[#27] check

CodersCampTeam · Feb 12, 2021 · 7ed17fb · 7ed17fb
1 parent d126468
commit 7ed17fb
Show file tree

Hide file tree

Showing 3 changed files with 66 additions and 11 deletions.
diff --git a/src/services/game-logic/Board.ts b/src/services/game-logic/Board.ts
@@ -11,7 +11,7 @@ import { Queen } from './pieces/Queen';
 class Board {
     public static BOARD_SIZE = 8;
 
-    private state: Array<Array<Piece | null>>;
+    public state: Array<Array<Piece | null>>;
 
     constructor() {
         this.state = new Array(Board.BOARD_SIZE);
@@ -26,6 +26,14 @@ class Board {
         return this.state[row][column];
     }
 
+    public checkAllSquares = (f: any) => {
+        this.state.forEach((row) => {
+            row.forEach((square) => {
+                f(square);
+            });
+        });
+    };
+
     public movePiece(location: Square, destination: Square): void {
         this.state[location.row][location.column]?.move(destination);
         this.state[destination.row][destination.column] = this.state[location.row][location.column];

diff --git a/src/services/game-logic/GameEngine.ts b/src/services/game-logic/GameEngine.ts
@@ -1,6 +1,7 @@
-import { PieceNames, Constants } from '../../enums';
+import { PieceNames, Constants, Colors } from '../../enums';
 import { Square } from '../../models/Square';
 import { Board } from './Board';
+import { King } from './pieces/King';
 import { Piece } from './pieces/Piece';
 
 class GameEngine {
@@ -12,13 +13,63 @@ class GameEngine {
 
     getLegalMoves = (square: Square): Square[] => {
         const piece = this.board.getPiece(square);
-        let legalMoves = piece?.getPossibleMoves(this.board).filter(this.isOnBoard) ?? [];
+        let legalMoves = piece?.getPossibleMoves(this.board) ?? [];
         if (piece?.name === PieceNames.KING) {
             legalMoves = legalMoves.filter(
                 (move) => !this.isCastling(move, piece) || this.isCastlingLegal(move, piece)
             );
         }
-        return legalMoves.filter((destination) => !this.isOccupiedBySameColor(destination, piece));
+        return legalMoves
+            .filter((destination) => !this.isOccupiedBySameColor(destination, piece))
+            .filter((move) => this.removeMovesIfCheck(move, piece, square));
+    };
+
+    private removeMovesIfCheck(move: Square, piece: Piece | null, square: Square) {
+        let potentialMove: Square = { row: move.row, column: move.column };
+        let potentialPiece = this.board.getPiece(potentialMove);
+
+        this.movePiece(square, potentialMove);
+        piece!.hasMoved = true;
+        let isMovePossible = !this.isCheck(piece);
+
+        this.movePiece(potentialMove, square);
+        piece!.hasMoved = false;
+
+        if (potentialPiece)
+            this.board.state[potentialPiece.position.row][potentialPiece.position.column] = potentialPiece;
+
+        return isMovePossible;
+    }
+
+    private isCheck(piece: Piece | null): Boolean {
+        const color = piece?.color === Colors.BLACK ? Colors.WHITE : Colors.BLACK;
+        let currentPlayerKing: Square | undefined = this.getKingForCheck(piece)?.position;
+        const isChecked = this.findOponentLegalMoves(color, currentPlayerKing);
+        return isChecked;
+    }
+
+    findOponentLegalMoves(color: Colors, piecePosition: Square | undefined): boolean {
+        let checked: boolean[] = [];
+        this.board.checkAllSquares((square: Piece) => {
+            if (square && square.color === color) {
+                square
+                    .getPossibleMoves(this.board)
+                    .forEach((move) =>
+                        move.row === piecePosition?.row && move.column === piecePosition.column
+                            ? checked.push(true)
+                            : checked.push(false)
+                    );
+            }
+        });
+        return checked.some((element) => element);
+    }
+
+    getKingForCheck = (piece: Piece | null): King | null => {
+        let king = null;
+        this.board.checkAllSquares((square: Piece) => {
+            if (square && square?.color === piece?.color && square.name === PieceNames.KING) king = square;
+        });
+        return king;
     };
 
     public movePiece(location: Square, destination: Square): void {
@@ -69,12 +120,7 @@ class GameEngine {
         return this.getLegalMoves(from).some(({ row, column }) => row === to.row && column === to.column);
     }; // might be useful for 'check'
 
-    private isOnBoard = (square: Square): boolean => {
-        // here or in knight.ts (for now knights can get outside the board)
-        return square.row >= 0 && square.row < 8 && square.column >= 0 && square.column < 8;
-    };
-
-    private isOccupiedBySameColor = (square: Square, piece: Piece | null): boolean =>
+    public isOccupiedBySameColor = (square: Square, piece: Piece | null): boolean =>
         this.board.getPiece(square)?.color === piece?.color;
 }
 

diff --git a/src/services/game-logic/pieces/Knight.ts b/src/services/game-logic/pieces/Knight.ts
@@ -16,7 +16,8 @@ class Knight extends Piece {
             destination.push(new Square(row + possibleRowMoves[i], column + possibleColumnMoves[i]));
         }
 
-        return destination;
+        const knightPossibleMoves = destination.filter((d) => d.row >= 0 && d.row < 8 && d.column >= 0 && d.column < 8);
+        return knightPossibleMoves;
     }
 }