From e5a124d1935137f0777d50b7c1f4455699f88d2f Mon Sep 17 00:00:00 2001
From: "A.M. Rowsell" <amrowsell@frozenelectronics.ca>
Date: Sat, 30 Aug 2025 18:45:04 -0400
Subject: [PATCH] FEN: major portion of FEN import is working and tested

---
 Board.cpp | 57 +++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 49 insertions(+), 8 deletions(-)

diff --git a/Board.cpp b/Board.cpp
index 68f61bf..86cf960 100644
--- a/Board.cpp
+++ b/Board.cpp
@@ -97,6 +97,7 @@ int Board::setupFromFEN(std::string strFEN) {
     std::vector<std::string> splitField1 = split(splitFEN[0], '/');
     int rank = 0, file = 0;
     int skip = 0;
+    Square whiteKing, blackKing;
     bool wKingPlaced = false, bKingPlaced = false;
     for(auto &ranks : splitField1) {
         for(auto &sym : ranks) {
@@ -104,34 +105,42 @@ int Board::setupFromFEN(std::string strFEN) {
                 case 'R':
                     // white rook
                     boardGrid[rank][file] = std::make_unique<Rook>(PIECE_WHITE);
+                    file++;
                     break;
                 case 'r':
                     // black rook
                     boardGrid[rank][file] = std::make_unique<Rook>(PIECE_BLACK);
+                    file++;
                     break;
                 case 'N':
                     // white knight
                     boardGrid[rank][file] = std::make_unique<Knight>(PIECE_WHITE);
+                    file++;
                     break;
                 case 'n':
                     // black knight
                     boardGrid[rank][file] = std::make_unique<Knight>(PIECE_BLACK);
+                    file++;
                     break;
                 case 'B':
                     // white bishop
                     boardGrid[rank][file] = std::make_unique<Bishop>(PIECE_WHITE);
+                    file++;
                     break;
                 case 'b':
                     // black bishop
                     boardGrid[rank][file] = std::make_unique<Bishop>(PIECE_BLACK);
+                    file++;
                     break;
                 case 'Q':
                     // white queen
                     boardGrid[rank][file] = std::make_unique<Queen>(PIECE_WHITE);
+                    file++;
                     break;
                 case 'q':
                     // black queen;
                     boardGrid[rank][file] = std::make_unique<Queen>(PIECE_BLACK);
+                    file++;
                     break;
                 case 'K':
                     // white king
@@ -141,6 +150,10 @@ int Board::setupFromFEN(std::string strFEN) {
                     } else {
                         boardGrid[rank][file] = std::make_unique<King>(PIECE_WHITE);
                         wKingPlaced = true;
+                        // store king position for later
+                        whiteKing.file = file;
+                        whiteKing.rank = rank;
+                        file++;
                     }
                     break;
                 case 'k':
@@ -151,15 +164,21 @@ int Board::setupFromFEN(std::string strFEN) {
                     } else {
                         boardGrid[rank][file] = std::make_unique<King>(PIECE_BLACK);
                         bKingPlaced = true;
+                        // store king position for later
+                        blackKing.file = file;
+                        blackKing.rank = rank;
+                        file++;
                     }
                     break;
                 case 'P':
                     // white pawn
                     boardGrid[rank][file] = std::make_unique<Pawn>(PIECE_WHITE);
+                    file++;
                     break;
                 case 'p':
                     // black pawn
                     boardGrid[rank][file] = std::make_unique<Pawn>(PIECE_BLACK);
+                    file++;
                     break;
                 case '1':
                 case '2':
@@ -171,11 +190,10 @@ int Board::setupFromFEN(std::string strFEN) {
                 case '8': {
                     std::string skipStr(1, sym);
                     skip = atoi(skipStr.c_str());
-                    skip--; // fix off by 1 error
-                    do {
-                        boardGrid[rank][file] = nullptr; // remove reference
-                        file = (file < 8) ? file + 1 : 0;
-                    } while(--skip);
+                    //skip--; // fix off by 1 error
+                    while(skip--) {
+                        boardGrid[rank][file++] = nullptr; // remove reference
+                    }
                     break;
                 }
                 default:
@@ -183,7 +201,6 @@ int Board::setupFromFEN(std::string strFEN) {
                     return -1;
                     break;
             }
-            file++;
             if(file > 7) {
                 file = 0;
                 break;
@@ -208,23 +225,47 @@ int Board::setupFromFEN(std::string strFEN) {
     // ====== END OF FIELD 2 ======
     // ====== START OF FIELD 3 ======
     std::string k = "k", K = "K", q = "q", Q = "Q";
+    auto &bKing = this->getPieceAt(blackKing);
+    auto &wKing = this->getPieceAt(whiteKing);
     if(splitFEN[2] == "-") {
         // nobody can castle, either side
-        // locate Kings and set appropriate variables
-        // canCastleKS, canCastleQS
+        bKing->setCastleKS(false);
+        bKing->setCastleQS(false);
+        wKing->setCastleKS(false);
+        wKing->setCastleQS(false);
     }
     if(splitFEN[2].find(k) != std::string::npos) {
         // black king can castle kingside
+        bKing->setCastleKS(true);
     }
     if(splitFEN[2].find(K) != std::string::npos) {
         // white king can castle kingside
+        wKing->setCastleKS(true);
     }
     if(splitFEN[2].find(q) != std::string::npos) {
         // black king can castle queenside
+        bKing->setCastleQS(true);
     }
     if(splitFEN[2].find(Q) != std::string::npos) {
         // white king can castle queenside
+        wKing->setCastleQS(true);
     }
+    // ====== END OF FIELD 3 ======
+    // ====== START OF FIELD 4 ======
+    // if a pawn has just moved and can be attacked enPassant, it will be listed here
+    
+    
+#ifdef DEBUG
+    for(auto &ranks : boardGrid) {
+        for(auto &files : ranks) {
+            if(files)
+                std::cout << files->getPieceName() << " ";
+            else
+                std::cout << "E ";
+        }
+        std::cout << "\n";
+    }
+#endif
     return 0;
 }