components/LiteCharms.Features/Extensions/Api.cs

using LiteCharms.Features.Abstractions;
using LiteCharms.Features.Api;
using LiteCharms.Features.Api.Configuration;

namespace LiteCharms.Features.Extensions;

public static class Api
{
    public const string Books = nameof(Books);
    public const string Payments = nameof(Payments);

    public static IServiceCollection AddAuthentikUiSecurity(this IServiceCollection services, IConfiguration configuration)
    {
        var configSection = configuration.GetSection(nameof(AuthentikSettings));

        var authOptions = new AuthentikSettings();
        configSection.Bind(authOptions);

        services.Configure<AuthentikSettings>(configSection);

        services.AddAuthentication(options =>
        {
            options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
            options.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
        })
        .AddCookie(CookieAuthenticationDefaults.AuthenticationScheme)
        .AddOpenIdConnect(OpenIdConnectDefaults.AuthenticationScheme, options =>
        {
            options.Authority = authOptions.Authority;
            options.MetadataAddress = authOptions.MetadataEndpoint;

            options.ClientId = authOptions.ClientId;
            options.ClientSecret = authOptions.ClientSecret;
            options.SignedOutCallbackPath = "/signout-callback-oidc";

            options.ResponseType = "code";
            options.SaveTokens = true;
            options.GetClaimsFromUserInfoEndpoint = true;

            options.Scope.Clear();
            options.Scope.Add("openid");
            options.Scope.Add("profile");
            options.Scope.Add("email");

            options.Events = new OpenIdConnectEvents
            {
                OnRedirectToIdentityProvider = context =>
                {
                    var fallbackUri = context.ProtocolMessage.RedirectUri;

                    if (fallbackUri.StartsWith("http://", StringComparison.OrdinalIgnoreCase))
                        context.ProtocolMessage.RedirectUri = fallbackUri.Replace("http://", "https://", StringComparison.OrdinalIgnoreCase);

                    return Task.CompletedTask;
                }
            };
        });

        return services;
    }

    public static IServiceCollection AddAuthentikApiSecurity(this IServiceCollection services, IConfiguration configuration)
    {
        var configSection = configuration.GetSection(nameof(AuthentikSettings));

        var authOptions = new AuthentikSettings();
        configSection.Bind(authOptions);

        services.Configure<AuthentikSettings>(configSection);

        services.AddAuthentication(OAuth2IntrospectionDefaults.AuthenticationScheme)
            .AddOAuth2Introspection(OAuth2IntrospectionDefaults.AuthenticationScheme, options =>
            {
                options.Authority = authOptions.Authority;
                options.IntrospectionEndpoint = authOptions.IntrospectionEndpoint;
                options.ClientId = authOptions.ClientId;
                options.ClientSecret = authOptions.ClientSecret;

                options.NameClaimType = "sub";
                options.DiscoveryPolicy.RequireHttps = authOptions.RequireHttpsMetadata;
                options.DiscoveryPolicy.ValidateEndpoints = false;
                options.EnableCaching = false;
            });

        if (!string.IsNullOrWhiteSpace(authOptions.RequiredClaimName) && !string.IsNullOrWhiteSpace(authOptions.RequiredClaimNameValue))
        {
            services.AddAuthorizationBuilder()
                .AddPolicy("RequiredScope", policy =>
                    policy.RequireClaim(authOptions.RequiredClaimName, authOptions.RequiredClaimNameValue));
        }
        else
            services.AddAuthorization();

        return services;
    }

    public static WebApplication AddSecurityEndpoints(this WebApplication app)
    {
        app.MapGet("/login", async (HttpContext context, string redirectUri = "/") =>
        {
            await context.ChallengeAsync(OpenIdConnectDefaults.AuthenticationScheme, new AuthenticationProperties
            {
                RedirectUri = redirectUri,                
            });
        });

        app.MapGet("/logout", async (HttpContext context, IHttpClientFactory httpClientFactory, IOptions<AuthentikSettings> settings) =>
        {
            await context.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);

            string currentBaseUrl = $"https://{context.Request.Host}{context.Request.PathBase}/";

            await context.SignOutAsync(OpenIdConnectDefaults.AuthenticationScheme, new AuthenticationProperties
            {
                RedirectUri = currentBaseUrl
            });
        });

        return app;
    }

    public static IServiceCollection AddApiServices(this IServiceCollection services, IConfiguration configuration)
    {
        services.AddHttpClient();

        services.AddApiVersioning(options =>
        {
            options.DefaultApiVersion = new ApiVersion(1);
            options.ReportApiVersions = true;
            options.AssumeDefaultVersionWhenUnspecified = true;
            options.ApiVersionReader = ApiVersionReader.Combine(new UrlSegmentApiVersionReader(),
                new QueryStringApiVersionReader("version"),
                new QueryStringApiVersionReader("version"),
                new MediaTypeApiVersionReader("version"));
        })
        .AddApiExplorer(options =>
        {
            options.GroupNameFormat = "'v'VVV";
            options.SubstituteApiVersionInUrl = true;
        });

        var urls = configuration["ASPNETCORE_URLS"] ?? configuration["Urls"];
        var healthUrl = "http://localhost:8080/health";

        if (!string.IsNullOrWhiteSpace(urls))
        {
            string firstUrl = urls.Split(';').FirstOrDefault(s => s.Contains("http://"))!
                .Replace("0.0.0.0", "localhost")
                .Replace("*", "localhost")
                .Replace("+", "localhost");

            healthUrl = $"{firstUrl.TrimEnd('/')}/health";
        }

        services.AddHealthChecksUI(setup =>
        {
            setup.SetNotifyUnHealthyOneTimeUntilChange();
            setup.AddHealthCheckEndpoint("primary, heal", healthUrl);
            setup.SetHeaderText("Midrand Books");
        })
        .AddInMemoryStorage();

        services.AddOutputCache(options =>
        {
            options.AddBasePolicy(builder => builder.Cache());
            options.DefaultExpirationTimeSpan = TimeSpan.FromSeconds(10);
        });

        services.AddOpenApi(options => options.AddDocumentTransformer<OpenApiBearerSecuritySchemeTransformer>());

        return services;
    }

    public static IApplicationBuilder MapEndpoints(this WebApplication app, IDictionary<int, RouteGroupBuilder> versionGroups)
    {
        var endpoints = app.Services.GetRequiredService<IEnumerable<IEndpoint>>();

        foreach (var endpoint in endpoints)
        {
            var versionAttributes = endpoint.GetType().GetCustomAttributes<ApiVersionTargetAttribute>().ToList();

            if (versionAttributes.Count != 0)
            {
                foreach (var attr in versionAttributes)
                    if (versionGroups.TryGetValue(attr.MajorVersion, out var targetGroup))
                        endpoint.Map(targetGroup);
            }
            else
                endpoint.Map(app);
        }

        return app;
    }

    public static IServiceCollection AddEndpoints(this IServiceCollection services, Assembly assembly)
    {
        ServiceDescriptor[] discriptors = [.. assembly.DefinedTypes
            .Where(t => t is { IsInterface: false, IsAbstract: false })
            .Where(t => t.IsAssignableTo(typeof(IEndpoint)))
            .Select(t => ServiceDescriptor.Transient(typeof(IEndpoint), t))];

        services.TryAddEnumerable(discriptors);

        return services;
    }

    public static string ToEndpointName(this Type target, string? annotation = "") =>
        $"{target.Name.Replace("Endpoint", string.Empty)}{annotation}".ToLower(CultureInfo.CurrentCulture);
}