using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Tango.Core.Helpers;
using Tango.Integration.Observables;
using Tango.Logging;
using Tango.MachineStudio.Common.Modules;
using Tango.MachineStudio.Common.Navigation;
using Tango.MachineStudio.Common.Notifications;
using Tango.SharedUI;

namespace Tango.MachineStudio.UI.ViewModels
{
    /// <summary>
    /// Represents the Machine Studio loading view, view model.
    /// </summary>
    /// <seealso cref="Tango.SharedUI.ViewModel" />
    public class LoadingViewVM : ViewModel
    {
        private INotificationProvider _notificationProvider;
        private INavigationManager _navigationManager;
        private IStudioModuleLoader _studioModuleLoader;

        /// <summary>
        /// Initializes a new instance of the <see cref="LoadingViewVM"/> class.
        /// </summary>
        /// <param name="navigationManager">The navigation manager.</param>
        /// <param name="studioModuleLoader">The studio module loader.</param>
        /// <param name="notificationProvider">The notification provider.</param>
        public LoadingViewVM(INavigationManager navigationManager, IStudioModuleLoader studioModuleLoader, INotificationProvider notificationProvider)
        {
            _navigationManager = navigationManager;
            _studioModuleLoader = studioModuleLoader;
            _notificationProvider = notificationProvider;
            Load();
        }

        /// <summary>
        /// Load application modules.
        /// </summary>
        private void Load()
        {
            ThreadsHelper.StartStaThread(() =>
            {
                try
                {
                    ObservablesEntitiesAdapter.Instance.Initialize();
                    InvokeUI(() =>
                    {
                        _studioModuleLoader.LoadModules();
                        _navigationManager.NavigateTo(NavigationView.LoginView);
                    });
                }
                catch (Exception ex)
                {
                    LogManager.Log(ex);

                    InvokeUINow(() =>
                    {
                        if (_notificationProvider.ShowQuestion("An error occurred while trying to connect to Twine database." + Environment.NewLine + "Would you like to try again?"))
                        {
                            Load();
                        }
                        else
                        {
                            Environment.Exit(0);
                        }
                    });
                }
            });
        }
    }
}