Demo/Domain/UseCase/UserUseCase.cs

using Posechaemost.Data.LocalData.Entity;
using Posechaemost.Data.RemoteData.RemoteDataBase.DAO;
using Posechaemost.Data.Repository;
using Posechaemost.Domain.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Posechaemost.Domain.UseCase
{
    public class UserUseCase
    {
        
        private readonly SQLUserRepositoryImpl _repositoryUserImpl;
        private readonly IGroupRepository _repositoryGroupImpl;

        public UserUseCase(SQLUserRepositoryImpl repositoryImpl, SQLGroupRepositoryImpl repositoryGroupImpl)
        {
            _repositoryUserImpl = repositoryImpl;
            _repositoryGroupImpl = repositoryGroupImpl;
        }

      private List<GroupDao> GetAllGroups() => _repositoryGroupImpl.GetAllGroups()
            .Select(it => new GroupDao { Id  = it.Id, Name = it.Name}).ToList();
      public List<UserDao> GetAllUsers() => _repositoryUserImpl.GetAllUser()
            .Join(_repositoryGroupImpl.GetAllGroups(),
            user => user.GroupId,
            group => group.Id,
            (user, group) => 
            new UserDao { FIO = user.FIO, 
                UserId = user.UserId, 
                GroupId = group.Id }
            ).ToList();
            

        public bool RemoveUserById(int userId) {
           return _repositoryUserImpl.RemoveUserById(userId);
        }
        public bool UpdateUser(UserDao user) {
            UserDao userDao = new UserDao { FIO = user.FIO, GroupId = user.GroupId };
            return _repositoryUserImpl.UpdateUser(userDao);
        }

        public UserDao GetUserById(int userId) {
            return _repositoryUserImpl.GetUserById(userId);
        }

        public bool UpdateUserById(int userId, String fio, int groupId) {
            UserDao userDao = new UserDao { FIO = fio, GroupId = groupId };
            return _repositoryUserImpl.UpdateUser(userDao);
        }
    }
}