src/Microsoft.Azure.SignalR/DependencyInjectionExtensions.cs

// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System;

#if !NETSTANDARD2_0
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Routing;
#endif

using Microsoft.AspNetCore.SignalR;
using Microsoft.Azure.SignalR;
using Microsoft.Azure.SignalR.Protocol;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Options;

namespace Microsoft.Extensions.DependencyInjection;

/// <summary>
/// Extension methods for <see cref="ISignalRServerBuilder"/>.
/// </summary>
public static class AzureSignalRDependencyInjectionExtensions
{
    /// <summary>
    /// Adds the minimum essential Azure SignalR services to the specified <see cref="ISignalRServerBuilder" />.
    /// </summary>
    /// <param name="builder">The <see cref="ISignalRServerBuilder"/>.</param>
    /// <returns>The same instance of the <see cref="ISignalRServerBuilder"/> for chaining.</returns>
    /// <remarks>
    /// It reads connection string from a configuration entry Azure:SignalR:ConnectionString.
    /// In development environment, try `dotnet user-secrets set Azure:SignalR:ConnectionString {YourConnectionString}`.
    /// </remarks>
    public static ISignalRServerBuilder AddAzureSignalR(this ISignalRServerBuilder builder)
    {
        return builder.AddAzureSignalR<ServiceOptionsSetup>();
    }

    /// <summary>
    /// Add Azure SignalR with specified name, the connection string will be read from ConnectionStrings_{name}, the settings are loaded from Azure:SignalR:{name} section
    /// </summary>
    /// <param name="builder">The <see cref="ISignalRServerBuilder"/>.</param>
    /// <param name="name">The name of the Azure SignalR service that settings and connection strings are read from</param>
    /// <returns>The same instance of the <see cref="ISignalRServerBuilder"/> for chaining.</returns>
    public static ISignalRServerBuilder AddNamedAzureSignalR(this ISignalRServerBuilder builder, string name)
    {
        if (string.IsNullOrEmpty(name))
        {
            throw name == null ? new ArgumentNullException(nameof(name)) : new ArgumentException("The value cannot be an empty string.", nameof(name));
        }

        builder.Services.SetupOptions<ServiceOptions, ServiceOptionsSetup>(s => ActivatorUtilities.CreateInstance<ServiceOptionsSetup>(s, name));
        return builder.AddAzureSignalRCore();
    }

    /// <summary>
    /// Adds the minimum essential Azure SignalR services to the specified <see cref="ISignalRServerBuilder" />.
    /// </summary>
    /// <param name="builder">The <see cref="ISignalRServerBuilder"/>.</param>
    /// <param name="connectionString">The connection string of an Azure SignalR Service instance.</param>
    /// <returns>The same instance of the <see cref="ISignalRServerBuilder"/> for chaining.</returns>
    public static ISignalRServerBuilder AddAzureSignalR(this ISignalRServerBuilder builder, string connectionString)
    {
        return builder.AddAzureSignalR(options =>
        {
            options.ConnectionString = connectionString;
        });
    }

    /// <summary>
    /// Adds the minimum essential Azure SignalR services to the specified <see cref="ISignalRServerBuilder" />.
    /// </summary>
    /// <param name="builder">The <see cref="ISignalRServerBuilder"/>.</param>
    /// <param name="configure">A callback to configure the <see cref="ServiceOptions"/>.</param>
    /// <returns>The same instance of the <see cref="ISignalRServerBuilder"/> for chaining.</returns>
    public static ISignalRServerBuilder AddAzureSignalR(this ISignalRServerBuilder builder, Action<ServiceOptions> configure)
    {
        builder.AddAzureSignalR()
               .Services.Configure(configure);

        return builder;
    }

    /// <typeparam name="TOptionsSetup">The set up class used to configure <see cref="ServiceOptions"/> and track changes.</typeparam>
    internal static ISignalRServerBuilder AddAzureSignalR<TOptionsSetup>(this ISignalRServerBuilder builder) where TOptionsSetup : class, IConfigureOptions<ServiceOptions>, IOptionsChangeTokenSource<ServiceOptions>
    {
        builder.Services.SetupOptions<ServiceOptions, TOptionsSetup>();
        return builder.AddAzureSignalRCore();
    }

    private static ISignalRServerBuilder AddAzureSignalRCore(this ISignalRServerBuilder builder)
    {
        builder.Services
            .PostConfigure<ServiceOptions>(o => o.Validate())
            .AddSingleton(typeof(HubLifetimeManager<>), typeof(ServiceLifetimeManager<>))
            .AddSingleton(typeof(IServiceProtocol), typeof(ServiceProtocol))
            .AddSingleton(typeof(IClientConnectionManager), typeof(ClientConnectionManager))
            .AddSingleton(typeof(IServiceConnectionManager<>), typeof(ServiceConnectionManager<>))
            .AddSingleton(typeof(IServiceEndpointManager), typeof(ServiceEndpointManager))
            .AddSingleton(typeof(IServerNameProvider), typeof(DefaultServerNameProvider))
            .AddSingleton(typeof(IBlazorDetector), typeof(DefaultBlazorDetector))
            .AddSingleton(typeof(IConnectionFactory), typeof(ConnectionFactory))
            .AddSingleton(typeof(ICultureFeatureManager), typeof(DefaultCultureFeatureManager))
            .AddSingleton(typeof(ServiceHubDispatcher<>))
            .AddSingleton(typeof(ServerLifetimeManager))
            .AddSingleton(typeof(AzureSignalRMarkerService))
            .AddSingleton<IClientConnectionFactory, ClientConnectionFactory>()
            .AddSingleton<IHostedService, HeartBeat>()
            .AddSingleton(typeof(NegotiateHandler<>));

        // If a custom router is added, do not add the default router
        builder.Services.TryAddSingleton(typeof(IEndpointRouter), typeof(DefaultEndpointRouter));
        builder.Services.TryAddSingleton(typeof(IConnectionRequestIdProvider), typeof(DefaultConnectionRequestIdProvider));

        // If a custom service event handler is added, do not add the default handler.
        builder.Services.TryAddSingleton<IServiceEventHandler, DefaultServiceEventHandler>();

        // IEndpointRouter and IAccessKeySynchronizer is required to build ClientInvocationManager.
        builder.Services
#if NET7_0_OR_GREATER
            .AddSingleton<IClientInvocationManager, ClientInvocationManager>();
#else
            .AddSingleton<IClientInvocationManager, DummyClientInvocationManager>();
#endif

#if !NETSTANDARD2_0
        builder.Services.TryAddSingleton<AzureSignalRHostedService>();
        builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IStartupFilter, AzureSignalRStartupFilter>());
        builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<MatcherPolicy, NegotiateMatcherPolicy>());
#endif

        return builder;
    }
}