using Shouldly;
using ZB.MOM.NatsNet.Server;

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

public sealed class ConsumerStateTests
{
    private static NatsConsumer CreateConsumer()
    {
        var account = new Account { Name = "A" };
        var stream = NatsStream.Create(account, new StreamConfig { Name = "S", Subjects = ["foo"] }, null, null, null, null)!;
        return NatsConsumer.Create(stream, new ConsumerConfig { Durable = "D", AckPolicy = AckPolicy.AckExplicit }, ConsumerAction.Create, null)!;
    }

    [Fact]
    public void ProposalAndPendingRequestFlow_ShouldBehave()
    {
        var consumer = CreateConsumer();

        consumer.Propose([1, 2, 3]);
        consumer.Propose([4]);
        consumer.LoopAndForwardProposals().ShouldBe(2);

        consumer.AddClusterPendingRequest("r1");
        consumer.AddClusterPendingRequest("r2");
        consumer.CheckPendingRequests(TimeSpan.FromMinutes(1)).ShouldBe(2);
        consumer.RemoveClusterPendingRequest("r2");
        consumer.CheckPendingRequests(TimeSpan.FromMinutes(1)).ShouldBe(1);

        consumer.SetPendingRequestsOk(false);
        consumer.PendingRequestsOk().ShouldBeFalse();
        consumer.CheckAndSetPendingRequestsOk(true).ShouldBeFalse();
        consumer.PendingRequestsOk().ShouldBeTrue();
        consumer.ReleaseAnyPendingRequests().ShouldBe(1);
    }

    [Fact]
    public void DeliveredAckReplyAndAcks_ShouldBehave()
    {
        var consumer = CreateConsumer();

        consumer.UpdateDelivered(10, 20, 2, DateTimeOffset.UtcNow.ToUnixTimeMilliseconds());
        consumer.AddAckReply(20, "reply");
        consumer.UpdateAcks().ShouldBe(1);

        var state = consumer.ReadStoredState();
        state.Delivered.Consumer.ShouldBeGreaterThanOrEqualTo(10UL);
        state.Delivered.Stream.ShouldBeGreaterThanOrEqualTo(20UL);
        state.Redelivered.ShouldNotBeNull();
        state.Redelivered!.ShouldContainKey(20UL);
    }

    [Fact]
    public void ReplicatedQueueAndNakTermFlow_ShouldBehave()
    {
        var consumer = CreateConsumer();

        consumer.AddReplicatedQueuedMsg(33, new JsPubMsg { Subject = "foo" });
        consumer.ProcessNak(33, 2, 1, "-NAK"u8.ToArray()).ShouldBeTrue();
        consumer.CheckRedelivered(33).ShouldBeTrue();
        consumer.ProcessNak(33, 2, 2, "-NAK"u8.ToArray()).ShouldBeTrue();
        consumer.CheckRedelivered(33).ShouldBeTrue();

        consumer.ProcessTerm(33, 2, 2, "done", "reply").ShouldBeTrue();
        consumer.AckWait(TimeSpan.Zero).ShouldBe(TimeSpan.FromSeconds(30));
        consumer.AckWait(TimeSpan.FromSeconds(5)).ShouldBe(TimeSpan.FromSeconds(5));
    }

    [Fact]
    public void ResetLocalStartingSeq_ShouldResetState()
    {
        var consumer = CreateConsumer();

        consumer.UpdateDelivered(1, 1, 1, DateTimeOffset.UtcNow.ToUnixTimeMilliseconds());
        consumer.ResetLocalStartingSeq(100);

        var state = consumer.GetConsumerState();
        state.Delivered.Stream.ShouldBe(100UL);
        state.AckFloor.Stream.ShouldBe(99UL);
    }

    [Fact]
    public void StoreStateAndInfoSamplingAndFiltering_ShouldBehave()
    {
        var consumer = CreateConsumer();
        var state = new ConsumerState
        {
            Delivered = new SequencePair { Consumer = 11, Stream = 22 },
            AckFloor = new SequencePair { Consumer = 10, Stream = 21 },
            Pending = new Dictionary<ulong, Pending> { [22] = new Pending { Sequence = 11, Timestamp = 1 } },
        };

        consumer.ApplyState(state);
        consumer.SetStoreState(state);
        consumer.WriteStoreState().Delivered.Stream.ShouldBe(22UL);
        consumer.WriteStoreStateUnlocked().Delivered.Stream.ShouldBe(22UL);
        consumer.ReadStoredState().Delivered.Stream.ShouldBe(22UL);

        consumer.InitialInfo().Stream.ShouldBe("S");
        consumer.ClearInitialInfo();
        consumer.Info().Name.ShouldBe("D");
        consumer.InfoWithSnap(state).Delivered.Stream.ShouldBe(22UL);
        var (info, reply) = consumer.InfoWithSnapAndReply("r", state);
        info.Stream.ShouldBe("S");
        reply.ShouldBe("r");

        consumer.SignalNewMessages();
        consumer.UpdateConfig(new ConsumerConfig { Durable = "D", SampleFrequency = "100%", FilterSubject = "foo.*", AckPolicy = AckPolicy.AckExplicit });
        consumer.ShouldSample().ShouldBeTrue();
        consumer.SampleAck("reply").ShouldBeTrue();
        consumer.ProcessAckMsg(22, 11, 2, "reply", doSample: true).ShouldBeTrue();
        consumer.IsFiltered("foo.bar").ShouldBeTrue();
        consumer.NeedAck().ShouldBeTrue();
    }

    [Fact]
    public void NextReqFromMsg_ShouldParseBatchAndJson()
    {
        var (simple, simpleErr) = NatsConsumer.NextReqFromMsg("5"u8);
        simpleErr.ShouldBeNull();
        simple.ShouldNotBeNull();
        simple!.Batch.ShouldBe(5);

        var (jsonReq, jsonErr) = NatsConsumer.NextReqFromMsg("{\"batch\":2,\"expires\":\"00:00:01\"}"u8);
        jsonErr.ShouldBeNull();
        jsonReq.ShouldNotBeNull();
        jsonReq!.Batch.ShouldBe(2);
    }
}