using Femto.Common.Domain;
using Femto.Modules.Media.Data;
using MediatR;

namespace Femto.Modules.Media.Infrastructure.PipelineBehaviours;

internal class DomainEventsPipelineBehaviour<TRequest, TResponse>(
    MediaContext context,
    IPublisher publisher) : IPipelineBehavior<TRequest, TResponse> 
    where TRequest : notnull
{
    public async Task<TResponse> Handle(
        TRequest request,
        RequestHandlerDelegate<TResponse> next,
        CancellationToken cancellationToken)
    {
        var response = await next(cancellationToken);

        var domainEvents = context.ChangeTracker
            .Entries<Entity>()
            .SelectMany(e =>
            {
                var events = e.Entity.DomainEvents;
                e.Entity.ClearDomainEvents();
                return events;
            })
            .ToList();

        foreach (var domainEvent in domainEvents)
        {
            await publisher.Publish(domainEvent, cancellationToken);
        }

        return response;
    }
}