From b7447c4da22205d50dd105ee96dfbcdef75448ec Mon Sep 17 00:00:00 2001
From: Thibault Duplessis <t@lichess.org>
Date: Wed, 12 Jun 2024 11:41:37 +0200
Subject: [PATCH] add Tags.boardNumber

---
 core/src/main/scala/format/pgn/Tag.scala | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/core/src/main/scala/format/pgn/Tag.scala b/core/src/main/scala/format/pgn/Tag.scala
index 4a82b7c2..f195ccc4 100644
--- a/core/src/main/scala/format/pgn/Tag.scala
+++ b/core/src/main/scala/format/pgn/Tag.scala
@@ -31,9 +31,7 @@ case class Tags(value: List[Tag]) extends AnyVal:
 
   def clockConfig: Option[Clock.Config] =
     value
-      .collectFirst { case Tag(Tag.TimeControl, str) =>
-        str
-      }
+      .collectFirst { case Tag(Tag.TimeControl, str) => str }
       .flatMap(Clock.readPgnConfig)
 
   def variant: Option[chess.variant.Variant] =
@@ -73,6 +71,14 @@ case class Tags(value: List[Tag]) extends AnyVal:
         Tags.tagIndex.getOrElse(tag.name, 999)
     )
 
+  def boardNumber: Option[Int] =
+    apply(_.Board)
+      .flatMap(_.toIntOption)
+      .orElse: // Round 1.x is sometimes used for board x
+        apply(_.Round)
+          .flatMap(_.split('.').lift(1))
+          .flatMap(_.toIntOption)
+
   def names: ByColor[Option[PlayerName]] = ByColor(apply(_.White), apply(_.Black)).map(PlayerName.from(_))
   def elos: ByColor[Option[Elo]] = ByColor(apply(_.WhiteElo), apply(_.BlackElo)).map: elo =>
     Elo.from(elo.flatMap(_.toIntOption))