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 *
 * OPC Foundation MIT License 1.00
 *
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 * obtaining a copy of this software and associated documentation
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 * http://opcfoundation.org/License/MIT/1.00/
 * ======================================================================*/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging.Abstractions;
using Moq;
using NUnit.Framework;
using Opc.Ua.Server.Fluent;
using Opc.Ua.Server.Hosting;

namespace Opc.Ua.Server.Tests.Hosting
{
    /// <summary>
    /// Coverage tests for <see cref="FluentNodeManagerFactory"/> and the
    /// <c>AddNodeManager</c> extension that creates and registers it.
    /// </summary>
    /// <remarks>
    /// Tests that exercise the constructor validation and property projection
    /// run without any server infrastructure. The <see cref="CreateAsync"/>
    /// path uses a mocked <see cref="IServerInternal"/> constructed in the
    /// same way as <see cref="AsyncCustomNodeManagerTests"/>.
    /// </remarks>
    [TestFixture]
    [Category("Hosting")]
    [SetCulture("en-us")]
    [SetUICulture("en-us")]
    [Parallelizable]
    public sealed class FluentNodeManagerFactoryCoverageTests
    {
        private const string TestNamespaceUri = "http://test.org/UA/FluentCoverage/";

        [Test]
        public void CtorWithEmptyNamespaceUriThrowsArgumentException()
        {
            Assert.That(
                () => new FluentNodeManagerFactory(string.Empty, _ => { }),
                Throws.TypeOf<ArgumentException>());
        }

        [Test]
        public void CtorWithWhitespaceNamespaceUriThrowsArgumentException()
        {
            Assert.That(
                () => new FluentNodeManagerFactory("   ", _ => { }),
                Throws.TypeOf<ArgumentException>());
        }

        [Test]
        public void CtorWithNullBuildThrowsArgumentNullException()
        {
            Action<INodeManagerBuilder>? nullBuild = null;

            Assert.That(
                () => new FluentNodeManagerFactory(TestNamespaceUri, nullBuild!),
                Throws.TypeOf<ArgumentNullException>());
        }

        [Test]
        public void CtorWithWhitespaceRootBrowseNameThrowsArgumentException()
        {
            Assert.That(
                () => new FluentNodeManagerFactory(TestNamespaceUri, _ => { }, " "),
                Throws.TypeOf<ArgumentException>());
        }

        [Test]
        public void CtorWithValidArgumentsSetsNamespacesUris()
        {
            var factory = new FluentNodeManagerFactory(TestNamespaceUri, _ => { });

            Assert.That(factory.NamespacesUris, Has.Count.EqualTo(1));
            Assert.That(factory.NamespacesUris[0], Is.EqualTo(TestNamespaceUri));
        }

        [Test]
        public async Task CreateAsyncReturnsFluentNodeManagerAsync()
        {
            Mock<IServerInternal> mockServer = BuildMockServer();
            var factory = new FluentNodeManagerFactory(TestNamespaceUri, _ => { });

            IAsyncNodeManager manager = await factory.CreateAsync(
                mockServer.Object,
                new ApplicationConfiguration(),
                CancellationToken.None)
                .ConfigureAwait(false);

            Assert.That(manager, Is.Not.Null);
            Assert.That(manager, Is.InstanceOf<FluentNodeManager>());

            ((IDisposable)manager).Dispose();
        }

        [Test]
        public async Task CreateAsyncInvokesProvidedBuildCallbackAsync()
        {
            Mock<IServerInternal> mockServer = BuildMockServer();
            bool buildCalled = false;
            var factory = new FluentNodeManagerFactory(
                TestNamespaceUri,
                _ => buildCalled = true);

            IAsyncNodeManager manager = await factory.CreateAsync(
                mockServer.Object,
                new ApplicationConfiguration(),
                CancellationToken.None)
                .ConfigureAwait(false);

            // The build callback is invoked during CreateAddressSpaceAsync, not CreateAsync.
            // CreateAsync only instantiates the manager; we verify it completed without error.
            Assert.That(manager, Is.Not.Null);
            Assert.That(buildCalled, Is.False, "Build callback must not be invoked during factory creation.");

            ((IDisposable)manager).Dispose();
        }

        [Test]
        public async Task CreateAddressSpaceAsyncDoesNotCreateImplicitRootFolderAsync()
        {
            Mock<IServerInternal> mockServer = BuildMockServer();
            var factory = new FluentNodeManagerFactory(TestNamespaceUri, _ => { });

            IAsyncNodeManager manager = await factory.CreateAsync(
                mockServer.Object,
                new ApplicationConfiguration(),
                CancellationToken.None)
                .ConfigureAwait(false);

            var externalReferences = new Dictionary<NodeId, IList<IReference>>();
            await manager.CreateAddressSpaceAsync(externalReferences, CancellationToken.None)
                .ConfigureAwait(false);

            Assert.That(
                externalReferences.ContainsKey(ObjectIds.ObjectsFolder),
                Is.False);
            Assert.That(
                await manager.GetManagerHandleAsync(
                    new NodeId("ReferenceServer", 1),
                    CancellationToken.None).ConfigureAwait(false),
                Is.Null);

            ((IDisposable)manager).Dispose();
        }

        [Test]
        public async Task ConfiguredRootFolderIsMirroredUnderObjectsFolderAsync()
        {
            Mock<IServerInternal> mockServer = BuildMockServer();
            var factory = new FluentNodeManagerFactory(
                TestNamespaceUri,
                builder => builder.Node("ReferenceServer"),
                "ReferenceServer");

            IAsyncNodeManager manager = await factory.CreateAsync(
                mockServer.Object,
                new ApplicationConfiguration(),
                CancellationToken.None)
                .ConfigureAwait(false);

            var externalReferences = new Dictionary<NodeId, IList<IReference>>();
            await manager.CreateAddressSpaceAsync(externalReferences, CancellationToken.None)
                .ConfigureAwait(false);

            var rootId = new NodeId("ReferenceServer", 1);
            Assert.That(externalReferences.ContainsKey(ObjectIds.ObjectsFolder), Is.True);
            Assert.That(
                externalReferences[ObjectIds.ObjectsFolder].Count(r =>
                    r.ReferenceTypeId == ReferenceTypeIds.Organizes &&
                    !r.IsInverse &&
                    r.TargetId == new ExpandedNodeId(rootId)),
                Is.EqualTo(1));
            Assert.That(
                await manager.GetManagerHandleAsync(rootId, CancellationToken.None)
                    .ConfigureAwait(false),
                Is.Not.Null);

            ((IDisposable)manager).Dispose();
        }

        [Test]
        public async Task BuildCreatedInstanceUnderObjectsFolderIsMirroredToExternalReferencesAsync()
        {
            Mock<IServerInternal> mockServer = BuildMockServer();
            NodeId instanceId = NodeId.Null;
            var factory = new FluentNodeManagerFactory(
                TestNamespaceUri,
                builder => instanceId = builder
                    .CreateInstance(
                        new QualifiedName("Boiler #2", 1),
                        p => new BaseObjectState(p))
                    .Configure(n => n.UnderObjectsFolder())
                    .Node.NodeId);

            IAsyncNodeManager manager = await factory.CreateAsync(
                mockServer.Object,
                new ApplicationConfiguration(),
                CancellationToken.None)
                .ConfigureAwait(false);

            var externalReferences = new Dictionary<NodeId, IList<IReference>>();
            await manager.CreateAddressSpaceAsync(externalReferences, CancellationToken.None)
                .ConfigureAwait(false);

            // The forward Organizes edge from the Objects folder to the
            // build-created instance must have been published for the
            // master node manager to distribute (issue #4329).
            Assert.That(instanceId.IsNull, Is.False);
            Assert.That(externalReferences.ContainsKey(ObjectIds.ObjectsFolder), Is.True);
            Assert.That(
                externalReferences[ObjectIds.ObjectsFolder].Count(r =>
                    r.ReferenceTypeId == ReferenceTypeIds.Organizes && !r.IsInverse),
                Is.EqualTo(1));
            Assert.That(
                externalReferences[ObjectIds.ObjectsFolder]
                    .Single(r =>
                        r.ReferenceTypeId == ReferenceTypeIds.Organizes &&
                        !r.IsInverse)
                    .TargetId,
                Is.EqualTo(new ExpandedNodeId(instanceId)));

            ((IDisposable)manager).Dispose();
        }

        [Test]
        public void AddNodeIdFactoryRegistersTheFactoryForEveryNodeManager()
        {
            var services = new ServiceCollection();
            services.AddLogging();
            services.AddOpcUa()
                .AddServer(o =>
                {
                    o.ApplicationName = "NodeIdFactoryServer";
                    o.ApplicationUri = "urn:test:NodeIdFactoryServer";
                    o.ProductUri = "urn:test:product";
                })
                .AddNodeIdFactory(NodeIdAssignmentMode.Guid);

            using ServiceProvider provider = services.BuildServiceProvider();
            var registered = provider.GetService<IRebasableNodeIdFactory>();

            Assert.That(registered, Is.Not.Null);
            Assert.That(registered!.Mode, Is.EqualTo(NodeIdAssignmentMode.Guid));
        }

        [Test]
        public void AddNodeIdFactoryReplacesAPreviousRegistration()
        {
            var services = new ServiceCollection();
            services.AddLogging();
            services.AddOpcUa()
                .AddServer(o =>
                {
                    o.ApplicationName = "NodeIdFactoryServer";
                    o.ApplicationUri = "urn:test:NodeIdFactoryServer";
                    o.ProductUri = "urn:test:product";
                })
                .AddNodeIdFactory(NodeIdAssignmentMode.Guid)
                .AddNodeIdFactory(new DefaultNodeIdFactory(NodeIdAssignmentMode.Counter, 7));

            using ServiceProvider provider = services.BuildServiceProvider();
            var registered = provider.GetService<IRebasableNodeIdFactory>();

            Assert.Multiple(() =>
            {
                Assert.That(registered!.Mode, Is.EqualTo(NodeIdAssignmentMode.Counter));
                Assert.That(registered.DefaultNamespaceIndex, Is.EqualTo(7));
            });
        }

        [Test]
        public void AddNodeIdFactoryRejectsMissingArguments()
        {
            var services = new ServiceCollection();
            services.AddLogging();
            IOpcUaServerBuilder builder = services.AddOpcUa()
                .AddServer(o =>
                {
                    o.ApplicationName = "NodeIdFactoryServer";
                    o.ApplicationUri = "urn:test:NodeIdFactoryServer";
                    o.ProductUri = "urn:test:product";
                });

            Assert.Multiple(() =>
            {
                Assert.Throws<ArgumentNullException>(
                    () => builder.AddNodeIdFactory((IRebasableNodeIdFactory)null!));
                Assert.Throws<ArgumentNullException>(
                    () => ((IOpcUaServerBuilder)null!).AddNodeIdFactory(
                        NodeIdAssignmentMode.String));
            });
        }

        [Test]
        public void AddNodeManagerExtensionRegistersAsyncNodeManagerFactory()
        {
            var services = new ServiceCollection();
            services.AddLogging();
            services.AddOpcUa()
                .AddServer(o =>
                {
                    o.ApplicationName = "FluentFactoryServer";
                    o.ApplicationUri = "urn:test:FluentFactoryServer";
                    o.ProductUri = "urn:test:product";
                })
                .AddNodeManager(TestNamespaceUri, _ => { });

            Assert.That(
                services,
                Has.Some.Matches<ServiceDescriptor>(
                    d => d.ServiceType == typeof(IAsyncNodeManagerFactory)));
        }

        [Test]
        public void AddNodeManagerExtensionRegistersNodeManagerRegistration()
        {
            var services = new ServiceCollection();
            services.AddLogging();
            services.AddOpcUa()
                .AddServer(o =>
                {
                    o.ApplicationName = "FluentFactoryServer";
                    o.ApplicationUri = "urn:test:FluentFactoryServer";
                    o.ProductUri = "urn:test:product";
                })
                .AddNodeManager(TestNamespaceUri, _ => { });

            Assert.That(
                services,
                Has.Some.Matches<ServiceDescriptor>(
                    d => d.ServiceType == typeof(OpcUaServerNodeManagerRegistration)));
        }

        [Test]
        public void AddNodeManagerExtensionResolvedFactoryHasCorrectNamespace()
        {
            var services = new ServiceCollection();
            services.AddLogging();
            services.AddOpcUa()
                .AddServer(o =>
                {
                    o.ApplicationName = "FluentFactoryServer";
                    o.ApplicationUri = "urn:test:FluentFactoryServer";
                    o.ProductUri = "urn:test:product";
                })
                .AddNodeManager(TestNamespaceUri, _ => { });

            using ServiceProvider sp = services.BuildServiceProvider();
            IAsyncNodeManagerFactory factory = sp.GetRequiredService<IAsyncNodeManagerFactory>();

            Assert.That(factory.NamespacesUris, Has.Count.EqualTo(1));
            Assert.That(factory.NamespacesUris[0], Is.EqualTo(TestNamespaceUri));
        }

        [Test]
        public async Task AddReferenceServerConfiguresNamedRootFolderAsync()
        {
            const string referenceNamespaceUri =
                "http://opcfoundation.org/UA/ReferenceServer";
            var services = new ServiceCollection();
            services.AddLogging();
            services.AddOpcUa().AddReferenceServer();
            using ServiceProvider sp = services.BuildServiceProvider();
            OpcUaServerNodeManagerRegistration registration = sp
                .GetServices<OpcUaServerNodeManagerRegistration>()
                .Single();
            IAsyncNodeManagerFactory factory = registration.AsyncFactory!;
            Mock<IServerInternal> mockServer = BuildMockServer(referenceNamespaceUri);
            IAsyncNodeManager manager = await factory.CreateAsync(
                mockServer.Object,
                new ApplicationConfiguration(),
                CancellationToken.None)
                .ConfigureAwait(false);

            try
            {
                var externalReferences = new Dictionary<NodeId, IList<IReference>>();
                await manager.CreateAddressSpaceAsync(
                    externalReferences,
                    CancellationToken.None).ConfigureAwait(false);

                var rootId = new NodeId("ReferenceServer", 1);
                Assert.That(
                    externalReferences[ObjectIds.ObjectsFolder].Count(reference =>
                        reference.ReferenceTypeId == ReferenceTypeIds.Organizes &&
                        !reference.IsInverse &&
                        reference.TargetId == new ExpandedNodeId(rootId)),
                    Is.EqualTo(1));
                Assert.That(
                    await manager.GetManagerHandleAsync(rootId, CancellationToken.None)
                        .ConfigureAwait(false),
                    Is.Not.Null);
            }
            finally
            {
                ((IDisposable)manager).Dispose();
            }
        }

        private static Mock<IServerInternal> BuildMockServer(
            string namespaceUri = TestNamespaceUri)
        {
            var namespaceTable = new NamespaceTable();
            namespaceTable.Append(namespaceUri);

            var mockTelemetry = new Mock<ITelemetryContext>();
            mockTelemetry
                .SetupGet(t => t.LoggerFactory)
                .Returns(NullLoggerFactory.Instance);

            var mockServer = new Mock<IServerInternal>();
            mockServer.SetupGet(s => s.Telemetry).Returns(mockTelemetry.Object);
            mockServer.SetupGet(s => s.NamespaceUris).Returns(namespaceTable);

            var systemContext = new ServerSystemContext(mockServer.Object);
            mockServer.SetupGet(s => s.DefaultSystemContext).Returns(systemContext);

            return mockServer;
        }
    }
}