using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Svrnty.CQRS.Abstractions.Security;
using Svrnty.CQRS.Altcha.Abstractions;

namespace Svrnty.CQRS.Altcha;

public static class ServiceCollectionExtensions
{
    /// <summary>
    /// Registers <see cref="AltchaAuthorizationCheck"/> as both an
    /// <see cref="ICommandAuthorizationCheck"/> and an
    /// <see cref="IQueryAuthorizationCheck"/>, plus a no-op
    /// <see cref="IAltchaDifficultyAdvisor"/> that defers to the upstream
    /// Altcha service's configured default complexity. Applications opt
    /// into adaptive difficulty by registering their own
    /// <see cref="IAltchaDifficultyAdvisor"/> before or after this call —
    /// the <c>TryAdd</c> registration here yields to any existing one.
    /// </summary>
    /// <remarks>
    /// The check is a no-op until an
    /// <see cref="IAltchaVerifier"/> implementation is also registered
    /// (typically via <c>AddSvrntyAltchaGrpcVerifier(...)</c> from
    /// <c>Svrnty.CQRS.Altcha.Grpc</c>). Idempotent for the concrete check;
    /// the multi-instance interface registrations are added unconditionally,
    /// so callers should invoke this exactly once per application startup.
    /// </remarks>
    public static IServiceCollection AddSvrntyAltcha(this IServiceCollection services)
    {
        services.TryAddSingleton<AltchaAuthorizationCheck>();
        services.AddSingleton<ICommandAuthorizationCheck>(sp => sp.GetRequiredService<AltchaAuthorizationCheck>());
        services.AddSingleton<IQueryAuthorizationCheck>(sp => sp.GetRequiredService<AltchaAuthorizationCheck>());
        services.TryAddSingleton<IAltchaDifficultyAdvisor, NullAltchaDifficultyAdvisor>();
        return services;
    }
}