EnvelopeGenerator/EnvelopeGenerator.Application/DIExtensions.cs

using EnvelopeGenerator.Application.Contracts;
using EnvelopeGenerator.Application.Services;
using Microsoft.Extensions.DependencyInjection;
using static EnvelopeGenerator.Common.Constants;

namespace EnvelopeGenerator.Application
{
    public static class DIExtensions
    {
        public static IServiceCollection AddHistoryService(this IServiceCollection services, Func<EnvelopeStatus, ReferenceType>? classifier = null) => services
            .AddSingleton(classifier ?? EnvelopeHistoryService.DefaultClassifier)
            .AddScoped<IEnvelopeHistoryService, EnvelopeHistoryService>();
    }
}