// Copyright 2018-2025 The NATS Authors
// Licensed under the Apache License, Version 2.0
//
// NoRace integration tests - corresponds to Go file:
//   golang/nats-server/server/norace_2_test.go (first 24 tests)
//
// These tests are equivalent to Go's //go:build !race tests.
// All tests require NATS_INTEGRATION_ENABLED=true to run.

using Shouldly;
using Xunit.Abstractions;
using ZB.MOM.NatsNet.Server.IntegrationTests.Helpers;

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

[Trait("Category", "NoRace")]
[Trait("Category", "Integration")]
public class NoRace2Tests : IntegrationTestBase
{
    public NoRace2Tests(ITestOutputHelper output) : base(output) { }

    // ---------------------------------------------------------------------------
    // 1. TestNoRaceJetStreamClusterLeafnodeConnectPerf
    // [skip(t) in Go — not run by default]
    // 500 leaf node vehicles connect to a 3-server cloud cluster.
    // Each vehicle creates a source stream referencing the cloud cluster.
    // Verifies each leaf node connect + stream create completes in < 2 seconds.
    // ---------------------------------------------------------------------------
    [SkippableFact]
    public async Task JetStreamClusterLeafnodeConnectPerf_ShouldSucceed()
    {
        Skip.If(true, "Explicitly skipped in Go source (skip(t)) — performance test requiring 500 leaf nodes on a large machine");
        await Task.CompletedTask;
    }

    // ---------------------------------------------------------------------------
    // 2. TestNoRaceJetStreamClusterDifferentRTTInterestBasedStreamPreAck
    // 3-server cluster with asymmetric RTT (S1 ↔ S2 proxied at 10ms delay).
    // Creates interest-policy stream EVENTS (replicas=3) with stream leader on S2
    // and consumer leader on S3. Publishes 1000 messages. Verifies:
    //   - S1 (slow path) receives pre-acks
    //   - Messages are cleaned up once all consumers ack (state.Msgs == 0)
    //   - No pending pre-acks after all messages processed
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamClusterDifferentRTTInterestBasedStreamPreAck_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamClusterDifferentRTTInterestBasedStreamPreAck:
        // 3-server cluster with asymmetric RTT and interest-policy stream pre-ack verification
    }

    // ---------------------------------------------------------------------------
    // 3. TestNoRaceCheckAckFloorWithVeryLargeFirstSeqAndNewConsumers
    // Creates a work-queue stream and purges it to firstSeq=1,200,000,000.
    // Publishes 1 message. Creates pull consumer. Fetches and AckSync.
    // Verifies that checkAckFloor completes in < 1 second (not O(firstSeq)).
    // Then purges to 2,400,000,000, simulates the slower walk path.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void CheckAckFloorWithVeryLargeFirstSeqAndNewConsumers_ShouldSucceed()
    {
        // Port of Go TestNoRaceCheckAckFloorWithVeryLargeFirstSeqAndNewConsumers:
        // WQ stream purged to firstSeq=1_200_000_000, verifies checkAckFloor is O(gap) not O(seq)
    }

    // ---------------------------------------------------------------------------
    // 4. TestNoRaceReplicatedMirrorWithLargeStartingSequenceOverLeafnode
    // Hub cluster B (3 servers) + leaf cluster A (3 servers).
    // Creates stream on B, purges to firstSeq=1,000,000,000.
    // Sends 1000 messages. Creates mirror on leaf cluster A (cross-domain).
    // Verifies mirror syncs to 1000 msgs, firstSeq=1,000,000,000 in < 1 second.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void ReplicatedMirrorWithLargeStartingSequenceOverLeafnode_ShouldSucceed()
    {
        // Port of Go TestNoRaceReplicatedMirrorWithLargeStartingSequenceOverLeafnode:
        // Hub cluster + leaf cluster cross-domain mirror with large starting sequence
    }

    // ---------------------------------------------------------------------------
    // 5. TestNoRaceBinaryStreamSnapshotEncodingBasic
    // Creates stream TEST with MaxMsgsPerSubject=1.
    // Publishes in a "swiss cheese" pattern: 1000 updates to key:2 (laggard),
    // then 998 keys each updated twice to create interior deletes.
    // Verifies: firstSeq=1, lastSeq=3000, msgs=1000, numDeleted=2000.
    // Encodes stream state → verifies binary snapshot is correct after decode.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void BinaryStreamSnapshotEncodingBasic_ShouldSucceed()
    {
        // Port of Go TestNoRaceBinaryStreamSnapshotEncodingBasic:
        // Swiss-cheese pattern publish, EncodedStreamState/DecodeStreamState round-trip
    }

    // ---------------------------------------------------------------------------
    // 6. TestNoRaceFilestoreBinaryStreamSnapshotEncodingLargeGaps
    // Creates file store with small block size (512 bytes).
    // Stores 20,000 messages, removes all except first and last.
    // Sync blocks to clean tombstones.
    // Verifies: encoded snapshot < 512 bytes, ss.Deleted.NumDeleted() == 19,998.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void FilestoreBinaryStreamSnapshotEncodingLargeGaps_ShouldSucceed()
    {
        // Port of Go TestNoRaceFilestoreBinaryStreamSnapshotEncodingLargeGaps:
        // File store with 512-byte blocks, compact binary encoding of large delete gaps
    }

    // ---------------------------------------------------------------------------
    // 7. TestNoRaceJetStreamClusterStreamSnapshotCatchup
    // 3-server cluster. Creates stream TEST (MaxMsgsPerSubject=1, replicas=3).
    // Shuts down a non-leader. Creates 50k gap (interior deletes via bar).
    // Snapshots stream. Restarts server — verifies it catches up via snapshot.
    // Repeats with one more publish + snapshot → verifies state (msgs=3).
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamClusterStreamSnapshotCatchup_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamClusterStreamSnapshotCatchup:
        // Cluster snapshot catchup after server shutdown with 50k interior deletes
    }

    // ---------------------------------------------------------------------------
    // 8. TestNoRaceStoreStreamEncoderDecoder
    // Runs two parallel 10-second stress tests (MemStore + FileStore).
    // Each goroutine: stores messages to random keys (0–256000),
    // every second encodes snapshot and verifies decode.
    // Asserts: encode time < 2s, encoded size < 700KB, decoded state valid.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void StoreStreamEncoderDecoder_ShouldSucceed()
    {
        // Port of Go TestNoRaceStoreStreamEncoderDecoder:
        // 10-second parallel stress test of MemStore + FileStore snapshot encode/decode
    }

    // ---------------------------------------------------------------------------
    // 9. TestNoRaceJetStreamClusterKVWithServerKill
    // 3-server cluster. Creates KV bucket TEST (replicas=3, history=10).
    // 3 workers (one per server): random KV get/create/update/delete at 100/s.
    // While workers run: randomly kill & restart each server 7 times.
    // After stopping workload: verifies all servers have identical stream state.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamClusterKVWithServerKill_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamClusterKVWithServerKill:
        // KV stress test with random server kill/restart while workers run
    }

    // ---------------------------------------------------------------------------
    // 10. TestNoRaceFileStoreLargeMsgsAndFirstMatching
    // Creates file store with 8MB blocks. Stores 150k messages to "foo.bar.N"
    // and 150k to "foo.baz.N". Removes messages from block 2 (except last 40).
    // Verifies LoadNextMsg("*.baz.*") completes in < 200 microseconds.
    // Removes remaining 40 and re-verifies (non-linear path).
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void FileStoreLargeMsgsAndFirstMatching_ShouldSucceed()
    {
        // Port of Go TestNoRaceFileStoreLargeMsgsAndFirstMatching:
        // LoadNextMsg performance < 200µs with 8MB blocks and large interior deletes
    }

    // ---------------------------------------------------------------------------
    // 11. TestNoRaceWSNoCorruptionWithFrameSizeLimit
    // Runs testWSNoCorruptionWithFrameSizeLimit with frameSize=50000.
    // Verifies that WebSocket connections with a frame size limit do not
    // produce corrupted messages.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running NATS server")]
    public void WSNoCorruptionWithFrameSizeLimit_ShouldSucceed()
    {
        // Port of Go TestNoRaceWSNoCorruptionWithFrameSizeLimit:
        // WebSocket frame size limit (50000) does not corrupt messages
    }

    // ---------------------------------------------------------------------------
    // 12. TestNoRaceJetStreamAPIDispatchQueuePending
    // 3-server cluster. Creates stream TEST with 500k messages (different subjects).
    // Creates 1000 filtered consumers (100 goroutines x 10 consumers, wildcard filter).
    // Verifies inflight API count is non-zero during peak.
    // Verifies all consumer creates succeed without error.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamAPIDispatchQueuePending_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamAPIDispatchQueuePending:
        // API dispatch queue stress test with 500k messages and 1000 concurrent consumers
    }

    // ---------------------------------------------------------------------------
    // 13. TestNoRaceJetStreamMirrorAndSourceConsumerFailBackoff
    // Verifies backoff calculation: attempts 1–11 = N*10s, attempts 12+ = max.
    // Creates mirror and source streams in a 3-server cluster.
    // Kills the source stream leader. Waits 6 seconds.
    // Verifies only 1 consumer create request is issued per mirror/source (backoff).
    // Verifies fails counter is exactly 1 for both mirror and source.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamMirrorAndSourceConsumerFailBackoff_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamMirrorAndSourceConsumerFailBackoff:
        // Mirror/source backoff timing verification after source leader kill
    }

    // ---------------------------------------------------------------------------
    // 14. TestNoRaceJetStreamClusterStreamCatchupLargeInteriorDeletes
    // 3-server cluster. Creates R1 stream with MaxMsgsPerSubject=100.
    // Creates interior deletes: 50k random + 100k to single subject + 50k random.
    // Scales stream up to R2. Verifies the new replica catches up correctly
    // (same message count as leader) within 10 seconds.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamClusterStreamCatchupLargeInteriorDeletes_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamClusterStreamCatchupLargeInteriorDeletes:
        // Stream scale-up catchup with 200k interior deletes
    }

    // ---------------------------------------------------------------------------
    // 15. TestNoRaceJetStreamClusterBadRestartsWithHealthzPolling
    // 3-server cluster. Creates stream TEST (replicas=3).
    // Polls healthz every 50ms in background goroutine.
    // Creates 500 pull consumers concurrently, then 200 additional streams.
    // Verifies consumer and stream counts are correct on all servers.
    // Deletes all consumers and streams, re-verifies counts go to 0.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamClusterBadRestartsWithHealthzPolling_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamClusterBadRestartsWithHealthzPolling:
        // Healthz polling + 500 concurrent consumer creates + 200 streams
    }

    // ---------------------------------------------------------------------------
    // 16. TestNoRaceJetStreamKVReplaceWithServerRestart
    // 3-server cluster. Creates KV bucket TEST (replicas=3), disables AllowDirect.
    // Creates key "foo". Runs concurrent KV update loop.
    // Kills and restarts the stream leader.
    // Verifies no data loss (value doesn't change unexpectedly between get and update).
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamKVReplaceWithServerRestart_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamKVReplaceWithServerRestart:
        // Concurrent KV update loop while killing and restarting stream leader
    }

    // ---------------------------------------------------------------------------
    // 17. TestNoRaceMemStoreCompactPerformance
    // Creates a memory store stream with MaxMsgsPerSubject=1.
    // Publishes 200k messages to 100k unique subjects (creates laggard pattern).
    // Verifies the compact operation completes in < 100ms.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void MemStoreCompactPerformance_ShouldSucceed()
    {
        // Port of Go TestNoRaceMemStoreCompactPerformance:
        // Memory store compact performance < 100ms with 200k messages to 100k unique subjects
    }

    // ---------------------------------------------------------------------------
    // 18. TestNoRaceJetStreamSnapshotsWithSlowAckDontSlowConsumer
    // Creates stream with push consumer. In parallel: publishes messages while
    // another goroutine calls JetStreamSnapshotStream.
    // Verifies the snapshot operation does not block message delivery to the consumer.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void JetStreamSnapshotsWithSlowAckDontSlowConsumer_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamSnapshotsWithSlowAckDontSlowConsumer:
        // Concurrent snapshot + publish does not block push consumer delivery
    }

    // ---------------------------------------------------------------------------
    // 19. TestNoRaceJetStreamWQSkippedMsgsOnScaleUp
    // Creates R1 work-queue stream with AckPolicy=Explicit.
    // Creates durable consumer, publishes 100 messages, acknowledges all.
    // Scales stream to R3. Publishes 100 more messages, acknowledges all.
    // Verifies no messages are skipped after scale-up (no ghost sequences).
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream cluster server")]
    public void JetStreamWQSkippedMsgsOnScaleUp_ShouldSucceed()
    {
        // Port of Go TestNoRaceJetStreamWQSkippedMsgsOnScaleUp:
        // WQ stream scale R1→R3, verify no ghost sequences after scale-up
    }

    // ---------------------------------------------------------------------------
    // 20. TestNoRaceConnectionObjectReleased
    // Verifies that after a client connection is closed, the server-side client
    // object is eventually garbage-collected (not held by strong references).
    // Tests for memory leaks in the connection object lifecycle.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running NATS server")]
    public void ConnectionObjectReleased_ShouldSucceed()
    {
        // Port of Go TestNoRaceConnectionObjectReleased:
        // Server-side connection objects are GC'd after client disconnect
    }

    // ---------------------------------------------------------------------------
    // 21. TestNoRaceFileStoreMsgLoadNextMsgMultiPerf
    // Creates file store, stores 1 million messages across 1000 subjects.
    // Verifies LoadNextMsg with multi-filter (matching multiple subjects) completes
    // at an acceptable rate (performance test with timing assertions).
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void FileStoreMsgLoadNextMsgMultiPerf_ShouldSucceed()
    {
        // Port of Go TestNoRaceFileStoreMsgLoadNextMsgMultiPerf:
        // LoadNextMsg multi-filter performance with 1M messages across 1000 subjects
    }

    // ---------------------------------------------------------------------------
    // 22. TestNoRaceWQAndMultiSubjectFilters
    // Creates work-queue stream with multiple filter subjects per consumer.
    // Publishes messages to various subjects. Verifies WQ semantics are correct:
    // each message delivered to exactly one consumer, correct filter matching.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void WQAndMultiSubjectFilters_ShouldSucceed()
    {
        // Port of Go TestNoRaceWQAndMultiSubjectFilters:
        // WQ stream with multiple filter subjects per consumer, each message delivered once
    }

    // ---------------------------------------------------------------------------
    // 23. TestNoRaceWQAndMultiSubjectFiltersRace
    // Same as WQAndMultiSubjectFilters but adds concurrent publisher goroutines
    // to stress test for race conditions in multi-filter WQ delivery.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void WQAndMultiSubjectFiltersRace_ShouldSucceed()
    {
        // Port of Go TestNoRaceWQAndMultiSubjectFiltersRace:
        // WQ multi-filter delivery race test with concurrent publishers
    }

    // ---------------------------------------------------------------------------
    // 24. TestNoRaceFileStoreWriteFullStateUniqueSubjects
    // Creates file store with MaxMsgsPerSubject=1, writes 100k messages to
    // 100k unique subjects. Forces a full-state write (used during recovery).
    // Verifies: the written state is correct, read-back after restart matches.
    // Asserts the full-state write completes in a reasonable time.
    // ---------------------------------------------------------------------------
    [Fact(Skip = "deferred: requires running JetStream server")]
    public void FileStoreWriteFullStateUniqueSubjects_ShouldSucceed()
    {
        // Port of Go TestNoRaceFileStoreWriteFullStateUniqueSubjects:
        // writeFullState correctness with 100k unique subjects, round-trip verify after reload
    }
}