation of the depth variable for the GetBestMove function. Comments with the old difficulty levels have been removed from both the ChessEngine service and the _Layout view.

src/Aiursoft.ChessServer/Services/ChessEngine.cs

@@ -28,25 +28,19 @@ public class ChessEngine
             4 => "Hard",
             5 => "Brutal",
             6 => "Grandmaster",
-            7 => "Unbeatable",
+            7 => "Torture",
+            8 => "Unbeatable",
             _ => "Unknown"
         };
     }
 
     public string GetBestMove(string fen, int difficulty)
-        // 1: Chimpanzee
-        // 2: Easy
-        // 3: Intermediate
-        // 4: Hard
-        // 5: Brutal
-        // 6: Grandmaster
-        // 7: Unbeatable
     {
         _engine.AdjustPosition($"position fen {fen}");
         var positionClone = new Position(_engine.Game.CurrentPosition);
 
         // Depth = difficulty, 50% of chance to be difficulty + 1
-        var depth = difficulty + (new Random().Next(2) == 0 ? 1 : 0);
+        var depth = difficulty - 1 + (new Random().Next(2) == 0 ? 1 : 0);
         var result = _engine.IDDFS(depth, 10);
         _engine.Game.ResetCurrentPositionToBeforeSearchState();
 

src/Aiursoft.ChessServer/Views/Shared/_Layout.cshtml

@@ -79,20 +79,14 @@
                 </button>
             </div>
             <div class="modal-body">
-                @* // 1: Chimpanzee *@
-                @* // 2: Easy *@
-                @* // 3: Intermediate *@
-                @* // 4: Hard *@
-                @* // 5: Brutal *@
-                @* // 6: Grandmaster *@
-                @* // 7: Unbeatable *@
                 <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="1">Chimpanzee</a>
                 <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="2">Easy</a>
                 <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="3">Intermediate</a>
                 <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="4">Hard</a>
                 <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="5">Brutal</a>
                 <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="6">Grandmaster</a>
-                <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="7">Unbeatable</a>
+                <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="7">Torture</a>
+                <a class="btn btn-secondary btn-block btn-difficulty" asp-controller="Pve" asp-action="New" asp-route-difficulty="8">Unbeatable</a>
             </div>
             <div class="modal-footer">
                 <button class="btn btn-secondary" type="button" data-dismiss="modal">Close</button>