using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using StellaOps.Router.Common.Abstractions;

namespace StellaOps.Router.Transport.InMemory;

/// <summary>
/// Extension methods for registering InMemory transport services.
/// </summary>
public static class ServiceCollectionExtensions
{
    /// <summary>
    /// Adds the InMemory transport for testing and development.
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configure">Optional configuration action.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddInMemoryTransport(
        this IServiceCollection services,
        Action<InMemoryTransportOptions>? configure = null)
    {
        services.AddOptions<InMemoryTransportOptions>();
        if (configure is not null)
        {
            services.Configure(configure);
        }

        // Singleton registry shared between server and client
        services.TryAddSingleton<InMemoryConnectionRegistry>();

        // Transport implementations
        services.TryAddSingleton<InMemoryTransportServer>();
        services.TryAddSingleton<InMemoryTransportClient>();

        // Register interfaces
        services.TryAddSingleton<ITransportServer>(sp => sp.GetRequiredService<InMemoryTransportServer>());
        services.TryAddSingleton<ITransportClient>(sp => sp.GetRequiredService<InMemoryTransportClient>());
        services.TryAddSingleton<IMicroserviceTransport>(sp => sp.GetRequiredService<InMemoryTransportClient>());

        return services;
    }

    /// <summary>
    /// Adds the InMemory transport server only (for Gateway).
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configure">Optional configuration action.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddInMemoryTransportServer(
        this IServiceCollection services,
        Action<InMemoryTransportOptions>? configure = null)
    {
        services.AddOptions<InMemoryTransportOptions>();
        if (configure is not null)
        {
            services.Configure(configure);
        }

        services.TryAddSingleton<InMemoryConnectionRegistry>();
        services.TryAddSingleton<InMemoryTransportServer>();
        services.TryAddSingleton<ITransportServer>(sp => sp.GetRequiredService<InMemoryTransportServer>());

        return services;
    }

    /// <summary>
    /// Adds the InMemory transport client only (for Microservice SDK).
    /// </summary>
    /// <param name="services">The service collection.</param>
    /// <param name="configure">Optional configuration action.</param>
    /// <returns>The service collection for chaining.</returns>
    public static IServiceCollection AddInMemoryTransportClient(
        this IServiceCollection services,
        Action<InMemoryTransportOptions>? configure = null)
    {
        services.AddOptions<InMemoryTransportOptions>();
        if (configure is not null)
        {
            services.Configure(configure);
        }

        services.TryAddSingleton<InMemoryConnectionRegistry>();
        services.TryAddSingleton<InMemoryTransportClient>();
        services.TryAddSingleton<ITransportClient>(sp => sp.GetRequiredService<InMemoryTransportClient>());
        services.TryAddSingleton<IMicroserviceTransport>(sp => sp.GetRequiredService<InMemoryTransportClient>());

        return services;
    }
}