using System;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using NUnit.Framework;
using Umbraco.Core.Cache;
using Umbraco.Core.Composing;
using Umbraco.Core.Composing.LightInject;
using Umbraco.Core.Configuration;
using Umbraco.Core.IO;
using Umbraco.Core.Logging;
using Umbraco.Core.Persistence;
using Umbraco.Core.Persistence.Mappers;
using Umbraco.Core.Scoping;
using Umbraco.Core.Strings;
using Umbraco.Tests.Common.Builders;
using Umbraco.Tests.Integration.Extensions;
using Umbraco.Tests.Integration.Implementations;
using Umbraco.Extensions;
using Umbraco.Tests.Testing;
using Umbraco.Web;
using Umbraco.Core.Runtime;
using Umbraco.Core;
using Moq;
using System.Collections.Generic;
using Microsoft.Extensions.Configuration;
using System.Data.SqlClient;
using System.Data.Common;
using System.IO;
using Umbraco.Core.Configuration.Models;
using Microsoft.Extensions.Options;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using Serilog;
using Umbraco.Core.Logging.Serilog;
using ConnectionStrings = Umbraco.Core.Configuration.Models.ConnectionStrings;
using ILogger = Microsoft.Extensions.Logging.ILogger;

namespace Umbraco.Tests.Integration.Testing
{

    /// <summary>
    /// Abstract class for integration tests
    /// </summary>
    /// <remarks>
    /// This will use a Host Builder to boot and install Umbraco ready for use
    /// </remarks>
    [SingleThreaded]
    [NonParallelizable]
    public abstract class UmbracoIntegrationTest
    {
        public static LightInjectContainer CreateUmbracoContainer(out UmbracoServiceProviderFactory serviceProviderFactory)
        {
            var container = UmbracoServiceProviderFactory.CreateServiceContainer();
            serviceProviderFactory = new UmbracoServiceProviderFactory(container, false);
            var umbracoContainer = serviceProviderFactory.GetContainer();
            return umbracoContainer;
        }

        private List<Action> _testTeardown = null;
        private List<Action> _fixtureTeardown = new List<Action>();

        public void OnTestTearDown(Action tearDown)
        {
            if (_testTeardown == null)
                _testTeardown = new List<Action>();
            _testTeardown.Add(tearDown);
        }

        public void OnFixtureTearDown(Action tearDown) => _fixtureTeardown.Add(tearDown);

        [OneTimeTearDown]
        public void FixtureTearDown()
        {
            foreach (var a in _fixtureTeardown) a();
        }

        [TearDown]
        public virtual void TearDown()
        {
            foreach (var a in _testTeardown) a();
            _testTeardown = null;
            FirstTestInFixture = false;
            FirstTestInSession = false;
        }

        [SetUp]
        public virtual void Setup()
        {
            var hostBuilder = CreateHostBuilder();
            var host = hostBuilder.StartAsync().GetAwaiter().GetResult();
            Services = host.Services;
            var app = new ApplicationBuilder(host.Services);
            Configure(app);

            OnFixtureTearDown(() => host.Dispose());
        }

        #region Generic Host Builder and Runtime

        private ILoggerFactory CreateLoggerFactory()
        {
            ILoggerFactory factory;
            var testOptions = TestOptionAttributeBase.GetTestOptions<UmbracoTestAttribute>();
            switch (testOptions.Logger)
            {
                case UmbracoTestOptions.Logger.Mock:
                    factory = NullLoggerFactory.Instance;
                    break;
                case UmbracoTestOptions.Logger.Serilog:
                    factory = Microsoft.Extensions.Logging.LoggerFactory.Create(builder => { builder.AddSerilog(); });
                    break;
                case UmbracoTestOptions.Logger.Console:
                    factory = Microsoft.Extensions.Logging.LoggerFactory.Create(builder => { builder.AddConsole(); });
                    break;
                default:
                    throw new NotSupportedException($"Logger option {testOptions.Logger} is not supported.");
            }

            return factory;
        }
        /// <summary>
        /// Create the Generic Host and execute startup ConfigureServices/Configure calls
        /// </summary>
        /// <returns></returns>
        public virtual IHostBuilder CreateHostBuilder()
        {
            UmbracoContainer = CreateUmbracoContainer(out var serviceProviderFactory);
            _serviceProviderFactory = serviceProviderFactory;

            var hostBuilder = Host.CreateDefaultBuilder()
                // IMPORTANT: We Cannot use UseStartup, there's all sorts of threads about this with testing. Although this can work
                // if you want to setup your tests this way, it is a bit annoying to do that as the WebApplicationFactory will
                // create separate Host instances. So instead of UseStartup, we just call ConfigureServices/Configure ourselves,
                // and in the case of the UmbracoTestServerTestBase it will use the ConfigureWebHost to Configure the IApplicationBuilder directly.
                //.ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup(GetType()); })
                .UseUmbraco(_serviceProviderFactory)
                .ConfigureAppConfiguration((context, configBuilder) =>
                {
                    context.HostingEnvironment = TestHelper.GetWebHostEnvironment();
                    Configuration = context.Configuration;
                    configBuilder.AddInMemoryCollection(InMemoryConfiguration);
                })
                .ConfigureServices((hostContext, services) =>
                {
                    services.AddTransient(_ => CreateLoggerFactory());
                    ConfigureServices(services);
                });
            return hostBuilder;
        }

        /// <summary>
        /// Creates a <see cref="CoreRuntime"/> instance for testing and registers an event handler for database install
        /// </summary>
        /// <param name="connectionStrings"></param>
        /// <param name="umbracoVersion"></param>
        /// <param name="ioHelper"></param>
        /// <param name="logger"></param>
        /// <param name="loggerFactory"></param>
        /// <param name="profiler"></param>
        /// <param name="hostingEnvironment"></param>
        /// <param name="backOfficeInfo"></param>
        /// <param name="typeFinder"></param>
        /// <param name="appCaches"></param>
        /// <param name="dbProviderFactoryCreator"></param>
        /// <param name="globalSettings"></param>
        /// <returns></returns>
        public CoreRuntime CreateTestRuntime(
            GlobalSettings globalSettings,
            ConnectionStrings connectionStrings,
            IUmbracoVersion umbracoVersion, IIOHelper ioHelper,
            ILogger logger, ILoggerFactory loggerFactory, IProfiler profiler, Core.Hosting.IHostingEnvironment hostingEnvironment, IBackOfficeInfo backOfficeInfo,
            ITypeFinder typeFinder, AppCaches appCaches, IDbProviderFactoryCreator dbProviderFactoryCreator)
        {
            var runtime = CreateTestRuntime(
                globalSettings,
                connectionStrings,
                umbracoVersion,
                ioHelper,
                logger,
                loggerFactory,
                profiler,
                hostingEnvironment,
                backOfficeInfo,
                typeFinder,
                appCaches,
                dbProviderFactoryCreator,
                TestHelper.MainDom, // SimpleMainDom
                UseTestLocalDb // DB Installation event handler
            );

            return runtime;
        }

        /// <summary>
        /// Creates a <see cref="CoreRuntime"/> instance for testing and registers an event handler for database install
        /// </summary>
        /// <param name="connectionStrings"></param>
        /// <param name="umbracoVersion"></param>
        /// <param name="ioHelper"></param>
        /// <param name="logger"></param>
        /// <param name="loggerFactory"></param>
        /// <param name="profiler"></param>
        /// <param name="hostingEnvironment"></param>
        /// <param name="backOfficeInfo"></param>
        /// <param name="typeFinder"></param>
        /// <param name="appCaches"></param>
        /// <param name="dbProviderFactoryCreator"></param>
        /// <param name="mainDom"></param>
        /// <param name="eventHandler">The event handler used for DB installation</param>
        /// <param name="globalSettings"></param>
        /// <returns></returns>
        public static CoreRuntime CreateTestRuntime(
            GlobalSettings globalSettings,
            ConnectionStrings connectionStrings,
            IUmbracoVersion umbracoVersion, IIOHelper ioHelper,
            ILogger logger, ILoggerFactory loggerFactory, IProfiler profiler, Core.Hosting.IHostingEnvironment hostingEnvironment, IBackOfficeInfo backOfficeInfo,
            ITypeFinder typeFinder, AppCaches appCaches, IDbProviderFactoryCreator dbProviderFactoryCreator,
            IMainDom mainDom, Action<CoreRuntime, RuntimeEssentialsEventArgs> eventHandler)
        {
            var runtime = new CoreRuntime(
                globalSettings,
                connectionStrings,
                umbracoVersion,
                ioHelper,
                logger,
                loggerFactory,
                profiler,
                Mock.Of<IUmbracoBootPermissionChecker>(),
                hostingEnvironment,
                backOfficeInfo,
                dbProviderFactoryCreator,
                mainDom,
                typeFinder,
                appCaches);

            runtime.RuntimeEssentials += (sender, args) => eventHandler(sender, args);

            return runtime;
        }

        #endregion

        #region IStartup

        public virtual void ConfigureServices(IServiceCollection services)
        {
            services.AddSingleton(TestHelper.DbProviderFactoryCreator);
            var webHostEnvironment = TestHelper.GetWebHostEnvironment();
            services.AddRequiredNetCoreServices(TestHelper, webHostEnvironment);

            // Add it!
            services.AddUmbracoConfiguration(Configuration);
            services.AddUmbracoCore(
                webHostEnvironment,
                UmbracoContainer,
                GetType().Assembly,
                AppCaches.NoCache, // Disable caches for integration tests
                TestHelper.GetLoggingConfiguration(),
                Configuration,
                CreateTestRuntime,
                out _);

            services.AddSignalR();

            services.AddUmbracoWebComponents();
            services.AddUmbracoRuntimeMinifier(Configuration);
            services.AddUmbracoBackOffice();
            services.AddUmbracoBackOfficeIdentity();

            services.AddMvc();

            CustomTestSetup(services);
        }

        public virtual void Configure(IApplicationBuilder app)
        {
            Services.GetRequiredService<IBackofficeSecurityFactory>().EnsureBackofficeSecurity();
            Services.GetRequiredService<IUmbracoContextFactory>().EnsureUmbracoContext();

            // get the currently set options
            var testOptions = TestOptionAttributeBase.GetTestOptions<UmbracoTestAttribute>();
            if (testOptions.Boot)
            {
                app.UseUmbracoCore();
            }
        }

        #endregion

        #region LocalDb


        private static readonly object _dbLocker = new object();
        private static LocalDbTestDatabase _dbInstance;

        /// <summary>
        /// Event handler for the <see cref="CoreRuntime.RuntimeEssentials"/> to install the database and register the <see cref="IRuntime"/> to Terminate
        /// </summary>
        /// <param name="runtime"></param>
        /// <param name="args"></param>
        protected void UseTestLocalDb(CoreRuntime runtime, RuntimeEssentialsEventArgs args)
        {
            // MUST be terminated on teardown
            OnTestTearDown(() => runtime.Terminate());

            // This will create a db, install the schema and ensure the app is configured to run
            InstallTestLocalDb(args.DatabaseFactory, runtime.RuntimeLoggerFactory, runtime.State, TestHelper.WorkingDirectory, out var connectionString);
            TestDBConnectionString = connectionString;
            InMemoryConfiguration["ConnectionStrings:" + Constants.System.UmbracoConnectionName] = TestDBConnectionString;
        }

        /// <summary>
        /// Get or create an instance of <see cref="LocalDbTestDatabase"/>
        /// </summary>
        /// <param name="filesPath"></param>
        /// <param name="logger"></param>
        /// <param name="loggerFactory"></param>
        /// <param name="globalSettings"></param>
        /// <param name="dbFactory"></param>
        /// <returns></returns>
        /// <remarks>
        /// There must only be ONE instance shared between all tests in a session
        /// </remarks>
        private static LocalDbTestDatabase GetOrCreateDatabase(string filesPath, ILoggerFactory loggerFactory, IUmbracoDatabaseFactory dbFactory)
        {
            lock (_dbLocker)
            {
                if (_dbInstance != null) return _dbInstance;

                var localDb = new LocalDb();
                if (localDb.IsAvailable == false)
                    throw new InvalidOperationException("LocalDB is not available.");
                _dbInstance = new LocalDbTestDatabase(loggerFactory, localDb, filesPath, dbFactory);
                return _dbInstance;
            }
        }

        /// <summary>
        /// Creates a LocalDb instance to use for the test
        /// </summary>
        /// <param name="runtimeState"></param>
        /// <param name="workingDirectory"></param>
        /// <param name="connectionString"></param>
        /// <param name="databaseFactory"></param>
        /// <param name="loggerFactory"></param>
        /// <param name="globalSettings"></param>
        /// <returns></returns>
        private void InstallTestLocalDb(
            IUmbracoDatabaseFactory databaseFactory, ILoggerFactory loggerFactory,
            IRuntimeState runtimeState, string workingDirectory, out string connectionString)
        {
            connectionString = null;
            var dbFilePath = Path.Combine(workingDirectory, "LocalDb");

            // get the currently set db options
            var testOptions = TestOptionAttributeBase.GetTestOptions<UmbracoTestAttribute>();

            if (testOptions.Database == UmbracoTestOptions.Database.None)
                return;

            // need to manually register this factory
            DbProviderFactories.RegisterFactory(Constants.DbProviderNames.SqlServer, SqlClientFactory.Instance);

            if (!Directory.Exists(dbFilePath))
                Directory.CreateDirectory(dbFilePath);

            var db = GetOrCreateDatabase(dbFilePath, loggerFactory, databaseFactory);

            switch (testOptions.Database)
            {
                case UmbracoTestOptions.Database.NewSchemaPerTest:

                    // New DB + Schema
                    var newSchemaDbId = db.AttachSchema();

                    // Add teardown callback
                    OnTestTearDown(() => db.Detach(newSchemaDbId));

                    // We must re-configure our current factory since attaching a new LocalDb from the pool changes connection strings
                    if (!databaseFactory.Configured)
                    {
                        databaseFactory.Configure(db.ConnectionString, Constants.DatabaseProviders.SqlServer);
                    }

                    // re-run the runtime level check
                    runtimeState.DetermineRuntimeLevel();

                    Assert.AreEqual(RuntimeLevel.Run, runtimeState.Level);

                    break;
                case UmbracoTestOptions.Database.NewEmptyPerTest:

                    var newEmptyDbId = db.AttachEmpty();

                    // Add teardown callback
                    OnTestTearDown(() => db.Detach(newEmptyDbId));


                    break;
                case UmbracoTestOptions.Database.NewSchemaPerFixture:
                    // Only attach schema once per fixture
                    // Doing it more than once will block the process since the old db hasn't been detached
                    // and it would be the same as NewSchemaPerTest even if it didn't block
                    if (FirstTestInFixture)
                    {
                        // New DB + Schema
                        var newSchemaFixtureDbId = db.AttachSchema();

                        // Add teardown callback
                        OnFixtureTearDown(() => db.Detach(newSchemaFixtureDbId));
                    }

                    // We must re-configure our current factory since attaching a new LocalDb from the pool changes connection strings
                    if (!databaseFactory.Configured)
                    {
                        databaseFactory.Configure(db.ConnectionString, Constants.DatabaseProviders.SqlServer);
                    }

                    // re-run the runtime level check
                    runtimeState.DetermineRuntimeLevel();

                    break;
                case UmbracoTestOptions.Database.NewEmptyPerFixture:

                    throw new NotImplementedException();

                    //// Add teardown callback
                    //integrationTest.OnFixtureTearDown(() => db.Detach());

                    break;
                default:
                    throw new ArgumentOutOfRangeException(nameof(testOptions), testOptions, null);
            }
            connectionString = db.ConnectionString;
        }

        #endregion

        #region Common services

        protected LightInjectContainer UmbracoContainer { get; private set; }
        private UmbracoServiceProviderFactory _serviceProviderFactory;

        protected virtual T GetRequiredService<T>() => Services.GetRequiredService<T>();

        public Dictionary<string, string> InMemoryConfiguration { get; } = new Dictionary<string, string>();

        public IConfiguration Configuration { get; protected set; }

        public TestHelper TestHelper = new TestHelper();

        protected string TestDBConnectionString { get; private set; }

        protected virtual Action<IServiceCollection> CustomTestSetup => services => { };

        /// <summary>
        /// Returns the DI container
        /// </summary>
        protected IServiceProvider Services { get; set; }

        /// <summary>
        /// Returns the <see cref="IScopeProvider"/>
        /// </summary>
        protected IScopeProvider ScopeProvider => Services.GetRequiredService<IScopeProvider>();

        /// <summary>
        /// Returns the <see cref="IScopeAccessor"/>
        /// </summary>
        protected IScopeAccessor ScopeAccessor => Services.GetRequiredService<IScopeAccessor>();

        /// <summary>
        /// Returns the <see cref="ILoggerFactory"/>
        /// </summary>
        protected ILoggerFactory LoggerFactory => Services.GetRequiredService<ILoggerFactory>();

        protected AppCaches AppCaches => Services.GetRequiredService<AppCaches>();
        protected IIOHelper IOHelper => Services.GetRequiredService<IIOHelper>();
        protected IShortStringHelper ShortStringHelper => Services.GetRequiredService<IShortStringHelper>();
        protected GlobalSettings GlobalSettings => Services.GetRequiredService<IOptions<GlobalSettings>>().Value;
        protected IMapperCollection Mappers => Services.GetRequiredService<IMapperCollection>();

        #endregion

        #region Builders

        protected UserBuilder UserBuilder = new UserBuilder();
        protected UserGroupBuilder UserGroupBuilder = new UserGroupBuilder();

        #endregion

        protected static bool FirstTestInSession = true;

        protected bool FirstTestInFixture = true;
    }
}