eShopOnContainers/src/Services/Coupon/Coupon.API/Extensions/IServiceCollectionExtensions.cs

namespace Coupon.API.Extensions
{
    using System;
    using System.Collections.Generic;
    using Autofac;
    using Coupon.API.Dtos;
    using Coupon.API.Filters;
    using Coupon.API.Infrastructure.Models;
    using Coupon.API.Infrastructure.Repositories;
    using Microsoft.AspNetCore.Authentication.JwtBearer;
    using Microsoft.AspNetCore.Http;
    using Microsoft.AspNetCore.Mvc;
    using Microsoft.Azure.ServiceBus;
    using Microsoft.eShopOnContainers.BuildingBlocks.EventBus;
    using Microsoft.eShopOnContainers.BuildingBlocks.EventBus.Abstractions;
    using Microsoft.eShopOnContainers.BuildingBlocks.EventBusRabbitMQ;
    using Microsoft.eShopOnContainers.BuildingBlocks.EventBusServiceBus;
    using Microsoft.Extensions.Configuration;
    using Microsoft.Extensions.DependencyInjection;
    using Microsoft.Extensions.Diagnostics.HealthChecks;
    using Microsoft.Extensions.Logging;
    using Microsoft.OpenApi.Models;
    using RabbitMQ.Client;

    public static class IServiceCollectionExtensions
    {
        public static IServiceCollection AddCouponRegister(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddTransient<ICouponRepository, CouponRepository>()
                .AddTransient<IServiceBusPersisterConnection, DefaultServiceBusPersisterConnection>(service =>
                {
                    var connection = new ServiceBusConnectionStringBuilder(configuration["EventBusConnection"]);

                    return new DefaultServiceBusPersisterConnection(connection, service.GetService<ILogger<DefaultServiceBusPersisterConnection>>());
                })
                .AddTransient<IRabbitMQPersistentConnection, DefaultRabbitMQPersistentConnection>(service =>
                {
                    var factory = new ConnectionFactory()
                    {
                        HostName = configuration["EventBusConnection"],
                        DispatchConsumersAsync = true
                    };

                    var retryCount = 5;

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

                    return new DefaultRabbitMQPersistentConnection(factory, service.GetService<ILogger<DefaultRabbitMQPersistentConnection>>(), retryCount);
                })
                .AddTransient<IEventBusSubscriptionsManager, InMemoryEventBusSubscriptionsManager>()
                .AddTransient<CouponContext>()
                .AddTransient<IMapper<CouponDto, Coupon>, Mapper>();

            return services;
        }

        public static IServiceCollection AddSwagger(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddSwaggerGen(options =>
            {
                options.SwaggerDoc("v1", new OpenApiInfo
                {
                    Title = "eShopOnContainers - Coupon HTTP API",
                    Version = "v1",
                    Description = "The Coupon Service HTTP API"
                });

                options.AddSecurityDefinition("oauth2", new OpenApiSecurityScheme
                {
                    Type = SecuritySchemeType.OAuth2,
                    Flows = new OpenApiOAuthFlows()
                    {
                        Implicit = new OpenApiOAuthFlow()
                        {
                            AuthorizationUrl = new Uri($"{configuration.GetValue<string>("IdentityUrlExternal")}/connect/authorize"),
                            TokenUrl = new Uri($"{configuration.GetValue<string>("IdentityUrlExternal")}/connect/token"),
                            Scopes = new Dictionary<string, string>()
                            {
                                { "coupon", "Coupon API" }
                            }
                        }
                    }
                });

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

            return services;
        }

        public static IServiceCollection AddCustomSettings(this IServiceCollection services, IConfiguration configuration)
        {
            services.Configure<CouponSettings>(configuration);
            services.Configure<ApiBehaviorOptions>(options =>
            {
                options.InvalidModelStateResponseFactory = context =>
                {
                    var problemDetails = new ValidationProblemDetails(context.ModelState)
                    {
                        Instance = context.HttpContext.Request.Path,
                        Status = StatusCodes.Status400BadRequest,
                        Detail = "Please refer to the errors property for additional details."
                    };

                    return new BadRequestObjectResult(problemDetails)
                    {
                        ContentTypes = { "application/problem+json", "application/problem+xml" }
                    };
                };
            });

            return services;
        }

        public static IServiceCollection AddEventBus(this IServiceCollection services, IConfiguration configuration)
        {
            var subscriptionClientName = configuration["SubscriptionClientName"];

            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>();

                    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, subscriptionClientName, retryCount);
                });
            }

            return services;
        }

        public static IServiceCollection AddCustomHealthCheck(this IServiceCollection services, IConfiguration configuration)
        {
            var accountName = configuration.GetValue<string>("AzureStorageAccountName");
            var accountKey = configuration.GetValue<string>("AzureStorageAccountKey");

            var hcBuilder = services.AddHealthChecks();

            hcBuilder.AddCheck("self", () => HealthCheckResult.Healthy())
                .AddMongoDb(
                    configuration["ConnectionString"],
                    name: "CouponCollection-check",
                    tags: new string[] { "couponcollection" });

            if (configuration.GetValue<bool>("AzureServiceBusEnabled"))
            {
                hcBuilder.AddAzureServiceBusTopic(
                    configuration["EventBusConnection"],
                    topicName: "eshop_event_bus",
                    name: "coupon-servicebus-check",
                    tags: new string[] { "servicebus" });
            }
            else
            {
                hcBuilder.AddRabbitMQ(
                    $"amqp://{configuration["EventBusConnection"]}",
                    name: "coupon-rabbitmqbus-check",
                    tags: new string[] { "rabbitmqbus" });
            }

            return services;
        }

        public static IServiceCollection AddCustomPolicies(this IServiceCollection services)
        {
            services.AddCors(options =>
            {
                options.AddPolicy("CorsPolicy",
                    builder => builder.SetIsOriginAllowed((host) => true)
                        .AllowAnyMethod()
                        .AllowAnyHeader()
                        .AllowCredentials());
            });

            return services;
        }

        public static IServiceCollection AddAppInsights(this IServiceCollection services, IConfiguration configuration)
        {
            services.AddApplicationInsightsTelemetry(configuration);
            services.AddApplicationInsightsKubernetesEnricher();

            return services;
        }

        public static IServiceCollection AddCustomAuthentication(this IServiceCollection services, IConfiguration configuration)
        {
            return services.AddAuthentication(options =>
            {
                options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
            }).AddJwtBearer(options =>
            {
                options.Authority = configuration["IdentityUrl"];
                options.RequireHttpsMetadata = false;
                options.Audience = "coupon";
            }).Services;
        }

        public static IServiceCollection AddCustomAuthorization(this IServiceCollection services) => services.AddAuthorization();
    }
}