using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.BL.Entities;
using Tango.Core.Commands;
using Tango.FSE.Common;
using Tango.FSE.MachineConfiguration.Navigation;

namespace Tango.FSE.MachineConfiguration.ViewModels
{
    public class SelectionViewVM : ConfigurationViewModel
    {
        private Machine _selectedMachine;
        /// <summary>
        /// Gets or sets the selected machine.
        /// </summary>
        public Machine SelectedMachine
        {
            get { return _selectedMachine; }
            set
            {
                _selectedMachine = value;
                RaisePropertyChangedAuto();
                InvalidateRelayCommands();
                OnSelectedMachineChanged();
            }
        }

        public RelayCommand ManageMachineCommand { get; set; }

        public SelectionViewVM()
        {
            ManageMachineCommand = new RelayCommand(ManageSelectedMachine, () => SelectedMachine != null);
        }

        private async void OnSelectedMachineChanged()
        {
            if (SelectedMachine != null)
            {
                await Task.Delay(100);
                this.SetFocus(() => ManageMachineCommand);
            }
        }

        private void ManageSelectedMachine()
        {
            if (SelectedMachine == null)
            {
                NotificationProvider.ShowError("No machine selected.");
                return;
            }

            ModularNavigationManager.NavigateTo(ConfigurationView.MachineView, new MachineViewVM.NavigationObject()
            {
                MachineGuid = SelectedMachine.Guid
            }, true);
        }

        public override void OnNavigatedTo()
        {
            base.OnNavigatedTo();

            if (SelectedMachine == null && MachineProvider.Machine != null)
            {
                SelectedMachine = MachineProvider.Machine;
            }
        }

        public override Task<bool> OnApplicationLogout()
        {
            ModularNavigationManager.NavigateTo(ConfigurationView.SelectionView);
            SelectedMachine = null;
            return base.OnApplicationLogout();
        }
    }
}