presenceNikita/Demo/Domain/UseCase/UserUseCase.cs

using Demo.Data.Repository;
using Demo.domain.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo.Domain.UseCase
{
    public class UserUseCase
    {
        private readonly UserRepositoryImpl _repositoryUserImpl;
        private readonly IGroupRepository _repositoryGroupImpl;

        public UserUseCase(UserRepositoryImpl repositoryImpl, IGroupRepository repositoryGroupImpl)
        {
            _repositoryUserImpl = repositoryImpl;
            _repositoryGroupImpl = repositoryGroupImpl;
        }

        private List<Group> GetAllGroups() => _repositoryGroupImpl.GetAllGroup()
              .Select(it => new Group { Id = it.Id, Name = it.Name }).ToList();

        public List<User> GetAllUsers() => _repositoryUserImpl.GetAllUsers
              .Join(_repositoryGroupImpl.GetAllGroup(),
              user => user.GroupID,
              group => group.Id,
              (user, group) =>
              new User
              {
                  FIO = user.FIO,
                  Guid = user.Guid,
                  Group = new Group { Id = group.Id, Name = group.Name }
              }
            ).ToList();

        // удалить пользователя по Giud
        public bool RemoveUserByGuid(Guid userGuid)
        {
            return _repositoryUserImpl.RemoveUserByGuid(userGuid);
        }


        // Обновить пользователя по Guid
        public User UpdateUser(User user)
        {
            UserLocalEnity userLocalEnity = new UserLocalEnity { FIO = user.FIO, GroupID = user.Group.Id, Guid = user.Guid };
            UserLocalEnity? result = _repositoryUserImpl.UpdateUser(userLocalEnity);

            if (result == null)
            {
                throw new Exception("");
            }
            Group? group = GetAllGroups().FirstOrDefault(it => it.Id == result!.GroupID);

            if (group == null) 
            { 
                throw new Exception(""); 
            }
            return new User { FIO = user.FIO, Guid = user.Guid, Group = group };
        }

        // Найти пользователя по Guid
        public User FindUserByGuid(Guid userGuid)
        {
            var user = _repositoryUserImpl.GetAllUsers
                .FirstOrDefault(u => u.Guid == userGuid);
            if (user == null) throw new Exception("Пользователь не найден");

            var group = _repositoryGroupImpl.GetAllGroup()
                .FirstOrDefault(g => g.Id == user.GroupID);

            return new User
            {
                FIO = user.FIO,
                Guid = user.Guid,
                Group = new Group { Id = group.Id, Name = group.Name }
            };
        }

        //public List<Group> GetAllGroups() => _repositoryGroupImpl.GetAllGroups().Select(it => new Group { Id = it.Id, Name = it.Name }).ToList();
    }
}