fix and restore activity truncation

modules/activity/src/main/ActivityWriteApi.scala

@@ -1,5 +1,7 @@
 package lila.activity
 
+import reactivemongo.api.bson._
+
 import lila.db.AsyncCollFailingSilently
 import lila.db.dsl._
 import lila.game.Game
@@ -152,9 +154,9 @@ final class ActivityWriteApi(
         !setters.isEmpty ?? {
           coll.update
             .one($id(activity.id), $set(setters), upsert = true)
-            // .flatMap {
-            //   _.upserted.nonEmpty ?? truncateAfterInserting(coll, activity.id)
-            // }
+            .flatMap {
+              _.upserted.nonEmpty ?? truncateAfterInserting(coll, activity.id)
+            }
             .void
         }
       }
@@ -170,8 +172,16 @@ final class ActivityWriteApi(
     .one[Bdoc]
     .flatMap {
       _.flatMap(_.getAsOpt[Activity.Id]("_id")) ?? { oldId =>
-        coll.delete.one($doc("_id" $lte oldId)).void
+        coll.delete
+          .one(
+            $doc(
+              "_id" -> $doc(
+                "$lte"   -> oldId,
+                "$regex" -> BSONRegex(s"^${id.userId}$idSep", "")
+              )
+            )
+          )
+          .void
       }
     }
-
 }

modules/activity/src/main/BSONHandlers.scala

@@ -19,18 +19,18 @@ private object BSONHandlers {
   import activities._
   import model._
 
-  def regexId(userId: User.ID): Bdoc = "_id" $startsWith s"$userId:"
+  val idSep                          = ':'
+  def regexId(userId: User.ID): Bdoc = "_id" $startsWith s"$userId$idSep"
 
   implicit lazy val activityIdHandler = {
-    val sep = ':'
     tryHandler[Id](
       { case BSONString(v) =>
-        v split sep match {
+        v split idSep match {
           case Array(userId, dayStr) => Success(Id(userId, Day(Integer.parseInt(dayStr))))
           case _                     => handlerBadValue(s"Invalid activity id $v")
         }
       },
-      id => BSONString(s"${id.userId}$sep${id.day.value}")
+      id => BSONString(s"${id.userId}$idSep${id.day.value}")
     )
   }