From 84c3af2bb13e8de1b3634548694bee3c59231989 Mon Sep 17 00:00:00 2001
From: Karma Riuk <riukkarma@gmail.com>
Date: Sun, 2 Feb 2025 23:05:42 +0100
Subject: [PATCH] fully support FEN strings now

---
 cpp/src/board.cpp | 21 +++++++++++++++++++--
 cpp/src/board.hpp |  2 ++
 cpp/tests/fen.cpp | 13 +++++++------
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/cpp/src/board.cpp b/cpp/src/board.cpp
index 440aafb..5203d82 100644
--- a/cpp/src/board.cpp
+++ b/cpp/src/board.cpp
@@ -82,6 +82,15 @@ Board Board::setup_fen_position(std::string fen) {
         index++;
     }
 
+    // -- Half move clock
+    index = fen.find(' ', index) + 1;
+    board.n_half_moves =
+        std::stoi(fen.substr(index, fen.find(' ', index + 1) - index));
+
+    // -- Full move number
+    index = fen.find(' ', index) + 1;
+    board.n_full_moves = std::stoi(fen.substr(index));
+
 
     return board;
 }
@@ -127,7 +136,7 @@ std::string Board::to_fen() const {
     ret += white_to_play ? 'w' : 'b';
     ret += " ";
 
-    // Castling Rights
+    // -- Castling Rights
     if (w_castle_rights == CastleSide::NeitherSide
         && b_castle_rights == CastleSide::NeitherSide)
         ret += '-';
@@ -143,10 +152,18 @@ std::string Board::to_fen() const {
     }
     ret += ' ';
 
-    // En passant target
+    // -- En passant target
     ret += en_passant_target == -1
              ? "-"
              : Coords::from_index(en_passant_target).to_algebraic();
+    ret += ' ';
+
+    // -- Half move clock
+    ret += std::to_string(n_half_moves);
+    ret += ' ';
+
+    // -- Full moves number
+    ret += std::to_string(n_full_moves);
 
     return ret;
 }
diff --git a/cpp/src/board.hpp b/cpp/src/board.hpp
index 750a7b0..9a04afb 100644
--- a/cpp/src/board.hpp
+++ b/cpp/src/board.hpp
@@ -16,6 +16,8 @@ struct Board {
     int8_t w_castle_rights = CastleSide::NeitherSide;
     int8_t b_castle_rights = CastleSide::NeitherSide;
     int8_t en_passant_target = -1;
+    uint8_t n_half_moves = 0;
+    uint8_t n_full_moves = 0;
 
     static Board setup_fen_position(std::string fen);
 
diff --git a/cpp/tests/fen.cpp b/cpp/tests/fen.cpp
index 68ff519..d9d51bd 100644
--- a/cpp/tests/fen.cpp
+++ b/cpp/tests/fen.cpp
@@ -2,21 +2,22 @@
 #include "lib.hpp"
 
 int main() {
-    std::string pos = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -";
+    std::string pos =
+        "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
     ASSERT_EQUALS(pos, Board::setup_fen_position(pos).to_fen());
 
-    pos = "r1bk3r/p2pBpNp/n4n2/1p1NP2P/6P1/3P4/P1P1K3/q5b1 b Qk -";
+    pos = "r1bk3r/p2pBpNp/n4n2/1p1NP2P/6P1/3P4/P1P1K3/q5b1 b Qk - 0 1";
     ASSERT_EQUALS(pos, Board::setup_fen_position(pos).to_fen());
 
-    pos = "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3";
+    pos = "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1";
     ASSERT_EQUALS(pos, Board::setup_fen_position(pos).to_fen());
 
-    pos = "4k2r/6r1/8/8/8/8/3R4/R3K3 w Qk -";
+    pos = "4k2r/6r1/8/8/8/8/3R4/R3K3 w Qk - 0 1";
     ASSERT_EQUALS(pos, Board::setup_fen_position(pos).to_fen());
 
-    pos = "8/8/8/4p1K1/2k1P3/8/8/8 b - -";
+    pos = "8/8/8/4p1K1/2k1P3/8/8/8 b - - 0 1";
     ASSERT_EQUALS(pos, Board::setup_fen_position(pos).to_fen());
 
-    pos = "8/5k2/3p4/1p1Pp2p/pP2Pp1P/P4P1K/8/8 b - -";
+    pos = "8/5k2/3p4/1p1Pp2p/pP2Pp1P/P4P1K/8/8 b - - 99 50";
     ASSERT_EQUALS(pos, Board::setup_fen_position(pos).to_fen());
 }