using System.Collections.Generic;
using System.Threading.Tasks;
using Shouldly;
using Xunit;
using ZB.MOM.WW.LmxOpcUa.Host;
using ZB.MOM.WW.LmxOpcUa.Host.Configuration;
using ZB.MOM.WW.LmxOpcUa.Host.Domain;
using ZB.MOM.WW.LmxOpcUa.Tests.Helpers;

namespace ZB.MOM.WW.LmxOpcUa.Tests.Wiring
{
    /// <summary>
    /// Verifies: OpcUaService Start() creates and wires all components with fakes.
    /// </summary>
    public class ServiceStartupSequenceTest
    {
        /// <summary>
        /// Confirms that startup with fake dependencies creates the expected bridge components and state.
        /// </summary>
        [Fact]
        public void Start_WithFakes_AllComponentsCreated()
        {
            var config = new AppConfiguration
            {
                OpcUa = new OpcUaConfiguration
                {
                    Port = 14840,
                    GalaxyName = "TestGalaxy",
                    EndpointPath = "/LmxOpcUa"
                },
                MxAccess = new MxAccessConfiguration { ClientName = "Test" },
                GalaxyRepository = new GalaxyRepositoryConfiguration(),
                Dashboard = new DashboardConfiguration { Enabled = false } // Don't start HTTP listener in tests
            };

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

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

            try
            {
                // Verify all components were created
                service.MxClient.ShouldNotBeNull();
                service.MxClient!.State.ShouldBe(ConnectionState.Connected);
                service.Metrics.ShouldNotBeNull();
                service.ServerHost.ShouldNotBeNull();
                service.ChangeDetectionInstance.ShouldNotBeNull();
                service.GalaxyStatsInstance.ShouldNotBeNull();
                service.GalaxyStatsInstance!.GalaxyName.ShouldBe("TestGalaxy");
                service.GalaxyStatsInstance.DbConnected.ShouldBe(true);
                service.StatusReportInstance.ShouldNotBeNull();

                // Dashboard disabled → no web server
                service.StatusWeb.ShouldBeNull();

                // MxProxy should have been registered
                proxy.IsRegistered.ShouldBe(true);
            }
            finally
            {
                service.Stop();
            }
        }

        /// <summary>
        /// Confirms that when MXAccess is initially unavailable, the background monitor reconnects it later.
        /// </summary>
        [Fact]
        public async Task Start_WhenMxAccessIsInitiallyDown_MonitorReconnectsInBackground()
        {
            var config = new AppConfiguration
            {
                OpcUa = new OpcUaConfiguration
                {
                    Port = 14841,
                    GalaxyName = "TestGalaxy",
                    EndpointPath = "/LmxOpcUa"
                },
                MxAccess = new MxAccessConfiguration
                {
                    ClientName = "Test",
                    MonitorIntervalSeconds = 1,
                    AutoReconnect = true
                },
                GalaxyRepository = new GalaxyRepositoryConfiguration(),
                Dashboard = new DashboardConfiguration { Enabled = false }
            };

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

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

            try
            {
                service.ServerHost.ShouldNotBeNull();
                service.MxClient.ShouldNotBeNull();
                service.MxClient!.State.ShouldBe(ConnectionState.Error);

                proxy.ShouldFailRegister = false;
                await Task.Delay(2500);

                service.MxClient.State.ShouldBe(ConnectionState.Connected);
                proxy.RegisterCallCount.ShouldBeGreaterThan(1);
            }
            finally
            {
                service.Stop();
            }
        }
    }
}