IServiceCollectionExtensions.cs

using System.ComponentModel;
using JustSaying;
using JustSaying.AwsTools;
using JustSaying.AwsTools.QueueCreation;
using JustSaying.Fluent;
using JustSaying.Messaging;
using JustSaying.Messaging.Channels.Receive;
using JustSaying.Messaging.Compression;
using JustSaying.Messaging.MessageHandling;
using JustSaying.Messaging.MessageSerialization;
using JustSaying.Messaging.Middleware.Logging;
using JustSaying.Messaging.Middleware.PostProcessing;
using JustSaying.Messaging.Monitoring;
using JustSaying.Models;
using JustSaying.Naming;
using Microsoft.Extensions.DependencyInjection.Extensions;

namespace Microsoft.Extensions.DependencyInjection;

/// <summary>
/// A class containing extension methods for the <see cref="IServiceCollection"/> interface. This class cannot be inherited.
/// </summary>
[EditorBrowsable(EditorBrowsableState.Never)]
public static class IServiceCollectionExtensions
{
    /// <summary>
    /// Adds JustSaying services to the service collection.
    /// </summary>
    /// <param name="services">The <see cref="IServiceCollection"/> to add JustSaying services to.</param>
    /// <returns>
    /// The <see cref="IServiceCollection"/> specified by <paramref name="services"/>.
    /// </returns>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="services"/> is <see langword="null"/>.
    /// </exception>
    public static IServiceCollection AddJustSaying(this IServiceCollection services)
    {
        if (services == null)
        {
            throw new ArgumentNullException(nameof(services));
        }

        return services.AddJustSaying((_) => { });
    }

    /// <summary>
    /// Adds JustSaying services to the service collection.
    /// </summary>
    /// <param name="services">The <see cref="IServiceCollection"/> to add JustSaying services to.</param>
    /// <param name="region">The AWS region to configure.</param>
    /// <returns>
    /// The <see cref="IServiceCollection"/> specified by <paramref name="services"/>.
    /// </returns>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="services"/> or <paramref name="region"/> is <see langword="null"/>.
    /// </exception>
    public static IServiceCollection AddJustSaying(this IServiceCollection services, string region)
    {
        if (services == null)
        {
            throw new ArgumentNullException(nameof(services));
        }

        if (string.IsNullOrWhiteSpace(region))
        {
            throw new ArgumentException("region must not be null or empty" ,nameof(region));
        }

        return services.AddJustSaying(
            (builder) => builder.Messaging(
                (options) => options.WithRegion(region)));
    }

    /// <summary>
    /// Adds JustSaying services to the service collection.
    /// </summary>
    /// <param name="services">The <see cref="IServiceCollection"/> to add JustSaying services to.</param>
    /// <param name="configure">A delegate to a method to use to configure JustSaying.</param>
    /// <returns>
    /// The <see cref="IServiceCollection"/> specified by <paramref name="services"/>.
    /// </returns>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="services"/> or <paramref name="configure"/> is <see langword="null"/>.
    /// </exception>
    public static IServiceCollection AddJustSaying(this IServiceCollection services, Action<MessagingBusBuilder> configure)
    {
        if (services == null)
        {
            throw new ArgumentNullException(nameof(services));
        }

        if (configure == null)
        {
            throw new ArgumentNullException(nameof(configure));
        }

        return services.AddJustSaying((builder, _) => configure(builder));
    }

    /// <summary>
    /// Adds JustSaying services to the service collection.
    /// </summary>
    /// <param name="services">The <see cref="IServiceCollection"/> to add JustSaying services to.</param>
    /// <param name="configure">A delegate to a method to use to configure JustSaying.</param>
    /// <returns>
    /// The <see cref="IServiceCollection"/> specified by <paramref name="services"/>.
    /// </returns>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="services"/> or <paramref name="configure"/> is <see langword="null"/>.
    /// </exception>
    public static IServiceCollection AddJustSaying(this IServiceCollection services, Action<MessagingBusBuilder, IServiceProvider> configure)
    {
        if (services == null)
        {
            throw new ArgumentNullException(nameof(services));
        }

        if (configure == null)
        {
            throw new ArgumentNullException(nameof(configure));
        }

        // Register as self so the same singleton instance implements two different interfaces
        services.TryAddSingleton((p) => new ServiceProviderResolver(p));
        services.TryAddSingleton<IHandlerResolver>((p) => p.GetRequiredService<ServiceProviderResolver>());
        services.TryAddSingleton<IServiceResolver>((p) => p.GetRequiredService<ServiceProviderResolver>());

        services.TryAddSingleton<IAwsClientFactory, DefaultAwsClientFactory>();
        services.TryAddSingleton<IAwsClientFactoryProxy>((p) => new AwsClientFactoryProxy(p.GetRequiredService<IAwsClientFactory>));
        services.TryAddSingleton<MessagingConfig>();
        services.TryAddSingleton<IMessagingConfig>((p) => p.GetRequiredService<MessagingConfig>());
        services.TryAddSingleton<IPublishConfiguration>((p) => p.GetRequiredService<MessagingConfig>());
        services.TryAddSingleton<IPublishBatchConfiguration>((p) => p.GetRequiredService<MessagingConfig>());
        services.TryAddSingleton<IMessageMonitor, NullOpMessageMonitor>();

        services.TryAddTransient<LoggingMiddleware>();
        services.TryAddTransient<SqsPostProcessorMiddleware>();

        services.AddSingleton<MessageContextAccessor>();
        services.TryAddSingleton<IMessageContextAccessor>(serviceProvider => serviceProvider.GetRequiredService<MessageContextAccessor>());
        services.TryAddSingleton<IMessageContextReader>(serviceProvider => serviceProvider.GetRequiredService<MessageContextAccessor>());

        services.TryAddSingleton<IMessageBodySerializationFactory, NewtonsoftSerializationFactory>();
        services.TryAddSingleton<IMessageSubjectProvider, GenericMessageSubjectProvider>();
        services.TryAddSingleton<IVerifyAmazonQueues, AmazonQueueCreator>();
        services.TryAddEnumerable(ServiceDescriptor.Singleton<IMessageBodyCompression, GzipMessageBodyCompression>());
        services.TryAddSingleton<MessageCompressionRegistry>();

        services.TryAddSingleton<IMessageReceivePauseSignal, MessageReceivePauseSignal>();

        services.TryAddSingleton(
            (serviceProvider) =>
            {
                var builder = new MessagingBusBuilder()
                    .WithServiceResolver(new ServiceProviderResolver(serviceProvider));

                configure(builder, serviceProvider);

                var contributors = serviceProvider.GetServices<IMessageBusConfigurationContributor>();

                foreach (var contributor in contributors)
                {
                    contributor.Configure(builder);
                }

                return builder;
            });

        services.TryAddSingleton(
            (serviceProvider) =>
            {
                var builder = serviceProvider.GetRequiredService<MessagingBusBuilder>();
                return builder.BuildPublisher();
            });

        services.TryAddSingleton(
            (serviceProvider) =>
            {
                var publisher = serviceProvider.GetRequiredService<IMessagePublisher>();

                if (publisher is IMessageBatchPublisher batchPublisher)
                {
                    return batchPublisher;
                }

                var builder = serviceProvider.GetRequiredService<MessagingBusBuilder>();
                return builder.BuildBatchPublisher();
            });

        services.TryAddSingleton(
            (serviceProvider) =>
            {
                var builder = serviceProvider.GetRequiredService<MessagingBusBuilder>();
                return builder.BuildSubscribers();
            });

        services.AddSingleton<DefaultNamingConventions>();
        services.TryAddSingleton<ITopicNamingConvention>((s) => s.GetRequiredService<DefaultNamingConventions>());
        services.TryAddSingleton<IQueueNamingConvention>((s) => s.GetRequiredService<DefaultNamingConventions>());

        return services;
    }

    /// <summary>
    /// Adds a JustSaying message handler to the service collection.
    /// </summary>
    /// <typeparam name="TMessage">The type of the message handled.</typeparam>
    /// <typeparam name="THandler">The type of the message handler to register.</typeparam>
    /// <param name="services">The <see cref="IServiceCollection"/> to add the message handler to.</param>
    /// <returns>
    /// The <see cref="IServiceCollection"/> specified by <paramref name="services"/>.
    /// </returns>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="services"/> is <see langword="null"/>.
    /// </exception>
    public static IServiceCollection AddJustSayingHandler<TMessage, THandler>(this IServiceCollection services)
        where TMessage : Message
        where THandler : class, IHandlerAsync<TMessage>
    {
        if (services == null)
        {
            throw new ArgumentNullException(nameof(services));
        }

        services.TryAddTransient<IHandlerAsync<TMessage>, THandler>();
        return services;
    }

    /// <summary>
    /// Adds a JustSaying message handler to the service collection that uses the specified handlers.
    /// </summary>
    /// <typeparam name="TMessage">The type of the message handled.</typeparam>
    /// <param name="services">The <see cref="IServiceCollection"/> to add the message handler to.</param>
    /// <param name="handlers">The message handlers to use.</param>
    /// <returns>
    /// The <see cref="IServiceCollection"/> specified by <paramref name="services"/>.
    /// </returns>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="services"/> or <paramref name="handlers"/> is <see langword="null"/>.
    /// </exception>
    /// <exception cref="ArgumentException">
    /// <paramref name="handlers"/> contains no handlers.
    /// </exception>
    public static IServiceCollection AddJustSayingHandlers<TMessage>(
        this IServiceCollection services,
        IEnumerable<IHandlerAsync<TMessage>> handlers)
        where TMessage : Message
    {
        if (services == null)
        {
            throw new ArgumentNullException(nameof(services));
        }

        if (handlers == null)
        {
            throw new ArgumentNullException(nameof(handlers));
        }

        var enumeratedHandlers = handlers.ToList();

        if (enumeratedHandlers.Count < 1)
        {
            throw new ArgumentException("At least one message handler must be specified.", nameof(handlers));
        }

        if (enumeratedHandlers.Count == 1)
        {
            services.TryAddTransient((_) => enumeratedHandlers[0]);
        }
        else
        {
            services.TryAddTransient<IHandlerAsync<TMessage>>((_) => new ListHandler<TMessage>(enumeratedHandlers));
        }

        return services;
    }

    /// <summary>
    /// Configures JustSaying using the specified service collection.
    /// </summary>
    /// <param name="services">The <see cref="IServiceCollection"/> to configure JustSaying with.</param>
    /// <param name="configure">A delegate to a method to use to configure JustSaying.</param>
    /// <returns>
    /// The <see cref="IServiceCollection"/> specified by <paramref name="services"/>.
    /// </returns>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="services"/> or <paramref name="configure"/> is <see langword="null"/>.
    /// </exception>
    public static IServiceCollection ConfigureJustSaying(this IServiceCollection services, Action<MessagingBusBuilder> configure)
    {
        if (services == null)
        {
            throw new ArgumentNullException(nameof(services));
        }

        if (configure == null)
        {
            throw new ArgumentNullException(nameof(configure));
        }

        return services.AddSingleton<IMessageBusConfigurationContributor>(new DelegatingConfigurationContributor(configure));
    }

    private sealed class DelegatingConfigurationContributor : IMessageBusConfigurationContributor
    {
        private readonly Action<MessagingBusBuilder> _configure;

        internal DelegatingConfigurationContributor(Action<MessagingBusBuilder> configure)
        {
            _configure = configure;
        }

        public void Configure(MessagingBusBuilder builder)
            => _configure(builder);
    }
}