eShopOnContainers/src/ApiGateways/Web.Bff.Shopping/aggregator/Startup.cs

namespace Microsoft.eShopOnContainers.Web.Shopping.HttpAggregator;

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

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddHealthChecks()
            .AddCheck("self", () => HealthCheckResult.Healthy())
            .AddUrlGroup(new Uri(Configuration["CatalogUrlHC"]), name: "catalogapi-check", tags: new string[] { "catalogapi" })
            .AddUrlGroup(new Uri(Configuration["OrderingUrlHC"]), name: "orderingapi-check", tags: new string[] { "orderingapi" })
            .AddUrlGroup(new Uri(Configuration["BasketUrlHC"]), name: "basketapi-check", tags: new string[] { "basketapi" })
            .AddUrlGroup(new Uri(Configuration["IdentityUrlHC"]), name: "identityapi-check", tags: new string[] { "identityapi" })
            .AddUrlGroup(new Uri(Configuration["PaymentUrlHC"]), name: "paymentapi-check", tags: new string[] { "paymentapi" });

        services.AddCustomMvc(Configuration)
            .AddCustomAuthentication(Configuration)
            .AddDevspaces()
            .AddApplicationServices()
            .AddGrpcServices();
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
    {
        var pathBase = Configuration["PATH_BASE"];
        if (!string.IsNullOrEmpty(pathBase))
        {
            loggerFactory.CreateLogger<Startup>().LogDebug("Using PATH BASE '{pathBase}'", pathBase);
            app.UsePathBase(pathBase);
        }

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseHttpsRedirection();

        app.UseSwagger().UseSwaggerUI(c =>
        {
            c.SwaggerEndpoint($"{ (!string.IsNullOrEmpty(pathBase) ? pathBase : string.Empty) }/swagger/v1/swagger.json", "Purchase BFF V1");

            c.OAuthClientId("webshoppingaggswaggerui");
            c.OAuthClientSecret(string.Empty);
            c.OAuthRealm(string.Empty);
            c.OAuthAppName("web shopping bff Swagger UI");
        });

        app.UseRouting();
        app.UseCors("CorsPolicy");
        app.UseAuthentication();
        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapDefaultControllerRoute();
            endpoints.MapControllers();
            endpoints.MapHealthChecks("/hc", new HealthCheckOptions()
            {
                Predicate = _ => true,
                ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse
            });
            endpoints.MapHealthChecks("/liveness", new HealthCheckOptions
            {
                Predicate = r => r.Name.Contains("self")
            });
        });
    }
}

public static class ServiceCollectionExtensions
{
    public static IServiceCollection AddCustomAuthentication(this IServiceCollection services, IConfiguration configuration)
    {
        JwtSecurityTokenHandler.DefaultInboundClaimTypeMap.Remove("sub");

        var identityUrl = configuration.GetValue<string>("urls:identity");
        services.AddAuthentication(options =>
        {
            options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
            options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;

        })
        .AddJwtBearer(options =>
        {
            options.Authority = identityUrl;
            options.RequireHttpsMetadata = false;
            options.Audience = "webshoppingagg";
            options.TokenValidationParameters = new TokenValidationParameters
            {
                ValidateAudience = false
            };
        });

        return services;
    }

    public static IServiceCollection AddCustomMvc(this IServiceCollection services, IConfiguration configuration)
    {
        services.AddOptions();
        services.Configure<UrlsConfig>(configuration.GetSection("urls"));

        services.AddControllers()
                .AddJsonOptions(options => options.JsonSerializerOptions.WriteIndented = true);

        services.AddSwaggerGen(options =>
        {
            options.DescribeAllEnumsAsStrings();

            options.SwaggerDoc("v1", new OpenApiInfo
            {
                Title = "Shopping Aggregator for Web Clients",
                Version = "v1",
                Description = "Shopping Aggregator for Web Clients"
            });

            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>()
                        {
                            { "webshoppingagg", "Shopping Aggregator for Web Clients" }
                        }
                    }
                }
            });

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

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

        return services;
    }
    public static IServiceCollection AddApplicationServices(this IServiceCollection services)
    {
        //register delegating handlers
        services.AddTransient<HttpClientAuthorizationDelegatingHandler>();
        services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

        //register http services

        services.AddHttpClient<IOrderApiClient, OrderApiClient>()
            .AddHttpMessageHandler<HttpClientAuthorizationDelegatingHandler>()
            .AddDevspacesSupport();

        return services;
    }

    public static IServiceCollection AddGrpcServices(this IServiceCollection services)
    {
        services.AddTransient<GrpcExceptionInterceptor>();

        services.AddScoped<IBasketService, BasketService>();

        services.AddGrpcClient<Basket.BasketClient>((services, options) =>
        {
            var basketApi = services.GetRequiredService<IOptions<UrlsConfig>>().Value.GrpcBasket;
            options.Address = new Uri(basketApi);
        }).AddInterceptor<GrpcExceptionInterceptor>();

        services.AddScoped<ICatalogService, CatalogService>();

        services.AddGrpcClient<Catalog.CatalogClient>((services, options) =>
        {
            var catalogApi = services.GetRequiredService<IOptions<UrlsConfig>>().Value.GrpcCatalog;
            options.Address = new Uri(catalogApi);
        }).AddInterceptor<GrpcExceptionInterceptor>();

        services.AddScoped<IOrderingService, OrderingService>();

        services.AddGrpcClient<OrderingGrpc.OrderingGrpcClient>((services, options) =>
        {
            var orderingApi = services.GetRequiredService<IOptions<UrlsConfig>>().Value.GrpcOrdering;
            options.Address = new Uri(orderingApi);
        }).AddInterceptor<GrpcExceptionInterceptor>();

        return services;
    }
}