Integration Events

public class IntegrationEvent : INotification
{
    public IntegrationEvent()
    {
        Id = Guid.CreateVersion7(DateTime.UtcNow);   // time-ordered v7
        CreatedAt = DateTime.UtcNow;
    }

    [JsonConstructor]
    public IntegrationEvent(Guid id, DateTime createdAt)
    {
        Id = id;
        CreatedAt = createdAt;
    }

    [JsonInclude] public Guid Id { get; private init; }
    [JsonInclude] public DateTime CreatedAt { get; private init; }
}

// Bus'a yayınlanan tüm event'lerin marker'ı
public interface IBusEvent : INotification, IBusMessage
{
    string GetEventKey();   // topic routing key üretimi için
}

public interface IBusMessage { }   // bus üzerinden taşınan tüm tipler için marker

string routingKey = @event is IBusEvent busEvent ? busEvent.GetEventKey() : @event.GetType().Name;
context.SetRoutingKey($"{_options.RoutingKeyPrefix}.{routingKey}");

[MessageUrn("urn:event:user-created:v1")]
public class UserCreatedIntegrationEvent : IntegrationEvent
{
    public Guid UserId { get; init; }
    public string? FullName { get; init; }
    public string Phone { get; init; } = string.Empty;
    public string Email { get; init; } = string.Empty;

    public UserCreatedIntegrationEvent() { }
    public UserCreatedIntegrationEvent(Guid userId, string? fullName, string phone, string email)
    {
        UserId = userId; FullName = fullName; Phone = phone; Email = email;
    }
}

public interface IIntegrationEventHandler<in TIntegrationEvent> : IIntegrationEventHandler
    where TIntegrationEvent : IntegrationEvent
{
    Task Handle(TIntegrationEvent @event);

    Task IIntegrationEventHandler.Handle(IntegrationEvent @event) => Handle((TIntegrationEvent)@event);
}

// Tipsiz handler — keyed DI registration için.
public interface IIntegrationEventHandler { Task Handle(IntegrationEvent @event); }

public static IEventBusBuilder AddMassTransitSubscription<T, TH>(this IEventBusBuilder builder)
    where T : IntegrationEvent
    where TH : class, IIntegrationEventHandler<T>
{
    // 1) Keyed handler kaydı + EventTypes mapping (RabbitMQ binding'i bunu kullanır)
    EventBusBuilderExtensions.AddSubscription<T, TH>(builder);
    // 2) MassTransit consumer'ı DI'a ekle
    builder.Services.AddScoped<IntegrationEventConsumer<T>>();
    return builder;
}

builder.Services.AddMassTransitRabbitMqEventBus(builder.Configuration, x =>
    {
        x.AddEntityFrameworkOutbox<DiyanetCleanArchitectureDbContext>(o => { /* ... */ });
    })
    .AddMassTransitSubscription<CacheInvalidationIntegrationEvent, CacheInvalidationIntegrationEventHandler>();

public class IntegrationEventConsumer<T>(IServiceProvider serviceProvider) : IConsumer<T>
    where T : IntegrationEvent
{
    public async Task Consume(ConsumeContext<T> context)
    {
        var handlers = serviceProvider.GetKeyedServices<IIntegrationEventHandler>(typeof(T));
        foreach (var handler in handlers)
            if (handler is IIntegrationEventHandler<T> integrationHandler)
                await integrationHandler.Handle(context.Message);
    }
}