using Opc.Ua;
using Opc.Ua.Client;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
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.Core.Authorization;
using static ZB.MOM.WW.OtOpcUa.OpcUaServer.IntegrationTests.ServerEventRig;

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

/// <summary>
///     Gitea #629 over the wire — every child of a materialised Part 9 condition (ActiveState/Id,
///     ShelvingState/UnshelveTime, Message, …) carries an instance-scoped NodeId in the condition's own
///     namespace, so a client that translates a child's browse path and then Reads it gets THIS condition's
///     value — not the condition type's ns=0 instance declaration.
/// </summary>
/// <remarks>
///     <para>
///         Before #629 <c>AlarmConditionState.Create(..., assignNodeIds: true)</c> asked the node manager's
///         <c>INodeIdFactory.New</c> for each child's id, and <c>CustomNodeManager2.New</c> returns the node's
///         CURRENT id — the type's instance-declaration id (<c>i=9189</c> for UnshelveTime). Every condition's
///         children therefore shared those ns=0 ids, a translate returned them, and a Read of one was served
///         by the core node manager from the TYPE, never reaching the condition.
///     </para>
///     <para>
///         Each read asserts a value only the instance holds (projected Active, unacked, a distinguishing
///         message, a timed shelve's remaining time), so a type-node answer fails it.
///     </para>
/// </remarks>
public sealed class ConditionChildNodeIdTests
{
    private const NodePermissions BrowseRead = NodePermissions.Browse | NodePermissions.Read;

    private static readonly string[][] ChildPaths =
    [
        ["ActiveState", "Id"],
        ["AckedState", "Id"],
        ["EnabledState", "Id"],
        ["Severity"],
        ["Message"],
        ["Retain"],
        ["ShelvingState", "UnshelveTime"],
        ["ShelvingState", "CurrentState", "Id"],
    ];

    /// <summary>
    ///     Translating a condition child's browse path returns an instance-scoped NodeId in the condition's
    ///     namespace (derived from the condition id), and a Read of that NodeId returns the instance's value —
    ///     for a native (raw) and a scripted (UNS) condition, with ACL enforcement on and off.
    /// </summary>
    [Theory]
    [InlineData(true, true)]
    [InlineData(false, true)]
    [InlineData(true, false)]
    [InlineData(false, false)]
    public async Task A_condition_child_resolves_to_an_instance_node_that_reads_the_instance_value(bool native, bool aclOn)
    {
        var ct = TestContext.Current.CancellationToken;
        var rig = await StartAsync($"CondChildIds{native}{aclOn}", encrypted: false, ct);
        try
        {
            rig.Enforce(aclOn, [Key()], ClusterGrant(KeyPrincipal, "acl-key", BrowseRead));
            rig.MaterialiseNative();
            rig.MaterialiseScripted();
            ProjectDistinguishingStates(rig);

            using var session = await rig.ConnectAsync(anonymous: false, ct);
            var condition = ConditionNodeId(session, native);
            var conditionId = (string)condition.Identifier;

            var resolved = await TranslateAsync(session, condition, ChildPaths, ct);
            for (var i = 0; i < ChildPaths.Length; i++)
            {
                var path = string.Join('/', ChildPaths[i]);
                resolved[i].NamespaceIndex.ShouldBe(condition.NamespaceIndex, $"{path} lives in the condition's namespace");
                resolved[i].Identifier.ShouldBe($"{conditionId}/{path}", $"{path} is scoped to the condition instance");
            }

            var values = await ReadAsync(session, resolved, ct);
            for (var i = 0; i < values.Count; i++)
                StatusCode.IsGood(values[i].StatusCode).ShouldBeTrue($"{string.Join('/', ChildPaths[i])}: {values[i].StatusCode}");

            var expectedMessage = native ? "native-distinct" : "scripted-distinct";
            values[0].Value.ShouldBe(true, "ActiveState/Id — the instance is active");
            values[1].Value.ShouldBe(false, "AckedState/Id — the instance is unacknowledged");
            values[2].Value.ShouldBe(true, "EnabledState/Id");
            values[3].Value.ShouldBe(
                rig.Nm.TryGetAlarmCondition(native ? RawAlarmPath : ScriptedAlarmId, native ? AddressSpaceRealm.Raw : AddressSpaceRealm.Uns)!
                    .Severity.Value,
                "Severity — the instance's mapped severity");
            ((ushort)values[3].Value).ShouldBeGreaterThan((ushort)0);
            (values[4].Value as LocalizedText)?.Text.ShouldBe(expectedMessage, "Message");
            values[5].Value.ShouldBe(true, "Retain — an active unacked condition is retained");
            if (native)
            {
                ((double)values[6].Value).ShouldBe(0d, "UnshelveTime — a native condition is never shelved");
                values[7].Value.ShouldBe(ObjectIds.ShelvedStateMachineType_Unshelved);
            }
            else
            {
                ((double)values[6].Value).ShouldBeInRange(50_000d, 60_000d, "UnshelveTime — the instance's timed shelve");
                values[7].Value.ShouldBe(ObjectIds.ShelvedStateMachineType_TimedShelved);
            }
        }
        finally { await rig.DisposeAsync(); }
    }

    /// <summary>
    ///     Two conditions never share a child NodeId, and a browse of a condition lists its children under
    ///     the same instance ids the translate returns.
    /// </summary>
    [Fact]
    public async Task Children_of_different_conditions_have_distinct_ids_and_browse_agrees_with_translate()
    {
        var ct = TestContext.Current.CancellationToken;
        var rig = await StartAsync("CondChildDistinct", encrypted: false, ct);
        try
        {
            rig.Enforce(false, [Key()], ClusterGrant(KeyPrincipal, "acl-key", BrowseRead));
            rig.MaterialiseNative();
            rig.MaterialiseScripted();
            rig.Sink.MaterialiseAlarmCondition("scripted-eqa-lo", EqA, "lo", "AlarmCondition", 300, AddressSpaceRealm.Uns);

            using var session = await rig.ConnectAsync(anonymous: false, ct);
            var ns = (ushort)session.NamespaceUris.GetIndex(V3NodeIds.UnsNamespaceUri);
            var conditions = new[]
            {
                ConditionNodeId(session, native: true), ConditionNodeId(session, native: false), new NodeId("scripted-eqa-lo", ns),
            };

            var all = new List<NodeId>();
            foreach (var c in conditions) all.AddRange(await TranslateAsync(session, c, ChildPaths, ct));
            all.Distinct().Count().ShouldBe(all.Count, "no two conditions share a child NodeId");
            all.ShouldAllBe(id => id.NamespaceIndex != 0, "no child resolves to a type's ns=0 instance declaration");

            // Browse the scripted condition's ShelvingState: the forward references are its instance children.
            var shelving = (await TranslateAsync(session, conditions[1], [["ShelvingState"]], ct))[0];
            shelving.ShouldBe(new NodeId($"{ScriptedAlarmId}/ShelvingState", ns));
            var browsed = await BrowseChildrenAsync(session, shelving, ct);
            browsed.ShouldContain(new NodeId($"{ScriptedAlarmId}/ShelvingState/UnshelveTime", ns));
            browsed.ShouldContain(new NodeId($"{ScriptedAlarmId}/ShelvingState/CurrentState", ns));
            browsed.ShouldNotContain(VariableIds.AlarmConditionType_ShelvingState_UnshelveTime);
        }
        finally { await rig.DisposeAsync(); }
    }

    /// <summary>
    ///     With ACL enforcement on, a condition child is governed like its condition: a Read grant on the
    ///     raw device covers the condition's children (allow), and a grant that does not cover the condition
    ///     denies them — the child neither falls through to an ungated type node nor to deny-all.
    /// </summary>
    [Fact]
    public async Task A_condition_child_read_is_governed_by_the_conditions_scope()
    {
        var ct = TestContext.Current.CancellationToken;
        var rig = await StartAsync("CondChildAcl", encrypted: false, ct);
        try
        {
            // The key holds Read on the native condition's raw device only; it holds nothing on the scripted
            // condition (whose scope is its ScriptedAlarmId, under no granted path).
            var deviceGrant = new NodeAcl
            {
                NodeAclId = "acl-dev1",
                ClusterId = ServerEventRig.Cluster,
                Principal = KeyPrincipal,
                ScopeKind = NodeAclScopeKind.RawDevice,
                ScopeId = "dev-1",
                PermissionFlags = BrowseRead,
            };
            rig.Enforce(
                true,
                [Key()],
                new Dictionary<AclScopeRef, IReadOnlyList<NodeAclPath>>
                {
                    [new AclScopeRef(NodeAclScopeKind.RawDevice, "dev-1")] =
                        [new NodeAclPath([NodeAclRealms.Raw, "Plant", "Modbus", "dev1"])],
                },
                deviceGrant);
            rig.MaterialiseNative();
            rig.MaterialiseScripted();
            ProjectDistinguishingStates(rig);

            using var session = await rig.ConnectAsync(anonymous: false, ct);
            var ns = (ushort)session.NamespaceUris.GetIndex(V3NodeIds.UnsNamespaceUri);
            var rawNs = (ushort)session.NamespaceUris.GetIndex(V3NodeIds.RawNamespaceUri);

            var values = await ReadAsync(session,
            [
                new NodeId($"{RawAlarmPath}/Message", rawNs),
                new NodeId($"{RawAlarmPath}/ActiveState/Id", rawNs),
                new NodeId($"{ScriptedAlarmId}/Message", ns),
                new NodeId($"{ScriptedAlarmId}/ActiveState/Id", ns),
            ], ct);

            StatusCode.IsGood(values[0].StatusCode).ShouldBeTrue($"granted child read: {values[0].StatusCode}");
            (values[0].Value as LocalizedText)?.Text.ShouldBe("native-distinct");
            values[1].Value.ShouldBe(true);
            values[2].StatusCode.ShouldBe((StatusCode)StatusCodes.BadUserAccessDenied, "ungranted condition's child");
            values[3].StatusCode.ShouldBe((StatusCode)StatusCodes.BadUserAccessDenied, "ungranted condition's child");
        }
        finally { await rig.DisposeAsync(); }
    }

    /// <summary>
    ///     Removing a condition removes its children too: once instance-scoped they are reachable by NodeId,
    ///     so a child left indexed would keep answering a Read with the removed condition's last value.
    /// </summary>
    [Fact]
    public async Task A_removed_conditions_children_are_no_longer_readable()
    {
        var ct = TestContext.Current.CancellationToken;
        var rig = await StartAsync("CondChildRemove", encrypted: false, ct);
        try
        {
            rig.Enforce(false, [Key()], ClusterGrant(KeyPrincipal, "acl-key", BrowseRead));
            rig.MaterialiseNative();
            rig.MaterialiseScripted();
            ProjectDistinguishingStates(rig);

            using var session = await rig.ConnectAsync(anonymous: false, ct);
            var ns = (ushort)session.NamespaceUris.GetIndex(V3NodeIds.UnsNamespaceUri);
            var child = new NodeId($"{ScriptedAlarmId}/Message", ns);
            var nested = new NodeId($"{ScriptedAlarmId}/ShelvingState/UnshelveTime", ns);

            // Positive control: readable while the condition exists.
            var before = await ReadAsync(session, [child, nested], ct);
            (before[0].Value as LocalizedText)?.Text.ShouldBe("scripted-distinct");
            StatusCode.IsGood(before[1].StatusCode).ShouldBeTrue();

            rig.Nm.RemoveAlarmConditionNode(ScriptedAlarmId, AddressSpaceRealm.Uns).ShouldBeTrue();

            var after = await ReadAsync(session, [child, nested], ct);
            after[0].StatusCode.ShouldBe((StatusCode)StatusCodes.BadNodeIdUnknown);
            after[1].StatusCode.ShouldBe((StatusCode)StatusCodes.BadNodeIdUnknown);

            // A rebuild forgets them the same way (the native condition's children, here).
            var rawNs = (ushort)session.NamespaceUris.GetIndex(V3NodeIds.RawNamespaceUri);
            var rawChild = new NodeId($"{RawAlarmPath}/Message", rawNs);
            StatusCode.IsGood((await ReadAsync(session, [rawChild], ct))[0].StatusCode).ShouldBeTrue();
            rig.Nm.RebuildAddressSpace();
            (await ReadAsync(session, [rawChild], ct))[0].StatusCode.ShouldBe((StatusCode)StatusCodes.BadNodeIdUnknown);
        }
        finally { await rig.DisposeAsync(); }
    }

    /// <summary>
    ///     The shelve methods resolve by the condition's OWN child method ids
    ///     (<c>{condition}/ShelvingState/TimedShelve</c>, <c>…/Unshelve</c>) — the ids a browse of the condition
    ///     returns — whether the call names the condition or its ShelvingState as the object, and each accepted
    ///     call reports its one condition event.
    /// </summary>
    [Theory]
    [InlineData(false)]
    [InlineData(true)]
    public async Task Shelve_methods_called_by_their_instance_ids_succeed_and_report(bool objectIsShelvingState)
    {
        var ct = TestContext.Current.CancellationToken;
        var rig = await StartAsync($"CondChildMethodIds{objectIsShelvingState}", encrypted: false, ct);
        try
        {
            rig.Enforce(true, [Key()], ClusterGrant(KeyPrincipal, "acl-key", AllMethods));
            rig.MaterialiseScripted();
            var current = ConditionMethodEventTests.PreState("TimedShelve", native: false) with { Message = "base" };
            ConditionMethodEventTests.WireSimulatedOwners(rig, native: false, () => current, s => current = s);

            using var session = await rig.ConnectAsync(anonymous: false, ct);
            var events = new RecordedEvents();
            var subscription = await RecordedEvents.SubscribeAsync(session, events, ct);
            var item = RecordedEvents.AddEventItem(subscription, ObjectIds.Server);
            await subscription.ApplyChangesAsync(ct);

            rig.Project(false, current);
            await RecordedEvents.WaitUntilAsync(() => events.Has(item, "base"));

            var condition = ConditionNodeId(session, native: false);
            var ns = condition.NamespaceIndex;
            var shelvingState = new NodeId($"{ScriptedAlarmId}/ShelvingState", ns);
            var target = objectIsShelvingState ? shelvingState : condition;

            await session.CallAsync(target, new NodeId($"{ScriptedAlarmId}/ShelvingState/TimedShelve", ns), ct, 60_000d);
            await rig.DrainProjectionsAsync();
            await RecordedEvents.WaitUntilAsync(() => events.ConditionEvents(item, "base").Count == 2);
            events.ConditionEvents(item, "base")[1][RecordedEvents.ShelvingField].Value
                .ShouldBe(ObjectIds.ShelvedStateMachineType_TimedShelved);

            await session.CallAsync(target, new NodeId($"{ScriptedAlarmId}/ShelvingState/Unshelve", ns), ct);
            await rig.DrainProjectionsAsync();
            await RecordedEvents.WaitUntilAsync(() => events.ConditionEvents(item, "base").Count == 3);
            events.ConditionEvents(item, "base")[2][RecordedEvents.ShelvingField].Value
                .ShouldBe(ObjectIds.ShelvedStateMachineType_Unshelved);

            await subscription.DeleteAsync(true, ct);
        }
        finally { await rig.DisposeAsync(); }
    }

    /// <summary>
    ///     Pins the #629 trade-off: the shelve methods resolve by the condition's instance ids and by the
    ///     <c>AlarmConditionType_ShelvingState_*</c> ids every client uses (the positive control), but NOT by
    ///     the <c>ShelvedStateMachineType_*</c> ids — those were the methods' SDK declarations, replaced by the
    ///     AlarmConditionType ones when the methods moved off their ns=0 NodeIds. Change this deliberately.
    /// </summary>
    [Fact]
    public async Task A_shelve_call_by_the_state_machine_types_method_id_is_not_supported()
    {
        var ct = TestContext.Current.CancellationToken;
        var rig = await StartAsync("CondChildMethodStateMachineId", encrypted: false, ct);
        try
        {
            rig.Enforce(true, [Key()], ClusterGrant(KeyPrincipal, "acl-key", AllMethods));
            rig.MaterialiseScripted();
            var current = ConditionMethodEventTests.PreState("OneShotShelve", native: false);
            ConditionMethodEventTests.WireSimulatedOwners(rig, native: false, () => current, s => current = s);
            rig.Project(false, current);

            using var session = await rig.ConnectAsync(anonymous: false, ct);
            var condition = ConditionNodeId(session, native: false);

            var refused = await Should.ThrowAsync<ServiceResultException>(
                session.CallAsync(condition, MethodIds.ShelvedStateMachineType_OneShotShelve, ct));
            refused.StatusCode.ShouldBe(StatusCodes.BadMethodInvalid);

            // Positive control: the AlarmConditionType declaration id resolves on the same condition.
            await session.CallAsync(condition, MethodIds.AlarmConditionType_ShelvingState_OneShotShelve, ct);
        }
        finally { await rig.DisposeAsync(); }
    }

    // ───────────────────────────── helpers ─────────────────────────────

    private const NodePermissions AllMethods =
        NodePermissions.Browse | NodePermissions.Read | NodePermissions.Subscribe | NodePermissions.AlarmRead
        | NodePermissions.AlarmAcknowledge | NodePermissions.AlarmConfirm | NodePermissions.AlarmShelve
        | NodePermissions.MethodCall;

    /// <summary>
    ///     Native: active, unacked, "native-distinct". Scripted: active, unacked, "scripted-distinct", timed
    ///     shelved for 60 s — none of which the condition type's instance declarations can hold.
    /// </summary>
    private static void ProjectDistinguishingStates(ServerEventRig rig)
    {
        rig.Project(native: true, new AlarmConditionSnapshot(
            Active: true, Acknowledged: false, Confirmed: true, Enabled: true,
            Shelving: AlarmShelvingKind.Unshelved, Severity: 700, Message: "native-distinct"));
        rig.Project(native: false, new AlarmConditionSnapshot(
            Active: true, Acknowledged: false, Confirmed: false, Enabled: true,
            Shelving: AlarmShelvingKind.Timed, Severity: 300, Message: "scripted-distinct",
            UnshelveAtUtc: DateTime.UtcNow.AddSeconds(60)));
    }

    private static async Task<IReadOnlyList<NodeId>> TranslateAsync(
        ISession session, NodeId start, IReadOnlyList<string[]> paths, CancellationToken ct)
    {
        var browsePaths = new BrowsePathCollection();
        foreach (var path in paths)
        {
            var relative = new RelativePath();
            foreach (var name in path)
            {
                relative.Elements.Add(new RelativePathElement
                {
                    ReferenceTypeId = ReferenceTypeIds.HierarchicalReferences,
                    IsInverse = false,
                    IncludeSubtypes = true,
                    TargetName = new QualifiedName(name),
                });
            }
            browsePaths.Add(new BrowsePath { StartingNode = start, RelativePath = relative });
        }

        var response = await session.TranslateBrowsePathsToNodeIdsAsync(null, browsePaths, ct);
        var results = new List<NodeId>();
        for (var i = 0; i < response.Results.Count; i++)
        {
            var r = response.Results[i];
            StatusCode.IsGood(r.StatusCode).ShouldBeTrue($"translate {string.Join('/', paths[i])}: {r.StatusCode}");
            r.Targets.Count.ShouldBe(1, $"translate {string.Join('/', paths[i])} has one target");
            results.Add(ExpandedNodeId.ToNodeId(r.Targets[0].TargetId, session.NamespaceUris));
        }
        return results;
    }

    private static async Task<IReadOnlyList<DataValue>> ReadAsync(ISession session, IReadOnlyList<NodeId> ids, CancellationToken ct)
    {
        var request = new ReadValueIdCollection(ids.Select(id => new ReadValueId { NodeId = id, AttributeId = Attributes.Value }));
        var response = await session.ReadAsync(null, 0, TimestampsToReturn.Neither, request, ct);
        return response.Results;
    }

    private static async Task<IReadOnlyList<NodeId>> BrowseChildrenAsync(ISession session, NodeId node, CancellationToken ct)
    {
        var request = new BrowseDescriptionCollection
        {
            new BrowseDescription
            {
                NodeId = node,
                BrowseDirection = BrowseDirection.Forward,
                ReferenceTypeId = ReferenceTypeIds.HierarchicalReferences,
                IncludeSubtypes = true,
                ResultMask = (uint)BrowseResultMask.All,
            },
        };
        var response = await session.BrowseAsync(null, null, 0, request, ct);
        return response.Results[0].References
            .Select(r => ExpandedNodeId.ToNodeId(r.NodeId, session.NamespaceUris))
            .ToList();
    }
}