implemented checkmate

src/controller/controller.py

@@ -55,3 +55,9 @@ class Controller:
             else:
                 move = legal_moves_positions[0]
                 self._make_move(move)
+
+        if self._board.is_checkmate_for(self._board._turn):
+            self._view.notify_checkmate(self._board._turn)
+            
+        if self._board.is_stalemate_for(self._board._turn):
+            self._view.notify_stalemate(self._board._turn)

src/logic/board.py

@@ -131,11 +131,27 @@ class Board:
                         if Position.is_within_bounds(x, y):
                             possible_pos.append(Position(x, y))
             else:
-                possible_pos += [move.pos for move in piece.legal_moves(self)]
+                possible_pos += [move.pos for move in piece.legal_moves(self, looking_for_check=True)]
             if king.pos in possible_pos:
                 return True
         return False
 
+    def is_checkmate_for(self, colour: Colour) -> bool:
+        """ Is it checkmate for the defending colour passed as parameter """
+        return self.is_check_for(colour) and self._no_legal_moves_for(colour)
+
+    def is_stalemate_for(self, colour: Colour) -> bool:
+        """ Is it stalemate for the defending colour passed as parameter """
+        return not self.is_check_for(colour) and self._no_legal_moves_for(colour)
+
+    def _no_legal_moves_for(self, colour: Colour) -> bool:
+        """ Return true if there are indeed no legal moves for the given colour (for checkmate or stalemate)"""
+        pieces = self._white if colour == Colour.WHITE else self._black
+        for piece in pieces.values():
+            if len(piece.legal_moves(self)) > 0:
+                return False
+        return True
+
     def castling_writes_for(self, colour: Colour) -> set[CastleSide]:
         return self._white_castling_write if colour == Colour.WHITE else self._black_castling_write
 

src/logic/pieces/bishop.py

@@ -2,7 +2,7 @@ from logic.move import Move
 from .piece import Piece
 
 class Bishop(Piece):
-    def legal_moves(self, board: "Board") -> list[Move]:
+    def legal_moves(self, board: "Board", / , looking_for_check = False) -> list[Move]:
         ret = []
 
         # looking north east
@@ -17,5 +17,8 @@ class Bishop(Piece):
         # looking north west
         ret.extend(self._look_direction(board, -1, 1))
 
+        if not looking_for_check and board.is_check_for(self.colour):
+            return self.keep_only_blocking(ret, board)
+
         return ret
 

src/logic/pieces/king.py

@@ -19,11 +19,13 @@ class King(Piece):
                     if not board_after_move.is_check_for(self.colour):
                         ret.append(move)
 
+        if board.is_check_for(self.colour):
+            return self.keep_only_blocking(ret, board)
+
         # -- Castles
         castling_writes = board.castling_writes_for(self.colour)
         if len(castling_writes) == 0:
             return ret
-        print(castling_writes)
 
         if CastleSide.King in castling_writes:
             clear = True
@@ -62,8 +64,6 @@ class King(Piece):
             if clear:
                 ret.append(Move(self, Position(2, self.pos.y), castle_side=CastleSide.Queen))
 
-        print(ret)
-
         return ret
 
 

src/logic/pieces/knight.py

@@ -4,7 +4,7 @@ class Knight(Piece):
     def letter(self):
         return "n"
 
-    def legal_moves(self, board: "Board") -> list["Move"]:
+    def legal_moves(self, board: "Board", / , looking_for_check = False) -> list["Move"]:
         ret = []
         for dx, dy in [
             (+2, +1), (+1, +2), # north east
@@ -15,5 +15,9 @@ class Knight(Piece):
             move = self._move_for_position(board, self.pos.x + dx, self.pos.y + dy)
             if move is not None:
                 ret.append(move)
+
+        if not looking_for_check and board.is_check_for(self.colour):
+            return self.keep_only_blocking(ret, board)
+
         return ret
 

src/logic/pieces/pawn.py

@@ -3,7 +3,7 @@ from logic.pieces.piece import Colour, Piece
 from logic.position import Position
 
 class Pawn(Piece):
-    def legal_moves(self, board) -> list[Move]:
+    def legal_moves(self, board, / , looking_for_check = False) -> list[Move]:
         ret = []
 
         # can we capture to the left?
@@ -37,4 +37,7 @@ class Pawn(Piece):
                 pos = Position(self.pos.x, self.pos.y - dy)
                 ret.append(Move(self, pos))
 
+        if not looking_for_check and board.is_check_for(self.colour):
+            return self.keep_only_blocking(ret, board)
+
         return ret

src/logic/pieces/piece.py

@@ -7,6 +7,9 @@ class Colour(Enum):
     WHITE = "white"
     BLACK = "black"
 
+    def __str__(self) -> str:
+        return self.value
+
 class Piece:
     def __init__(self, pos: Position, colour: Colour) -> None:
         self.pos = pos
@@ -16,6 +19,14 @@ class Piece:
     def letter(self):
         return type(self).__name__[0].lower()
 
+    def keep_only_blocking(self, candidates: list[Move], board: "Board") -> list[Move]:
+        ret = []
+        for move in candidates:
+            board_after_move = board.make_move(move)
+            if not board_after_move.is_check_for(self.colour):
+                ret.append(move)
+        return ret
+
     def _look_direction(self, board: "Board", mult_dx: int, mult_dy: int):
         ret = []
         for d in range(1, 8):
@@ -50,5 +61,5 @@ class Piece:
         ret = type(self)(pos, self.colour)
         return ret
 
-    def legal_moves(self, board: "Board") -> list["Move"]:
+    def legal_moves(self, board: "Board", / , looking_for_check = False) -> list["Move"]:
         raise NotImplementedError(f"Can't say what the legal moves are for {type(self).__name__}, the method hasn't been implemented yet")

src/logic/pieces/queen.py

@@ -2,7 +2,7 @@ from logic.move import Move
 from .piece import Piece
 
 class Queen(Piece):
-    def legal_moves(self, board: "Board") -> list[Move]:
+    def legal_moves(self, board: "Board", / , looking_for_check = False) -> list[Move]:
         ret = []
 
         # looking north east
@@ -29,4 +29,7 @@ class Queen(Piece):
         # looking north
         ret.extend(self._look_direction(board, 0, 1))
 
+        if not looking_for_check and board.is_check_for(self.colour):
+            return self.keep_only_blocking(ret, board)
+
         return ret

src/logic/pieces/rook.py

@@ -2,7 +2,7 @@ from logic.move import Move
 from .piece import Piece
 
 class Rook(Piece):
-    def legal_moves(self, board: "Board") -> list[Move]:
+    def legal_moves(self, board: "Board", / , looking_for_check = False) -> list[Move]:
         ret = []
 
         # looking east
@@ -17,4 +17,7 @@ class Rook(Piece):
         # looking north
         ret.extend(self._look_direction(board, 0, 1))
 
+        if not looking_for_check and board.is_check_for(self.colour):
+            return self.keep_only_blocking(ret, board)
+
         return ret

src/view/gui.py

@@ -1,4 +1,5 @@
 import tkinter as tk
+from tkinter import messagebox
 from typing import Type
 from PIL import ImageTk, Image
 import os
@@ -60,6 +61,12 @@ class GUI(View):
 
         self._controller.on_tile_selected(x, y)
 
+    def notify_checkmate(self, colour: Colour) -> None:
+        messagebox.showinfo("Checkmate",  f"{colour} is currently checkmated") 
+        
+    def notify_stalemate(self, colour: Colour) -> None:
+        messagebox.showinfo("Stalemate",  f"{colour} is currently stalemated") 
+        
 
     def update_board(self, board: Board, selected_piece: Piece, legal_moves: list[Move]) -> None:
         self.canvas.delete("all")

src/view/view.py

@@ -1,6 +1,6 @@
 from logic.board import Board
 from logic.move import Move
-from logic.pieces.piece import Piece
+from logic.pieces.piece import Colour, Piece
 
 
 class View:
@@ -13,6 +13,12 @@ class View:
     def update_board(self, board: Board, selected_piece: Piece, legal_moves: list[Move]) -> None:
         raise NotImplementedError(f"Can't update the board, the update_board() method of {type(self)} is not implemented")
 
+    def notify_checkmate(self, colour: Colour) -> None:
+        raise NotImplementedError(f"Can't notify of the checkmate, the notify_checkmate() method of {type(self)} is not implemented")
+
+    def notify_stalemate(self, colour: Colour) -> None:
+        raise NotImplementedError(f"Can't notify of the stalemate, the notify_stalemate() method of {type(self)} is not implemented")
+
     def set_controller(self, controller: "Controller") -> None:
         self._controller = controller