using System.Text.Json;
using Akka.Actor;
using Akka.TestKit;
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.OpcUa;
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.Driver.FOCAS;
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>
///     Gitea #647 — a FOCAS CNC alarm reaches its Part 9 condition END TO END: the REAL <see cref="FocasDriver"/>
///     (over a fake CNC client), fed the raw tags exactly as the deployment artifact delivers them, raises into the
///     REAL <see cref="DriverHostActor"/>, whose <c>ForwardNativeAlarm</c> + <c>NativeAlarmProjector</c> must turn it
///     into an Active and then an inactive condition at the tag's RawPath.
/// </summary>
/// <remarks>
///     The lesson this exists for: OpcUaClient and AbCip native alarms were "routed" — events raised, unit tests
///     green — but never reached a condition, because nothing checked the event against the key the host actually
///     routes on (ConditionId == RawPath) or the field its projector actually reads (Kind). A test that stops at the
///     driver's event cannot see either.
/// </remarks>
public sealed class FocasNativeAlarmEndToEndTests : RuntimeActorTestBase
{
    private static readonly NodeId TestNode = NodeId.Parse("focas-alarm-e2e");
    private static readonly RevisionHash Rev = RevisionHash.Parse(new string('f', 64));
    private const string Host = "focas://10.0.0.5:8193";
    private const string DriverId = "drv-focas";
    private const string ExpectedRawPath = "Plant/Cnc/m1/servo_alarms";

    [Fact]
    public async Task A_CNC_servo_alarm_activates_then_clears_the_condition_at_the_RawPath()
    {
        var db = NewInMemoryDbFactory();
        var blob = BuildArtifact();
        var deploymentId = Seed(db, blob);
        var (host, publish) = SpawnHostAndApply(db, deploymentId);

        // The raw tags exactly as the driver receives them: the artifact's merged DriverConfig RawTags array.
        var rawTags = RawTagsFor(blob, DriverId);
        rawTags.Select(t => t.RawPath).ShouldBe([ExpectedRawPath]);

        var cnc = new AlarmOnlyFocasClient();
        var driver = new FocasDriver(new FocasDriverOptions
        {
            Devices = [new FocasDeviceOptions(Host, DeviceName: "m1")],
            RawTags = rawTags,
            Probe = new FocasProbeOptions { Enabled = false },
            AlarmProjection = new FocasAlarmProjectionOptions { PollInterval = TimeSpan.FromMilliseconds(20) },
        }, DriverId, new SingleClientFactory(cnc));
        driver.OnAlarmEvent += (_, e) => host.Tell(new DriverInstanceActor.AttributeAlarmPublished(DriverId, e));

        await driver.InitializeAsync("{}", CancellationToken.None);
        // The host's alarm subscription set is the alarm-bearing raw tags' RawPaths. Called directly, as the
        // DriverInstanceActor would through its invoker: the routing is under test, not resilience wrapping.
#pragma warning disable OTOPCUA0001
        await driver.SubscribeAlarmsAsync([.. rawTags.Select(t => t.RawPath)], CancellationToken.None);
#pragma warning restore OTOPCUA0001
        try
        {
            cnc.SetAlarms(new FocasActiveAlarm(401, FocasAlarmType.Servo, 1, "SERVO V-READY OFF"));
            var active = publish.FishForMessage<OpcUaPublishActor.AlarmStateUpdate>(_ => true, TimeSpan.FromSeconds(5));
            active.AlarmNodeId.ShouldBe(ExpectedRawPath);
            active.Realm.ShouldBe(AddressSpaceRealm.Raw);
            active.State.Active.ShouldBeTrue("the Raise must project to an ACTIVE condition, not 'keep prior state'");
            active.State.Acknowledged.ShouldBeFalse();
            active.State.Severity.ShouldBe((ushort)800, "the authored alarm.severity is the condition's severity");
            active.State.Message.ShouldStartWith("401 SERVO V-READY OFF");

            cnc.SetAlarms();
            var cleared = publish.FishForMessage<OpcUaPublishActor.AlarmStateUpdate>(_ => true, TimeSpan.FromSeconds(5));
            cleared.AlarmNodeId.ShouldBe(ExpectedRawPath);
            cleared.State.Active.ShouldBeFalse();
        }
        finally
        {
            await driver.ShutdownAsync(CancellationToken.None);
        }
    }

    /// <summary>The seeded artifact's FOCAS driver raw tags, decoded through the production artifact reader.</summary>
    private static List<RawTagEntry> RawTagsFor(byte[] blob, string driverInstanceId)
    {
        using var artifact = DeploymentArtifact.Open(blob);
        var spec = artifact.ParseDriverInstances().Single(s => s.DriverInstanceId == driverInstanceId);
        using var doc = JsonDocument.Parse(spec.DriverConfig);
        return JsonSerializer.Deserialize<List<RawTagEntry>>(
            doc.RootElement.GetProperty("RawTags").GetRawText(),
            new JsonSerializerOptions { PropertyNameCaseInsensitive = true })!;
    }

    private static byte[] BuildArtifact() => JsonSerializer.SerializeToUtf8Bytes(new
    {
        RawFolders = new[] { new { RawFolderId = "rf-plant", ParentRawFolderId = (string?)null, Name = "Plant", ClusterId = "c1" } },
        DriverInstances = new[]
        {
            // Enabled=false: the host must not spawn a real wire driver — the test drives its own instance.
            new { DriverInstanceId = DriverId, RawFolderId = "rf-plant", Name = "Cnc", DriverType = "FOCAS", DriverConfig = "{}", ClusterId = "c1", Enabled = false },
        },
        Devices = new[]
        {
            new { DeviceId = "dev-m1", DriverInstanceId = DriverId, Name = "m1", DeviceConfig = JsonSerializer.Serialize(new { HostAddress = Host }) },
        },
        TagGroups = Array.Empty<object>(),
        Tags = new[]
        {
            new
            {
                TagId = "tag-servo",
                DeviceId = "dev-m1",
                TagGroupId = (string?)null,
                Name = "servo_alarms",
                DataType = "Int32",
                AccessLevel = 0,
                TagConfig = JsonSerializer.Serialize(new
                {
                    address = "ALARM:Servo",
                    dataType = "Int32",
                    alarm = new { alarmType = "AlarmCondition", severity = 800 },
                }),
            },
        },
    });

    private static DeploymentId Seed(IDbContextFactory<OtOpcUaConfigDbContext> db, byte[] blob)
    {
        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 = blob,
        });
        ctx.SaveChanges();
        return id;
    }

    private (IActorRef Actor, TestProbe Publish) SpawnHostAndApply(
        IDbContextFactory<OtOpcUaConfigDbContext> db, DeploymentId deploymentId)
    {
        var coordinator = CreateTestProbe();
        var publish = this.CreateCleanOutcomePublishProbe();
        var actor = Sys.ActorOf(DriverHostActor.Props(
            db, TestNode, coordinator.Ref,
            localRoles: new HashSet<string> { "driver" },
            dependencyMux: CreateTestProbe().Ref,
            opcUaPublishActor: publish.Ref,
            virtualTagEvaluator: NullVirtualTagEvaluator.Instance,
            virtualTagHostOverride: CreateTestProbe().Ref));

        actor.Tell(new DispatchDeployment(deploymentId, Rev, CorrelationId.NewId()));
        coordinator.ExpectMsg<ApplyAck>(TimeSpan.FromSeconds(5)).Outcome.ShouldBe(ApplyAckOutcome.Applied);
        publish.ExpectMsg<OpcUaPublishActor.RebuildAddressSpace>(TimeSpan.FromSeconds(5));
        return (actor, publish);
    }

    private sealed class SingleClientFactory(IFocasClient client) : IFocasClientFactory
    {
        public IFocasClient Create() => client;

        public void EnsureUsable() { }
    }

    /// <summary>A CNC that only answers the alarm list — everything else this test never reaches.</summary>
    private sealed class AlarmOnlyFocasClient : IFocasClient
    {
        private readonly Lock _gate = new();
        private FocasActiveAlarm[] _alarms = [];

        public bool IsConnected { get; private set; }

        public void SetAlarms(params FocasActiveAlarm[] alarms)
        {
            lock (_gate) _alarms = alarms;
        }

        public Task ConnectAsync(FocasHostAddress address, TimeSpan timeout, CancellationToken cancellationToken)
        {
            IsConnected = true;
            return Task.CompletedTask;
        }

        public Task<IReadOnlyList<FocasActiveAlarm>> ReadAlarmsAsync(CancellationToken cancellationToken)
        {
            lock (_gate) return Task.FromResult<IReadOnlyList<FocasActiveAlarm>>([.. _alarms]);
        }

        public Task<bool> ProbeAsync(CancellationToken cancellationToken) => Task.FromResult(true);

        public void Dispose() => IsConnected = false;

        public Task<(object? value, uint status)> ReadAsync(FocasAddress address, FocasDataType type, CancellationToken cancellationToken) => throw Unused();
        public Task<uint> WriteAsync(FocasAddress address, FocasDataType type, object? value, CancellationToken cancellationToken) => throw Unused();
        public Task<(IReadOnlyList<long>? slots, uint status)> ReadPmcSlotsAsync(string letter, FocasDataType slotType, int start, int end, CancellationToken cancellationToken) => throw Unused();
        public Task<FocasSysInfo> GetSysInfoAsync(CancellationToken cancellationToken) => throw Unused();
        public Task<IReadOnlyList<FocasAxisName>> GetAxisNamesAsync(CancellationToken cancellationToken) => throw Unused();
        public Task<IReadOnlyList<FocasSpindleName>> GetSpindleNamesAsync(CancellationToken cancellationToken) => throw Unused();
        public Task<FocasDynamicSnapshot> ReadDynamicAsync(int axisIndex, CancellationToken cancellationToken) => throw Unused();
        public Task<FocasProgramInfo> GetProgramInfoAsync(CancellationToken cancellationToken) => throw Unused();
        public Task<FocasStatus> GetStatusAsync(CancellationToken cancellationToken) => throw Unused();
        public Task<FocasTimer> GetTimerAsync(FocasTimerKind kind, CancellationToken cancellationToken) => throw Unused();
        public Task<IReadOnlyList<FocasServoLoad>> GetServoLoadsAsync(CancellationToken cancellationToken) => throw Unused();
        public Task<IReadOnlyList<double?>> GetSpindleLoadsAsync(CancellationToken cancellationToken) => throw Unused();
        public Task<IReadOnlyList<double?>> GetSpindleMotorSpeedsAsync(CancellationToken cancellationToken) => throw Unused();

        private static NotSupportedException Unused() => new("not reached by the alarm end-to-end test");
    }
}