Synnefo » Pithos MS Client

using System.Collections.Concurrent;

using System.ComponentModel.Composition;

using System.Diagnostics;

using System.Diagnostics.Contracts;

using System.IO;

using System.Net;

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.Properties;

using Pithos.Core;

using Pithos.Interfaces;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

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

namespace Pithos.Client.WPF {

    using System.ComponentModel.Composition;

    [Export(typeof(IShell))]

    public class ShellViewModel : ViewAware, IStatusNotification, IShell, IHandle<Notification>

    {

        private IStatusChecker _statusChecker;

        private IEventAggregator _events;

        public PithosSettings Settings { get; private set; }

        public IScreen Parent { get; set; }

        private Dictionary<string, PithosMonitor> _monitors = new Dictionary<string, PithosMonitor>();

        public Dictionary<string, PithosMonitor> Monitors

        {

            get { return _monitors; }

        }

        private ServiceHost _statusService { get; set; }

        private static readonly log4net.ILog Log = log4net.LogManager.GetLogger("Pithos");

        [ImportingConstructor]

        public ShellViewModel(IWindowManager windowManager, IEventAggregator events, IStatusChecker statusChecker, PithosSettings settings)

        {

            _windowManager = windowManager;

            OpenPithosFolderCommand = new PithosCommand(OpenPithosFolder);

            _statusChecker = statusChecker;

            _events = events;            

            Settings = settings;

            UsageMessage = "Using 15% of 50 GB";

            StatusMessage = "In Synch";

            foreach (var account in settings.Accounts)

            {

                MonitorAccount(account);

            }

            StartStatusService();

        }

        public void MonitorAccount(AccountSettings account)

        {

            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;

            }

            //PithosMonitor uses MEF so we need to resolve it

            monitor = new PithosMonitor

                          {

                              UserName = accountName,

                              ApiKey = account.ApiKey,

                              UsePithos = account.UsePithos,

                              StatusNotification = this,

                              RootPath=account.RootPath                             

                          };          

            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)

        {

            var window = (Window)view;

            window.Hide();

            UpdateStatus();

            base.OnViewLoaded(view);

        }

        #region Status Properties

        private string _statusMessage;

        public string StatusMessage

        {

            get { return _statusMessage; }

            set

            {

                _statusMessage = value;

                NotifyOfPropertyChange(() => StatusMessage);

            }

        }

        private string _usageMessage;

        public string UsageMessage

        {

            get { return _usageMessage; }

            set

            {

                _usageMessage = value;

                NotifyOfPropertyChange(() => UsageMessage);

            }

        }

        private string _pauseSyncCaption="Pause Syncing";

        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/Tray.ico";

        public string StatusIcon

        {

            get { return _statusIcon; }

            set

            {

                _statusIcon = value;

                NotifyOfPropertyChange(() => StatusIcon);

            }

        }

        #endregion

        #region Commands

        public void ShowPreferences()

        {

            Settings.Reload();

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

            _windowManager.ShowDialog(preferences);

        }

        public PithosCommand OpenPithosFolderCommand { get; private set; }

        public void OpenPithosFolder()

        {

            Process.Start(Settings.PithosPath);

        }

        public void GoToSite()

        {

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

            if (activeAccount == null)

                return;            

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

                Properties.Settings.Default.PithosSite,activeAccount.ApiKey,

                activeAccount.AccountName);

            Process.Start(site);

        }

        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;

        public void UpdateStatus()

        {

            var pithosStatus = _statusChecker.GetPithosStatus();

            if (iconNames.ContainsKey(pithosStatus))

            {

                var info = iconNames[pithosStatus];

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

                StatusMessage = String.Format("Pithos 1.0\r\n{0}", info.StatusText);

            }

            var tv=this.GetView();

            _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);

                        }

                        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 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 });

            var authorize= PithosAccount.RetrieveCredentialsAsync(Settings.PithosSite);

            return authorize.ContinueWith(t =>

            {

                if (t.IsFaulted)

                {                    

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

                    Log.Error(message,t.Exception.InnerException);

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

                    return;

                }

                var credentials = t.Result;

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

                account.ApiKey = credentials.Password;

                monitor.ApiKey = credentials.Password;

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

            });

        }

        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 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;

            }

            var tv = (ShellView)this.GetView();

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

        }

        public void RemoveMonitor(string accountName)

        {

            if (String.IsNullOrWhiteSpace(accountName))

                return;

            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);

                }

            }

        }

        private void StartStatusService()

        {

            // Create a ServiceHost for the CalculatorService type and provide the base address.

            var baseAddress = new Uri("net.pipe://localhost/pithos");

            _statusService = new ServiceHost(typeof(StatusService), baseAddress);

            var binding = new NetNamedPipeBinding(NetNamedPipeSecurityMode.None);

            _statusService.AddServiceEndpoint(typeof(IStatusService), binding, "net.pipe://localhost/pithos/statuscache");

            _statusService.AddServiceEndpoint(typeof(ISettingsService), binding, "net.pipe://localhost/pithos/settings");

            //// Add a mex endpoint

            var smb = new ServiceMetadataBehavior

            {

                HttpGetEnabled = true,

                HttpGetUrl = new Uri("http://localhost:30000/pithos/mex")

            };

            _statusService.Description.Behaviors.Add(smb);

            _statusService.Open();

        }

        private void StopStatusService()

        {

            if (_statusService == null)

                return;

            if (_statusService.State == CommunicationState.Faulted)

                _statusService.Abort();

            else if (_statusService.State != CommunicationState.Closed)

                _statusService.Close();

            _statusService = null;

        }

    }

}