feat: Add PDN copy and load buttons to the UI, update version to 1.5.0

- Added buttons for copying and loading PDN in the index.html template.
- Updated version number in pyproject.toml to 1.5.0.
- Introduced random PDNs for testing in a new JSON file.
- Enhanced test coverage for engine evaluation consistency.
- Added edge case tests for king captures in standard board tests.
- Implemented a script to fetch random PDNs from Lidraughts API.

Author: miskibin

.github/workflows/python-app.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.11"
+          python-version: "3.12"
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
@@ -34,7 +34,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.11"
+          python-version: "3.12"
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip

draughts/boards/base.py

@@ -395,11 +395,43 @@ def pdn(self) -> str:
                 history.append([(idx // 2) + 1, str(move)])
             else:
                 history[-1].append(str(move))
-        return (
-            data
-            + " ".join(f"{h[0]}. {' '.join(str(x) for x in h[1:])}" for h in history)
-            + self.result * (len(self.result) - 1)
-        )
+        moves_str = " ".join(f"{h[0]}. {' '.join(str(x) for x in h[1:])}" for h in history)
+        result_str = "" if self.result == "-" else f" {self.result}"
+        return data + moves_str + result_str
+
+
+    @classmethod
+    def from_pdn(cls: Type[BaseBoard], pdn: str) -> BaseBoard:
+        """
+        Creates a board from a PDN string.
+        """
+        logger.debug(f"Initializing board from PDN:\n{pdn}")
+        re_gametype = re.compile(r'\[GameType\s*"(\d+)"\]')
+        # Match move numbers followed by actual moves (must contain - or x)
+        re_moves = re.compile(r"(\d+)\.\s*(\d+[-x]\d+(?:[-x]\d+)*)(?:\s+(\d+[-x]\d+(?:[-x]\d+)*))?")
+        # Game results that should not be parsed as moves
+        game_results = {"2-0", "0-2", "1-1", "1-0", "0-1", "*"}
+        gametype_match = re_gametype.search(pdn)
+        if not gametype_match:
+            raise ValueError("Invalid PDN: missing GameType")
+        gametype = int(gametype_match.group(1))
+        if gametype != cls.GAME_TYPE:
+            raise ValueError(
+                f"Invalid PDN: expected GameType {cls.GAME_TYPE}, got {gametype}"
+            )
+        board = cls()
+        moves_matches = re_moves.findall(pdn)
+        for match in moves_matches:
+            white_move_str = match[1].strip()
+            if white_move_str in game_results:
+                break
+            board.push_uci(white_move_str)
+            black_move_str = match[2].strip() if match[2] else None
+            if black_move_str:
+                if black_move_str in game_results:
+                    break
+                board.push_uci(black_move_str)
+        return board
 
     @staticmethod
     def is_capture(move: Move) -> bool:

draughts/boards/frisian.py

@@ -127,14 +127,14 @@ def _legal_moves_from(self, square: int | np.intp, is_capture_mandatory=False) -
         return moves
 
     def _get_man_legal_moves_from(
-        self, square: int, is_captrue_mandatory: bool
+        self, square: int | np.intp, is_captrue_mandatory: bool
     ) -> list[Move]:
         # legal_moves  = self.DIAGONAL_SHORT_MOVES +
 
         raise NotImplementedError
 
     def _get_king_legal_moves_from(
-        self, square: int, is_captrue_mandatory: bool
+        self, square: int | np.intp, is_captrue_mandatory: bool
     ) -> list[Move]:
         raise NotImplementedError
 

draughts/boards/standard.py

@@ -183,11 +183,13 @@ def _get_king_legal_moves_from(
                         moves = [m for m in moves if len(m) == max_len]
                         i += 1
                     break
-                if (
-                    self._pos[target] == Figure.EMPTY.value and not is_capture_mandatory
-                ):  # casual move
-                    moves.append(Move([square, target]))
+                if self._pos[target] == Figure.EMPTY.value:
+                    if not is_capture_mandatory:
+                        # casual move - only when not in capture chain
+                        moves.append(Move([square, target]))
+                    # Continue searching for capturable pieces further along diagonal
                 else:
+                    # Any piece (own or enemy without landing space) blocks the path
                     break
         return moves
 
@@ -203,10 +205,17 @@ def _legal_moves_from(self, square: int, is_capture_mandatory=False) -> list[Mov
 
 
 if __name__ == "__main__":
-    board = Board()
-    for i in range(10):
-        # random move
-        move = np.random.choice(list(board.legal_moves))
-        board.push(move)
-
-    print(board.pdn)
+    # board = Board()
+    # for i in range(10):
+    #     # random move
+    #     move = np.random.choice(list(board.legal_moves))
+    #     board.push(move)
+#     pdn = """
+# [GameType \"20\"]\n1. 33-28 18-23 2. 39-33 13-18 3. 44-39 18-22 4. 31-27 22x31 5. 36x27 8-13 6. 50-44 2-8 7. 41-36 20-24 8. 34-29 23x34 9. 40x20 14x25 10. 46-41 10-14 11. 44-40 5-10 12. 39-34 17-21 13. 43-39 21-26 14. 49-43 12-17 15. 27-21 16x27 16. 32x12 7x18 17. 37-32 11-16 18. 41-37 1-7 19. 37-31 26x37 20. 42x31 7-11 21. 31-27 14-20 22. 47-42 10-14 23. 42-37 20-24 24. 27-21 16x27 25. 32x21 8-12 26. 21-16 3-8 27. 16x7 12x1 28. 37-32 8-12 29. 28-23 19x37 30. 34-30 25x34 31. 39x17 14-19 32. 43-39 1-7 33. 38-32 37x28 34. 33x24 9-13 35. 40-34 4-9 36. 34-30 9-14 37. 30-25 13-18 38. 17-12 18-22 39. 12x1 22-27 40. 48-42 6-11 41. 1-23 11-17 42. 23x5 17-21 43. 5-37 21-26 44. 39-34 15-20 45. 24x15 26-31 46. 37x26 27-32 47. 42-37 32x41 48. 36x47 2-0
+#     """
+#     board = Board.from_pdn(pdn)
+
+#     print(board.pdn)
+    board = Board.from_fen('[FEN "W:B:WK2,28,31,44:B20,K50"])')
+    print(board)
+    print(board.legal_moves)

draughts/server/server.py

@@ -51,11 +51,21 @@ def __init__(
             "/move/{source}/{target}", self.move, methods=["POST"]
         )
         self.router.add_api_route("/pop", self.pop, methods=["GET"])
+        self.router.add_api_route("/pdn", self.get_pdn, methods=["GET"])
+        self.router.add_api_route("/load_pdn", self.load_pdn, methods=["POST"])
         self.APP.include_router(self.router)
 
     def get_fen(self):
         return {"fen": self.board.fen}
 
+    def get_pdn(self):
+        return {"pdn": self.board.pdn}
+
+    async def load_pdn(self, request: Request) -> PositionResponse:
+        data = await request.json()
+        self.board = type(self.board).from_pdn(data["pdn"])
+        return self.position_json
+
     def set_board(self, request: Request, board_type: Literal["standard", "american"]):
         if board_type == "standard":
             from draughts import StandardBoard

draughts/server/static/js/script.js

@@ -4,8 +4,8 @@
 
 // Piece colors
 const COLORS = {
-    1: '#f0f0f0', '-1': '#1a1a1a',
-    2: '#f0f0f0', '-2': '#1a1a1a'
+    1: '#1a1a1a', '-1': '#f0f0f0',
+    2: '#1a1a1a', '-2': '#f0f0f0'
 };
 
 // Game state
@@ -46,8 +46,8 @@ function updateBoard() {
         if (piece !== 0) {
             $tile.append(`<div class="piece" style="background:${COLORS[piece]}"></div>`);
             if (Math.abs(piece) > 1) {
-                const isBlack = piece < 0;
-                $tile.append(`<img src="${crownIcon}" class="crown ${isBlack ? 'crown-light' : ''}" alt="K">`);
+                const isWhite = piece > 0;
+                $tile.append(`<img src="${crownIcon}" class="crown ${isWhite ? 'crown-light' : ''}" alt="K">`);
             }
         }
     });
@@ -149,6 +149,23 @@ async function copyFen() {
     notify('Copied', data.fen, 'success');
 }
 
+async function copyPdn() {
+    const data = await api.get('/pdn');
+    navigator.clipboard.writeText(data.pdn);
+    notify('Copied', 'PDN copied to clipboard', 'success');
+}
+
+async function loadPdn() {
+    const pdn = prompt('Paste PDN:');
+    if (!pdn) return;
+    try {
+        const data = await $.ajax({ url: '/load_pdn', method: 'POST', contentType: 'application/json', data: JSON.stringify({ pdn }) });
+        board = data.position; history = data.history; turn = data.turn;
+        updateBoard();
+        notify('Loaded', 'PDN loaded', 'success');
+    } catch { notify('Error', 'Invalid PDN', 'error'); }
+}
+
 function toggleAutoPlay() {
     const $btn = $('#autoPlay');
     if (autoPlayId) {
@@ -171,5 +188,7 @@ $(async () => {
     $('#popBtn').on('click', undo);
     $('#randomPos').on('click', randomPosition);
     $('#copyFen').on('click', copyFen);
+    $('#copyPdn').on('click', copyPdn);
+    $('#loadPdn').on('click', loadPdn);
     $('#autoPlay').on('click', toggleAutoPlay);
 });

draughts/server/templates/index.html

@@ -47,6 +47,14 @@
               <i class="bi bi-clipboard"></i>
               Copy FEN
             </button>
+            <button id="copyPdn" class="btn btn-game" type="button">
+              <i class="bi bi-file-text"></i>
+              Copy PDN
+            </button>
+            <button id="loadPdn" class="btn btn-game" type="button">
+              <i class="bi bi-upload"></i>
+              Load PDN
+            </button>
             <button id="autoPlay" class="btn btn-game" type="button">
               <i class="bi bi-play-fill"></i>
               Auto Play

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "py-draughts"
-version = "1.4.2"
+version = "1.5.0"
 description = "A draughts library with advanced (customizable) WEB UI move generation and validation, PDN parsing and writing. Supports multiple variants of game."
 readme = "readme.md"
 license = {file = "LICENSE"}