using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Tango.Core.Commands;
using Tango.MachineStudio.Common.Authentication;
using Tango.MachineStudio.Common.Navigation;
using Tango.MachineStudio.Common.Notifications;
using Tango.MachineStudio.Common.StudioApplication;
using Tango.MachineStudio.Common.Update;
using Tango.SharedUI;

namespace Tango.MachineStudio.UI.ViewModels
{
    public enum UpdateStatus
    {
        None,
        CheckingForUpdate,
        UpToDate,
        UpdateAvailable,
        Downloading,
        Updating,
        UpdateCompleted,
        Error,
    }

    public class UpdateViewVM : ViewModel
    {
        private INotificationProvider _notification;
        private INavigationManager _navigation;
        private IStudioApplicationManager _application;
        private IAuthenticationProvider _authentication;

        private UpdateStatus _status;
        public UpdateStatus Status
        {
            get { return _status; }
            set { _status = value; RaisePropertyChangedAuto(); }
        }

        private String _latestVersion;
        public String LatestVersion
        {
            get { return _latestVersion; }
            set { _latestVersion = value; RaisePropertyChangedAuto(); }
        }

        private double _downloadProgress;

        public double DownloadProgress
        {
            get { return _downloadProgress; }
            set { _downloadProgress = value; RaisePropertyChangedAuto(); }
        }

        private double _updateProgress;

        public double UpdateProgress
        {
            get { return _updateProgress; }
            set { _updateProgress = value; RaisePropertyChangedAuto(); }
        }

        public RelayCommand UpdateCommand { get; set; }

        public RelayCommand BackCommand { get; set; }

        public RelayCommand RestartCommand { get; set; }

        public RelayCommand TryAgainCommand { get; set; }

        public UpdateViewVM(INotificationProvider notification, IAuthenticationProvider authentication, INavigationManager navigation, IStudioApplicationManager application)
        {
            _notification = notification;
            _navigation = navigation;
            _application = application;
            _authentication = authentication;

            LatestVersion = "1.0.0.2";
            Status = UpdateStatus.CheckingForUpdate;
            UpdateCommand = new RelayCommand(StartUpdate, () => Status == UpdateStatus.UpdateAvailable);
            BackCommand = new RelayCommand(BackToApplication, () => Status != UpdateStatus.Updating);
            RestartCommand = new RelayCommand(RestartApplication, () => Status == UpdateStatus.UpdateCompleted);
            TryAgainCommand = new RelayCommand(TryAgain, () => Status == UpdateStatus.CheckingForUpdate);
        }

        public void OnNavigatedInto()
        {
            CheckForUpdates();
        }

        private void CheckForUpdates()
        {
            Status = UpdateStatus.CheckingForUpdate;

            Task.Factory.StartNew(() =>
            {
                var service = UpdateServiceHelper.GetUpdateServiceChannel();
                var client = service.CreateChannel();

                CheckForUpdatesResponse response =  client.CheckForUpdates(new CheckForUpdatesRequest()
                {
                    Email = _authentication.CurrentUser.Email,
                    Password = _authentication.CurrentUser.Password,
                    Version = _application.Version,
                });

                var a = response;

                Thread.Sleep(5000);
                Status = UpdateStatus.UpdateAvailable;
            });
        }

        private void BackToApplication()
        {
            if (Status == UpdateStatus.Downloading)
            {
                if (!_notification.ShowQuestion("This will abort all update operations. Are you sure?"))
                {
                    return;
                }
            }

            _navigation.NavigateTo(NavigationView.MainView);
            Status = UpdateStatus.None;
        }

        private void StartUpdate()
        {
            DownloadProgress = 0;
            UpdateProgress = 0;

            Status = UpdateStatus.Downloading;

            Task.Factory.StartNew(() =>
            {
                for (int i = 0; i < 100; i++)
                {
                    DownloadProgress++;
                    Thread.Sleep(30);
                }

                Status = UpdateStatus.Updating;

                for (int i = 0; i < 100; i++)
                {
                    UpdateProgress++;
                    Thread.Sleep(30);
                }

                Status = UpdateStatus.UpdateCompleted;
            });
        }

        private void TryAgain()
        {
            CheckForUpdates();
        }

        private void RestartApplication()
        {
            _application.ShutDown();
        }

        protected override void RaisePropertyChangedAuto([CallerMemberName] string caller = null)
        {
            base.RaisePropertyChangedAuto(caller);
            InvalidateRelayCommands();
        }
    }
}