using Akka.Actor;
using Akka.Cluster.Tools.Client;
using Akka.TestKit.Xunit2;
using ScadaLink.Commons.Messages.Deployment;
using ScadaLink.Commons.Messages.Lifecycle;
using ScadaLink.Commons.Messages.Integration;
using ScadaLink.Commons.Messages.Notification;
using ScadaLink.Commons.Messages.RemoteQuery;
using ScadaLink.Communication.Actors;

namespace ScadaLink.Communication.Tests;

/// <summary>
/// WP-4: Tests for SiteCommunicationActor message routing to local actors.
/// </summary>
public class SiteCommunicationActorTests : TestKit
{
    private readonly CommunicationOptions _options = new();

    public SiteCommunicationActorTests()
        : base(@"akka.loglevel = DEBUG")
    {
    }

    [Fact]
    public void DeployCommand_ForwardedToDeploymentManager()
    {
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        var command = new DeployInstanceCommand(
            "dep1", "inst1", "hash1", "{}", "admin", DateTimeOffset.UtcNow);
        siteActor.Tell(command);

        dmProbe.ExpectMsg<DeployInstanceCommand>(msg => msg.DeploymentId == "dep1");
    }

    [Fact]
    public void LifecycleCommands_ForwardedToDeploymentManager()
    {
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        siteActor.Tell(new DisableInstanceCommand("cmd1", "inst1", DateTimeOffset.UtcNow));
        dmProbe.ExpectMsg<DisableInstanceCommand>();

        siteActor.Tell(new EnableInstanceCommand("cmd2", "inst1", DateTimeOffset.UtcNow));
        dmProbe.ExpectMsg<EnableInstanceCommand>();

        siteActor.Tell(new DeleteInstanceCommand("cmd3", "inst1", DateTimeOffset.UtcNow));
        dmProbe.ExpectMsg<DeleteInstanceCommand>();
    }

    [Fact]
    public void DeploymentStateQuery_ForwardedToDeploymentManager()
    {
        // DeploymentManager-006: the site-before-redeploy query travels over the
        // ClusterClient command/control transport and is routed to the local
        // Deployment Manager, which owns the deployed-config store.
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        var request = new DeploymentStateQueryRequest("corr-q", "inst1", DateTimeOffset.UtcNow);
        siteActor.Tell(request);

        dmProbe.ExpectMsg<DeploymentStateQueryRequest>(msg => msg.CorrelationId == "corr-q");
    }

    [Fact]
    public void IntegrationCall_WithoutHandler_ReturnsFailure()
    {
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        var request = new IntegrationCallRequest(
            "corr1", "site1", "inst1", "ExtSys1", "GetData",
            new Dictionary<string, object?>(), DateTimeOffset.UtcNow);

        siteActor.Tell(request);

        ExpectMsg<IntegrationCallResponse>(msg =>
            !msg.Success && msg.ErrorMessage == "Integration handler not available");
    }

    [Fact]
    public void IntegrationCall_WithHandler_ForwardedToHandler()
    {
        var dmProbe = CreateTestProbe();
        var handlerProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        // Register integration handler
        siteActor.Tell(new RegisterLocalHandler(LocalHandlerType.Integration, handlerProbe.Ref));

        var request = new IntegrationCallRequest(
            "corr1", "site1", "inst1", "ExtSys1", "GetData",
            new Dictionary<string, object?>(), DateTimeOffset.UtcNow);

        siteActor.Tell(request);
        handlerProbe.ExpectMsg<IntegrationCallRequest>(msg => msg.CorrelationId == "corr1");
    }

    [Fact]
    public void NotificationSubmit_WithCentralClient_ForwardedToCentralAndAckRoutedBack()
    {
        // The site forwards a buffered notification to central over the ClusterClient
        // command/control transport; the central ack must route back to the original
        // sender (the S&F forwarder's Ask), not to the SiteCommunicationActor.
        var dmProbe = CreateTestProbe();
        var centralClientProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        siteActor.Tell(new RegisterCentralClient(centralClientProbe.Ref));

        var submit = new NotificationSubmit(
            "notif-1", "Operators", "Subj", "Body", "site1", "inst1", "alarmScript",
            DateTimeOffset.UtcNow);
        siteActor.Tell(submit);

        // Central client (acting as ClusterClient) receives a ClusterClient.Send wrapping
        // the NotificationSubmit, addressed to the central communication actor. Fish past
        // any periodic HeartbeatMessage the actor's timer may interleave.
        var send = centralClientProbe.FishForMessage<ClusterClient.Send>(
            s => s.Message is NotificationSubmit);
        Assert.Equal("/user/central-communication", send.Path);
        var forwarded = Assert.IsType<NotificationSubmit>(send.Message);
        Assert.Equal("notif-1", forwarded.NotificationId);

        // The ack is sent to the ClusterClient.Send's Sender — replying as that probe
        // must land back at the test actor (the original Tell sender).
        centralClientProbe.Reply(new NotificationSubmitAck("notif-1", Accepted: true, Error: null));
        ExpectMsg<NotificationSubmitAck>(ack => ack.NotificationId == "notif-1" && ack.Accepted);
    }

    [Fact]
    public void NotificationSubmit_WithoutCentralClient_RepliesWithNonAccepted()
    {
        // No ClusterClient registered yet: the submit cannot be forwarded, so the actor
        // replies with a non-accepted ack and the S&F forwarder treats it as transient.
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        var submit = new NotificationSubmit(
            "notif-2", "Operators", "Subj", "Body", "site1", null, null,
            DateTimeOffset.UtcNow);
        siteActor.Tell(submit);

        ExpectMsg<NotificationSubmitAck>(ack => ack.NotificationId == "notif-2" && !ack.Accepted);
    }

    [Fact]
    public void NotificationStatusQuery_WithCentralClient_ForwardedToCentralAndResponseRoutedBack()
    {
        // Notify.Status(id) issues a NotificationStatusQuery; the site actor forwards it
        // to central over the ClusterClient command/control transport and the central
        // response must route back to the original sender (the helper's Ask).
        var dmProbe = CreateTestProbe();
        var centralClientProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        siteActor.Tell(new RegisterCentralClient(centralClientProbe.Ref));

        var query = new NotificationStatusQuery("corr-99", "notif-1");
        siteActor.Tell(query);

        var send = centralClientProbe.FishForMessage<ClusterClient.Send>(
            s => s.Message is NotificationStatusQuery);
        Assert.Equal("/user/central-communication", send.Path);
        var forwarded = Assert.IsType<NotificationStatusQuery>(send.Message);
        Assert.Equal("notif-1", forwarded.NotificationId);

        // The response is sent to the ClusterClient.Send's Sender — replying as that
        // probe must land back at the test actor (the original Tell sender).
        centralClientProbe.Reply(new NotificationStatusResponse(
            "corr-99", Found: true, Status: "Delivered", RetryCount: 0,
            LastError: null, DeliveredAt: DateTimeOffset.UtcNow));
        ExpectMsg<NotificationStatusResponse>(r => r.CorrelationId == "corr-99" && r.Found);
    }

    [Fact]
    public void NotificationStatusQuery_WithoutCentralClient_RepliesWithNotFound()
    {
        // No ClusterClient registered yet: the query cannot reach central, so the actor
        // replies Found: false. Notify.Status then falls back to the site S&F buffer.
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        siteActor.Tell(new NotificationStatusQuery("corr-100", "notif-2"));

        ExpectMsg<NotificationStatusResponse>(
            r => r.CorrelationId == "corr-100" && !r.Found);
    }

    [Fact]
    public void EventLogQuery_WithoutHandler_ReturnsFailure()
    {
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        var request = new EventLogQueryRequest(
            "corr1", "site1", null, null, null, null, null, null, null, 25, DateTimeOffset.UtcNow);

        siteActor.Tell(request);

        ExpectMsg<EventLogQueryResponse>(msg => !msg.Success);
    }

    // ── Task 5 (#22): central→site Retry/Discard relay for parked cached calls ──

    [Fact]
    public void RetryParkedOperation_WithHandler_ForwardedToParkedMessageHandler()
    {
        var dmProbe = CreateTestProbe();
        var handlerProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        siteActor.Tell(new RegisterLocalHandler(LocalHandlerType.ParkedMessages, handlerProbe.Ref));

        var id = Commons.Types.TrackedOperationId.New();
        siteActor.Tell(new RetryParkedOperation("corr-rp", id));

        handlerProbe.ExpectMsg<RetryParkedOperation>(msg =>
            msg.CorrelationId == "corr-rp" && msg.TrackedOperationId.Equals(id));
    }

    [Fact]
    public void DiscardParkedOperation_WithHandler_ForwardedToParkedMessageHandler()
    {
        var dmProbe = CreateTestProbe();
        var handlerProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        siteActor.Tell(new RegisterLocalHandler(LocalHandlerType.ParkedMessages, handlerProbe.Ref));

        var id = Commons.Types.TrackedOperationId.New();
        siteActor.Tell(new DiscardParkedOperation("corr-dp", id));

        handlerProbe.ExpectMsg<DiscardParkedOperation>(msg =>
            msg.CorrelationId == "corr-dp" && msg.TrackedOperationId.Equals(id));
    }

    [Fact]
    public void RetryParkedOperation_WithoutHandler_RepliesNotAppliedAck()
    {
        // No parked-message handler registered — the relay must get a definitive
        // non-applied ack, not silence (the SiteCallAuditActor's Ask must not
        // hang and then mis-report site-unreachable when the site IS reachable).
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        siteActor.Tell(new RetryParkedOperation("corr-no-handler", Commons.Types.TrackedOperationId.New()));

        var ack = ExpectMsg<ParkedOperationActionAck>();
        Assert.Equal("corr-no-handler", ack.CorrelationId);
        Assert.False(ack.Applied);
        Assert.NotNull(ack.ErrorMessage);
    }

    [Fact]
    public void DiscardParkedOperation_WithoutHandler_RepliesNotAppliedAck()
    {
        var dmProbe = CreateTestProbe();
        var siteActor = Sys.ActorOf(Props.Create(() =>
            new SiteCommunicationActor("site1", _options, dmProbe.Ref)));

        siteActor.Tell(new DiscardParkedOperation("corr-no-handler", Commons.Types.TrackedOperationId.New()));

        var ack = ExpectMsg<ParkedOperationActionAck>();
        Assert.False(ack.Applied);
        Assert.NotNull(ack.ErrorMessage);
    }
}