borepin/Borepin/Borepin/PageModel/AddServerProcess/AuthPlainPageModel.cs

using System;
using System.Threading.Tasks;
using System.Windows.Input;
using Borepin.Base;
using Borepin.Model;
using Borepin.Service.BFFH;
using Borepin.Service.BFFH.Exceptions;
using FabAccessAPI.Exceptions;
using Prism.Commands;
using Prism.Navigation;
using Prism.Services;

namespace Borepin.PageModel.AddServerProcess
{
    public class AuthPlainPageModel : PageModelBase
    {
        #region Private Fields
        private readonly IBFFHService _BFFHService;
        private readonly IPageDialogService _PageDialogService;

        private Connection _Connection;
        #endregion

        #region Constructors
        public AuthPlainPageModel(INavigationService navigationService, IBFFHService bffhService, IPageDialogService pageDialogService) : base(navigationService)
        {
            _BFFHService = bffhService;
            _PageDialogService = pageDialogService;

            AuthenticateCommand = new DelegateCommand(async () => await AuthenticateCommandExecute().ConfigureAwait(false));
        }
        #endregion

        #region LoadData
        public override Task LoadData()
        {
            Username = _Connection.Username;
            
            IsBusy = false;
            return Task.CompletedTask;
        }
        #endregion

        #region Fields
        private string _Username;
        public string Username
        {
            get => _Username;
            set => SetProperty(ref _Username, value);
        }

        private string _Password;
        public string Password
        {
            get => _Password;
            set => SetProperty(ref _Password, value);
        }
        #endregion

        #region Commands
        private ICommand _AuthenticateCommand;
        public ICommand AuthenticateCommand
        {
            get => _AuthenticateCommand;
            set => SetProperty(ref _AuthenticateCommand, value);
        }
        public async Task AuthenticateCommandExecute()
        {
            IsBusy = true;

            _Connection.Username = Username;

            if (_BFFHService.IsConnected)
            {
                await _BFFHService.Disconnect().ConfigureAwait(true);
            }

            try
            {
                await _BFFHService.Connect(_Connection, Password).ConfigureAwait(true);
            }
            catch (ConnectingFailedException)
            {
                await _PageDialogService.DisplayAlertAsync("Connection failed", "Unable to connect to server.", "Ok").ConfigureAwait(false);

                IsBusy = false;
                return;
            }
            catch (AuthenticationFailedException)
            {
                await _PageDialogService.DisplayAlertAsync("Connection failed", "Unable to authenticate to server.", "Ok").ConfigureAwait(false);

                IsBusy = false;
                return;
            }
            catch(Exception)
            {
                await _PageDialogService.DisplayAlertAsync("Connection failed", "Unexpected Error.", "Ok").ConfigureAwait(false);

                IsBusy = false;
                return;
            }

            await _NavigationService.NavigateAsync("/MainPage/NavigationPage/MachineListPage").ConfigureAwait(false);
        }
        #endregion

        #region INavigationAware
        public override void OnNavigatedTo(INavigationParameters parameters)
        {
            if (parameters.ContainsKey("instance") && parameters["instance"] is Connection)
            {
                _Connection = parameters["instance"] as Connection;
            }
            else
            {
                _Connection = new Connection();
            }

            LoadData();
        }

        public override void OnNavigatedFrom(INavigationParameters parameters)
        {
            if(parameters.GetNavigationMode() == NavigationMode.Back)
            {
                parameters.Add("instance", _Connection);
            }
        }
        #endregion
    }
}