Synnefo » Pithos MS Client

using System.Collections.Concurrent;

using System.ComponentModel;

using System.ComponentModel.Composition;

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.ServiceModel.Description;

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.Properties;

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 System.Text;

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 IStatusChecker _statusChecker;

        private IEventAggregator _events;

        public PithosSettings Settings { get; private set; }        

        private Dictionary<string, PithosMonitor> _monitors = new Dictionary<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 Dictionary<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 { get; set; }

		//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 Task StartMonitoring()

        {

            try

            {                

                foreach (var account in Settings.Accounts)

                {

                    await MonitorAccount(account);

                }

                _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 = null;

                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

                        monitor.Start();

                    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,

                                  UsePithos = account.UsePithos,

                                  StatusNotification = this,

                                  RootPath = account.RootPath

                              };

                //PithosMonitor uses MEF so we need to resolve it

                IoC.BuildUp(monitor);

                var appSettings = Properties.Settings.Default;

                monitor.AuthenticationUrl = account.UsePithos

                                                ? appSettings.PithosAuthenticationUrl

                                                : appSettings.CloudfilesAuthenticationUrl;

                _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

            {

                //_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}",

                Properties.Settings.Default.PithosSite,account.Token,

                account.UserName);

            Process.Start(site);

        }

        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))

                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 account = pair.Key;

            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 account = pair.Key;

            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 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.FirstOrDefault(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 });

                return;

            }

            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 });

                return;

            }

        }

        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)

        {

            this.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=this.RecentFiles;

            FileEntry popped;

            while (files.Count > 5)

                files.TryTake(out popped);

            files.TryAdd(entry);

        }

        public void NotifyAccount(AccountInfo account)

        {

            if (account== null)

                return;

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

                Properties.Settings.Default.PithosSite, account.Token,

                account.UserName);

            IProducerConsumerCollection<AccountInfo> accounts = Accounts;

            for (var i = 0; i < _accounts.Count; i++)

            {

                AccountInfo item;

                if (accounts.TryTake(out item))

                {

                    if (item.UserName!=account.UserName)

                    {

                        accounts.TryAdd(item);

                    }

                }

            }

            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.TryGetValue(accountName, out monitor))

            {

                Monitors.Remove(accountName);

                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 = BalloonIcon.None;

            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) this.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;

            if (File.Exists(fileName))

                this.ShowFileProperties(fileName);

            else if (Directory.Exists(fileName))

                this.ShowContainerProperties(fileName);

        }

    }

}