gray out cheaters on swiss podiums

since they can't be removed because it makes
the tournament pairings become wrong

modules/swiss/src/main/SwissJson.scala

@@ -11,7 +11,7 @@ import lila.db.dsl._
 import lila.game.Game
 import lila.quote.Quote.quoteWriter
 import lila.socket.Socket.SocketVersion
-import lila.user.User
+import lila.user.{ User, UserRepo }
 
 final class SwissJson(
     colls: SwissColls,
@@ -19,6 +19,7 @@ final class SwissJson(
     rankingApi: SwissRankingApi,
     boardApi: SwissBoardApi,
     statsApi: SwissStatsApi,
+    userRepo: UserRepo,
     lightUserApi: lila.user.LightUserApi
 )(implicit ec: ExecutionContext) {
 
@@ -116,20 +117,26 @@ final class SwissJson(
           .find($doc(f.swissId -> swiss.id))
           .sort($sort desc f.score)
           .cursor[SwissPlayer]()
-          .list(3) map { top3 =>
+          .list(3) flatMap { top3 =>
           // check that the winner is still correctly denormalized
-          top3.headOption.map(_.userId).filter(w => swiss.winnerId.fold(true)(w !=)) foreach {
-            colls.swiss.updateField($id(swiss.id), "winnerId", _).void
-          }
-          JsArray {
-            top3.map { player =>
-              playerJsonBase(
-                player,
-                lightUserApi.sync(player.userId) | LightUser.fallback(player.userId),
-                performance = true
-              )
+          top3.headOption
+            .map(_.userId)
+            .filter(w => swiss.winnerId.fold(true)(w !=))
+            .foreach {
+              colls.swiss.updateField($id(swiss.id), "winnerId", _).void
             }
-          }.some
+            .unit
+          userRepo.filterEngine(top3.map(_.userId)) map { engines =>
+            JsArray(
+              top3.map { player =>
+                playerJsonBase(
+                  player,
+                  lightUserApi.sync(player.userId) | LightUser.fallback(player.userId),
+                  performance = true
+                ).add("engine", engines(player.userId))
+              }
+            ).some
+          }
         }
       }
     }

modules/user/src/main/UserRepo.scala

@@ -357,6 +357,9 @@ final class UserRepo(val coll: Coll)(implicit ec: scala.concurrent.ExecutionCont
 
   def isEngine(id: ID): Fu[Boolean] = coll.exists($id(id) ++ engineSelect(true))
 
+  def filterEngine(ids: Seq[ID]): Fu[Set[ID]] =
+    coll.distinct[ID, Set]("_id", Some($inIds(ids) ++ engineSelect(true)))
+
   def isTroll(id: ID): Fu[Boolean] = coll.exists($id(id) ++ trollSelect(true))
 
   def isCreatedSince(id: ID, since: DateTime): Fu[Boolean] =

ui/common/css/component/_podium.scss

@@ -26,6 +26,18 @@
 
     display: inline-block;
     text-align: center;
+
+    &.engine {
+      opacity: .5;
+      .user-link {
+        text-decoration: line-through;
+        font-weight: normal;
+      }
+      .trophy {
+        opacity: .3;
+        filter: grayscale(100%) contrast(10%);
+      }
+    }
   }
 
   .first {

ui/swiss/src/interfaces.ts

@@ -96,6 +96,7 @@ export interface BasePlayer {
 }
 
 export interface PodiumPlayer extends BasePlayer {
+  engine?: boolean;
 }
 
 export interface Player extends BasePlayer {

ui/swiss/src/view/podium.ts

@@ -14,7 +14,11 @@ function podiumStats(p: PodiumPlayer, trans: Trans): VNode {
 }
 
 function podiumPosition(p: PodiumPlayer, pos: string, trans: Trans): VNode | undefined {
-  return p ? h('div.' + pos, [
+  return p ? h('div.' + pos, {
+    class: {
+      engine: !!p.engine
+    }
+  }, [
     h('div.trophy'),
     h('a.text.ulpt.user-link', {
       attrs: { href: '/@/' + p.user.name }