using Akka.Actor;
using Akka.TestKit.Xunit2;
using Microsoft.Extensions.DependencyInjection;
using NSubstitute;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Sites;
using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Repositories;
using ZB.MOM.WW.ScadaBridge.Commons.Messages.Deployment;
using ZB.MOM.WW.ScadaBridge.Commons.Messages.Lifecycle;
using ZB.MOM.WW.ScadaBridge.Commons.Types.Enums;
using ZB.MOM.WW.ScadaBridge.Communication.Actors;

namespace ZB.MOM.WW.ScadaBridge.Communication.Tests;

/// <summary>
/// T1B.3 seam tests: <see cref="CentralCommunicationActor"/> routing a <see cref="SiteEnvelope"/>
/// through an injected <see cref="ISiteCommandTransport"/> (transport-agnostic), proving the
/// envelope reaches the transport, the reply routes back to the waiting Ask, and the DB refresh
/// tick reconciles per-site transport resources.
/// </summary>
public class CentralCommunicationActorTransportTests : TestKit
{
    public CentralCommunicationActorTransportTests() : base(@"akka.loglevel = WARNING") { }

    private static Site GrpcSite(string id, string? grpcA = "http://a:8083", string? grpcB = "http://b:8083") =>
        new("Test " + id, id)
        {
            NodeAAddress = $"akka.tcp://scadabridge@{id}-a:8081",
            GrpcNodeAAddress = grpcA,
            GrpcNodeBAddress = grpcB
        };

    private (IActorRef actor, ISiteCommandTransport transport, ISiteRepository repo) CreateActor(
        IEnumerable<Site>? sites = null)
    {
        var repo = Substitute.For<ISiteRepository>();
        repo.GetAllSitesAsync(Arg.Any<CancellationToken>()).Returns(sites?.ToList() ?? new List<Site>());

        var services = new ServiceCollection();
        services.AddScoped(_ => repo);
        var sp = services.BuildServiceProvider();

        var transport = Substitute.For<ISiteCommandTransport>();
        var actor = Sys.ActorOf(Props.Create(() => new CentralCommunicationActor(sp, transport)));
        return (actor, transport, repo);
    }

    [Fact]
    public void SiteEnvelope_IsRoutedToTheTransport_WithTheSenderAsReplyTo()
    {
        var (actor, transport, _) = CreateActor();
        var probe = CreateTestProbe();

        var cmd = new EnableInstanceCommand("cmd-1", "Site1.Pump1", DateTimeOffset.UtcNow);
        actor.Tell(new SiteEnvelope("site-a", cmd), probe.Ref);

        AwaitAssert(() => transport.Received(1).Send(
            Arg.Is<SiteEnvelope>(e => e.SiteId == "site-a" && ReferenceEquals(e.Message, cmd)),
            probe.Ref));
    }

    [Fact]
    public async Task AskReply_FromTransport_RoutesBackToTheWaitingAsk()
    {
        var (actor, transport, _) = CreateActor();

        // The transport substitute stands in for the site: when handed the envelope it delivers a
        // reply to the captured replyTo, exactly as a real transport pipes the site's reply back.
        var reply = new DeploymentStatusResponse(
            "dep-1", "Site1.Pump1", DeploymentStatus.Success, null, DateTimeOffset.UtcNow);
        transport
            .When(t => t.Send(Arg.Any<SiteEnvelope>(), Arg.Any<IActorRef>()))
            .Do(ci => ci.Arg<IActorRef>().Tell(reply));

        var cmd = new RefreshDeploymentCommand(
            "dep-1", "Site1.Pump1", "hash", "multi-role", DateTimeOffset.UtcNow, "http://c:5000", "tok");
        var result = await actor.Ask<DeploymentStatusResponse>(
            new SiteEnvelope("site-a", cmd), TimeSpan.FromSeconds(3));

        Assert.Equal("dep-1", result.DeploymentId);
        Assert.Equal(DeploymentStatus.Success, result.Status);
    }

    [Fact]
    public void DbRefresh_ReconcilesTheTransport_WithTheLoadedGrpcEndpoints()
    {
        var (_, transport, _) = CreateActor(new[] { GrpcSite("site-a") });

        // PreStart fires the refresh at Zero; the loaded cache is handed to the transport.
        AwaitAssert(() => transport.Received().ReconcileSites(
            Arg.Is<SiteAddressCacheLoaded>(c =>
                c.KnownSiteIds.Contains("site-a")
                && c.GrpcContacts.ContainsKey("site-a")
                && c.GrpcContacts["site-a"].NodeA == "http://a:8083"
                && c.GrpcContacts["site-a"].NodeB == "http://b:8083")),
            TimeSpan.FromSeconds(3));
    }

    [Fact]
    public void SiteAddedAndRemoved_AcrossRefreshes_FlowsThroughToTheTransport()
    {
        var (actor, transport, repo) = CreateActor(new[] { GrpcSite("site-a") });

        AwaitAssert(() => transport.Received().ReconcileSites(
            Arg.Is<SiteAddressCacheLoaded>(c => c.GrpcContacts.ContainsKey("site-a"))),
            TimeSpan.FromSeconds(3));

        // site-a removed, site-b added.
        repo.GetAllSitesAsync(Arg.Any<CancellationToken>()).Returns(new List<Site> { GrpcSite("site-b") });
        actor.Tell(new RefreshSiteAddresses());

        AwaitAssert(() => transport.Received().ReconcileSites(
            Arg.Is<SiteAddressCacheLoaded>(c =>
                c.GrpcContacts.ContainsKey("site-b")
                && !c.GrpcContacts.ContainsKey("site-a")
                && c.KnownSiteIds.Contains("site-b")
                && !c.KnownSiteIds.Contains("site-a"))),
            TimeSpan.FromSeconds(3));
    }

    [Fact]
    public void SiteWithoutGrpcAddresses_IsAbsentFromGrpcContacts_ButStillKnown()
    {
        // A site with only Akka addresses (no gRPC columns) is a known site but carries no gRPC
        // endpoint — the gRPC transport must not try to dial it, the Akka one still can.
        var akkaOnly = new Site("Akka only", "site-x")
        {
            NodeAAddress = "akka.tcp://scadabridge@site-x-a:8081"
        };
        var (_, transport, _) = CreateActor(new[] { akkaOnly });

        AwaitAssert(() => transport.Received().ReconcileSites(
            Arg.Is<SiteAddressCacheLoaded>(c =>
                c.KnownSiteIds.Contains("site-x") && !c.GrpcContacts.ContainsKey("site-x"))),
            TimeSpan.FromSeconds(3));
    }
}
