mongo-service.cs

public interface ISampleService
{
    ServiceDataResult GetAll();
    ServiceDataResult Get(string id);
    ServiceResult Add(AddSampleRequest request);
    ServiceResult Update(UpdateSampleRequest request);
    ServiceResult Delete(string id);
}

public class SampleService : ISampleService
{
        private readonly ISampleRepository repository;
        private readonly ISampleFactory factory;

        public SampleService(ISampleRepository repository, ISampleFactory factory)
        {
            this.repository = repository;
            this.factory = factory;
        }

        public ServiceDataResult GetAll()
        {
            var samples = repository.AsQueryable()
                .Select(p => new {p.Id, p.Title})
                .ToList();

            return ServiceDataResult.Success(samples);
        }

        public ServiceDataResult Get(string id)
        {
            var sample = repository.FindById(id);
            return ServiceDataResult.Success(sample);
        }

        public ServiceResult Add(AddSampleRequest request)
        {
            var sample = factory.CreateAddSample(request);
            var result = repository.Insert(sample);

            return string.IsNullOrEmpty(result)
                ? ServiceResult.Error(Messages.AddingFailed)
                : ServiceResult.Success(Messages.AddingSuccess);
        }

        public ServiceResult Update(UpdateSampleRequest request)
        {
            var currentSample = repository.FindById(request.Id);
            var sample = factory.CreateUpdateSample(currentSample, request);
            var result = repository.ReplaceOne(sample);

            return !result
                ? ServiceResult.Error(Messages.UpdatingFailed)
                : ServiceResult.Success(Messages.UpdatingSuccess);
        }

        public ServiceResult Delete(string id)
        {
            var result = repository.DeleteById(id);

            return !result
                ? ServiceResult.Error(Messages.DeletingFailed)
                : ServiceResult.Success(Messages.DeletingSuccess);
        }
}