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.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.Diagnostics;
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.Builder;
using Umbraco.Web.Common.Builder;
using ConnectionStrings = Umbraco.Core.Configuration.Models.ConnectionStrings;

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
    {
        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()
        {
            if (_testTeardown != null)
            {
                foreach (var a in _testTeardown) a();
            }
            _testTeardown = null;
            FirstTestInFixture = false;
            FirstTestInSession = false;
        }

        [TearDown]
        public virtual void TearDown_Logging()
        {
            TestContext.Progress.Write($"  {TestContext.CurrentContext.Result.Outcome.Status}");
        }

        [SetUp]
        public virtual void SetUp_Logging()
        {
            TestContext.Progress.Write($"Start test {TestCount++}: {TestContext.CurrentContext.Test.Name}");
        }

        [SetUp]
        public virtual void Setup()
        {
            InMemoryConfiguration[Constants.Configuration.ConfigGlobal + ":" + nameof(GlobalSettings.InstallEmptyDatabase)] = "true";
            var hostBuilder = CreateHostBuilder();

            var host = hostBuilder.Start();

            Services = host.Services;
            var app = new ApplicationBuilder(host.Services);

            Configure(app);

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

        #region Generic Host Builder and Runtime

        private ILoggerFactory CreateLoggerFactory()
        {
            try
            {
                var testOptions = TestOptionAttributeBase.GetTestOptions<UmbracoTestAttribute>();
                switch (testOptions.Logger)
                {
                    case UmbracoTestOptions.Logger.Mock:
                        return NullLoggerFactory.Instance;
                    case UmbracoTestOptions.Logger.Serilog:
                        return Microsoft.Extensions.Logging.LoggerFactory.Create(builder => { builder.AddSerilog(); });
                    case UmbracoTestOptions.Logger.Console:
                        return Microsoft.Extensions.Logging.LoggerFactory.Create(builder => { builder.AddConsole(); });
                }
            }
            catch
            {
                // ignored
                Debugger.Break();
            }

            return NullLoggerFactory.Instance;
        }

        /// <summary>
        /// Create the Generic Host and execute startup ConfigureServices/Configure calls
        /// </summary>
        /// <returns></returns>
        public virtual IHostBuilder CreateHostBuilder()
        {
            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()
                .ConfigureAppConfiguration((context, configBuilder) =>
                {
                    context.HostingEnvironment = TestHelper.GetWebHostEnvironment();
                    configBuilder.Sources.Clear();
                    configBuilder.AddInMemoryCollection(InMemoryConfiguration);

                    Configuration = configBuilder.Build();
                })
                .ConfigureServices((hostContext, services) =>
                {
                    services.AddTransient(_ => CreateLoggerFactory());
                    ConfigureServices(services);
                });
            return hostBuilder;
        }
        
        #endregion

        #region IStartup

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

            // Add it!

            var builder = new UmbracoBuilder(services, Configuration);
            builder.AddConfiguration()
                .AddUmbracoCore(
                    webHostEnvironment,
                    GetType().Assembly,
                    GetAppCaches(),
                    TestHelper.GetLoggingConfiguration(),
                    Configuration
                );

            builder.Services.AddUnique<IUmbracoBootPermissionChecker>(Mock.Of<IUmbracoBootPermissionChecker>());
            builder.Services.AddUnique<IMainDom>(TestHelper.MainDom);

            services.AddSignalR();

            builder.AddWebComponents();
            builder.AddRuntimeMinifier();
            builder.AddBackOffice();
            services.AddUmbracoBackOfficeIdentity();

            services.AddMvc();

            builder.Build();

            CustomTestSetup(services);
        }

        protected virtual AppCaches GetAppCaches()
        {
            // Disable caches for integration tests
            return AppCaches.NoCache;
        }

        public virtual void Configure(IApplicationBuilder app)
        {
            UseTestLocalDb(app.ApplicationServices);

            //get the currently set options
            var testOptions = TestOptionAttributeBase.GetTestOptions<UmbracoTestAttribute>();
            if (testOptions.Boot)
            {
                Services.GetRequiredService<IBackOfficeSecurityFactory>().EnsureBackOfficeSecurity();
                Services.GetRequiredService<IUmbracoContextFactory>().EnsureUmbracoContext();
                app.UseUmbracoCore(); // Takes 200 ms

                OnTestTearDown(TerminateCoreRuntime);
            }
        }

        /// <remarks>
        /// Some IComponents hook onto static events (e.g. Published in ContentService)
        /// If these fire after the components host has been shutdown, errors can occur.
        /// If CoreRuntime.Start() is called We also need to de-register the events.
        /// </remarks>
        protected void TerminateCoreRuntime()
        {
            Services.GetRequiredService<IRuntime>().Terminate();
            StaticApplicationLogging.Initialize(null);
        }

        #endregion

        #region LocalDb

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

        protected void UseTestLocalDb(IServiceProvider serviceProvider)
        {
            var state = serviceProvider.GetRequiredService<IRuntimeState>();
            var databaseFactory = serviceProvider.GetRequiredService<IUmbracoDatabaseFactory>();

            // This will create a db, install the schema and ensure the app is configured to run
            InstallTestLocalDb(databaseFactory, TestHelper.ConsoleLoggerFactory, state, TestHelper.WorkingDirectory);
            TestDBConnectionString = databaseFactory.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)
        {
            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));

                    // 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.Install, runtimeState.Level);

                    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:
                    // 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 newEmptyFixtureDbId = db.AttachEmpty();

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

                    // 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);
                    }

                    break;
                default:
                    throw new ArgumentOutOfRangeException(nameof(testOptions), testOptions, null);
            }
        }

        #endregion

        #region Common services

        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 virtual 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 UserBuilderInstance = new UserBuilder();
        protected UserGroupBuilder UserGroupBuilderInstance = new UserGroupBuilder();

        #endregion

        protected static bool FirstTestInSession = true;

        protected bool FirstTestInFixture = true;
        protected static int TestCount = 1;
    }
}