introduced internal chess engine, fixed bugs

app/chess_sim/game_board.py

@@ -153,12 +153,17 @@ class ChessBoard:
         return len(self.move_history) >= 75
     
     def is_fivefold_repetition(self) -> bool:
+        
         return self.highest_repetiton_amount() >= 5
 
     def outcome(self) -> Outcome:
         if self.is_checkmate():
             return Outcome.from_color(self.turn)
-        if self.is_stalemate() or self.is_seventyfive_moves or self.is_fivefold_repetition:
+        if self.is_stalemate():
+            return Outcome.DRAW
+        if self.is_seventyfive_moves():
+            return Outcome.DRAW
+        if self.is_fivefold_repetition():
             return Outcome.DRAW
         return Outcome.NOT_FINISHED
 
@@ -204,7 +209,7 @@ class ChessBoard:
     def init_default(cls) -> "ChessBoard":
         empty_board = [[BoardField() for _ in range(8)] for _ in range(8)]
         brd = cls(
-            empty_board, 0, [], empty_board
+            empty_board, 0, [], copy.deepcopy(empty_board)
         )
 
         # place pawns
@@ -232,8 +237,8 @@ class ChessBoard:
         for col, piece_type in enumerate(back_rank):
             brd.place(7, col, piece_type, Color.WHITE)
 
-        #set the inital board for later ref
-        brd.initial_board = brd.fields
+        # set the initial board for later ref (must be a copy, not a reference)
+        brd.initial_board = copy.deepcopy(brd.fields)
 
         return brd
     
@@ -427,10 +432,15 @@ class ChessBoard:
                     else:
                         # occupied
                         if target_field.piece.color == piece.color:
+                            if non_sliding:
+                                continue
+                            # for sliding pieces a blocker stops further squares
                             break
                         else:
-                            # opponent piece
+                            # opponent piece: capture is allowed
                             moves.append(BoardMove(pos, BoardPos((tr, tc))))
+                            if non_sliding:
+                                continue
                             break
         
         
@@ -739,3 +749,39 @@ class ChessBoard:
         bm = BoardMove(src, dst, move_type, promotion_piece=promo_piece)
         return self.make_move(bm, color)
 
+    def print_legal_moves(self, color: Color) -> None:
+        moves = self.generate_moves(color)
+        
+        if not moves:
+            print(f"{color.name}: no legal moves")
+            return
+        
+        move_strings = []
+        for move in moves:
+            from_sq = self.pos_to_algebraic(move.m_from)
+            to_sq = self.pos_to_algebraic(move.m_to)
+            move_str = f"{from_sq}-{to_sq}"
+            
+            # Add move type notation
+            if move.move_type.name == "CASTLING_KINGSIDE":
+                move_str += " (O-O)"
+            elif move.move_type.name == "CASTLING_QUEENSIDE":
+                move_str += " (O-O-O)"
+            elif move.move_type.name == "EN_PASSANT":
+                move_str += " (e.p.)"
+            elif move.promotion_piece:
+                move_str += f" (={move.promotion_piece.name[0]})"
+            
+            move_strings.append(move_str)
+        
+        print(f"\n{color.name} Legal Moves ({len(moves)} total):")
+        print("-" * 50)
+        
+        # Print in columns (6 moves per row)
+        moves_per_row = 6
+        for i in range(0, len(move_strings), moves_per_row):
+            row = move_strings[i:i + moves_per_row]
+            print("  " + "  |  ".join(f"{m:12}" for m in row))
+        print("-" * 50 + "\n")
+
+