using System;
using System.Collections.Generic;
using System.Net;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Host;
using ZB.MOM.WW.OtOpcUa.Host.Configuration;
using ZB.MOM.WW.OtOpcUa.Host.Domain;
using ZB.MOM.WW.OtOpcUa.Tests.Helpers;

namespace ZB.MOM.WW.OtOpcUa.Tests.Wiring
{
    /// <summary>
    ///     Regression for stability review 2026-04-13 Finding 2. Confirms that when the dashboard
    ///     port is already bound, the service continues to start (degraded mode) and the
    ///     <see cref="OpcUaService.DashboardStartFailed"/> flag is raised.
    /// </summary>
    public class OpcUaServiceDashboardFailureTests
    {
        [Fact]
        public void Start_DashboardPortInUse_ContinuesInDegradedMode()
        {
            var dashboardPort = new Random().Next(19500, 19999);
            using var blocker = new HttpListener();
            blocker.Prefixes.Add($"http://localhost:{dashboardPort}/");
            blocker.Start();

            var config = new AppConfiguration
            {
                OpcUa = new OpcUaConfiguration
                {
                    Port = 14842,
                    GalaxyName = "TestGalaxy",
                    EndpointPath = "/LmxOpcUa"
                },
                MxAccess = new MxAccessConfiguration { ClientName = "Test" },
                GalaxyRepository = new GalaxyRepositoryConfiguration(),
                Dashboard = new DashboardConfiguration { Enabled = true, Port = dashboardPort }
            };

            var proxy = new FakeMxProxy();
            var repo = new FakeGalaxyRepository
            {
                Hierarchy = new List<GalaxyObjectInfo>
                {
                    new()
                    {
                        GobjectId = 1, TagName = "TestObj", BrowseName = "TestObj",
                        ParentGobjectId = 0, IsArea = false
                    }
                },
                Attributes = new List<GalaxyAttributeInfo>
                {
                    new()
                    {
                        GobjectId = 1, TagName = "TestObj", AttributeName = "TestAttr",
                        FullTagReference = "TestObj.TestAttr", MxDataType = 5, IsArray = false
                    }
                }
            };

            var service = new OpcUaService(config, proxy, repo);
            service.Start();

            try
            {
                // Service continues despite dashboard bind failure — degraded mode policy.
                service.ServerHost.ShouldNotBeNull();
                service.DashboardStartFailed.ShouldBeTrue();
                service.StatusWeb.ShouldBeNull();
            }
            finally
            {
                service.Stop();
            }
        }
    }
}