using System.Reflection;
using Opc.Ua;
using Opc.Ua.Server;
using Shouldly;
using Xunit;

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

/// <summary>
///     Gitea #838 review: <c>OtOpcUaNodeManager.DeliverConditionEventAsync</c> re-implements the SDK's event walk
///     (<c>NodeState.ReportEventAsync</c>, plus <c>BaseInstanceState</c>'s forward to its Parent) so it can re-check the
///     condition's liveness before every hop. That copy is only faithful while no other node type changes the walk —
///     missing the Parent hop alone silently stopped condition events reaching their folders. This pins the set of
///     types that define <c>ReportEvent</c> / <c>ReportEventAsync</c> across the SDK and this server.
/// </summary>
public sealed class ConditionEventWalkGuardTests
{
    [Fact]
    public void Only_NodeState_and_BaseInstanceState_define_the_event_walk()
    {
        Assembly[] assemblies =
        [
            typeof(NodeState).Assembly,              // Opc.Ua.Types
            typeof(ApplicationConfiguration).Assembly, // Opc.Ua.Core
            typeof(StandardServer).Assembly,         // Opc.Ua.Server
            typeof(OtOpcUaNodeManager).Assembly,     // this server
        ];

        var definers = assemblies.Distinct()
            .SelectMany(a => a.GetTypes())
            .Where(t => typeof(NodeState).IsAssignableFrom(t))
            .Where(t => t.GetMethods(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.DeclaredOnly)
                .Any(m => m.Name is nameof(NodeState.ReportEvent) or nameof(NodeState.ReportEventAsync)))
            .Select(t => t.FullName)
            .Order()
            .ToArray();

        definers.ShouldBe(["Opc.Ua.BaseInstanceState", "Opc.Ua.NodeState"],
            "a new override changes the event walk — mirror it in OtOpcUaNodeManager.DeliverConditionEventAsync");
    }
}