Synnefo » Pithos MS Client

#region

/* -----------------------------------------------------------------------

 * <copyright file="ShellViewModel.cs" company="GRNet">

 * 

 * Copyright 2011-2012 GRNET S.A. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or

 * without modification, are permitted provided that the following

 * conditions are met:

 *

 *   1. Redistributions of source code must retain the above

 *      copyright notice, this list of conditions and the following

 *      disclaimer.

 *

 *   2. Redistributions in binary form must reproduce the above

 *      copyright notice, this list of conditions and the following

 *      disclaimer in the documentation and/or other materials

 *      provided with the distribution.

 *

 *

 * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 *

 * The views and conclusions contained in the software and

 * documentation are those of the authors and should not be

 * interpreted as representing official policies, either expressed

 * or implied, of GRNET S.A.

 * </copyright>

 * -----------------------------------------------------------------------

 */

#endregion

using System.Collections.Concurrent;

using System.Diagnostics;

using System.Diagnostics.Contracts;

using System.IO;

using System.Net;

using System.Reflection;

using System.Runtime.InteropServices;

using System.ServiceModel;

using System.Threading.Tasks;

using System.Windows;

using System.Windows.Controls.Primitives;

using AppLimit.NetSparkle;

using Caliburn.Micro;

using Hardcodet.Wpf.TaskbarNotification;

using Pithos.Client.WPF.Configuration;

using Pithos.Client.WPF.FileProperties;

using Pithos.Client.WPF.Preferences;

using Pithos.Client.WPF.SelectiveSynch;

using Pithos.Client.WPF.Services;

using Pithos.Client.WPF.Shell;

using Pithos.Core;

using Pithos.Core.Agents;

using Pithos.Interfaces;

using System;

using System.Collections.Generic;

using System.Linq;

using Pithos.Network;

using StatusService = Pithos.Client.WPF.Services.StatusService;

namespace Pithos.Client.WPF {

	using System.ComponentModel.Composition;

	///<summary>

	/// The "shell" of the Pithos application displays the taskbar  icon, menu and notifications.

	/// The shell also hosts the status service called by shell extensions to retrieve file info

	///</summary>

	///<remarks>

	/// It is a strange "shell" as its main visible element is an icon instead of a window

	/// The shell subscribes to the following events:

	/// * Notification:  Raised by components that want to notify the user. Usually displayed in a balloon

	/// * SelectiveSynchChanges: Notifies that the user made changes to the selective synch folders for an account. Raised by the Selective Synch dialog. Located here because the monitors are here

	/// * ShowFilePropertiesEvent: Raised when a shell command requests the display of the file/container properties dialog

	///</remarks>		

	//TODO: CODE SMELL Why does the shell handle the SelectiveSynchChanges?

    [Export(typeof(IShell)), Export(typeof(ShellViewModel))]

	public class ShellViewModel : Screen, IStatusNotification, IShell,

		IHandle<Notification>, IHandle<SelectiveSynchChanges>, IHandle<ShowFilePropertiesEvent>

	{

		//The Status Checker provides the current synch state

		//TODO: Could we remove the status checker and use events in its place?

		private readonly IStatusChecker _statusChecker;

		private readonly IEventAggregator _events;

		public PithosSettings Settings { get; private set; }

		private readonly ConcurrentDictionary<Uri, PithosMonitor> _monitors = new ConcurrentDictionary<Uri, PithosMonitor>();

		///<summary>

		/// Dictionary of account monitors, keyed by account

		///</summary>

		///<remarks>

		/// One monitor class is created for each account. The Shell needs access to the monitors to execute start/stop/pause commands,

		/// retrieve account and boject info		

		///</remarks>

		// TODO: Does the Shell REALLY need access to the monitors? Could we achieve the same results with a better design?

		// TODO: The monitors should be internal to Pithos.Core, even though exposing them makes coding of the Object and Container windows easier

		public ConcurrentDictionary<Uri, PithosMonitor> Monitors

		{

			get { return _monitors; }

		}

		///<summary>

		/// The status service is used by Shell extensions to retrieve file status information

		///</summary>

		//TODO: CODE SMELL! This is the shell! While hosting in the shell makes executing start/stop commands easier, it is still a smell

		private ServiceHost _statusService;

		//Logging in the Pithos client is provided by log4net

        private static readonly log4net.ILog Log = log4net.LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

	    private readonly PollAgent _pollAgent;

	    private readonly NetworkAgent _networkAgent;

	    [Import]

	    public Selectives Selectives { get; set; }

	    private MiniStatusViewModel _miniStatus;

	    [Import]

        public MiniStatusViewModel MiniStatus

	    {

	        get { return _miniStatus; }

	        set

	        {

	            _miniStatus = value;

	            _miniStatus.Shell = this;

	            _miniStatus.Deactivated += (sender, arg) =>

	                                           {

	                                               _statusVisible = false;

                                                   NotifyOfPropertyChange(()=>MiniStatusCaption);

	                                           };

	        }

	    }

	    ///<summary>

		/// The Shell depends on MEF to provide implementations for windowManager, events, the status checker service and the settings

		///</summary>

		///<remarks>

		/// The PithosSettings class encapsulates the app's settings to abstract their storage mechanism (App settings, a database or registry)

		///</remarks>

		[ImportingConstructor]		

		public ShellViewModel(IWindowManager windowManager, IEventAggregator events, IStatusChecker statusChecker, PithosSettings settings,PollAgent pollAgent,NetworkAgent networkAgent)

		{

			try

			{

				_windowManager = windowManager;

				//CHECK: Caliburn doesn't need explicit command construction

				//OpenPithosFolderCommand = new PithosCommand(OpenPithosFolder);

				_statusChecker = statusChecker;

				//The event subst

				_events = events;

				_events.Subscribe(this);

			    _pollAgent = pollAgent;

			    _networkAgent = networkAgent;

				Settings = settings;

				Proxy.SetFromSettings(settings);

                StatusMessage = Settings.Accounts.Count==0 

                    ? "No Accounts added\r\nPlease add an account" 

                    : "Starting";

				_accounts.CollectionChanged += (sender, e) =>

												   {

													   NotifyOfPropertyChange(() => OpenFolderCaption);

													   NotifyOfPropertyChange(() => HasAccounts);

												   };

                SetVersionMessage();

			}

			catch (Exception exc)

			{

				Log.Error("Error while starting the ShellViewModel",exc);

				throw;

			}

		}

	    private void SetVersionMessage()

	    {

	        Assembly assembly = Assembly.GetExecutingAssembly();

	        var fileVersion = FileVersionInfo.GetVersionInfo(assembly.Location);

	        VersionMessage = String.Format("Pithos+ {0}", fileVersion.FileVersion);

	    }

        public void CurrentSyncStatus()

        {

            if (Accounts.Count == 0)

            {

                ShowPreferences("AccountTab");

            }

            else

            {

                if (!_statusVisible)

                    _windowManager.ShowWindow(MiniStatus);

                else

                {

                    if (MiniStatus.IsActive)

                        MiniStatus.TryClose();

                }

                _statusVisible = !_statusVisible;

                NotifyOfPropertyChange(() => MiniStatusCaption);

            }

        }

	    protected override void OnActivate()

		{

			base.OnActivate();

            InitializeSparkle();

	        //Must delay opening the upgrade window

            //to avoid Windows Messages sent by the TaskbarIcon

            TaskEx.Delay(5000).ContinueWith(_=>

                Execute.OnUIThread(()=> _sparkle.StartLoop(true,Settings.UpdateForceCheck,Settings.UpdateCheckInterval)));

			StartMonitoring();                    

		}

	    private void OnCheckFinished(object sender, bool updaterequired)

	    {

            Log.InfoFormat("Upgrade check finished. Need Upgrade: {0}", updaterequired);

            if (_manualUpgradeCheck)

            {

                _manualUpgradeCheck = false;

                if (!updaterequired)

                    //Sparkle raises events on a background thread

                    Execute.OnUIThread(()=>

                        ShowBalloonFor(new Notification{Title="Pithos+ is up to date",Message="You have the latest Pithos+ version. No update is required"}));

            }

	    }

	    private void OnUpgradeDetected(object sender, UpdateDetectedEventArgs e)

	    {            

	        Log.InfoFormat("Update detected {0}",e.LatestVersion);

	    }

        public void CheckForUpgrade()

        {

            ShowBalloonFor(new Notification{Title="Checking for upgrades",Message="Contacting the server to retrieve the latest Pithos+ version."});

            _sparkle.StopLoop();

            _sparkle.updateDetected -= OnUpgradeDetected;

            _sparkle.checkLoopFinished -= OnCheckFinished;

            _sparkle.Dispose();

            _manualUpgradeCheck = true;

            InitializeSparkle();

            _sparkle.StartLoop(true,true,Settings.UpdateCheckInterval);

        }

        private void InitializeSparkle()

        {

            _sparkle = new Sparkle(Settings.UpdateUrl);

            _sparkle.updateDetected += OnUpgradeDetected;

            _sparkle.checkLoopFinished += OnCheckFinished;

            _sparkle.ShowDiagnosticWindow = Settings.UpdateDiagnostics;

        }

	    private async void StartMonitoring()

		{

			try

			{

                if (Settings.IgnoreCertificateErrors)

                {

                    ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, errors) => true;

                }

				var accounts = Settings.Accounts.Select(MonitorAccount);

				await TaskEx.WhenAll(accounts);

				_statusService = StatusService.Start();

			}

			catch (AggregateException exc)

			{

				exc.Handle(e =>

				{

					Log.Error("Error while starting monitoring", e);

					return true;

				});

				throw;

			}

		}

		protected override void OnDeactivate(bool close)

		{

			base.OnDeactivate(close);

			if (close)

			{

				StatusService.Stop(_statusService);

				_statusService = null;

			}

		}

		public Task MonitorAccount(AccountSettings account)

		{

			return Task.Factory.StartNew(() =>

			{                                                

				PithosMonitor monitor;

				var accountName = account.AccountName;

			    MigrateFolders(account);

			    Selectives.SetIsSelectiveEnabled(account.AccountKey, account.SelectiveSyncEnabled);

				if (Monitors.TryGetValue(account.AccountKey, out monitor))

				{

					//If the account is active

                    if (account.IsActive)

                    {

                        //The Api Key may have changed throuth the Preferences dialog

                        monitor.ApiKey = account.ApiKey;

						Debug.Assert(monitor.StatusNotification == this,"An existing monitor should already have a StatusNotification service object");

                        monitor.RootPath = account.RootPath;

                        //Start the monitor. It's OK to start an already started monitor,

                        //it will just ignore the call                        

                        StartMonitor(monitor).Wait();

                    }

                    else

                    {

                        //If the account is inactive

                        //Stop and remove the monitor

                        RemoveMonitor(account.ServerUrl,accountName);

                    }

					return;

				}

				//Create a new monitor/ Can't use MEF here, it would return a single instance for all monitors

				monitor = new PithosMonitor

							  {

								  UserName = accountName,

								  ApiKey = account.ApiKey,                                  

								  StatusNotification = this,

								  RootPath = account.RootPath

							  };

				//PithosMonitor uses MEF so we need to resolve it

				IoC.BuildUp(monitor);

				monitor.AuthenticationUrl = account.ServerUrl;

				Monitors[account.AccountKey] = monitor;

				if (account.IsActive)

				{

					//Don't start a monitor if it doesn't have an account and ApiKey

					if (String.IsNullOrWhiteSpace(monitor.UserName) ||

						String.IsNullOrWhiteSpace(monitor.ApiKey))

						return;

					StartMonitor(monitor);

				}

			});

		}

	    private void MigrateFolders(AccountSettings account)

	    {

	        var oldOthersFolder=Path.Combine(account.RootPath, FolderConstants.OldOthersFolder);

	        var newOthersFolder = Path.Combine(account.RootPath, FolderConstants.OthersFolder);

	        var oldFolder = new DirectoryInfo(oldOthersFolder);

	        var newFolder = new DirectoryInfo(newOthersFolder);

            if (oldFolder.Exists && !newFolder.Exists)

            {

                oldFolder.MoveTo(newOthersFolder);

            }

	    }

	    protected override void OnViewLoaded(object view)

		{

			UpdateStatus();

			var window = (Window)view;            

			TaskEx.Delay(1000).ContinueWith(t => Execute.OnUIThread(window.Hide));

			base.OnViewLoaded(view);

		}

		#region Status Properties

		private string _statusMessage;

		public string StatusMessage

		{

			get { return _statusMessage; }

			set

			{

				_statusMessage = value;

				NotifyOfPropertyChange(() => StatusMessage);

                NotifyOfPropertyChange(() => TooltipMessage);

			}

		}

        public string VersionMessage { get; set; }

	    public string TooltipMessage

	    {

	        get

	        {

	            return String.Format("{0}\r\n{1}",VersionMessage,StatusMessage);

	        }

	    }

        public string TooltipMiniStatus

        {

            get

            {

                return String.Format("{0}\r\n{1}", "Status Window", "Enable / Dissable the stuatus window");

            }

        }

        public string ToggleStatusWindowMessage

        {

            get

            {

                return String.Format("{0}" + Environment.NewLine + "{1} Toggle Mini Status");

            }

        }

	    private readonly ObservableConcurrentCollection<AccountInfo> _accounts = new ObservableConcurrentCollection<AccountInfo>();

		public ObservableConcurrentCollection<AccountInfo> Accounts

		{

			get { return _accounts; }

		}

		public bool HasAccounts

		{

			get { return _accounts.Count > 0; }

		}

		public string OpenFolderCaption

		{

			get

			{

				return (_accounts.Count == 0)

						? "No Accounts Defined"

						: "Open Pithos Folder";

			}

		}

		private string _pauseSyncCaption="Pause Synching";

		public string PauseSyncCaption

		{

			get { return _pauseSyncCaption; }

			set

			{

				_pauseSyncCaption = value;

				NotifyOfPropertyChange(() => PauseSyncCaption);

			}

		}

		private readonly ObservableConcurrentCollection<FileEntry> _recentFiles = new ObservableConcurrentCollection<FileEntry>();

		public ObservableConcurrentCollection<FileEntry> RecentFiles

		{

			get { return _recentFiles; }

		}

		private string _statusIcon="../Images/Pithos.ico";

		public string StatusIcon

		{

			get { return _statusIcon; }

			set

			{

				//TODO: Ensure all status icons use the Pithos logo

				_statusIcon = value;

				NotifyOfPropertyChange(() => StatusIcon);

			}

		}

		#endregion

		#region Commands

        public void CancelCurrentOperation()

        {

            _networkAgent.CancelCurrentOperation();

        }

        public void ShowPreferences()

        {

            ShowPreferences(null);

        }

		public void ShowPreferences(string currentTab)

		{

			//Settings.Reload();

		    var preferences = new PreferencesViewModel(_windowManager, _events, this, Settings,currentTab);

		    _windowManager.ShowDialog(preferences);

		}

		public void AboutPithos()

		{

			var about = IoC.Get<AboutViewModel>();

		    about.LatestVersion=_sparkle.LatestVersion;

			_windowManager.ShowWindow(about);

		}

		public void SendFeedback()

		{

			var feedBack =  IoC.Get<FeedbackViewModel>();

			_windowManager.ShowWindow(feedBack);

		}

		//public PithosCommand OpenPithosFolderCommand { get; private set; }

		public void OpenPithosFolder()

		{

			var account = Settings.Accounts.FirstOrDefault(acc => acc.IsActive);

			if (account == null)

				return;

			Process.Start(account.RootPath);

		}

		public void OpenPithosFolder(AccountInfo account)

		{

			Process.Start(account.AccountPath);

		}

		public void GoToSite()

		{            

			var site = Properties.Settings.Default.ProductionServer;

			Process.Start(site);            

		}

		public void GoToSite(AccountInfo account)

		{

		    var uri = account.SiteUri.Replace("http://","https://");            

		    Process.Start(uri);

		}

	    private bool _statusVisible;

	    public string MiniStatusCaption

	    {

	        get

	        {

	            return  _statusVisible ? "Hide Status Window" : "Show Status Window";

	        }

	    }

	    public bool HasConflicts

	    {

            get { return true; }

	    }

        public void ShowConflicts()

        {

            _windowManager.ShowWindow(IoC.Get<ConflictsViewModel>());            

        }

	    /// <summary>

        /// Open an explorer window to the target path's directory

        /// and select the file

        /// </summary>

        /// <param name="entry"></param>

        public void GoToFile(FileEntry entry)

        {

            var fullPath = entry.FullPath;

            if (!File.Exists(fullPath) && !Directory.Exists(fullPath))

                return;

            Process.Start("explorer.exe","/select, " + fullPath);

        }

        public void OpenLogPath()

        {

            var pithosDataPath = PithosSettings.PithosDataPath;

            Process.Start(pithosDataPath);

        }

        public void ShowFileProperties()

		{

			var account = Settings.Accounts.First(acc => acc.IsActive);            

			var dir = new DirectoryInfo(account.RootPath + @"\pithos");

			var files=dir.GetFiles();

			var r=new Random();

			var idx=r.Next(0, files.Length);

			ShowFileProperties(files[idx].FullName);            

		}

		public void ShowFileProperties(string filePath)

		{

			if (String.IsNullOrWhiteSpace(filePath))

				throw new ArgumentNullException("filePath");

			if (!File.Exists(filePath) && !Directory.Exists(filePath))

				throw new ArgumentException(String.Format("Non existent file {0}",filePath),"filePath");

			Contract.EndContractBlock();

			var pair=(from monitor in  Monitors

							   where filePath.StartsWith(monitor.Value.RootPath, StringComparison.InvariantCultureIgnoreCase)

								   select monitor).FirstOrDefault();

			var accountMonitor = pair.Value;

			if (accountMonitor == null)

				return;

			var infoTask=Task.Factory.StartNew(()=>accountMonitor.GetObjectInfo(filePath));

			var fileProperties = new FilePropertiesViewModel(this, infoTask,filePath);

			_windowManager.ShowWindow(fileProperties);

		} 

		public void ShowContainerProperties()

		{

			var account = Settings.Accounts.First(acc => acc.IsActive);            

			var dir = new DirectoryInfo(account.RootPath);

			var fullName = (from folder in dir.EnumerateDirectories()

							where (folder.Attributes & FileAttributes.Hidden) == 0

							select folder.FullName).First();

			ShowContainerProperties(fullName);            

		}

		public void ShowContainerProperties(string filePath)

		{

			if (String.IsNullOrWhiteSpace(filePath))

				throw new ArgumentNullException("filePath");

			if (!Directory.Exists(filePath))

				throw new ArgumentException(String.Format("Non existent file {0}",filePath),"filePath");

			Contract.EndContractBlock();

			var pair=(from monitor in  Monitors

							   where filePath.StartsWith(monitor.Value.RootPath, StringComparison.InvariantCultureIgnoreCase)

								   select monitor).FirstOrDefault();

			var accountMonitor = pair.Value;            

			var info = accountMonitor.GetContainerInfo(filePath);

			var containerProperties = new ContainerPropertiesViewModel(this, info,filePath);

			_windowManager.ShowWindow(containerProperties);

		}

		public void SynchNow()

		{

			_pollAgent.SynchNow();

		}

		public ObjectInfo RefreshObjectInfo(ObjectInfo currentInfo)

		{

			if (currentInfo==null)

				throw new ArgumentNullException("currentInfo");

			Contract.EndContractBlock();		    

            var monitor = Monitors[currentInfo.AccountKey];

			var newInfo=monitor.CloudClient.GetObjectInfo(currentInfo.Account, currentInfo.Container, currentInfo.Name);

			return newInfo;

		}

		public ContainerInfo RefreshContainerInfo(ContainerInfo container)

		{

			if (container == null)

				throw new ArgumentNullException("container");

			Contract.EndContractBlock();

			var monitor = Monitors[container.AccountKey];

			var newInfo = monitor.CloudClient.GetContainerInfo(container.Account, container.Name);

			return newInfo;

		}

	    private bool _isPaused;

	    public bool IsPaused

	    {

	        get { return _isPaused; }

	        set

	        {

	            _isPaused = value;

                PauseSyncCaption = IsPaused ? "Resume syncing" : "Pause syncing";

                var iconKey = IsPaused ? "TraySyncPaused" : "TrayInSynch";

                StatusIcon = String.Format(@"../Images/{0}.ico", iconKey);

                NotifyOfPropertyChange(() => IsPaused);

	        }

	    }

	    public void ToggleSynching()

		{

			IsPaused=!IsPaused;

			foreach (var monitor in Monitors.Values)

			{

			    monitor.Pause = IsPaused ;

			}

            _pollAgent.Pause = IsPaused;

            _networkAgent.Pause = IsPaused;

		}

        public void ExitPithos()

        {

            try

            {

                foreach (var monitor in Monitors.Select(pair => pair.Value))

                {

                    monitor.Stop();

                }

                var view = GetView() as Window;

                if (view != null)

                    view.Close();

            }

            catch (Exception exc)

            {

                Log.Info("Exception while exiting", exc);                

            }

            finally

            {

                Application.Current.Shutdown();

            }

        }

	    #endregion

		private readonly Dictionary<PithosStatus, StatusInfo> _iconNames = new List<StatusInfo>

			{

				new StatusInfo(PithosStatus.InSynch, "All files up to date", "TrayInSynch"),

				new StatusInfo(PithosStatus.PollSyncing, "Polling Files", "TraySynching"),

                new StatusInfo(PithosStatus.LocalSyncing, "Syncing Files", "TraySynching"),

				new StatusInfo(PithosStatus.SyncPaused, "Sync Paused", "TraySyncPaused")

			}.ToDictionary(s => s.Status);

		readonly IWindowManager _windowManager;

        //private int _syncCount=0;

        private PithosStatus _pithosStatus = PithosStatus.Disconnected;

        public void SetPithosStatus(PithosStatus status)

        {

            if (_pithosStatus == PithosStatus.LocalSyncing && status == PithosStatus.PollComplete)

                return;

            if (_pithosStatus == PithosStatus.PollSyncing && status == PithosStatus.LocalComplete)

                return;

            if (status == PithosStatus.LocalComplete || status == PithosStatus.PollComplete)

                _pithosStatus = PithosStatus.InSynch;

            else

                _pithosStatus = status;

            UpdateStatus();

        }

        public void SetPithosStatus(PithosStatus status,string message)

        {

            StatusMessage = message;

            SetPithosStatus(status);

        }

	  /*  public Notifier GetNotifier(Notification startNotification, Notification endNotification)

	    {

	        return new Notifier(this, startNotification, endNotification);

	    }*/

	    public Notifier GetNotifier(string startMessage, string endMessage, params object[] args)

	    {

	        return new Notifier(this, 

                new StatusNotification(String.Format(startMessage,args)), 

                new StatusNotification(String.Format(endMessage,args)));

	    }

	    ///<summary>

		/// Updates the visual status indicators of the application depending on status changes, e.g. icon, stat		

		///</summary>

		public void UpdateStatus()

		{

			if (_iconNames.ContainsKey(_pithosStatus))

			{

				var info = _iconNames[_pithosStatus];

				StatusIcon = String.Format(@"../Images/{0}.ico", info.IconName);

			}

            if (_pithosStatus == PithosStatus.InSynch)

                StatusMessage = "All files up to date";

		}

		private Task StartMonitor(PithosMonitor monitor,int retries=0)

		{

			return Task.Factory.StartNew(() =>

			{

				using (log4net.ThreadContext.Stacks["Monitor"].Push("Start"))

				{

					try

					{

						Log.InfoFormat("Start Monitoring {0}", monitor.UserName);

						monitor.Start();

					}

					catch (WebException exc)

					{

						if (AbandonRetry(monitor, retries))

							return;

						HttpStatusCode statusCode =HttpStatusCode.OK;

						var response = exc.Response as HttpWebResponse;

						if(response!=null)

							statusCode = response.StatusCode;

						switch (statusCode)

						{

							case HttpStatusCode.Unauthorized:

								var message = String.Format("API Key Expired for {0}. Starting Renewal",

															monitor.UserName);

								Log.Error(message, exc);

                                var account = Settings.Accounts.Find(acc => acc.AccountKey == new Uri(new Uri(monitor.AuthenticationUrl), monitor.UserName));                                

						        account.IsExpired = true;

                                Notify(new ExpirationNotification(account));

								//TryAuthorize(monitor.UserName, retries).Wait();

								break;

							case HttpStatusCode.ProxyAuthenticationRequired:

								TryAuthenticateProxy(monitor,retries);

								break;

							default:

								TryLater(monitor, exc, retries);

								break;

						}

					}

					catch (Exception exc)

					{

						if (AbandonRetry(monitor, retries)) 

							return;

						TryLater(monitor,exc,retries);

					}

				}

			});

		}

		private void TryAuthenticateProxy(PithosMonitor monitor,int retries)

		{

			Execute.OnUIThread(() =>

								   {                                       

									   var proxyAccount = IoC.Get<ProxyAccountViewModel>();

										proxyAccount.Settings = Settings;

									   if (true != _windowManager.ShowDialog(proxyAccount)) 

										   return;

									   StartMonitor(monitor, retries);

									   NotifyOfPropertyChange(() => Accounts);

								   });

		}

		private bool AbandonRetry(PithosMonitor monitor, int retries)

		{

			if (retries > 1)

			{

				var message = String.Format("Monitoring of account {0} has failed too many times. Will not retry",

											monitor.UserName);

				_events.Publish(new Notification

									{Title = "Account monitoring failed", Message = message, Level = TraceLevel.Error});

				return true;

			}

			return false;

		}

	    private void TryLater(PithosMonitor monitor, Exception exc,int retries)

		{

			var message = String.Format("An exception occured. Can't start monitoring\nWill retry in 10 seconds");

			Task.Factory.StartNewDelayed(10000, () => StartMonitor(monitor,retries+1));

			_events.Publish(new Notification

								{Title = "Error", Message = message, Level = TraceLevel.Error});

			Log.Error(message, exc);

		}

		public void NotifyChange(string status, TraceLevel level=TraceLevel.Info)

		{

			StatusMessage = status;

			_events.Publish(new Notification { Title = "Pithos+", Message = status, Level = level });

		}

		public void NotifyChangedFile(string filePath)

		{

            if (RecentFiles.Any(e => e.FullPath == filePath))

                return;

			IProducerConsumerCollection<FileEntry> files=RecentFiles;

			FileEntry popped;

			while (files.Count > 5)

				files.TryTake(out popped);

            var entry = new FileEntry { FullPath = filePath };

			files.TryAdd(entry);

		}

		public void NotifyAccount(AccountInfo account)

		{

			if (account== null)

				return;

			//TODO: What happens to an existing account whose Token has changed?

			account.SiteUri= String.Format("{0}/ui/?token={1}&user={2}",

				account.SiteUri, Uri.EscapeDataString(account.Token),

				Uri.EscapeDataString(account.UserName));

			if (!Accounts.Any(item => item.UserName == account.UserName && item.SiteUri == account.SiteUri))

				Accounts.TryAdd(account);

		}

		public void NotifyConflicts(IEnumerable<FileSystemInfo> conflictFiles, string message)

		{

			if (conflictFiles == null)

				return;

		    //Convert to list to avoid multiple iterations

            var files = conflictFiles.ToList();

			if (files.Count==0)

				return;

			UpdateStatus();

			//TODO: Create a more specific message. For now, just show a warning

			NotifyForFiles(files,message,TraceLevel.Warning);

		}

		public void NotifyForFiles(IEnumerable<FileSystemInfo> files, string message,TraceLevel level=TraceLevel.Info)

		{

			if (files == null)

				return;

			if (!files.Any())

				return;

			StatusMessage = message;

			_events.Publish(new Notification { Title = "Pithos+", Message = message, Level = level});

		}

		public void Notify(Notification notification)

		{

			_events.Publish(notification);

		}

		public void RemoveMonitor(string serverUrl,string accountName)

		{

			if (String.IsNullOrWhiteSpace(accountName))

				return;

			var accountInfo=_accounts.FirstOrDefault(account => account.UserName == accountName && account.StorageUri.ToString().StartsWith(serverUrl));

            if (accountInfo != null)

            {

                _accounts.TryRemove(accountInfo);

                _pollAgent.RemoveAccount(accountInfo);

            }

            var accountKey = new Uri(new Uri(serverUrl),accountName);

		    PithosMonitor monitor;

			if (Monitors.TryRemove(accountKey, out monitor))

			{

				monitor.Stop();

                //TODO: Also remove any pending actions for this account

                //from the network queue                

			}

		}

		public void RefreshOverlays()

		{

			foreach (var pair in Monitors)

			{

				var monitor = pair.Value;

				var path = monitor.RootPath;

				if (String.IsNullOrWhiteSpace(path))