eShopOnContainers/src/Services/Ordering/Ordering.API/Startup.cs

namespace Microsoft.eShopOnContainers.Services.Ordering.API
{
    using AspNetCore.Http;
    using Autofac;
    using Autofac.Extensions.DependencyInjection;
    using global::Ordering.API.Application.IntegrationEvents;
    using global::Ordering.API.Application.IntegrationEvents.Events;
    using global::Ordering.API.Infrastructure.Filters;
    using global::Ordering.API.Infrastructure.HostedServices;
    using Infrastructure.AutofacModules;
    using Infrastructure.Filters;
    using Infrastructure.Services;
    using Microsoft.ApplicationInsights.Extensibility;
    using Microsoft.ApplicationInsights.ServiceFabric;
    using Microsoft.AspNetCore.Authentication.JwtBearer;
    using Microsoft.AspNetCore.Builder;
    using Microsoft.AspNetCore.Hosting;
    using Microsoft.Azure.ServiceBus;
    using Microsoft.EntityFrameworkCore;
    using Microsoft.eShopOnContainers.BuildingBlocks.EventBus;
    using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
    using Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ;
    using Microsoft.eShopOnContainers.BuildingBlocks.EventBusServiceBus;
    using Microsoft.eShopOnContainers.BuildingBlocks.IntegrationEventLogEF;
    using Microsoft.eShopOnContainers.BuildingBlocks.IntegrationEventLogEF.Services;
    using Microsoft.Extensions.Configuration;
    using Microsoft.Extensions.DependencyInjection;
    using Microsoft.Extensions.HealthChecks;
    using Microsoft.Extensions.Hosting;
    using Microsoft.Extensions.Logging;
    using Ordering.Infrastructure;
    using RabbitMQ.Client;
    using Swashbuckle.AspNetCore.Swagger;
    using System;
    using System.Collections.Generic;
    using System.Data.Common;
    using System.IdentityModel.Tokens.Jwt;
    using System.Reflection;

    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            RegisterAppInsights(services);

            // Add framework services.
            services.AddMvc(options =>
            {
                options.Filters.Add(typeof(HttpGlobalExceptionFilter));
            }).AddControllersAsServices();  //Injecting Controllers themselves thru DI
                                            //For further info see: http://docs.autofac.org/en/latest/integration/aspnetcore.html#controllers-as-services

            // Configure GracePeriodManager Hosted Service
            services.AddSingleton<IHostedService, GracePeriodManagerService>();

            services.AddTransient<IOrderingIntegrationEventService, OrderingIntegrationEventService>();

            services.AddHealthChecks(checks =>
            {
                var minutes = 1;
                if (int.TryParse(Configuration["HealthCheck:Timeout"], out var minutesParsed))
                {
                    minutes = minutesParsed;
                }
                checks.AddSqlCheck("OrderingDb", Configuration["ConnectionString"], TimeSpan.FromMinutes(minutes));
            });

            services.AddEntityFrameworkSqlServer()
                    .AddDbContext<OrderingContext>(options =>
                    {
                        options.UseSqlServer(Configuration["ConnectionString"],
                            sqlServerOptionsAction: sqlOptions =>
                            {
                                sqlOptions.MigrationsAssembly(typeof(Startup).GetTypeInfo().Assembly.GetName().Name);
                                sqlOptions.EnableRetryOnFailure(maxRetryCount: 10, maxRetryDelay: TimeSpan.FromSeconds(30), errorNumbersToAdd: null);
                            });
                    },
                        ServiceLifetime.Scoped  //Showing explicitly that the DbContext is shared across the HTTP request scope (graph of objects started in the HTTP request)
                    );

            services.AddDbContext<IntegrationEventLogContext>(options =>
            {
                options.UseSqlServer(Configuration["ConnectionString"],
                                     sqlServerOptionsAction: sqlOptions =>
                                     {
                                         sqlOptions.MigrationsAssembly(typeof(Startup).GetTypeInfo().Assembly.GetName().Name);
                                         //Configuring Connection Resiliency: https://docs.microsoft.com/en-us/ef/core/miscellaneous/connection-resiliency 
                                         sqlOptions.EnableRetryOnFailure(maxRetryCount: 10, maxRetryDelay: TimeSpan.FromSeconds(30), errorNumbersToAdd: null);
                                     });
            });
           

            services.Configure<OrderingSettings>(Configuration);

            services.AddSwaggerGen(options =>
            {
                options.DescribeAllEnumsAsStrings();
                options.SwaggerDoc("v1", new Swashbuckle.AspNetCore.Swagger.Info
                {
                    Title = "Ordering HTTP API",
                    Version = "v1",
                    Description = "The Ordering Service HTTP API",
                    TermsOfService = "Terms Of Service"
                });

                options.AddSecurityDefinition("oauth2", new OAuth2Scheme
                {
                    Type = "oauth2",
                    Flow = "implicit",
                    AuthorizationUrl = $"{Configuration.GetValue<string>("IdentityUrlExternal")}/connect/authorize",
                    TokenUrl = $"{Configuration.GetValue<string>("IdentityUrlExternal")}/connect/token",
                    Scopes = new Dictionary<string, string>()
                    {
                        { "orders", "Ordering API" }
                    }
                });

                options.OperationFilter<AuthorizeCheckOperationFilter>();
            });

            services.AddCors(options =>
            {
                options.AddPolicy("CorsPolicy",
                    builder => builder.AllowAnyOrigin()
                    .AllowAnyMethod()
                    .AllowAnyHeader()
                    .AllowCredentials());
            });

            // Add application services.
            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
            services.AddTransient<IIdentityService, IdentityService>();
            services.AddTransient<Func<DbConnection, IIntegrationEventLogService>>(
                sp => (DbConnection c) => new IntegrationEventLogService(c));

            services.AddTransient<IOrderingIntegrationEventService, OrderingIntegrationEventService>();

            if (Configuration.GetValue<bool>("AzureServiceBusEnabled"))
            {
                services.AddSingleton<IServiceBusPersisterConnection>(sp =>
                {
                    var logger = sp.GetRequiredService<ILogger<DefaultServiceBusPersisterConnection>>();

                    var serviceBusConnectionString = Configuration["EventBusConnection"];
                    var serviceBusConnection = new ServiceBusConnectionStringBuilder(serviceBusConnectionString);

                    return new DefaultServiceBusPersisterConnection(serviceBusConnection, logger);
                });
            }
            else
            {
                services.AddSingleton<IRabbitMQPersistentConnection>(sp =>
                {
                    var logger = sp.GetRequiredService<ILogger<DefaultRabbitMQPersistentConnection>>();


                    var factory = new ConnectionFactory()
                    {
                        HostName = Configuration["EventBusConnection"]
                    };

                    if (!string.IsNullOrEmpty(Configuration["EventBusUserName"]))
                    {
                        factory.UserName = Configuration["EventBusUserName"];
                    }

                    if (!string.IsNullOrEmpty(Configuration["EventBusPassword"]))
                    {
                        factory.Password = Configuration["EventBusPassword"];
                    }

                    var retryCount = 5;
                    if (!string.IsNullOrEmpty(Configuration["EventBusRetryCount"]))
                    {
                        retryCount = int.Parse(Configuration["EventBusRetryCount"]);
                    }

                    return new DefaultRabbitMQPersistentConnection(factory, logger, retryCount);
                });
            }

            RegisterEventBus(services);
            ConfigureAuthService(services);
            services.AddOptions();

            //configure autofac

            var container = new ContainerBuilder();
            container.Populate(services);

            container.RegisterModule(new MediatorModule());
            container.RegisterModule(new ApplicationModule(Configuration["ConnectionString"]));

            return new AutofacServiceProvider(container.Build());
        }


        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();
            loggerFactory.AddAzureWebAppDiagnostics();
            loggerFactory.AddApplicationInsights(app.ApplicationServices, LogLevel.Trace);

            var pathBase = Configuration["PATH_BASE"];
            if (!string.IsNullOrEmpty(pathBase))
            {
                loggerFactory.CreateLogger("init").LogDebug($"Using PATH BASE '{pathBase}'");
                app.UsePathBase(pathBase);
            }            
            
            app.UseCors("CorsPolicy");

            ConfigureAuth(app);
            app.UseMvcWithDefaultRoute();

            app.UseSwagger()
               .UseSwaggerUI(c =>
               {
                   c.SwaggerEndpoint($"{ (!string.IsNullOrEmpty(pathBase) ? pathBase : string.Empty) }/swagger/v1/swagger.json", "My API V1");
                   c.ConfigureOAuth2("orderingswaggerui", "", "", "Ordering Swagger UI");
               });

            ConfigureEventBus(app);
        }

        private void RegisterAppInsights(IServiceCollection services)
        {
            services.AddApplicationInsightsTelemetry(Configuration);
            var orchestratorType = Configuration.GetValue<string>("OrchestratorType");
            if (string.IsNullOrEmpty(orchestratorType))
            {
                return;
            }
            if (orchestratorType.ToUpper().Equals("K8S"))
            {
                // Enable K8s telemetry initializer
                services.EnableKubernetes();
            }
            if (orchestratorType.ToUpper().Equals("SF"))
            {
                // Enable SF telemetry initializer
                services.AddSingleton<ITelemetryInitializer>((serviceProvider) =>
                    new FabricTelemetryInitializer());
            }
        }

        private void ConfigureEventBus(IApplicationBuilder app)
        {
            var eventBus = app.ApplicationServices.GetRequiredService<BuildingBlocks.EventBus.Abstractions.IEventBus>();

            eventBus.Subscribe<UserCheckoutAcceptedIntegrationEvent, IIntegrationEventHandler<UserCheckoutAcceptedIntegrationEvent>>();
            eventBus.Subscribe<GracePeriodConfirmedIntegrationEvent, IIntegrationEventHandler<GracePeriodConfirmedIntegrationEvent>>();
            eventBus.Subscribe<OrderStockConfirmedIntegrationEvent, IIntegrationEventHandler<OrderStockConfirmedIntegrationEvent>>();
            eventBus.Subscribe<OrderStockRejectedIntegrationEvent, IIntegrationEventHandler<OrderStockRejectedIntegrationEvent>>();
            eventBus.Subscribe<OrderPaymentFailedIntegrationEvent, IIntegrationEventHandler<OrderPaymentFailedIntegrationEvent>>();
            eventBus.Subscribe<OrderPaymentSuccededIntegrationEvent, IIntegrationEventHandler<OrderPaymentSuccededIntegrationEvent>>();
        }

        private void ConfigureAuthService(IServiceCollection services)
        {
            // prevent from mapping "sub" claim to nameidentifier.
            JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Clear();

            var identityUrl = Configuration.GetValue<string>("IdentityUrl");

            services.AddAuthentication(options =>
            {
                options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;

            }).AddJwtBearer(options =>
            {
                options.Authority = identityUrl;
                options.RequireHttpsMetadata = false;
                options.Audience = "orders";
            });
        }

        protected virtual void ConfigureAuth(IApplicationBuilder app)
        {
            app.UseAuthentication();
        }

        private void RegisterEventBus(IServiceCollection services)
        {
            if (Configuration.GetValue<bool>("AzureServiceBusEnabled"))
            {
                services.AddSingleton<IEventBus, EventBusServiceBus>(sp =>
                {
                    var serviceBusPersisterConnection = sp.GetRequiredService<IServiceBusPersisterConnection>();
                    var iLifetimeScope = sp.GetRequiredService<ILifetimeScope>();
                    var logger = sp.GetRequiredService<ILogger<EventBusServiceBus>>();
                    var eventBusSubcriptionsManager = sp.GetRequiredService<IEventBusSubscriptionsManager>();
                    var subscriptionClientName = Configuration["SubscriptionClientName"];

                    return new EventBusServiceBus(serviceBusPersisterConnection, logger,
                        eventBusSubcriptionsManager, subscriptionClientName, iLifetimeScope);
                });
            }
            else
            {
                services.AddSingleton<IEventBus, EventBusRabbitMQ>(sp =>
                {
                    var rabbitMQPersistentConnection = sp.GetRequiredService<IRabbitMQPersistentConnection>();
                    var iLifetimeScope = sp.GetRequiredService<ILifetimeScope>();
                    var logger = sp.GetRequiredService<ILogger<EventBusRabbitMQ>>();
                    var eventBusSubcriptionsManager = sp.GetRequiredService<IEventBusSubscriptionsManager>();

                    var retryCount = 5;
                    if (!string.IsNullOrEmpty(Configuration["EventBusRetryCount"]))
                    {
                        retryCount = int.Parse(Configuration["EventBusRetryCount"]);
                    }

                    return new EventBusRabbitMQ(rabbitMQPersistentConnection, logger, iLifetimeScope, eventBusSubcriptionsManager, retryCount);
                });
            }

            services.AddSingleton<IEventBusSubscriptionsManager, InMemoryEventBusSubscriptionsManager>();
        }
    }
}