Move from the hand.

Shogi.UI/Pages/Home/GameBoard/SeatedGameBoard.razor

@@ -9,7 +9,9 @@
                        Perspective="Perspective"
                        OnClickHand="OnClickHand"
                        OnClickTile="OnClickTile"
-                       SelectedPosition="@selectedBoardPosition" />
+                       SelectedPosition="@selectedBoardPosition"
+                       SelectedPieceFromHand="@selectedPieceFromHand"
+                       IsMyTurn="IsMyTurn" />
 
 @code {
     [Parameter, EditorRequired]
@@ -23,6 +25,8 @@
     protected override void OnParametersSet()
     {
         base.OnParametersSet();
+        selectedBoardPosition = null;
+        selectedPieceFromHand = null;
         if (Session == null)
         {
             throw new ArgumentException($"{nameof(Session)} cannot be null.", nameof(Session));
@@ -42,51 +46,77 @@
         return false;
     }
 
-    async Task OnClickTile(Piece? piece, string position)
+    async Task OnClickTile(Piece? pieceAtPosition, string position)
     {
-        Console.WriteLine("Is my turn?");
-        Console.WriteLine(true);
         if (!IsMyTurn) return;
 
-        if (selectedBoardPosition == null || piece?.Owner == Perspective)
-        {
-            // Select a position.
-            Console.WriteLine("Position {0}", position);
-            selectedBoardPosition = position;
-            StateHasChanged();
-            return;
-        }
+
         if (selectedBoardPosition == position)
         {
             // Deselect the selected position.
             selectedBoardPosition = null;
+            StateHasChanged();
             return;
         }
-        if (piece == null)
+
+        if (selectedBoardPosition == null && pieceAtPosition?.Owner == Perspective)
         {
-            if (ShouldPromptForPromotion(position) || ShouldPromptForPromotion(selectedBoardPosition))
+            // Select an owned piece.
+            Console.WriteLine("Selecting piece owned by {0} while I am perspective {1}", pieceAtPosition?.Owner, Perspective);
+            selectedBoardPosition = position;
+            // Prevent selecting pieces from the hand and board at the same time.
+            selectedPieceFromHand = null;
+            StateHasChanged();
+            return;
+        }
+
+        if (selectedPieceFromHand is not null)
+        {
+            if (pieceAtPosition is null)
             {
-                PromotePrompt.Show(Session.SessionName, new MovePieceCommand
-                    {
-                        From = selectedBoardPosition,
-                        To = position
-                    });
+                Console.WriteLine("Moving piece from hand.");
+                // Placing a piece from the hand to an empty space.
+                // await ShogiApi.Move(
+                //  Session.SessionName,
+                // new MovePieceCommand(selectedPieceFromHand.Value, position));
             }
-            else
+            StateHasChanged();
+            return;
+        }
+
+        if (selectedBoardPosition != null)
+        {
+            if (pieceAtPosition == null || pieceAtPosition?.Owner != Perspective)
             {
-                await ShogiApi.Move(Session.SessionName, new MovePieceCommand
-                    {
-                        From = selectedBoardPosition,
-                        IsPromotion = false,
-                        To = position
-                    });
+                // Moving to an empty space or capturing an opponent's piece.
+                if (ShouldPromptForPromotion(position) || ShouldPromptForPromotion(selectedBoardPosition))
+                {
+                    PromotePrompt.Show(
+                        Session.SessionName,
+                        new MovePieceCommand(selectedBoardPosition, position, false));
+                }
+                else
+                {
+                    await ShogiApi.Move(Session.SessionName, new MovePieceCommand(selectedBoardPosition, position, false));
+                }
+                StateHasChanged();
+                return;
             }
         }
     }
 
     async Task OnClickHand(Piece piece)
     {
-        selectedPieceFromHand = piece.WhichPiece;
-        await Task.CompletedTask;
+        if (!IsMyTurn) return;
+
+        // Prevent selecting from both the hand and the board.
+        selectedBoardPosition = null;
+
+        selectedPieceFromHand = piece.WhichPiece == selectedPieceFromHand
+            // Deselecting the already-selected piece
+            ? selectedPieceFromHand = null
+            : selectedPieceFromHand = piece.WhichPiece;
+
+        StateHasChanged();
     }
 }