Enable to retreive SAN move

src/Board.cpp

@@ -83,6 +83,20 @@ void Board::Move(std::string move) {
   }
 }
 
+bool Board::IsPieceMoveUnique(char piece, std::string move_dst) {
+  bool isBlack = std::islower(piece);
+  unsigned char count = 0;
+  for (std::string &move : ListPossibleMoves(isBlack)) {
+    std::string src = move.substr(0, 2);
+    std::string dst = move.substr(2, 2);
+    Piece p = GetPieceAt(src); // Never fails since it is legal
+    if (p.piece == piece && move_dst == dst) {
+      count++;
+    }
+  }
+  return (count <= 1);
+}
+
 std::string Board::Serialize() {
   std::string s;
   for (short i = 0; i < 8; i++) {

src/Board.hpp

@@ -22,6 +22,8 @@ public:
   std::vector<Piece> GetPlayerPieces(bool);
   /// @brief Count the number of a specific piece on the board
   short CountPiece(char);
+  /// @brief Return true if at most 1 similar piece can go to move_dst
+  bool IsPieceMoveUnique(char piece, std::string move_dst);
   /// @brief Get the location of the first king found on the board
   std::string GetKingLocation(bool);
   /// @brief Check if a move is technically possible (does not means it is

src/ChessArbiter.cpp

@@ -2,7 +2,8 @@
 
 namespace chessarbiter {
 ChessArbiter::ChessArbiter()
-    : wPawn(1), wRook(5), wKnight(3), wBishop(3), wQueen(9), wKing(0) {}
+    : wPawn(1), wRook(5), wKnight(3), wBishop(3), wQueen(9), wKing(0), SAN("") {
+}
 
 void ChessArbiter::Setup(std::string fen) {
   positions.clear();
@@ -45,6 +46,8 @@ bool ChessArbiter::Play(std::string move) {
     std::string dst = move.substr(2, 2);
     bool IsCapture = !board.IsEmpty(dst);
     FEN newFen = fen;
+    SAN_last = SAN;
+    SAN = "";
 
     // Perform the move
     if (move == "O-O" || move == "O-O-O") {
@@ -61,7 +64,31 @@ bool ChessArbiter::Play(std::string move) {
         board.Move("e1c1");
         board.Move("a1d1");
       }
+      SAN = move;
     } else {
+      // Update SAN move
+      if (moved.piece == 'p' || moved.piece == 'P') {
+        if (IsCapture) {
+          SAN = src[0];
+          SAN += "x" + dst;
+        } else {
+          SAN = dst;
+        }
+      } else {
+        SAN = std::toupper(moved.piece);
+        if (!board.IsPieceMoveUnique(moved.piece, dst)) {
+          if (src[0] == dst[0]) {
+            SAN += src[1];
+          } else {
+            SAN += src[0];
+          }
+        }
+        if (IsCapture) {
+          SAN += "x";
+        }
+        SAN += dst;
+      }
+      // Perform the move
       board.Move(move);
     }
 
@@ -113,6 +140,7 @@ bool ChessArbiter::Play(std::string move) {
     // Check for illegal move
     if (IsCheck(!fen.player)) {
       SetFEN(fen_last);
+      SAN = SAN_last;
       return (false);
     }
 
@@ -309,6 +337,7 @@ bool ChessArbiter::IsDrawByNoMoves() {
       if (Play(move)) {
         positions[fen.board]--; // If move work, remove its position
         SetFEN(fen_last);
+        SAN = SAN_last;
         return (false);
       }
     }
@@ -338,6 +367,7 @@ bool ChessArbiter::IsCheckMate() {
       if (Play(move)) {
         positions[fen.board]--; // If move work, remove its position
         SetFEN(fen_last);
+        SAN = SAN_last;
         return (false);
       }
     }
@@ -346,4 +376,6 @@ bool ChessArbiter::IsCheckMate() {
   return (false);
 }
 
+std::string ChessArbiter::GetSAN() { return (SAN); }
+
 } // namespace chessarbiter

src/ChessArbiter.hpp

@@ -15,7 +15,7 @@ class ChessArbiter {
   /// @brief FEN methods used internally
   void SetFEN(std::string);
   void SetFEN(FEN);
-
+  std::string SAN,SAN_last;
 public:
   ChessArbiter();
   void Setup(std::string);
@@ -36,6 +36,8 @@ public:
   bool IsPlayable();
   /// @brief Get pieces captures by a player
   std::string GetCaptures(bool);
+  /// @brief Get the english SAN format of the last move
+  std::string GetSAN();
   /// @brief List all the legal moves of a player
   std::vector<std::string> ListLegalMoves(bool);
   /// @brief Check if a specific castle is possible by a player

tests/board.cpp

@@ -416,3 +416,15 @@ TEST_CASE("Serialize", "[board/Serialize]") {
                          "P       ");
 }
 
+TEST_CASE("IsPieceMoveUnique", "[board/IsPieceMoveUnique]") {
+  Board b;
+  b.AddPiece('N', "a1");
+  b.AddPiece('n', "c1");
+
+  CHECK(b.IsPieceMoveUnique('n', "b3"));
+  CHECK(b.IsPieceMoveUnique('N', "b3"));
+
+  b.AddPiece('N', "d2");
+  CHECK(b.IsPieceMoveUnique('n', "b3"));
+  CHECK_FALSE(b.IsPieceMoveUnique('N', "b3"));
+}