pr1/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 UserRepositoryImpl _repositoryUserImpl;
        private GroupRepositoryImpl _repositoryGroupImpl;

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

        public List<Group> GetAllGroups() => _repositoryGroupImpl.GetAllGroups()
              .Select(it => new Group { Id = it.Id, Name = it.Name }).ToList();
        public List<User> GetAllUsers() => _repositoryUserImpl.GetAllUsers
              .Join(_repositoryGroupImpl.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)
        {
            return _repositoryUserImpl.RemoveUserByGuid(userGuid);
        }
        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 };
        }
        public User FindUserByGuid(Guid userGuid)
        {
            Dictionary<Guid, User> users = new Dictionary<Guid, User>();

            if (users.ContainsKey(userGuid))
            {
                return users[userGuid];
            }
            else
            {
                return null;
            }

        }
    }
}