using Akka.Actor;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Commons.Messages.Audit;
using ZB.MOM.WW.OtOpcUa.Commons.Types;
using ZB.MOM.WW.OtOpcUa.ControlPlane.Audit;
using ZB.MOM.WW.OtOpcUa.ControlPlane.Tests.Harness;

namespace ZB.MOM.WW.OtOpcUa.ControlPlane.Tests;

public sealed class AuditWriterActorTests : ControlPlaneActorTestBase
{
    private static AuditEvent NewEvent(Guid eventId, string action = "Edit", string actor = "joe") =>
        new(
            eventId,
            "Config",
            action,
            actor,
            DateTime.UtcNow,
            DetailsJson: "{\"field\":\"value\"}",
            SourceNode: NodeId.Parse("node-a"),
            CorrelationId: CorrelationId.NewId());

    [Fact]
    public void Buffered_events_flush_on_count_threshold()
    {
        var dbFactory = NewInMemoryDbFactory();
        var actor = Sys.ActorOf(AuditWriterActor.Props(dbFactory));

        // Sending exactly FlushBatchSize events triggers a flush.
        for (var i = 0; i < AuditWriterActor.FlushBatchSize; i++)
            actor.Tell(NewEvent(Guid.NewGuid()));

        // Give the actor a beat to process the messages.
        AwaitAssert(() =>
        {
            using var db = dbFactory.CreateDbContext();
            db.ConfigAuditLogs.Count().ShouldBe(AuditWriterActor.FlushBatchSize);
        }, duration: TimeSpan.FromSeconds(2));
    }

    [Fact]
    public void Duplicate_eventIds_within_a_batch_dedup_in_buffer()
    {
        var dbFactory = NewInMemoryDbFactory();
        var actor = Sys.ActorOf(AuditWriterActor.Props(dbFactory));

        // Send 1000 messages, but only 100 unique EventIds (10x duplication).
        var uniqueIds = Enumerable.Range(0, 100).Select(_ => Guid.NewGuid()).ToArray();
        for (var i = 0; i < 1000; i++)
            actor.Tell(NewEvent(uniqueIds[i % 100]));

        // Force a flush — send PoisonPill, which triggers PostStop → FlushBuffer.
        Watch(actor);
        actor.Tell(PoisonPill.Instance);
        ExpectTerminated(actor);

        using var db = dbFactory.CreateDbContext();
        db.ConfigAuditLogs.Count().ShouldBe(100, "in-buffer dedup should collapse duplicate EventIds");
    }

    [Fact]
    public void PostStop_flushes_pending_buffer()
    {
        var dbFactory = NewInMemoryDbFactory();
        var actor = Sys.ActorOf(AuditWriterActor.Props(dbFactory));

        // 10 events — well below the threshold, so they sit in-buffer.
        for (var i = 0; i < 10; i++)
            actor.Tell(NewEvent(Guid.NewGuid()));

        Watch(actor);
        actor.Tell(PoisonPill.Instance);
        ExpectTerminated(actor);

        using var db = dbFactory.CreateDbContext();
        db.ConfigAuditLogs.Count().ShouldBe(10);
    }

    [Fact]
    public void Details_wrapper_embeds_eventId_and_correlationId()
    {
        var dbFactory = NewInMemoryDbFactory();
        var actor = Sys.ActorOf(AuditWriterActor.Props(dbFactory));

        var eventId = Guid.NewGuid();
        actor.Tell(NewEvent(eventId));

        Watch(actor);
        actor.Tell(PoisonPill.Instance);
        ExpectTerminated(actor);

        using var db = dbFactory.CreateDbContext();
        var row = db.ConfigAuditLogs.Single();
        row.DetailsJson.ShouldNotBeNull();
        row.DetailsJson.ShouldContain(eventId.ToString("N"));
        row.DetailsJson.ShouldContain("\"correlationId\":");
        row.EventType.ShouldBe("Config:Edit");
        row.NodeId.ShouldBe("node-a");
    }
}