using System.Collections.Concurrent;
using System.Text.Json;
using Akka.Actor;
using Microsoft.EntityFrameworkCore;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Commons.Engines;
using ZB.MOM.WW.OtOpcUa.Commons.Messages.Deploy;
using ZB.MOM.WW.OtOpcUa.Commons.Messages.Fleet;
using ZB.MOM.WW.OtOpcUa.Commons.Messages.Redundancy;
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.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Runtime.Drivers;
using ZB.MOM.WW.OtOpcUa.Runtime.Tests.Harness;

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

/// <summary>
///     v3 Batch 4 (B4-WP4) — the inbound native-condition <b>acknowledge</b> routing wired into
///     <see cref="DriverHostActor"/> re-expressed for the v3 raw-condition model. An OPC UA client Acknowledges
///     a NATIVE condition (materialised at the raw tag, ConditionId = its RawPath); the node manager invokes
///     <c>NativeAlarmAckRouter</c> and the host receives a <see cref="DriverHostActor.RouteNativeAlarmAck"/>.
///     The host resolves the condition NodeId (== the RawPath) → owning <c>(DriverInstanceId, RawPath)</c> via
///     the <c>_driverRefByAlarmNodeId</c> inverse map (built alongside the alarm forward map in
///     <c>PushDesiredSubscriptions</c> from the alarm-bearing <c>composition.RawTags</c>), applies the SAME
///     primary gate the inbound write path uses, and routes to the owning driver child's
///     <see cref="IAlarmSource.AcknowledgeAsync"/> carrying the principal.
///
///     <para>
///         Mirrors <c>DriverHostActorLiveValueTests</c>: a real apply through the harness spawns a real
///         (non-stubbed) <see cref="DriverInstanceActor"/> child backed by a recording <see cref="IAlarmSource"/>
///         driver (DriverType "GalaxyMxGateway", Enabled), so the inverse map is populated authentically and the
///         forwarded acknowledge request can be observed. The seeded raw tag carries an <c>alarm</c> object so it
///         materialises as a Part 9 condition at its RawPath, not a value variable.
///     </para>
/// </summary>
public sealed class DriverHostActorNativeAlarmAckRoutingTests : RuntimeActorTestBase
{
    private static readonly NodeId TestNode = NodeId.Parse("driver-ack-test");
    private static readonly RevisionHash RevA = RevisionHash.Parse(new string('a', 64));
    private static readonly TimeSpan Timeout = TimeSpan.FromSeconds(5);

    // The v3 RawPath for the seeded alarm tag: RawFolder "Plant" / DriverName "gw" / Device "dev1" / Tag.
    private const string AlarmRawPath = "Plant/gw/dev1/temp_hi";

    /// <summary>On the PRIMARY (role unknown ⇒ Primary), a RouteNativeAlarmAck for a mapped raw condition NodeId
    /// (== the RawPath) forwards exactly one <see cref="AlarmAcknowledgeRequest"/> to the owning driver's
    /// <see cref="IAlarmSource.AcknowledgeAsync"/>, correlated on the RawPath, with the operator principal + the
    /// comment.</summary>
    [Fact]
    public void RouteNativeAlarmAck_routes_to_driver_AcknowledgeAsync_with_principal()
    {
        var db = NewInMemoryDbFactory();
        var recorder = new RecordingAlarmDriverFactory("GalaxyMxGateway");
        var deploymentId = SeedV3AlarmDeployment(db, RevA, Driver: "drv-1", Tag: "temp_hi");

        var actor = SpawnHostAndApply(db, deploymentId, recorder);

        // Local role unknown ⇒ treated as Primary ⇒ ack allowed (default-allow semantics).
        actor.Tell(new DriverHostActor.RouteNativeAlarmAck(AlarmRawPath, "cmt", "alice"));

        // The driver received exactly one acknowledge, correlated on its wire-ref RawPath, with principal.
        AwaitAssert(() =>
        {
            recorder.Acks.Count.ShouldBe(1);
            recorder.Acks[0].ConditionId.ShouldBe(AlarmRawPath);
            recorder.Acks[0].SourceNodeId.ShouldBe(AlarmRawPath);
            recorder.Acks[0].Comment.ShouldBe("cmt");
            recorder.Acks[0].OperatorUser.ShouldBe("alice");
        }, duration: Timeout);
    }

    /// <summary>An ack for an unmapped condition NodeId is dropped: no throw, and the driver's
    /// <see cref="IAlarmSource.AcknowledgeAsync"/> is never called.</summary>
    [Fact]
    public void RouteNativeAlarmAck_unknown_node_is_dropped()
    {
        var db = NewInMemoryDbFactory();
        var recorder = new RecordingAlarmDriverFactory("GalaxyMxGateway");
        var deploymentId = SeedV3AlarmDeployment(db, RevA, Driver: "drv-1", Tag: "temp_hi");

        var actor = SpawnHostAndApply(db, deploymentId, recorder);

        actor.Tell(new DriverHostActor.RouteNativeAlarmAck("Plant/gw/dev1/does-not-exist", "cmt", "alice"));

        // Give the (fire-and-forget) handler time to run; the unmapped node must produce no ack.
        AwaitAssert(() => recorder.Acks.ShouldBeEmpty(), duration: TimeSpan.FromMilliseconds(800));
    }

    /// <summary>On a SECONDARY node the ack is gated off (same primary gate as the inbound write path): the
    /// driver's <see cref="IAlarmSource.AcknowledgeAsync"/> is NOT called.</summary>
    [Fact]
    public void RouteNativeAlarmAck_on_non_primary_is_dropped()
    {
        var db = NewInMemoryDbFactory();
        var recorder = new RecordingAlarmDriverFactory("GalaxyMxGateway");
        var deploymentId = SeedV3AlarmDeployment(db, RevA, Driver: "drv-1", Tag: "temp_hi");

        var actor = SpawnHostAndApply(db, deploymentId, recorder);

        // Force this node Secondary so the primary gate rejects the ack.
        actor.Tell(new RedundancyStateChanged(
            new[]
            {
                new NodeRedundancyState(TestNode, RedundancyRole.Secondary,
                    IsClusterLeader: false, IsRoleLeaderForDriver: false, AsOfUtc: DateTime.UtcNow),
            },
            CorrelationId.NewId()));

        actor.Tell(new DriverHostActor.RouteNativeAlarmAck(AlarmRawPath, "cmt", "alice"));

        // No ack reached the driver — the gate short-circuited before the inverse-map lookup.
        AwaitAssert(() => recorder.Acks.ShouldBeEmpty(), duration: TimeSpan.FromMilliseconds(800));
    }

    /// <summary>Spawns the host with the recording alarm-driver factory, dispatches the deployment, and waits
    /// for the Applied ACK so the apply (and thus the inverse-map build in PushDesiredSubscriptions) has
    /// completed before the test routes an ack.</summary>
    private IActorRef SpawnHostAndApply(
        IDbContextFactory<OtOpcUaConfigDbContext> db, DeploymentId deploymentId, IDriverFactory factory)
    {
        var coordinator = CreateTestProbe();
        var actor = Sys.ActorOf(DriverHostActor.Props(
            db, TestNode, coordinator.Ref,
            driverFactory: factory,
            localRoles: new HashSet<string> { "driver" }));

        actor.Tell(new DispatchDeployment(deploymentId, RevA, CorrelationId.NewId()));
        coordinator.ExpectMsg<ApplyAck>(Timeout).Outcome.ShouldBe(ApplyAckOutcome.Applied);

        return actor;
    }

    /// <summary>
    ///     Seeds a Sealed deployment whose artifact carries the v3 raw-tag chain (RawFolder "Plant" →
    ///     DriverInstance(RawFolderId, Name "gw", DriverType "GalaxyMxGateway", Enabled) → Device "dev1" → Tag)
    ///     with the tag's <c>TagConfig</c> carrying an <c>alarm</c> object so the composer projects a non-null
    ///     <c>EquipmentTagAlarmInfo</c> — making the raw tag a Part 9 condition at its RawPath. The non-Windows
    ///     <c>DriverType</c> + Enabled flag spawn a REAL <see cref="DriverInstanceActor"/> child.
    /// </summary>
    private static DeploymentId SeedV3AlarmDeployment(
        IDbContextFactory<OtOpcUaConfigDbContext> db, RevisionHash rev, string Driver, string Tag)
    {
        var artifact = JsonSerializer.SerializeToUtf8Bytes(new
        {
            RawFolders = new[] { new { RawFolderId = "rf-plant", ParentRawFolderId = (string?)null, Name = "Plant", ClusterId = "c1" } },
            DriverInstances = new[]
            {
                new
                {
                    DriverInstanceRowId = Guid.NewGuid(),
                    DriverInstanceId = Driver,
                    RawFolderId = "rf-plant",
                    Name = "gw",
                    DriverType = "GalaxyMxGateway", // not Windows-only ⇒ a real child is spawned (not stubbed)
                    Enabled = true,
                    DriverConfig = "{}",
                    ClusterId = "c1",
                },
            },
            Devices = new[]
            {
                new { DeviceId = $"{Driver}:dev1", DriverInstanceId = Driver, Name = "dev1", DeviceConfig = "{}" },
            },
            TagGroups = Array.Empty<object>(),
            Tags = new[]
            {
                new
                {
                    TagId = "tag-0",
                    DeviceId = $"{Driver}:dev1",
                    TagGroupId = (string?)null,
                    Name = Tag,
                    DataType = "Boolean",
                    AccessLevel = 0, // TagAccessLevel.Read
                    TagConfig = JsonSerializer.Serialize(new { alarm = new { alarmType = "OffNormalAlarm", severity = 700 } }),
                },
            },
        });

        var id = DeploymentId.NewId();
        using var ctx = db.CreateDbContext();
        ctx.Deployments.Add(new Deployment
        {
            DeploymentId = id.Value,
            RevisionHash = rev.Value,
            Status = DeploymentStatus.Sealed,
            CreatedBy = "test",
            SealedAtUtc = DateTime.UtcNow,
            ArtifactBlob = artifact,
        });
        ctx.SaveChanges();
        return id;
    }

    /// <summary>Factory producing a single <see cref="RecordingAlarmDriver"/> for the supported type, whose
    /// recorded acknowledge list is exposed for assertions.</summary>
    private sealed class RecordingAlarmDriverFactory : IDriverFactory
    {
        private readonly string _supportedType;
        private readonly RecordingAlarmDriver _driver = new();
        public RecordingAlarmDriverFactory(string supportedType) { _supportedType = supportedType; }

        /// <summary>The acknowledge requests the spawned driver received (thread-safe — AcknowledgeAsync runs
        /// off the actor thread).</summary>
        public IReadOnlyList<AlarmAcknowledgeRequest> Acks => _driver.Acks;

        /// <inheritdoc />
        public IDriver? TryCreate(string driverType, string driverInstanceId, string driverConfigJson)
        {
            if (!string.Equals(driverType, _supportedType, StringComparison.Ordinal)) return null;
            _driver.Bind(driverInstanceId, driverType);
            return _driver;
        }

        /// <inheritdoc />
        public IReadOnlyCollection<string> SupportedTypes => new[] { _supportedType };
    }

    /// <summary>An <see cref="IDriver"/> + <see cref="IAlarmSource"/> that records every acknowledge.</summary>
    private sealed class RecordingAlarmDriver : IDriver, IAlarmSource
    {
        private readonly ConcurrentQueue<AlarmAcknowledgeRequest> _acks = new();
        /// <inheritdoc />
        public string DriverInstanceId { get; private set; } = string.Empty;
        /// <inheritdoc />
        public string DriverType { get; private set; } = string.Empty;
        /// <summary>The acknowledge requests received so far.</summary>
        public IReadOnlyList<AlarmAcknowledgeRequest> Acks => _acks.ToArray();
        /// <summary>Sets the identity once the factory is asked to create it.</summary>
        public void Bind(string id, string type) { DriverInstanceId = id; DriverType = type; }
        /// <inheritdoc />
        public Task InitializeAsync(string driverConfigJson, CancellationToken cancellationToken) => Task.CompletedTask;
        /// <inheritdoc />
        public Task ReinitializeAsync(string driverConfigJson, CancellationToken cancellationToken) => Task.CompletedTask;
        /// <inheritdoc />
        public Task ShutdownAsync(CancellationToken cancellationToken) => Task.CompletedTask;
        /// <inheritdoc />
        public DriverHealth GetHealth() => new(DriverState.Healthy, DateTime.UtcNow, LastError: null);
        /// <inheritdoc />
        public long GetMemoryFootprint() => 0;
        /// <inheritdoc />
        public Task FlushOptionalCachesAsync(CancellationToken cancellationToken) => Task.CompletedTask;

        /// <inheritdoc />
        public Task<IAlarmSubscriptionHandle> SubscribeAlarmsAsync(
            IReadOnlyList<string> sourceNodeIds, CancellationToken cancellationToken) =>
            Task.FromResult<IAlarmSubscriptionHandle>(new StubAlarmHandle());

        /// <inheritdoc />
        public Task UnsubscribeAlarmsAsync(IAlarmSubscriptionHandle handle, CancellationToken cancellationToken) =>
            Task.CompletedTask;

        /// <inheritdoc />
        public Task AcknowledgeAsync(
            IReadOnlyList<AlarmAcknowledgeRequest> acknowledgements, CancellationToken cancellationToken)
        {
            foreach (var a in acknowledgements) _acks.Enqueue(a);
            return Task.CompletedTask;
        }

        /// <inheritdoc />
        public event EventHandler<AlarmEventArgs>? OnAlarmEvent
        {
            add { }
            remove { }
        }

        private sealed class StubAlarmHandle : IAlarmSubscriptionHandle
        {
            public string DiagnosticId => "stub-alarm-sub";
        }
    }
}