From 697f1f304487b65ec0408030c97dbb3567403a30 Mon Sep 17 00:00:00 2001
From: Thibault Duplessis <t@lichess.org>
Date: Wed, 3 Feb 2021 08:55:37 +0100
Subject: [PATCH] ignore invalid chapter nodes

---
 modules/study/src/main/BSONHandlers.scala  | 49 ++++++++++++++--------
 modules/study/src/main/StudyFlatTree.scala | 16 +++----
 2 files changed, 40 insertions(+), 25 deletions(-)

diff --git a/modules/study/src/main/BSONHandlers.scala b/modules/study/src/main/BSONHandlers.scala
index 29295a9fed..8d3d76b016 100644
--- a/modules/study/src/main/BSONHandlers.scala
+++ b/modules/study/src/main/BSONHandlers.scala
@@ -158,24 +158,37 @@ object BSONHandlers {
     )
   }
 
-  def readNode(doc: Bdoc, id: UciCharPair): Node = {
-    import Node.BsonFields._
-    val r = new Reader(doc)
-    Node(
-      id = id,
-      ply = r int ply,
-      move = WithSan(r.get[Uci](uci), r.str(san)),
-      fen = r.get[FEN](fen),
-      check = r boolD check,
-      shapes = r.getO[Shapes](shapes) | Shapes.empty,
-      comments = r.getO[Comments](comments) | Comments.empty,
-      gamebook = r.getO[Gamebook](gamebook),
-      glyphs = r.getO[Glyphs](glyphs) | Glyphs.empty,
-      score = r.getO[Score](score),
-      crazyData = r.getO[Crazyhouse.Data](crazy),
-      clock = r.getO[Centis](clock),
-      children = Node.emptyChildren,
-      forceVariation = r boolD forceVariation
+  def readNode(doc: Bdoc, id: UciCharPair): Option[Node] = {
+    import Node.{ BsonFields => F }
+    for {
+      ply <- doc.getAsOpt[Int](F.ply)
+      uci <- doc.getAsOpt[Uci](F.uci)
+      san <- doc.getAsOpt[String](F.san)
+      fen <- doc.getAsOpt[FEN](F.fen)
+      check          = ~doc.getAsOpt[Boolean](F.check)
+      shapes         = doc.getAsOpt[Shapes](F.shapes) getOrElse Shapes.empty
+      comments       = doc.getAsOpt[Comments](F.comments) getOrElse Comments.empty
+      gamebook       = doc.getAsOpt[Gamebook](F.gamebook)
+      glyphs         = doc.getAsOpt[Glyphs](F.glyphs) getOrElse Glyphs.empty
+      score          = doc.getAsOpt[Score](F.score)
+      clock          = doc.getAsOpt[Centis](F.clock)
+      crazy          = doc.getAsOpt[Crazyhouse.Data](F.crazy)
+      forceVariation = ~doc.getAsOpt[Boolean](F.forceVariation)
+    } yield Node(
+      id,
+      ply,
+      WithSan(uci, san),
+      fen,
+      check,
+      shapes,
+      comments,
+      gamebook,
+      glyphs,
+      score,
+      clock,
+      crazy,
+      Node.emptyChildren,
+      forceVariation
     )
   }
 
diff --git a/modules/study/src/main/StudyFlatTree.scala b/modules/study/src/main/StudyFlatTree.scala
index fefa0cf7d8..1c9e97aabd 100644
--- a/modules/study/src/main/StudyFlatTree.scala
+++ b/modules/study/src/main/StudyFlatTree.scala
@@ -13,9 +13,10 @@ private object StudyFlatTree {
   private case class FlatNode(path: Path, data: Bdoc) {
     val depth = path.ids.size
 
-    def toNodeWithChildren(children: Option[Children]): Node = {
-      readNode(data, path.ids.last)
-    }.copy(children = children | Node.emptyChildren)
+    def toNodeWithChildren(children: Option[Children]): Option[Node] =
+      readNode(data, path.ids.last) map {
+        _.copy(children = children | Node.emptyChildren)
+      }
   }
 
   object reader {
@@ -41,10 +42,11 @@ private object StudyFlatTree {
 
     // assumes that node has a greater depth than roots (sort beforehand)
     private def update(roots: Map[Path, Children], flat: FlatNode): Map[Path, Children] = {
-      val node = flat.toNodeWithChildren(roots get flat.path)
-      roots.removed(flat.path).updatedWith(flat.path.parent) {
-        case None           => Children(Vector(node)).some
-        case Some(siblings) => siblings.addNode(node).some
+      flat.toNodeWithChildren(roots get flat.path).fold(roots) { node =>
+        roots.removed(flat.path).updatedWith(flat.path.parent) {
+          case None           => Children(Vector(node)).some
+          case Some(siblings) => siblings.addNode(node).some
+        }
       }
     }
   }