feat(batch34): implement and verify group B cluster consumer features

dotnet/src/ZB.MOM.NatsNet.Server/NatsServer.JetStreamClusterConsumers.cs

@@ -1,7 +1,22 @@
+using System.Text;
+
 namespace ZB.MOM.NatsNet.Server;
 
 public sealed partial class NatsServer
 {
+    internal void SendDomainLeaderElectAdvisory()
+    {
+        var (_, cluster) = GetJetStreamCluster();
+        var meta = cluster?.Meta;
+        if (meta == null)
+            return;
+
+        Noticef(
+            "JetStream domain leader elected advisory for leader {0} in cluster {1}",
+            meta.GroupLeader(),
+            CachedClusterName());
+    }
+
     internal void SendConsumerLostQuorumAdvisory(NatsConsumer? consumer)
     {
         if (consumer == null || !consumer.ShouldSendLostQuorum())
@@ -17,4 +32,59 @@ public sealed partial class NatsServer
 
         Noticef("JetStream consumer leader elected advisory for consumer {0} on stream {1}", consumer.Name, consumer.Stream);
     }
+
+    internal void JsClusteredStreamRequest(
+        ClientInfo clientInfo,
+        Account account,
+        string subject,
+        string reply,
+        byte[] rawMessage,
+        StreamConfigRequest configRequest)
+    {
+        var (js, cluster) = GetJetStreamCluster();
+        if (js == null || cluster == null)
+            return;
+
+        var cfg = configRequest.Config;
+        var engine = new JetStreamEngine(js);
+        var limitsError = engine.JsClusteredStreamLimitsCheck(account, cfg);
+        if (limitsError != null)
+        {
+            var response = new ApiResponse
+            {
+                Type = JsApiSubjects.JsApiStreamCreateResponseType,
+                Error = limitsError,
+            };
+            SendAPIErrResponse(clientInfo, account, subject, reply, string.Empty, JsonResponse(response));
+            return;
+        }
+
+        var (group, createError) = engine.CreateGroupForStream(clientInfo, cfg);
+        if (group == null || createError != null)
+        {
+            var response = new ApiResponse
+            {
+                Type = JsApiSubjects.JsApiStreamCreateResponseType,
+                Error = JsApiErrors.NewJSClusterNoPeersError(createError ?? new SelectPeerError { Misc = true }),
+            };
+            SendAPIErrResponse(clientInfo, account, subject, reply, string.Empty, JsonResponse(response));
+            return;
+        }
+
+        var assignment = new StreamAssignment
+        {
+            Group = group,
+            Config = cfg,
+            Subject = subject,
+            Reply = reply,
+            Client = clientInfo,
+            Created = DateTime.UtcNow,
+        };
+
+        if (cluster.Meta != null)
+        {
+            cluster.Meta.Propose(Encoding.UTF8.GetBytes($"create-stream:{account.Name}:{cfg.Name}"));
+            cluster.TrackInflightStreamProposal(account.Name, assignment, deleted: false);
+        }
+    }
 }