Mikrotik-Installer/src/MikrotikInstaller.App/ViewModels/Steps/ConnectionStepViewModel.cs

using System.Collections.ObjectModel;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using MikrotikInstaller.App.Credentials;
using MikrotikInstaller.Core.Connectivity;
using MikrotikInstaller.Core.Devices;

namespace MikrotikInstaller.App.ViewModels.Steps;

/// <summary>
/// Erster Schritt: Verbindungsdaten zum MikroTik-Gerät erfassen und testen.
/// Erst nach einer erfolgreich getesteten Verbindung darf im Assistenten weitergegangen werden.
/// "Bekannte Router" (zuvor erfolgreich verbundene Geräte) werden erst im nächsten Schritt
/// (Geräte-Erkennung) tatsächlich gespeichert/aktualisiert — dort sind Modell und Seriennummer für
/// den Namensvorschlag bzw. die Unterscheidung zweier Geräte mit gleichem Host+Benutzername bekannt.
/// </summary>
public partial class ConnectionStepViewModel : WizardStepViewModelBase
{
    private readonly WizardSession _session;
    private readonly SavedRoutersStore _savedRoutersStore = new();

    public ConnectionStepViewModel(WizardSession session)
        : base(
            title: "Verbindung",
            description: "Gib die Adresse deines MikroTik-Geräts sowie Benutzername und Passwort ein.")
    {
        _session = session;
        RefreshSavedRouters();
    }

    public ObservableCollection<SavedRouterEntry> SavedRouters { get; } = [];

    public bool HasSavedRouters => SavedRouters.Count > 0;

    [ObservableProperty]
    private string _host = string.Empty;

    [ObservableProperty]
    private string _username = "admin";

    [ObservableProperty]
    private string _password = string.Empty;

    [ObservableProperty]
    private bool _useEncryption;

    [ObservableProperty]
    private bool _isTesting;

    [ObservableProperty]
    private string? _statusMessage;

    [ObservableProperty]
    private bool _statusIsError;

    [ObservableProperty]
    [NotifyPropertyChangedFor(nameof(CanGoNext))]
    private bool _isConnected;

    public override bool CanGoNext => IsConnected;

    private bool CanTestConnection => !IsTesting && !string.IsNullOrWhiteSpace(Host) && !string.IsNullOrWhiteSpace(Username);

    public override Task OnActivatedAsync()
    {
        RefreshSavedRouters();
        return Task.CompletedTask;
    }

    private void RefreshSavedRouters()
    {
        SavedRouters.Clear();
        var routers = _savedRoutersStore.Load().OrderByDescending(r => r.LastConnectedAt);

        foreach (var router in routers)
        {
            var entry = new SavedRouterEntry(router);
            entry.PropertyChanged += (_, _) => _savedRoutersStore.Update(entry.ToSavedRouter());
            SavedRouters.Add(entry);
        }

        OnPropertyChanged(nameof(HasSavedRouters));
    }

    [RelayCommand]
    private void UseSavedRouter(SavedRouterEntry entry)
    {
        Host = entry.Host;
        Username = entry.Username;
        Password = WindowsCredentialStore.TryRead(entry.Id) ?? string.Empty;
    }

    [RelayCommand]
    private void RemoveSavedRouter(SavedRouterEntry entry)
    {
        _savedRoutersStore.Remove(entry.Id);
        WindowsCredentialStore.Delete(entry.Id);
        SavedRouters.Remove(entry);
        OnPropertyChanged(nameof(HasSavedRouters));
    }

    [RelayCommand(CanExecute = nameof(CanTestConnection))]
    private async Task TestConnectionAsync()
    {
        IsTesting = true;
        StatusMessage = "Verbindung wird getestet …";
        StatusIsError = false;
        IsConnected = false;

        await _session.DisposeClientAsync();
        _session.Device = null;

        try
        {
            var credentials = new RouterOsCredentials(Host.Trim(), Username.Trim(), Password)
            {
                UseEncryption = UseEncryption,
            };

            _session.Client = await RouterOsClientFactory.ConnectAsync(credentials);
            _session.Credentials = credentials;

            IsConnected = true;
            StatusIsError = false;
            StatusMessage = "Verbindung erfolgreich hergestellt.";
        }
        catch (RouterOsException ex)
        {
            IsConnected = false;
            StatusIsError = true;
            StatusMessage = ex.Message;
        }
        finally
        {
            IsTesting = false;
        }
    }

    partial void OnHostChanged(string value) => TestConnectionCommand.NotifyCanExecuteChanged();

    partial void OnUsernameChanged(string value) => TestConnectionCommand.NotifyCanExecuteChanged();

    partial void OnIsTestingChanged(bool value) => TestConnectionCommand.NotifyCanExecuteChanged();
}