live secret keys to bypass live game export delay

app/Env.scala

@@ -2,14 +2,15 @@ package lila.app
 
 import akka.actor._
 import com.softwaremill.macwire._
+import lila.memo.SettingStore.Strings._
 import play.api.libs.ws.WSClient
 import play.api.mvc.{ ControllerComponents, SessionCookieBaker }
 import play.api.{ Configuration, Environment, Mode }
 import scala.concurrent.duration._
 import scala.concurrent.{ ExecutionContext, Future }
 
-import lila.common.{ Bus, Lilakka }
 import lila.common.config._
+import lila.common.{ Bus, Lilakka, Strings }
 
 final class Env(
     val config: Configuration,
@@ -99,6 +100,12 @@ final class Env(
     default = 10,
     text = "API timeline entries to serve".some
   )
+  lazy val noDelaySecretSetting = memo.settingStore[Strings](
+    "noDelaySecrets",
+    default = Strings(Nil),
+    text =
+      "Secret tokens that allows fetching ongoing games without the 3-moves delay. Separated by commas.".some
+  )
 
   lazy val preloader     = wire[mashup.Preload]
   lazy val socialInfo    = wire[mashup.UserInfo.SocialApi]

app/controllers/Dev.scala

@@ -17,7 +17,8 @@ final class Dev(env: Env) extends LilaController(env) {
     env.streamer.alwaysFeaturedSetting,
     env.rating.ratingFactorsSetting,
     env.plan.donationGoalSetting,
-    env.apiTimelineSetting
+    env.apiTimelineSetting,
+    env.noDelaySecretSetting
   )
 
   def settings =

app/controllers/Game.scala

@@ -41,7 +41,8 @@ final class Game(
         val config = GameApiV2.OneConfig(
           format = if (HTTPRequest acceptsJson req) GameApiV2.Format.JSON else GameApiV2.Format.PGN,
           imported = getBool("imported", req),
-          flags = requestPgnFlags(req, extended = true)
+          flags = requestPgnFlags(req, extended = true),
+          noDelay = get("key", req).exists(env.noDelaySecretSetting.get().value.contains)
         )
         env.api.gameApiV2.exportOne(game, config) flatMap { content =>
           env.api.gameApiV2.filename(game, config.format) map { filename =>

modules/api/src/main/GameApiV2.scala

@@ -31,7 +31,7 @@ final class GameApiV2(
   def exportOne(game: Game, configInput: OneConfig): Fu[String] = {
     val config = configInput.copy(
       flags = configInput.flags.copy(
-        delayMoves = game.playable ?? 3,
+        delayMoves = (game.playable && !configInput.noDelay) ?? 3,
         evals = configInput.flags.evals && !game.playable
       )
     )
@@ -237,7 +237,8 @@ object GameApiV2 {
   case class OneConfig(
       format: Format,
       imported: Boolean,
-      flags: WithFlags
+      flags: WithFlags,
+      noDelay: Boolean
   ) extends Config
 
   case class ByUserConfig(