presence/Demo/Domain/UseCase/UserUseCase.cs

using Demo.Data.Repository;
using Demo.Domain.Models;
using Demo.Data.Exceptions;
using System;
using System.Collections.Generic;
using System.Linq;
using Demo.domain.Models;

namespace Demo.Domain.UseCase
{
    public class UserUseCase
    {
        private readonly UserRepositoryImpl _userRepository;
        private readonly IGroupRepository _groupRepository;

        public UserUseCase(UserRepositoryImpl userRepository, IGroupRepository groupRepository)
        {
            _userRepository = userRepository;
            _groupRepository = groupRepository;
        }

        private List<Group> GetAllGroups() =>
            _groupRepository.GetAllGroups()
                .Select(g => new Group { Id = g.Id, Name = g.Name })
                .ToList();

        public List<User> GetAllUsers() =>
            _userRepository.GetAllUsers
                .Join(_groupRepository.GetAllGroups(),
                    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();

        public bool RemoveUserByGuid(Guid userGuid)
        {
            try
            {
                _userRepository.DeleteUserByGuid(userGuid);
                return true;
            }
            catch (GuidNotFoundException)
            {
                return false;
            }
        }

        public User UpdateUser(User user)
        {
            try
            {
                _userRepository.UpdateUser(user.Guid.ToString(), user.FIO, user.Group.Id);

                var group = GetAllGroups().FirstOrDefault(g => g.Id == user.Group.Id);
                if (group == null)
                {
                    throw new Exception($"Группа с ID {user.Group.Id} не найдена.");
                }

                return new User { FIO = user.FIO, Guid = user.Guid, Group = group };
            }
            catch (GuidNotFoundException ex)
            {
                throw new Exception("Пользователь не найден.", ex);
            }
            catch (ArgumentException ex)
            {
                throw new Exception("Некорректный GUID.", ex);
            }
        }
    }
}