using Opc.Ua;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;

namespace ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests;

/// <summary>
///     Gitea #641 — a full <see cref="OtOpcUaNodeManager.RebuildAddressSpace"/> recreates every native condition
///     inactive, and when the alarm-tag set is unchanged nothing tells the new node its state again (the driver
///     does not re-subscribe, and Galaxy / OpcUaClient have nothing to replay anyway). The node manager therefore
///     carries each NATIVE condition's live state across the rebuild: captured before the clear, restored when
///     the same id is re-materialised native in the same apply, and reported as ONE condition event when the
///     apply completes (<see cref="OtOpcUaNodeManager.CompleteAddressSpaceApply"/>).
/// </summary>
/// <remarks>
///     "One event" is observed here through the condition's <c>EventId</c>, which every report stamps fresh.
///     The exact count over the wire is pinned by <c>NativeAlarmRebuildCarryOverWireTests</c>.
/// </remarks>
public sealed class NodeManagerNativeAlarmRebuildCarryOverTests : IDisposable
{
    private const string Device = "Plant/MTConnect/dev1";
    private const string Alarm = "Plant/MTConnect/dev1/Xtravel";

    private static CancellationToken Ct => TestContext.Current.CancellationToken;

    private readonly string _pkiRoot = Path.Combine(Path.GetTempPath(), $"otopcua-641-{Guid.NewGuid():N}");

    private static AlarmConditionSnapshot Fault(bool acked) => new(
        Active: true, Acknowledged: acked, Confirmed: true, Enabled: true,
        Shelving: AlarmShelvingKind.Unshelved, Severity: 800, Message: "Xtravel FAULT 1001",
        StatusCode: OpcUaStatus.Good);

    [Trait("Category", "Unit")]
    [Fact]
    public async Task An_active_unacked_native_condition_survives_a_rebuild_and_is_reported_once()
    {
        var (host, nm) = await BootAsync();
        var raisedAt = new DateTime(2026, 10, 8, 9, 0, 0, DateTimeKind.Utc);
        Materialise(nm, native: true);
        nm.WriteAlarmCondition(Alarm, Fault(acked: false), raisedAt, AddressSpaceRealm.Raw);

        nm.RebuildAddressSpace();
        Materialise(nm, native: true);
        var restored = Condition(nm);
        var idBeforeComplete = (byte[]?)restored.EventId.Value?.Clone();

        // State is back as soon as the node exists — a Read or a ConditionRefresh in between already sees it.
        restored.ActiveState.Id.Value.ShouldBeTrue();
        restored.AckedState.Id.Value.ShouldBeFalse();
        restored.Retain.Value.ShouldBeTrue();
        restored.Severity.Value.ShouldBe((ushort)800);
        restored.Message.Value.Text.ShouldBe("Xtravel FAULT 1001");
        restored.Quality.Value.Code.ShouldBe(StatusCodes.Good);

        nm.CompleteAddressSpaceApply();

        // The report happens at the END of the apply (after the notifier wiring), stamped with the instant the
        // state came about, not the deploy time.
        restored.EventId.Value.ShouldNotBe(idBeforeComplete);
        restored.Time.Value.ShouldBe(raisedAt);

        // ...and only once: a second completion with nothing pending reports nothing.
        var idAfterComplete = (byte[]?)restored.EventId.Value?.Clone();
        nm.CompleteAddressSpaceApply();
        restored.EventId.Value.ShouldBe(idAfterComplete);

        await host.DisposeAsync();
    }

    /// <summary>
    ///     The acknowledgement a CLIENT applied lives only on the node (the SDK applied it; no driver or projector
    ///     saw it) — the reason the carry-over reads the node rather than any host-side cache.
    /// </summary>
    [Trait("Category", "Unit")]
    [Fact]
    public async Task A_client_acknowledgement_survives_the_rebuild()
    {
        var (host, nm) = await BootAsync();
        Materialise(nm, native: true);
        nm.WriteAlarmCondition(Alarm, Fault(acked: false), DateTime.UtcNow, AddressSpaceRealm.Raw);
        // What the SDK's Acknowledge handler does to the node; nothing else hears of it.
        Condition(nm).SetAcknowledgedState(nm.SystemContext, true);

        nm.RebuildAddressSpace();
        Materialise(nm, native: true);
        nm.CompleteAddressSpaceApply();

        var restored = Condition(nm);
        restored.ActiveState.Id.Value.ShouldBeTrue();
        restored.AckedState.Id.Value.ShouldBeTrue();
        restored.Retain.Value.ShouldBeTrue();

        await host.DisposeAsync();
    }

    /// <summary>
    ///     Gitea #641 review — the comment a client left with its acknowledgement is condition state too (native
    ///     conditions support AddComment), and an event the condition reported AFTER the restore (a client method
    ///     call landing on an SDK thread before the apply completes) must not have its newer <c>Time</c> rolled
    ///     back by the deferred restore report.
    /// </summary>
    [Trait("Category", "Unit")]
    [Fact]
    public async Task The_comment_is_carried_and_a_newer_report_is_not_rolled_back()
    {
        var (host, nm) = await BootAsync();
        var raisedAt = new DateTime(2026, 10, 8, 9, 0, 0, DateTimeKind.Utc);
        Materialise(nm, native: true);
        nm.WriteAlarmCondition(Alarm, Fault(acked: false), raisedAt, AddressSpaceRealm.Raw);
        Condition(nm).Comment.Value = new LocalizedText("on it");

        nm.RebuildAddressSpace();
        Materialise(nm, native: true);
        var later = raisedAt.AddMinutes(5);
        nm.WriteAlarmQuality(Alarm, StatusCodes.BadNoCommunication, later, AddressSpaceRealm.Raw); // reports at `later`
        nm.CompleteAddressSpaceApply();

        var restored = Condition(nm);
        restored.Comment.Value.Text.ShouldBe("on it");
        restored.Time.Value.ShouldBe(later, "the restore report must not stamp the condition back to the raise time");

        await host.DisposeAsync();
    }

    /// <summary>Falsification control: a condition in the no-event position comes back exactly as a fresh
    /// materialise builds it, and reports nothing.</summary>
    [Trait("Category", "Unit")]
    [Fact]
    public async Task A_normal_native_condition_reports_nothing_and_keeps_the_fresh_state()
    {
        var (host, nm) = await BootAsync();
        Materialise(nm, native: true);
        nm.WriteAlarmCondition(Alarm, Fault(acked: false) with { Active = false, Acknowledged = true, Message = "cleared" },
            DateTime.UtcNow, AddressSpaceRealm.Raw);

        nm.RebuildAddressSpace();
        Materialise(nm, native: true);
        var fresh = Condition(nm);
        var idBefore = (byte[]?)fresh.EventId.Value?.Clone();
        nm.CompleteAddressSpaceApply();

        fresh.EventId.Value.ShouldBe(idBefore);
        fresh.ActiveState.Id.Value.ShouldBeFalse();
        fresh.AckedState.Id.Value.ShouldBeTrue();
        fresh.Retain.Value.ShouldBeFalse();
        fresh.Message.Value.Text.ShouldBe("Xtravel", "a normal condition keeps the materialise's message");
        fresh.Severity.Value.ShouldBe((ushort)700, "and its authored severity");

        await host.DisposeAsync();
    }

    /// <summary>
    ///     The source-data quality is carried for a NORMAL condition too, silently: quality is annotated only on a
    ///     driver's connectivity edge, so without the carry a rebuild left every normal native condition reading
    ///     <c>BadWaitingForInitialData</c> until the driver next flapped.
    /// </summary>
    [Trait("Category", "Unit")]
    [Fact]
    public async Task A_normal_condition_keeps_its_quality_without_an_event()
    {
        var (host, nm) = await BootAsync();
        Materialise(nm, native: true);
        nm.WriteAlarmQuality(Alarm, OpcUaStatus.Good, DateTime.UtcNow, AddressSpaceRealm.Raw);

        nm.RebuildAddressSpace();
        Materialise(nm, native: true);
        var fresh = Condition(nm);
        var idBefore = (byte[]?)fresh.EventId.Value?.Clone();
        nm.CompleteAddressSpaceApply();

        fresh.Quality.Value.Code.ShouldBe(StatusCodes.Good);
        fresh.EventId.Value.ShouldBe(idBefore);

        await host.DisposeAsync();
    }

    /// <summary>A condition the rebuild did NOT re-create has its captured state discarded when the apply
    /// completes, so a later deploy that adds the same RawPath back gets a fresh node, not a resurrection.</summary>
    [Trait("Category", "Unit")]
    [Fact]
    public async Task A_condition_removed_by_the_rebuild_is_not_resurrected_by_a_later_add()
    {
        var (host, nm) = await BootAsync();
        Materialise(nm, native: true);
        nm.WriteAlarmCondition(Alarm, Fault(acked: false), DateTime.UtcNow, AddressSpaceRealm.Raw);

        nm.RebuildAddressSpace();
        nm.CompleteAddressSpaceApply(); // the alarm was removed: nothing re-materialised it

        Materialise(nm, native: true); // a later, surgical re-add of the same RawPath
        nm.CompleteAddressSpaceApply();

        var readded = Condition(nm);
        readded.ActiveState.Id.Value.ShouldBeFalse();
        readded.AckedState.Id.Value.ShouldBeTrue();

        await host.DisposeAsync();
    }

    /// <summary>A native condition re-materialised as SCRIPTED under the same id is a different alarm: nothing
    /// is restored onto it (and the scripted engine's own #487 re-assert owns scripted state).</summary>
    [Trait("Category", "Unit")]
    [Fact]
    public async Task A_kind_swap_on_the_same_id_is_not_restored()
    {
        var (host, nm) = await BootAsync();
        Materialise(nm, native: true);
        nm.WriteAlarmCondition(Alarm, Fault(acked: false), DateTime.UtcNow, AddressSpaceRealm.Raw);

        nm.RebuildAddressSpace();
        Materialise(nm, native: false);
        nm.CompleteAddressSpaceApply();

        Condition(nm).ActiveState.Id.Value.ShouldBeFalse();

        await host.DisposeAsync();
    }

    /// <summary>Scripted conditions are not captured — <c>ScriptedAlarmHostActor.ReassertConditionNodes</c>
    /// (#487) already re-projects them after a reload, and a second source would double-report.</summary>
    [Trait("Category", "Unit")]
    [Fact]
    public async Task A_scripted_condition_is_not_carried()
    {
        var (host, nm) = await BootAsync();
        Materialise(nm, native: false);
        nm.WriteAlarmCondition(Alarm, Fault(acked: false), DateTime.UtcNow, AddressSpaceRealm.Raw);

        nm.RebuildAddressSpace();
        Materialise(nm, native: false);
        nm.CompleteAddressSpaceApply();

        Condition(nm).ActiveState.Id.Value.ShouldBeFalse();

        await host.DisposeAsync();
    }

    private static void Materialise(OtOpcUaNodeManager nm, bool native)
    {
        nm.EnsureFolder(Device, parentNodeId: null, displayName: "dev1", realm: AddressSpaceRealm.Raw);
        nm.MaterialiseAlarmCondition(Alarm, Device, "Xtravel", "OffNormalAlarm", 700, AddressSpaceRealm.Raw, isNative: native);
    }

    private static Opc.Ua.AlarmConditionState Condition(OtOpcUaNodeManager nm) =>
        nm.TryGetAlarmCondition(Alarm, AddressSpaceRealm.Raw).ShouldNotBeNull();

    private async Task<(OpcUaApplicationHost Host, OtOpcUaNodeManager Nm)> BootAsync()
    {
        var applicationUri = $"urn:OtOpcUa.Gitea641Test:{Guid.NewGuid():N}";
        var started = await OpcUaHostStart.StartAsync(
            port => new OpcUaApplicationHost(
                new OpcUaApplicationHostOptions
                {
                    ApplicationName = "OtOpcUa.Gitea641Test",
                    ApplicationUri = applicationUri,
                    OpcUaPort = port,
                    PublicHostname = "localhost",
                    PkiStoreRoot = _pkiRoot,
                },
                Microsoft.Extensions.Logging.Abstractions.NullLogger<OpcUaApplicationHost>.Instance),
            () => new OtOpcUaSdkServer(), Ct);
        var host = started.Host;
        var server = started.Server;
        return (host, server.NodeManager!);
    }

    /// <summary>Cleans up the PKI root directory.</summary>
    public void Dispose()
    {
        if (Directory.Exists(_pkiRoot))
        {
            try { Directory.Delete(_pkiRoot, recursive: true); }
            catch { /* best-effort cleanup */ }
        }
    }
}