using Akka.Actor;
using Microsoft.EntityFrameworkCore;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Commons.Messages.Deploy;
using ZB.MOM.WW.OtOpcUa.Commons.Types;
using ZB.MOM.WW.OtOpcUa.Configuration;
using ZB.MOM.WW.OtOpcUa.Configuration.Entities;
using ZB.MOM.WW.OtOpcUa.Configuration.Enums;
using ZB.MOM.WW.OtOpcUa.Runtime.Drivers;
using ZB.MOM.WW.OtOpcUa.Runtime.OpcUa;
using ZB.MOM.WW.OtOpcUa.Runtime.Tests.Harness;

namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.Drivers;

/// <summary>
///     lmxopcua#868 fourth review M2: a revision a node ADOPTS without an outcome-reporting apply — Stale recovery, a
///     failed bootstrap restore — is not known to be served. A dispatch of that same revision must RE-APPLY (the
///     publish actor gets a rebuild) instead of short-circuiting a clean Applied over an empty address space.
/// </summary>
public sealed class DriverHostActorUnconfirmedRevisionTests : RuntimeActorTestBase
{
    private static readonly NodeId TestNode = NodeId.Parse("driver-test");
    private static readonly RevisionHash RevA = RevisionHash.Parse(new string('a', 64));

    [Fact]
    public void A_revision_adopted_by_Stale_recovery_is_reapplied_on_redispatch()
    {
        var db = new SwitchableDbFactory(Guid.NewGuid().ToString("N"));
        var deploymentId = Seed(db);
        db.Down = true;
        var publish = CreateTestProbe();
        var actor = Sys.ActorOf(DriverHostActor.Props(
            db, TestNode, CreateTestProbe().Ref, localRoles: new HashSet<string> { "driver" },
            opcUaPublishActor: publish.Ref));

        // Bootstrap fails (DB down) ⇒ Stale. Bring the DB back and drive the recovery tick by hand.
        // Barrier: Stale answers RouteNodeWrite with a "stale" refusal, so a reply proves the host is in Stale.
        var asker = CreateTestProbe();
        actor.Tell(new DriverHostActor.RouteNodeWrite("eq-x/speed", 0.0, ZB.MOM.WW.OtOpcUa.Commons.OpcUa.AddressSpaceRealm.Uns), asker.Ref);
        asker.ExpectMsg<DriverHostActor.NodeWriteResult>(PresenceBudget, cancellationToken: TestContext.Current.CancellationToken)
            .Reason!.ShouldContain("stale");
        db.Down = false;
        actor.Tell(DriverHostActor.RetryConfigDbConnection.Instance);
        AwaitAssert(() =>
        {
            using var ctx = db.CreateDbContext();
            ctx.NodeDeploymentStates.Single(r => r.NodeId == TestNode.Value).Status.ShouldBe(NodeDeploymentStatus.Applied);
        }, PresenceBudget, cancellationToken: TestContext.Current.CancellationToken);
        publish.ExpectNoMsg(TimeSpan.FromMilliseconds(200), TestContext.Current.CancellationToken); // recovery restores nothing

        actor.Tell(new DispatchDeployment(deploymentId, RevA, CorrelationId.NewId()));

        publish.FishForMessage<OpcUaPublishActor.RebuildAddressSpace>(
            m => m.DeploymentId == deploymentId && m.ReportOutcome, PresenceBudget, cancellationToken: TestContext.Current.CancellationToken);
    }

    [Fact]
    public void A_revision_whose_bootstrap_restore_failed_is_reapplied_on_redispatch()
    {
        var db = new SwitchableDbFactory(Guid.NewGuid().ToString("N"));
        var deploymentId = Seed(db);
        using (var ctx = db.CreateDbContext())
        {
            ctx.NodeDeploymentStates.Add(new NodeDeploymentState
            {
                NodeId = TestNode.Value, DeploymentId = deploymentId.Value, Status = NodeDeploymentStatus.Applied,
                StartedAtUtc = DateTime.UtcNow, AppliedAtUtc = DateTime.UtcNow,
            });
            ctx.SaveChanges();
        }
        db.FailRestore = true;   // the restore's artifact read throws; the bootstrap's own row read does not
        var publish = CreateTestProbe();
        var actor = Sys.ActorOf(DriverHostActor.Props(
            db, TestNode, CreateTestProbe().Ref, localRoles: new HashSet<string> { "driver" },
            opcUaPublishActor: publish.Ref));
        AwaitCondition(() => db.RestoreFailures > 0, PresenceBudget, cancellationToken: TestContext.Current.CancellationToken);
        db.FailRestore = false;

        actor.Tell(new DispatchDeployment(deploymentId, RevA, CorrelationId.NewId()));

        publish.FishForMessage<OpcUaPublishActor.RebuildAddressSpace>(
            m => m.DeploymentId == deploymentId && m.ReportOutcome, PresenceBudget, cancellationToken: TestContext.Current.CancellationToken);
    }

    private static DeploymentId Seed(IDbContextFactory<OtOpcUaConfigDbContext> db) =>
        V3ArtifactSeeder.SeedV3Deployment(db, RevA,
            rawTags: new[] { (Driver: "drv-1", DriverName: "Modbus", Device: "dev1", Tag: "speed", DataType: "Double", Writable: false) },
            unsRefs: new[] { (Area: "filling", Line: "line1", Equip: "station1", BackingTag: "speed", Effective: (string?)null) });

    /// <summary>In-memory ConfigDb that can be down, or fail only the bootstrap restore's artifact read.</summary>
    private sealed class SwitchableDbFactory(string dbName) : IDbContextFactory<OtOpcUaConfigDbContext>
    {
        private volatile bool _down;
        private volatile bool _failRestore;
        private int _attempts;
        private int _restoreFailures;

        public bool Down { get => _down; set => _down = value; }
        public bool FailRestore { get => _failRestore; set => _failRestore = value; }
        public int Attempts => Volatile.Read(ref _attempts);
        public int RestoreFailures => Volatile.Read(ref _restoreFailures);

        public OtOpcUaConfigDbContext CreateDbContext()
        {
            Interlocked.Increment(ref _attempts);
            if (_down) throw new InvalidOperationException("ConfigDb unreachable (simulated)");
            if (_failRestore && new System.Diagnostics.StackTrace().ToString().Contains("RestoreApplied"))
            {
                Interlocked.Increment(ref _restoreFailures);
                throw new InvalidOperationException("ConfigDb read failed during restore (simulated)");
            }
            return new OtOpcUaConfigDbContext(new DbContextOptionsBuilder<OtOpcUaConfigDbContext>()
                .UseInMemoryDatabase(dbName).Options);
        }
    }
}