using Akka.Actor;
using Akka.TestKit.Xunit2;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using NSubstitute;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.Deployment;
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.Types.Deployment;
using ZB.MOM.WW.ScadaBridge.Communication.Actors;

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

/// <summary>
/// Tests that <see cref="CentralCommunicationActor"/> routes a site→central
/// <see cref="ReconcileSiteRequest"/> through the scoped <see cref="ReconcileService"/>
/// and pipes the resulting <see cref="ReconcileSiteResponse"/> back to the original
/// sender (the site's transport path). Mirrors the audit-ingest routing tests.
/// </summary>
public class CentralCommunicationActorReconcileTests : TestKit
{
    /// <summary>Verifies that the response to a reconcile request is routed back to the original sender.</summary>
    [Fact]
    public void ReconcileSiteRequest_RoutesResponseToSender()
    {
        var deploymentRepo = Substitute.For<IDeploymentManagerRepository>();
        var siteRepo = Substitute.For<ISiteRepository>();

        // GetAllSitesAsync is called by the actor's periodic refresh; keep it empty.
        siteRepo.GetAllSitesAsync(Arg.Any<CancellationToken>())
            .Returns(new List<Site>());

        siteRepo.GetSiteByIdentifierAsync("site1", Arg.Any<CancellationToken>())
            .Returns(new Site("Site One", "site1") { Id = 7 });

        deploymentRepo.GetExpectedDeploymentsForSiteAsync(7, Arg.Any<CancellationToken>())
            .Returns(new List<ExpectedDeployment>
            {
                new(2, "inst-B", "rev2", "dep-B", true),
            });
        deploymentRepo.GetDeployedSnapshotsByInstanceIdsAsync(
                Arg.Any<IReadOnlyCollection<int>>(), Arg.Any<CancellationToken>())
            .Returns(new Dictionary<int, DeployedConfigSnapshot>
            {
                [2] = new("dep-B", "rev2", "{\"cfg\":\"B\"}") { InstanceId = 2 },
            });
        // Every candidate is staged fresh: the batch hands each one back as its live row.
        deploymentRepo.StagePendingBatchIfAbsentAsync(
                Arg.Any<IReadOnlyList<PendingDeployment>>(), Arg.Any<DateTimeOffset>(), Arg.Any<CancellationToken>())
            .Returns(ci => (IReadOnlyDictionary<int, PendingDeployment>)ci.ArgAt<IReadOnlyList<PendingDeployment>>(0)
                .ToDictionary(p => p.InstanceId));

        var options = Options.Create(new CommunicationOptions
        {
            CentralFetchBaseUrl = "https://central.example:9000",
            PendingDeploymentTtl = TimeSpan.FromMinutes(5),
        });

        var services = new ServiceCollection();
        services.AddScoped(_ => deploymentRepo);
        services.AddScoped(_ => siteRepo);
        services.AddSingleton(options);
        services.AddSingleton<Microsoft.Extensions.Logging.ILogger<ReconcileService>>(
            NullLogger<ReconcileService>.Instance);
        services.AddScoped<ReconcileService>();
        var sp = services.BuildServiceProvider();

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

        // Node B is missing inst-B entirely → it should come back as a gap item.
        actor.Tell(new ReconcileSiteRequest(
            "site1", "node-b",
            new Dictionary<string, string>()));

        var response = ExpectMsg<ReconcileSiteResponse>(TimeSpan.FromSeconds(5));
        var gap = Assert.Single(response.Gap);
        Assert.Equal("inst-B", gap.InstanceUniqueName);
        Assert.Equal("dep-B", gap.DeploymentId);
        Assert.False(string.IsNullOrWhiteSpace(gap.FetchToken));
    }

    /// <summary>Verifies that cancelling the originating gRPC call stops central reconcile work (review 2026-10-21 03/P-1b).</summary>
    [Fact]
    public void CancelledCall_StopsCentralReconcileWork()
    {
        var deploymentRepo = Substitute.For<IDeploymentManagerRepository>();
        var siteRepo = Substitute.For<ISiteRepository>();
        siteRepo.GetAllSitesAsync(Arg.Any<CancellationToken>()).Returns(new List<Site>());

        var lookupStarted = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
        CancellationToken observed = default;
        siteRepo.GetSiteByIdentifierAsync("site1", Arg.Any<CancellationToken>()).Returns(async ci =>
        {
            observed = ci.Arg<CancellationToken>();
            lookupStarted.TrySetResult();
            await Task.Delay(Timeout.Infinite, observed); // a slow central DB
            return (Site?)new Site("Site One", "site1") { Id = 7 };
        });

        var services = new ServiceCollection();
        services.AddScoped(_ => deploymentRepo);
        services.AddScoped(_ => siteRepo);
        services.AddSingleton(Options.Create(new CommunicationOptions()));
        services.AddSingleton<Microsoft.Extensions.Logging.ILogger<ReconcileService>>(
            NullLogger<ReconcileService>.Instance);
        services.AddScoped<ReconcileService>();
        var sp = services.BuildServiceProvider();

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

        using var call = new CancellationTokenSource();
        actor.Tell(new ReconcileSiteCall(
            new ReconcileSiteRequest("site1", "node-b", new Dictionary<string, string>()), call.Token));
        AwaitCondition(() => lookupStarted.Task.IsCompleted, TimeSpan.FromSeconds(3));

        // The site gives up (deadline / disconnect).
        call.Cancel();

        AwaitCondition(() => observed.IsCancellationRequested, TimeSpan.FromSeconds(3));
        ExpectMsg<Status.Failure>(TimeSpan.FromSeconds(3));
        deploymentRepo.DidNotReceiveWithAnyArgs().GetExpectedDeploymentsForSiteAsync(default, default);
    }
}