Synnefo » Pithos MS Client

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 Caliburn.Micro;

using Hardcodet.Wpf.TaskbarNotification;

using Pithos.Client.WPF.Configuration;

using Pithos.Client.WPF.FileProperties;

using Pithos.Client.WPF.SelectiveSynch;

using Pithos.Client.WPF.Services;

using Pithos.Client.WPF.Shell;

using Pithos.Core;

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))]

	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<string, PithosMonitor> _monitors = new ConcurrentDictionary<string, 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<string, 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("Pithos");

		///<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)

		{

			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);

				Settings = settings;

				StatusMessage = "In Synch";

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

												   {

													   NotifyOfPropertyChange(() => OpenFolderCaption);

													   NotifyOfPropertyChange(() => HasAccounts);

												   };

			}

			catch (Exception exc)

			{

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

				throw;

			}

		}

		protected override void OnActivate()

		{

			base.OnActivate();

			StartMonitoring();                    

		}

		private async void StartMonitoring()

		{

			try

			{

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

				await TaskEx.WhenAll(accounts);

				_statusService = StatusService.Start();

/*

				foreach (var account in Settings.Accounts)

				{

					await MonitorAccount(account);

				}

*/

			}

			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;

				if (_monitors.TryGetValue(accountName, out monitor))

				{

					//If the account is active

					if (account.IsActive)

						//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(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[accountName] = 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);

				}

			});

		}

		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);

			}

		}

		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 ShowPreferences()

		{

			Settings.Reload();

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

			_windowManager.ShowDialog(preferences);

		}

		public void AboutPithos()

		{

			var about = new AboutViewModel();

			_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.PithosSite;

			Process.Start(site);            

		}

*/

		public void GoToSite(AccountInfo account)

		{

			/*var site = String.Format("{0}/ui/?token={1}&user={2}",

				account.SiteUri,account.Token,

				account.UserName);*/

			Process.Start(account.SiteUri);

		}

		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 ObjectInfo RefreshObjectInfo(ObjectInfo currentInfo)

		{

			if (currentInfo==null)

				throw new ArgumentNullException("currentInfo");

			Contract.EndContractBlock();

			var monitor = Monitors[currentInfo.Account];

			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.Account];

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

			return newInfo;

		}

		public void ToggleSynching()

		{

			bool isPaused=false;

			foreach (var pair in Monitors)

			{

				var monitor = pair.Value;

				monitor.Pause = !monitor.Pause;

				isPaused = monitor.Pause;

			}

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

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

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

		}

		public void ExitPithos()

		{

			foreach (var pair in Monitors)

			{

				var monitor = pair.Value;

				monitor.Stop();

			}

			((Window)GetView()).Close();

		}

		#endregion

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

			{

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

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

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

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

		readonly IWindowManager _windowManager;

		///<summary>

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

		///</summary>

		public void UpdateStatus()

		{

			var pithosStatus = _statusChecker.GetPithosStatus();

			if (_iconNames.ContainsKey(pithosStatus))

			{

				var info = _iconNames[pithosStatus];

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

				Assembly assembly = Assembly.GetExecutingAssembly();                               

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

				StatusMessage = String.Format("Pithos {0}\r\n{1}", fileVersion.FileVersion,info.StatusText);

			}

			_events.Publish(new Notification { Title = "Start", Message = "Start Monitoring", Level = TraceLevel.Info});

		}

		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;

						if (IsUnauthorized(exc))

						{

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

							Log.Error(message,exc);

							TryAuthorize(monitor,retries).Wait();

						}

						else

						{

							TryLater(monitor, exc,retries);

						}

					}

					catch (Exception exc)

					{

						if (AbandonRetry(monitor, retries)) 

							return;

						TryLater(monitor,exc,retries);

					}

				}

			});

		}

		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 async Task TryAuthorize(PithosMonitor monitor,int retries)

		{

			_events.Publish(new Notification { Title = "Authorization failed", Message = "Your API Key has probably expired. You will be directed to a page where you can renew it", Level = TraceLevel.Error });

			try

			{

				var credentials = await PithosAccount.RetrieveCredentials(Settings.PithosLoginUrl);

				var account = Settings.Accounts.First(act => act.AccountName == credentials.UserName);

				account.ApiKey = credentials.Password;

				monitor.ApiKey = credentials.Password;

				Settings.Save();

				await TaskEx.Delay(10000);

				StartMonitor(monitor, retries + 1);

				NotifyOfPropertyChange(()=>Accounts);

			}

			catch (AggregateException exc)

			{

				string message = String.Format("API Key retrieval for {0} failed", monitor.UserName);

				Log.Error(message, exc.InnerException);

				_events.Publish(new Notification { Title = "Authorization failed", Message = message, Level = TraceLevel.Error });

			}

			catch (Exception exc)

			{

				string message = String.Format("API Key retrieval for {0} failed", monitor.UserName);

				Log.Error(message, exc);

				_events.Publish(new Notification { Title = "Authorization failed", Message = message, Level = TraceLevel.Error });

			}

		}

		private static bool IsUnauthorized(WebException exc)

		{

			if (exc==null)

				throw new ArgumentNullException("exc");

			Contract.EndContractBlock();

			var response = exc.Response as HttpWebResponse;

			if (response == null)

				return false;

			return (response.StatusCode == HttpStatusCode.Unauthorized);

		}

		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)

		{

			var entry = new FileEntry {FullPath=filePath};

			IProducerConsumerCollection<FileEntry> files=RecentFiles;

			FileEntry popped;

			while (files.Count > 5)

				files.TryTake(out popped);

			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, account.Token,

				account.UserName);

			if (Accounts.All(item => item.UserName != account.UserName))

				Accounts.TryAdd(account);

		}

		public void RemoveMonitor(string accountName)

		{

			if (String.IsNullOrWhiteSpace(accountName))

				return;

			var accountInfo=_accounts.FirstOrDefault(account => account.UserName == accountName);

			_accounts.TryRemove(accountInfo);

			PithosMonitor monitor;

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

			{

				monitor.Stop();

			}

		}

		public void RefreshOverlays()

		{

			foreach (var pair in Monitors)

			{

				var monitor = pair.Value;

				var path = monitor.RootPath;

				if (String.IsNullOrWhiteSpace(path))

					continue;

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

					continue;

				IntPtr pathPointer = Marshal.StringToCoTaskMemAuto(path);

				try

				{

					NativeMethods.SHChangeNotify(HChangeNotifyEventID.SHCNE_UPDATEITEM,

												 HChangeNotifyFlags.SHCNF_PATHW | HChangeNotifyFlags.SHCNF_FLUSHNOWAIT,

												 pathPointer, IntPtr.Zero);

				}

				finally

				{

					Marshal.FreeHGlobal(pathPointer);

				}

			}

		}

		#region Event Handlers

		public void Handle(SelectiveSynchChanges message)

		{

			var accountName = message.Account.AccountName;

			PithosMonitor monitor;

			if (_monitors.TryGetValue(accountName, out monitor))

			{

				monitor.AddSelectivePaths(message.Added);

				monitor.RemoveSelectivePaths(message.Removed);

			}

		}

		public void Handle(Notification notification)

		{

			if (!Settings.ShowDesktopNotifications)

				return;

			BalloonIcon icon;

			switch (notification.Level)

			{

				case TraceLevel.Error:

					icon = BalloonIcon.Error;

					break;

				case TraceLevel.Info:

				case TraceLevel.Verbose:

					icon = BalloonIcon.Info;

					break;

				case TraceLevel.Warning:

					icon = BalloonIcon.Warning;

					break;

				default:

					icon = BalloonIcon.None;

					break;

			}

			if (Settings.ShowDesktopNotifications)

			{

				var tv = (ShellView) GetView();

				tv.TaskbarView.ShowBalloonTip(notification.Title, notification.Message, icon);

			}

		}

		#endregion

		public void Handle(ShowFilePropertiesEvent message)

		{

			if (message == null)

				throw new ArgumentNullException("message");

			if (String.IsNullOrWhiteSpace(message.FileName) )

				throw new ArgumentException("message");

			Contract.EndContractBlock();

			var fileName = message.FileName;

            //TODO: Display file properties for non-container folders

			if (File.Exists(fileName))

                //Retrieve the full name with exact casing. Pithos names are case sensitive				

                ShowFileProperties(FileInfoExtensions.GetProperFilePathCapitalization(fileName));

			else if (Directory.Exists(fileName))

                //Retrieve the full name with exact casing. Pithos names are case sensitive

			{

                var path = FileInfoExtensions.GetProperDirectoryCapitalization(fileName);

                if (IsContainer(path))

			        ShowContainerProperties(path);

                else

                    ShowFileProperties(path);

			}

		}

	    private bool IsContainer(string path)

	    {

	        var matchingFolders = from account in _accounts

	                              from rootFolder in Directory.GetDirectories(account.AccountPath)

	                              where rootFolder.Equals(path, StringComparison.InvariantCultureIgnoreCase)

	                              select rootFolder;

	        return matchingFolders.Any();

	    }

	}

}