presence_new/not relevant/UserViewModel.cs

using domain.UseCase;
using DynamicData;
using DynamicData.Binding;
using Microsoft.EntityFrameworkCore.Metadata.Internal;
using Presence.Desktop.Models;
using ReactiveUI;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Reactive.Linq;
using Tmds.DBus.Protocol;

namespace Presence.Desktop.ViewModels
{
    public class UserViewModel: ViewModelBase, IRoutableViewModel
    {
        private readonly List<UserPresenter> _userPresentersDataSource = new List<UserPresenter>();
        private ObservableCollection<UserPresenter> _users;
        public ObservableCollection<UserPresenter> Users => _users;
        private IUserUseCase _userUseCase;
        private UserPresenter? _selectedUserItem;
        public UserPresenter? SelectedUserItem
        {
            get => _selectedUserItem;
            set => this.RaiseAndSetIfChanged(ref _selectedUserItem, value);
        }

        public string? UrlPathSegment { get; }

        public IScreen HostScreen { get; }
        public UserViewModel(IUserUseCase userUseCase)
        {
            foreach (var user in userUseCase.GetStudents())
            {
                UserPresenter userPresenter = new UserPresenter 
                {
                    Id = user.Id,
                    Name = user.FIO,
                    Group = new GroupPresenter
                    {
                        Name = user.Group.Name,
                        Id = user.Group.Id,
                    }
                };
                _userPresentersDataSource.Add(userPresenter);

            }
            _users = new ObservableCollection<UserPresenter>(_userPresentersDataSource);
            _userUseCase = userUseCase;
            RefreshUsers();
            this.WhenAnyValue(vm => vm.SelectedUserItem)
                .Subscribe(_ =>
                {
                    RefreshUsers();

                });

        }

        private void RefreshUsers()
        {
            _userPresentersDataSource.Clear();
            foreach (var user in _userUseCase.GetStudents())
            {
                UserPresenter userPresenter = new UserPresenter 
                {
                    Id = user.Id,
                    Name = user.FIO,
                    Group = new GroupPresenter
                    {
                        Name = user.Group.Name,
                        Id = user.Group.Id,
                    }
                };
                _userPresentersDataSource.Add(userPresenter);

            }
            _users = new ObservableCollection<UserPresenter>(_userPresentersDataSource);
            

        }
    }
}