feat(official-bots): consume GameOver stream for bot cleanup (#67)

Add consumer group official-bots-game-over on {prefix}:game-over stream.
Track pub/sub subscribers per gameId in gameWatches map. On GameOver event,
unsubscribe from the game s2c channel and remove from watch map.
XACK after cleanup; DLQ after maxRetries failures.

Closes NCS-103
https://knockoutwhist.youtrack.cloud/issue/NCS-103

Reviewed-on: #67

modules/official-bots/src/main/scala/de/nowchess/bot/service/OfficialBotService.scala

@@ -24,8 +24,9 @@ import scala.jdk.CollectionConverters.*
 import scala.util.{Failure, Success, Try}
 import java.time.Duration
 import java.util.UUID
+import io.quarkus.redis.datasource.pubsub.PubSubCommands
+import java.util.concurrent.{ConcurrentHashMap, TimeUnit}
 import java.util.function.Consumer
-import java.util.concurrent.TimeUnit
 
 @ApplicationScoped
 class OfficialBotService:
@@ -48,14 +49,18 @@ class OfficialBotService:
   private val terminalStatuses =
     Set("checkmate", "resign", "timeout", "stalemate", "insufficientMaterial", "draw")
 
-  private val groupName    = "official-bot"
-  private val consumerId   = UUID.randomUUID().toString
-  private val maxRetries   = 3
-  private val maxStreamLen = 1000L
+  private val groupName     = "official-bot"
+  private val gameOverGroup = "official-bots-game-over"
+  private val consumerId    = UUID.randomUUID().toString
+  private val maxRetries    = 3
+  private val maxStreamLen  = 1000L
 
   private def eventStream(botName: String): String = s"${redisConfig.prefix}:bot:$botName:events:stream"
+  private def gameOverStream: String               = s"${redisConfig.prefix}:game-over"
   private def dlqStream: String                    = s"${redisConfig.prefix}:dlq"
 
+  private val gameWatches = new ConcurrentHashMap[String, (String, PubSubCommands.RedisSubscriber)]()
+
   @PostConstruct
   def initializeMetrics(): Unit =
     BotController.listBots.foreach { bot =>
@@ -68,6 +73,7 @@ class OfficialBotService:
     try accountServiceClient.syncBots(SyncOfficialBotsRequest(bots))
     catch case ex: Exception => log.errorf(ex, "Failed to auto-register official bots with account service")
     bots.foreach(subscribeToEventChannel)
+    subscribeToGameOverStream()
 
   private def subscribeToEventChannel(botName: String): Unit =
     createGroupIfAbsent(botName)
@@ -165,9 +171,80 @@ class OfficialBotService:
       botAccountId: String,
   ): Unit =
     val handler: Consumer[String] = msg => handleGameEvent(botName, gameId, playingAs, difficulty, botAccountId, msg)
-    redis.pubsub(classOf[String]).subscribe(s"${redisConfig.prefix}:game:$gameId:s2c", handler)
+    val subscriber = redis.pubsub(classOf[String]).subscribe(s"${redisConfig.prefix}:game:$gameId:s2c", handler)
+    gameWatches.put(gameId, (botName, subscriber))
     ()
 
+  private def subscribeToGameOverStream(): Unit =
+    Try(
+      redis
+        .stream(classOf[String])
+        .xgroupCreate(gameOverStream, gameOverGroup, "$", new XGroupCreateArgs().mkstream()),
+    ) match
+      case Failure(ex) if Option(ex.getMessage).exists(_.contains("BUSYGROUP")) => ()
+      case Failure(ex) => log.warnf(ex, "Failed to create game-over consumer group")
+      case Success(_)  => ()
+    executor.submit(
+      new Runnable:
+        def run(): Unit = gameOverPollLoop(),
+    )
+    log.infof("Listening to game-over stream (consumer=%s)", consumerId)
+
+  private def gameOverPollLoop(): Unit =
+    while true do
+      Try {
+        val messages = redis
+          .stream(classOf[String])
+          .xreadgroup(
+            gameOverGroup,
+            consumerId,
+            gameOverStream,
+            ">",
+            new XReadGroupArgs().count(10).block(Duration.ofSeconds(2)),
+          )
+        Option(messages).foreach(_.forEach(msg => handleGameOverMessage(msg)))
+      } match
+        case Failure(ex) => log.warnf(ex, "Error in game-over poll loop")
+        case Success(_)  => ()
+
+  private def handleGameOverMessage(msg: StreamMessage[String, String, String]): Unit =
+    val json    = msg.payload().get("data")
+    val attempt = Option(msg.payload().get("attempt")).flatMap(_.toIntOption).getOrElse(0)
+    Try {
+      val node   = objectMapper.readTree(json)
+      val gameId = node.path("payload").path("gameId").asText()
+      if gameId.nonEmpty then
+        Option(gameWatches.remove(gameId)).foreach { (botName, subscriber) =>
+          val topic = s"${redisConfig.prefix}:game:$gameId:s2c"
+          Try(subscriber.unsubscribe(topic)) match
+            case Failure(ex) => log.warnf(ex, "Failed to unsubscribe from game %s", gameId)
+            case Success(_)  => log.infof("Bot %s cleaned up game %s after GameOver", botName, gameId)
+        }
+    } match
+      case Success(_) =>
+        ackGameOver(msg.id())
+      case Failure(ex) if attempt + 1 < maxRetries =>
+        log.warnf(ex, "GameOver handling failed (attempt %d), retrying", attempt)
+        xadd(gameOverStream, Map("data" -> json, "attempt" -> (attempt + 1).toString))
+        ackGameOver(msg.id())
+      case Failure(ex) =>
+        log.errorf(ex, "GameOver handling failed after %d attempts, sending to DLQ", maxRetries)
+        xadd(
+          dlqStream,
+          Map(
+            "data"      -> json,
+            "eventType" -> "GameOver",
+            "error"     -> Option(ex.getMessage).getOrElse(ex.getClass.getName),
+            "attempt"   -> attempt.toString,
+          ),
+        )
+        ackGameOver(msg.id())
+
+  private def ackGameOver(id: String): Unit =
+    Try(redis.stream(classOf[String]).xack(gameOverStream, gameOverGroup, id)) match
+      case Failure(ex) => log.warnf(ex, "Failed to ack game-over message %s", id)
+      case Success(_)  => ()
+
   private def handleGameEvent(
       botName: String,
       gameId: String,