elsa-core/src/modules/Elsa.Http/ShellFeatures/HttpFeature.cs

using CShells.AspNetCore.Features;
using CShells.Features;
using Elsa.Expressions.Options;
using Elsa.Extensions;
using Elsa.Http.Bookmarks;
using Elsa.Http.ContentWriters;
using Elsa.Http.DownloadableContentHandlers;
using Elsa.Http.FileCaches;
using Elsa.Http.Handlers;
using Elsa.Http.Middleware;
using Elsa.Http.Options;
using Elsa.Http.Parsers;
using Elsa.Http.PortResolvers;
using Elsa.Http.Resilience;
using Elsa.Http.Selectors;
using Elsa.Http.Services;
using Elsa.Http.Tasks;
using Elsa.Http.TriggerPayloadValidators;
using Elsa.Http.UIHints;
using Elsa.Resilience.Extensions;
using Elsa.Workflows;
using Elsa.Workflows.Management.Extensions;
using FluentStorage;
using JetBrains.Annotations;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;
using Microsoft.AspNetCore.StaticFiles;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;

namespace Elsa.Http.ShellFeatures;

/// <summary>
/// Installs services related to HTTP services and activities.
/// </summary>
[ShellFeature(
    DisplayName = "HTTP",
    Description = "Provides HTTP-related activities and services for workflow execution",
    DependsOn = ["HttpJavaScript", "Resilience"])]
[UsedImplicitly]
public class HttpFeature : IMiddlewareShellFeature
{
    /// <summary>
    /// The <see cref="HttpActivityOptions"/> to configure.
    /// </summary>
    public HttpActivityOptions HttpActivityOptions { get; set; } = new();

    /// <summary>
    /// A delegate to configure <see cref="HttpFileCacheOptions"/>.
    /// </summary>
    public Action<HttpFileCacheOptions>? ConfigureHttpFileCacheOptions { get; set; }

    /// <summary>
    /// A delegate that is invoked when authorizing an inbound HTTP request.
    /// </summary>
    public Func<IServiceProvider, IHttpEndpointAuthorizationHandler> HttpEndpointAuthorizationHandler { get; set; } = sp => sp.GetRequiredService<AuthenticationBasedHttpEndpointAuthorizationHandler>();

    /// <summary>
    /// A delegate that is invoked when an HTTP workflow faults.
    /// </summary>
    public Func<IServiceProvider, IHttpEndpointFaultHandler> HttpEndpointWorkflowFaultHandler { get; set; } = sp => sp.GetRequiredService<DefaultHttpEndpointFaultHandler>();

    /// <summary>
    /// A delegate to configure the <see cref="IContentTypeProvider"/>.
    /// </summary>
    public Func<IServiceProvider, IContentTypeProvider> ContentTypeProvider { get; set; } = _ => new FileExtensionContentTypeProvider();

    /// <summary>
    /// A delegate to configure the <see cref="IFileCacheStorageProvider"/>.
    /// </summary>
    public Func<IServiceProvider, IFileCacheStorageProvider> FileCache { get; set; } = sp =>
    {
        var options = sp.GetRequiredService<IOptions<HttpFileCacheOptions>>().Value;
        var blobStorage = StorageFactory.Blobs.DirectoryFiles(options.LocalCacheDirectory);
        return new BlobFileCacheStorageProvider(blobStorage);
    };

    /// <summary>
    /// A delegate to configure the <see cref="HttpClient"/> used when by the <see cref="FlowSendHttpRequest"/> and <see cref="SendHttpRequest"/> activities.
    /// </summary>
    public Action<IServiceProvider, HttpClient> HttpClient { get; set; } = (_, _) => { };

    /// <summary>
    /// A delegate to configure the <see cref="HttpClientBuilder"/> for <see cref="HttpClient"/>.
    /// </summary>
    public Action<IHttpClientBuilder> HttpClientBuilder { get; set; } = _ => { };

    /// <summary>
    /// A list of <see cref="IHttpCorrelationIdSelector"/> types to register with the service collection.
    /// </summary>
    public ICollection<Type> HttpCorrelationIdSelectorTypes { get; } = new List<Type>
    {
        typeof(HeaderHttpCorrelationIdSelector),
        typeof(QueryStringHttpCorrelationIdSelector)
    };

    /// <summary>
    /// A list of <see cref="IHttpWorkflowInstanceIdSelector"/> types to register with the service collection.
    /// </summary>
    public ICollection<Type> HttpWorkflowInstanceIdSelectorTypes { get; } = new List<Type>
    {
        typeof(HeaderHttpWorkflowInstanceIdSelector),
        typeof(QueryStringHttpWorkflowInstanceIdSelector)
    };

    public void ConfigureServices(IServiceCollection services)
    {
        // Register HTTP activities.
        services.AddActivitiesFrom<HttpFeature>();

        // Register HTTP variable types.
        services.AddVariableDescriptors([
            new(typeof(HttpRouteData), "HTTP", null),
            new(typeof(HttpRequest), "HTTP", null),
            new(typeof(HttpResponse), "HTTP", null),
            new(typeof(HttpResponseMessage), "HTTP", null),
            new(typeof(HttpHeaders), "HTTP", null),
            new(typeof(IFormFile), "HTTP", null),
            new(typeof(HttpFile), "HTTP", null),
            new(typeof(Downloadable), "HTTP", null),
        ]);

        // Register the HTTP resilience strategy.
        services.AddResilienceStrategy<HttpResilienceStrategy>();

        var configureFileCacheOptions = ConfigureHttpFileCacheOptions ?? (options => { options.TimeToLive = TimeSpan.FromDays(7); });

        services.Configure<HttpActivityOptions>(options =>
        {
            options.BasePath = HttpActivityOptions.BasePath;
            options.BaseUrl = HttpActivityOptions.BaseUrl;
            options.AvailableContentTypes = HttpActivityOptions.AvailableContentTypes;
            options.WriteHttpResponseSynchronously = HttpActivityOptions.WriteHttpResponseSynchronously;
        });

        services.Configure(configureFileCacheOptions);

        var httpClientBuilder = services.AddHttpClient<SendHttpRequestBase>(HttpClient);
        HttpClientBuilder(httpClientBuilder);

        services
            .AddScoped<IRouteMatcher, RouteMatcher>()
            .AddScoped<IRouteTable, RouteTable>()
            .AddScoped<IAbsoluteUrlProvider, DefaultAbsoluteUrlProvider>()
            .AddScoped<IRouteTableUpdater, DefaultRouteTableUpdater>()
            .AddScoped<IHttpWorkflowLookupService, HttpWorkflowLookupService>()
            .AddScoped(ContentTypeProvider)
            .AddHttpContextAccessor()

            // Handlers.
            .AddNotificationHandler<UpdateRouteTable>()

            // Content parsers.
            .AddSingleton<IHttpContentParser, JsonHttpContentParser>()
            .AddSingleton<IHttpContentParser, XmlHttpContentParser>()
            .AddSingleton<IHttpContentParser, PlainTextHttpContentParser>()
            .AddSingleton<IHttpContentParser, TextHtmlHttpContentParser>()
            .AddSingleton<IHttpContentParser, FileHttpContentParser>()

            // HTTP content factories.
            .AddScoped<IHttpContentFactory, TextContentFactory>()
            .AddScoped<IHttpContentFactory, JsonContentFactory>()
            .AddScoped<IHttpContentFactory, XmlContentFactory>()
            .AddScoped<IHttpContentFactory, FormUrlEncodedHttpContentFactory>()

            // Activity property options providers.
            .AddScoped<IPropertyUIHandler, HttpContentTypeOptionsProvider>()
            .AddScoped<IPropertyUIHandler, HttpEndpointPathUIHandler>()

            // Default providers.
            .AddScoped<DefaultHttpEndpointBasePathProvider>()
            .AddScoped<IHttpEndpointBasePathProvider>(sp => sp.GetRequiredService<DefaultHttpEndpointBasePathProvider>())

            // Port resolvers.
            .AddScoped<IActivityResolver, SendHttpRequestActivityResolver>()

            // HTTP endpoint handlers.
            .AddScoped<AuthenticationBasedHttpEndpointAuthorizationHandler>()
            .AddScoped<AllowAnonymousHttpEndpointAuthorizationHandler>()
            .AddScoped<DefaultHttpEndpointFaultHandler>()
            .AddScoped<DefaultHttpEndpointRoutesProvider>()
            .AddScoped(HttpEndpointWorkflowFaultHandler)
            .AddScoped(HttpEndpointAuthorizationHandler)
            .AddScoped<IHttpEndpointRoutesProvider>(sp => sp.GetRequiredService<DefaultHttpEndpointRoutesProvider>())

            // Startup tasks.
            .AddStartupTask<UpdateRouteTableStartupTask>()

            // Downloadable content handlers.
            .AddScoped<IDownloadableManager, DefaultDownloadableManager>()
            .AddScoped<IDownloadableContentHandler, MultiDownloadableContentHandler>()
            .AddScoped<IDownloadableContentHandler, BinaryDownloadableContentHandler>()
            .AddScoped<IDownloadableContentHandler, StreamDownloadableContentHandler>()
            .AddScoped<IDownloadableContentHandler, FormFileDownloadableContentHandler>()
            .AddScoped<IDownloadableContentHandler, DownloadableDownloadableContentHandler>()
            .AddScoped<IDownloadableContentHandler, UrlDownloadableContentHandler>()
            .AddScoped<IDownloadableContentHandler, StringDownloadableContentHandler>()
            .AddScoped<IDownloadableContentHandler, HttpFileDownloadableContentHandler>()

            //Trigger payload validators.
            .AddTriggerPayloadValidator<HttpEndpointTriggerPayloadValidator, HttpEndpointBookmarkPayload>()

            // File caches.
            .AddScoped(FileCache)
            .AddScoped<ZipManager>()

            // AuthenticationBasedHttpEndpointAuthorizationHandler requires Authorization services.
            .AddAuthorization();

        // HTTP clients.
        services.AddHttpClient<IFileDownloader, HttpClientFileDownloader>();

        // Add selectors.
        foreach (var httpCorrelationIdSelectorType in HttpCorrelationIdSelectorTypes)
            services.AddScoped(typeof(IHttpCorrelationIdSelector), httpCorrelationIdSelectorType);

        foreach (var httpWorkflowInstanceIdSelectorType in HttpWorkflowInstanceIdSelectorTypes)
            services.AddScoped(typeof(IHttpWorkflowInstanceIdSelector), httpWorkflowInstanceIdSelectorType);

        services.Configure<ExpressionOptions>(options =>
        {
            options.AddTypeAlias<HttpRequest>("HttpRequest");
            options.AddTypeAlias<HttpResponse>("HttpResponse");
            options.AddTypeAlias<HttpResponseMessage>("HttpResponseMessage");
            options.AddTypeAlias<HttpHeaders>("HttpHeaders");
            options.AddTypeAlias<HttpRouteData>("RouteData");
            options.AddTypeAlias<IFormFile>("FormFile");
            options.AddTypeAlias<IFormFile[]>("FormFile[]");
            options.AddTypeAlias<HttpFile>("HttpFile");
            options.AddTypeAlias<HttpFile[]>("HttpFile[]");
            options.AddTypeAlias<Downloadable>("Downloadable");
            options.AddTypeAlias<Downloadable[]>("Downloadable[]");
        });
    }

    /// <inheritdoc />
    public void UseMiddleware(IApplicationBuilder app, IHostEnvironment? environment)
    {
        app.UseWorkflows();
    }
}