// Copyright 2020-2025 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Mirrors server/jetstream_super_cluster_test.go (first 36 tests) and
// server/jetstream_leafnode_test.go (first 3 tests) from the NATS server Go source.
// All tests require a running JetStream super-cluster or leaf-node topology and
// are deferred until the full server runtime is available.

using ZB.MOM.NatsNet.Server.IntegrationTests.Helpers;

namespace ZB.MOM.NatsNet.Server.IntegrationTests.JetStream;

/// <summary>
/// Integration tests for JetStream super-cluster scenarios and leaf-node
/// JetStream cross-domain interactions.
/// Mirrors server/jetstream_super_cluster_test.go and
/// server/jetstream_leafnode_test.go.
/// All tests are deferred pending multi-server cluster infrastructure.
/// </summary>
[Collection("SuperClusterIntegration")]
[Trait("Category", "Integration")]
public sealed class JetStreamSuperClusterTests : IntegrationTestBase
{
    // -------------------------------------------------------------------------
    // From server/jetstream_super_cluster_test.go
    // -------------------------------------------------------------------------

    /// <summary>
    /// Verifies that the JetStream meta-leader can step down with placement
    /// constraints (cluster, tags, preferred server) and that invalid placements
    /// return the expected error codes.
    /// Mirrors TestJetStreamSuperClusterMetaStepDown.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void MetaStepDown_ShouldSucceed()
    {
        // Go source: createJetStreamTaggedSuperCluster — 3 clusters (C1/C2/C3),
        // each with 3 servers, tagged cloud:aws/gcp/az and node:1/2/3.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
        sc.WaitOnLeader();

        // Verify step-down to unknown cluster returns JSClusterNoPeersErrF (400).
        // Verify step-down to unknown preferred server returns 400.
        // Verify step-down with unknown tag returns 400.
        // Verify step-down when preferred server is already leader returns 400.
        // Verify successful placement by preferred server name.
        // Verify successful placement by cluster name.
        // Verify successful placement by single tag.
        // Verify successful placement by multiple tags (must match all).
        // Verify successful placement by cluster name and tag combination.
    }

    /// <summary>
    /// Verifies that a stream leader can step down with placement constraints
    /// and that non-participant clusters and other invalid placements return errors.
    /// Mirrors TestJetStreamSuperClusterStreamStepDown.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void StreamStepDown_ShouldSucceed()
    {
        // Go source: createJetStreamTaggedSuperCluster; stream "foo" placed in C1
        // with cloud:aws tag, R3. Step-down tested for:
        // UnknownCluster, UnknownPreferredServer, UnknownTag, NonParticipantCluster,
        // PreferredServerAlreadyLeader, PlacementByPreferredServer,
        // PlacementByCluster, PlacementByTag, PlacementByMultipleTags, PlacementByClusterAndTag.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
        sc.WaitOnLeader();
    }

    /// <summary>
    /// Verifies that a consumer leader can step down with placement constraints
    /// and that invalid placements return the correct errors.
    /// Mirrors TestJetStreamSuperClusterConsumerStepDown.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void ConsumerStepDown_ShouldSucceed()
    {
        // Go source: createJetStreamTaggedSuperCluster; stream "foo" + consumer
        // "consumer" in C1 with cloud:aws tag. Consumer step-down tested for
        // the same set of sub-tests as StreamStepDown.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
        sc.WaitOnLeader();
    }

    /// <summary>
    /// Verifies that unique_tag placement (az tag) ensures replicas land on
    /// servers in different availability zones, and fails when no suitable
    /// diverse peers exist.
    /// Mirrors TestJetStreamSuperClusterUniquePlacementTag.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void UniquePlacementTag_ShouldSucceed()
    {
        // Go source: createJetStreamSuperClusterWithTemplateAndModHook — 5 servers
        // per cluster, 2 clusters. C1 servers all tagged az:same; C2 servers
        // alternating az:1 / az:2. Tests R1 and R2 placement with/without az tags.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(5, 2);
        sc.WaitOnLeader();
    }

    /// <summary>
    /// Verifies that a super-cluster of 3×3 allows creating and publishing to
    /// replicated streams and that streams can be explicitly placed in a named cluster.
    /// Mirrors TestJetStreamSuperClusterBasics.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void Basics_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3)
        // Creates stream "TEST" R3, publishes 10 messages, verifies state.
        // Creates stream "TEST2" placed explicitly in "C3" and verifies cluster name.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
        sc.WaitOnLeader();
    }

    /// <summary>
    /// Verifies that push and pull consumers created in one cluster correctly
    /// receive messages whose stream is homed in another cluster (cross-cluster
    /// consumer interest via gateways).
    /// Mirrors TestJetStreamSuperClusterCrossClusterConsumerInterest.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void CrossClusterConsumerInterest_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3)
        // Stream "foo" placed in C2, consumer connected from C1.
        // Pull and push delivery tested across gateway.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that a stream's peers can be reassigned across the super-cluster
    /// when the current peer set is insufficient.
    /// Mirrors TestJetStreamSuperClusterPeerReassign.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void PeerReassign_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3)
        // Stream "TEST" placed in C2, R3. Checks peer reassignment after
        // removing/replacing a server.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies interest-only gateway mode is triggered and cleared correctly
    /// when a super-cluster account has/lacks active subscribers.
    /// Mirrors TestJetStreamSuperClusterInterestOnlyMode.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void InterestOnlyMode_ShouldSucceed()
    {
        // Go source: createJetStreamSuperClusterWithTemplate with account template.
        // Checks gateway transitions into/out of interest-only mode.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that internal JetStream connection counts are not reported as
    /// active client connections in account connection queries.
    /// Mirrors TestJetStreamSuperClusterConnectionCount.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void ConnectionCount_ShouldSucceed()
    {
        // Go source: createJetStreamSuperClusterWithTemplate with accounts template.
        // Creates source streams and a mirror, verifies account NumConnections == 0.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that a sourcing stream in C2 continues to replicate messages from
    /// a stream in C1 even when the gateway connection is broken mid-publish and
    /// subsequently reconnects.
    /// Mirrors TestJetStreamSuperClusterConsumersBrokenGateways.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void ConsumersBrokenGateways_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 1, 2)
        // Stream "TEST" in C1, sourced by stream "S" in C2. Publishes 100 msgs,
        // breaks GW connection at ~50, waits for reconnect and verifies all 200 msgs present.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(1, 2);
    }

    /// <summary>
    /// Verifies that a leaf-node cluster sharing the system account in the same
    /// JetStream domain does not become a meta-leader and can publish/consume messages.
    /// Mirrors TestJetStreamSuperClusterLeafNodesWithSharedSystemAccountAndSameDomain.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster with leaf nodes")]
    public void LeafNodesWithSharedSystemAccountAndSameDomain_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2) + sc.createLeafNodes("LNC", 2).
        // Verifies meta-leader is always in supercluster, not the leaf cluster.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that a leaf-node cluster with a different JetStream domain from
    /// the super-cluster behaves correctly regarding meta-leadership.
    /// Mirrors TestJetStreamSuperClusterLeafNodesWithSharedSystemAccountAndDifferentDomain.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster with leaf nodes")]
    public void LeafNodesWithSharedSystemAccountAndDifferentDomain_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2) + sc.createLeafNodes("LNC", 2).
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies a single leaf node using the shared system account works correctly
    /// with the super-cluster's JetStream.
    /// Mirrors TestJetStreamSuperClusterSingleLeafNodeWithSharedSystemAccount.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster with leaf nodes")]
    public void SingleLeafNodeWithSharedSystemAccount_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2) + single leaf node.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that pull-consumer GetNext requests are correctly rewritten when
    /// proxied through a gateway to a leaf-node cluster.
    /// Mirrors TestJetStreamSuperClusterGetNextRewrite.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster with leaf nodes")]
    public void GetNextRewrite_ShouldSucceed()
    {
        // Go source: createJetStreamSuperClusterWithTemplate accounts template, 2×2.
        // Leaf node attached to C1, client connects to C2; pull consumer GetNext
        // subject must be rewritten to correct account subject.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(2, 2);
    }

    /// <summary>
    /// Verifies that ephemeral source consumers are cleaned up once the sourcing
    /// stream is deleted, both for same-cluster and cross-cluster sources.
    /// Mirrors TestJetStreamSuperClusterEphemeralCleanup.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void EphemeralCleanup_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2).
        // Tests "local" (same cluster) and "remote" (cross cluster) source streams.
        // After deleting the sourcing stream the direct consumer count on the origin
        // stream must drop to 0.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Reproduces a race condition where GetNext requests could be lost when
    /// a gateway connection had no inbound side for a cluster.
    /// Mirrors TestJetStreamSuperClusterGetNextSubRace.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster with leaf nodes")]
    public void GetNextSubRace_ShouldSucceed()
    {
        // Go source: createJetStreamSuperClusterWithTemplate accounts template, 2×2.
        // Leaf attached to C1; one C1 server shut down; 100 messages published and
        // fetched to ensure no race on the GetNext subject delivery.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(2, 2);
    }

    /// <summary>
    /// Verifies that pull consumers work correctly across gateways and that
    /// message headers survive gateway hops.
    /// Mirrors TestJetStreamSuperClusterPullConsumerAndHeaders.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void PullConsumerAndHeaders_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2).
        // Publishes messages with headers from C1, pull-consumes from C2.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that the statsz API reports the correct number of active servers
    /// as servers are shut down and restarted.
    /// Mirrors TestJetStreamSuperClusterStatszActiveServers.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void StatszActiveServers_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 2, 2).
        // Checks Stats.ActiveServers == 4 initially, == 3 after one shutdown,
        // == 4 after restart.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(2, 2);
    }

    /// <summary>
    /// Verifies that only one direct consumer per origin stream is maintained
    /// after multiple leader changes on a sourcing/mirroring stream.
    /// Mirrors TestJetStreamSuperClusterSourceAndMirrorConsumersLeaderChange.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void SourceAndMirrorConsumersLeaderChange_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2).
        // 10 origin streams in C1; sourcing stream "S" R2 in C2.
        // Two forced leader changes on "S". numDirectConsumers on a random origin
        // stream must equal 1.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that push consumers created in one cluster receive messages after
    /// the connection is re-established in a different cluster.
    /// Mirrors TestJetStreamSuperClusterPushConsumerInterest.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void PushConsumerInterest_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2).
        // Tests non-queue and queue push consumers crossing the cluster boundary.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that overflow placement correctly spills streams to another cluster
    /// when the requested cluster is full.
    /// Mirrors TestJetStreamSuperClusterOverflowPlacement.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void OverflowPlacement_ShouldSucceed()
    {
        // Go source: createJetStreamSuperClusterWithTemplate max-bytes template, 3×3.
        // MaxBytes required opt-in; stream "foo" R2 in C2. Subsequent R3 placement
        // must overflow to other clusters.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that concurrent stream placements across the super-cluster do not
    /// conflict when both overflow from the same cluster simultaneously.
    /// Mirrors TestJetStreamSuperClusterConcurrentOverflow.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void ConcurrentOverflow_ShouldSucceed()
    {
        // Go source: createJetStreamSuperClusterWithTemplate max-bytes template, 3×3.
        // Two goroutines concurrently place R3 streams; both must succeed.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that stream placement using server tags correctly routes streams
    /// to clusters matching the requested tags (case-insensitive).
    /// Mirrors TestJetStreamSuperClusterStreamTagPlacement.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void StreamTagPlacement_ShouldSucceed()
    {
        // Go source: createJetStreamTaggedSuperCluster (3 clusters with cloud and country tags).
        // cloud:aws → C1, country:jp → C3, cloud:gcp + country:uk → C2.
        // Case-insensitive matching verified.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that removed peers are reflected in stream and consumer listings
    /// and that streams can still be deleted after their peer set changes.
    /// Mirrors TestJetStreamSuperClusterRemovedPeersAndStreamsListAndDelete.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void RemovedPeersAndStreamsListAndDelete_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3).
        // Removes a server; verifies STREAM.LIST and STREAM.DELETE still work.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Reproduces a bug where push consumers with DeliverNew policy did not
    /// deliver messages when the first published sequence was not 1.
    /// Mirrors TestJetStreamSuperClusterConsumerDeliverNewBug.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void ConsumerDeliverNewBug_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2).
        // Publishes a message, then creates a DeliverNew consumer; next publish
        // must be delivered.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that streams and their consumers can be moved between clusters
    /// and that data is not lost during the move.
    /// Mirrors TestJetStreamSuperClusterMovingStreamsAndConsumers.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void MovingStreamsAndConsumers_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3).
        // Tests moving R1 and R3 streams across clusters with active consumers.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that a mirror stream can be moved to a different cluster while
    /// maintaining data integrity.
    /// Mirrors TestJetStreamSuperClusterMovingStreamsWithMirror.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void MovingStreamsWithMirror_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3).
        // Stream "TEST" moved; mirror "M" must track correctly.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that a stream can be moved to another cluster and then moved back
    /// to the original cluster.
    /// Mirrors TestJetStreamSuperClusterMovingStreamAndMoveBack.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void MovingStreamAndMoveBack_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3).
        // Stream moved from C1→C2, then back to C1; message count must be preserved.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that a consumer's ack subject is correctly remapped when the
    /// stream owner imports the consumer subject from another account.
    /// Mirrors TestJetStreamSuperClusterImportConsumerStreamSubjectRemap.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void ImportConsumerStreamSubjectRemap_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2) with account imports.
        // Consumer ack subject must survive gateway hops and subject remapping.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that system-level HA asset limits (MaxHaAssets) are enforced
    /// across the super-cluster.
    /// Mirrors TestJetStreamSuperClusterMaxHaAssets.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void MaxHaAssets_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3) with MaxHaAssets system limit.
        // Adding replicated streams beyond the limit must return an error.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that stream alternates are correctly listed and used for direct-get
    /// requests when a stream has mirrors in multiple clusters.
    /// Mirrors TestJetStreamSuperClusterStreamAlternates.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void StreamAlternates_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3).
        // Stream "TEST" with a mirror in another cluster; Alternates list checked.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that a server with stale state on restart does not prevent
    /// consumer recovery on streams that have been moved.
    /// Mirrors TestJetStreamSuperClusterStateOnRestartPreventsConsumerRecovery.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void StateOnRestartPreventsConsumerRecovery_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 2).
        // Moves a stream; restarts a server that had stale entries; consumer
        // must still be accessible after recovery.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 2);
    }

    /// <summary>
    /// Verifies that a direct-get on a mirror stream correctly uses a queue group
    /// to distribute load across replicas.
    /// Mirrors TestJetStreamSuperClusterStreamDirectGetMirrorQueueGroup.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void StreamDirectGetMirrorQueueGroup_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3).
        // Mirror stream direct-get must be served by any replica via queue group.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that a tag-induced stream move can be cancelled and the stream
    /// remains operational on its original cluster.
    /// Mirrors TestJetStreamSuperClusterTagInducedMoveCancel.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void TagInducedMoveCancel_ShouldSucceed()
    {
        // Go source: createJetStreamTaggedSuperCluster.
        // Updates stream tags to trigger a move, then cancels it; stream must
        // still be in the original cluster.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that a stream move can be initiated and then cancelled, leaving
    /// the stream in its original cluster with data intact.
    /// Mirrors TestJetStreamSuperClusterMoveCancel.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void MoveCancel_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3).
        // Stream "TEST" move initiated; JSApiStreamUpdate with empty placement
        // cancels the move; stream stays on original cluster.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    /// <summary>
    /// Verifies that two consecutive move requests for the same stream are handled
    /// correctly without data loss.
    /// Mirrors TestJetStreamSuperClusterDoubleStreamMove.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream super-cluster")]
    public void DoubleStreamMove_ShouldSucceed()
    {
        // Go source: createJetStreamSuperCluster(t, 3, 3).
        // Stream moved from C1 to C2 then to C3; message counts verified at each step.
        using var sc = TestSuperCluster.CreateJetStreamSuperCluster(3, 3);
    }

    // -------------------------------------------------------------------------
    // From server/jetstream_leafnode_test.go (first 3 tests)
    // -------------------------------------------------------------------------

    /// <summary>
    /// Verifies that when two servers with the same server name connect via leaf
    /// nodes to the same hub cluster with the same or different JetStream domains,
    /// their IDs are tracked correctly and do not collide.
    /// Mirrors TestJetStreamLeafNodeUniqueServerNameCrossJSDomain.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream leaf-node topology")]
    public void LeafNodeUniqueServerNameCrossJSDomain_ShouldSucceed()
    {
        // Go source: hub server + 2 leaf nodes both named "NOT-UNIQUE".
        // t.Run("same-domain"): leaf uses domain "hub" — sL.ID() expected in nodeToInfo.
        // t.Run("different-domain"): leaf uses domain "spoke" — sA.ID() expected.
        // Verified via $SYS server stats messages.
        using var cluster = TestCluster.CreateJetStreamCluster(1, "hub");
    }

    /// <summary>
    /// Verifies that JWT-based permissions and JetStream domain isolation work
    /// correctly when a leaf node connects to a hub with account-scoped credentials.
    /// Mirrors TestJetStreamLeafNodeJwtPermsAndJSDomains.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream leaf-node topology with JWT")]
    public void LeafNodeJwtPermsAndJSDomains_ShouldSucceed()
    {
        // Go source: hub with operator JWT, leaf with local accounts.
        // Sub/pub deny permissions set via JWT UserPermissionLimits.
        // Four sub-tests: sub-on-ln-pass, sub-on-ln-fail, pub-on-ln-pass, pub-on-ln-fail.
        using var cluster = TestCluster.CreateJetStreamCluster(1, "hub");
    }

    /// <summary>
    /// Verifies that a leaf-node cluster can extend a system account from the hub
    /// cluster and that JetStream operations work bidirectionally through the
    /// leaf-node topology.
    /// Mirrors TestJetStreamLeafNodeClusterExtensionWithSystemAccount.
    /// </summary>
    [Fact(Skip = "deferred: requires running JetStream leaf-node cluster topology")]
    public void LeafNodeClusterExtensionWithSystemAccount_ShouldSucceed()
    {
        // Go source: 2-server hub cluster (A+B) + 2-server leaf cluster (LA+LB).
        // System account shared; proxy used to control leaf connection timing.
        // Two topologies tested (same == true/false — whether LA connects to A or A+B).
        using var cluster = TestCluster.CreateJetStreamCluster(2, "hub");
    }
}