path: root/Software/Visual_Studio/FSE/Tango.FSE.UI/FileSystem/DefaultFileSystemProvider.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Tango.BL.Enumerations;
using Tango.Core;
using Tango.Core.DI;
using Tango.Core.ExtensionMethods;
using Tango.Core.IO;
using Tango.Core.Threading;
using Tango.FileSystem;
using Tango.FileSystem.Network;
using Tango.FSE.Common.Authentication;
using Tango.FSE.Common.Connection;
using Tango.FSE.Common.FileSystem;
using Tango.FSE.Common.Notifications;
using Tango.Transport;
using Tango.Transport.Transporters;
using Tango.WebRTC;

namespace Tango.FSE.UI.FileSystem
{
    /// <summary>
    /// Represents the <see cref="IFileSystemProvider"/> default implementation.
    /// </summary>
    /// <seealso cref="Tango.Core.ExtendedObject" />
    /// <seealso cref="Tango.FSE.Common.FileSystem.IFileSystemProvider" />
    public class DefaultFileSystemProvider : ExtendedObject, IFileSystemProvider
    {
        private IMachineProvider _machineProvider;
        private BasicTransporter _webRtcTransporter;
        private const string WEB_RTC_CHANNEL_NAME = "FileSystemChannel";
        private const long MAX_CHUNK_SIZE = 1024 * 100; //Max chunk size for the standard channel (WebSockets/SignalR).
        private const long MIN_CHUNK_SIZE = 1024; //Min chunk size for the standard channel.
        private const long MAX_CHUNK_SIZE_WEB_RTC = 1024 * 50; //Max chunk size for the WebRTC channel.
        private const long MIN_CHUNK_SIZE_WEB_RTC = 1024; //Min chunk size for the WebRTC channel.
        private const int WEB_RTC_MAX_RETRIES = 8; //Maximum number of retries per chunk for the WebRTC channel until falling back to standard channel.
        private List<FileSystemHandler> _activeHandlers;

        [TangoInject]
        private INotificationProvider NotificationProvider { get; set; }

        [TangoInject]
        private IAuthenticationProvider AuthenticationProvider { get; set; }

        #region Properties

        private bool _enableWebRTC;
        /// <summary>
        /// Gets or sets a value indicating whether to enable a P2P WebRTC channel for fast transport.
        /// </summary>
        public bool EnableWebRTC
        {
            get { return _enableWebRTC; }
            set
            {
                _enableWebRTC = value;
                RaisePropertyChangedAuto();

                if (value)
                {
                    LogManager.Log("File system WebRTC channel is now enabled.");
                }
                else
                {
                    LogManager.Log("File system WebRTC channel is now disabled.");
                }
            }
        }

        private bool _isWebRtcAvailable;
        /// <summary>
        /// Gets a value indicating whether the WebRTC channel is available.
        /// </summary>
        public bool IsWebRtcAvailable
        {
            get { return _isWebRtcAvailable; }
            private set
            {
                _isWebRtcAvailable = value;
                RaisePropertyChangedAuto();

                if (value)
                {
                    LogManager.Log("File system WebRTC channel is now available.");
                }
                else
                {
                    LogManager.Log("File system WebRTC channel is now available.");
                }
            }
        }

        #endregion

        #region Constructors

        /// <summary>
        /// Initializes a new instance of the <see cref="DefaultFileSystemProvider"/> class.
        /// </summary>
        /// <param name="machineProvider">The machine provider.</param>
        public DefaultFileSystemProvider(IMachineProvider machineProvider)
        {
            _activeHandlers = new List<FileSystemHandler>();

            EnableWebRTC = true; //TODO: From Settings..
            _machineProvider = machineProvider;
            _machineProvider.MachineConnected += _machineProvider_MachineConnected;
            _machineProvider.MachineDisconnected += _machineProvider_MachineDisconnected;
        }

        #endregion

        #region Machine Connection Event Handlers

        private async void _machineProvider_MachineDisconnected(object sender, MachineDisconnectedEventArgs e)
        {
            IsWebRtcAvailable = false;

            foreach (var handler in _activeHandlers.ToList())
            {
                try
                {
                    handler.RaiseFailed(new TransporterDisconnectedException("Machine disconnected."));
                }
                catch (Exception ex)
                {
                    Debug.WriteLine(ex);
                }
            }

            _activeHandlers.Clear();

            if (_webRtcTransporter != null)
            {
                try
                {
                    LogManager.Log("Machine disconnected. Disconnecting FileSystem WebRTC Transporter...");
                    await _webRtcTransporter.Disconnect();
                }
                catch (Exception ex)
                {
                    LogManager.Log(ex, "Error while disconnecting FileSystem WebRTC Transporter.");
                }
            }
        }

        private async void _machineProvider_MachineConnected(object sender, MachineConnectedEventArgs e)
        {
            if (_machineProvider.ConnectionType.IsRemote())
            {
                try
                {
                    IsWebRtcAvailable = false;

                    await _machineProvider.MachineOperator.SendGenericRequest<InitWebRtcRequest, InitWebRtcResponse>(new InitWebRtcRequest()
                    {
                        DataChannelName = WEB_RTC_CHANNEL_NAME
                    }, new TransportRequestConfig()
                    {
                        Timeout = TimeSpan.FromSeconds(60),
                        Priority = QueuePriority.Low
                    });

                    _webRtcTransporter = new BasicTransporter(new WebRtcTransportAdapter(_machineProvider.MachineOperator, WebRtcTransportAdapterMode.Active, WEB_RTC_CHANNEL_NAME));
                    _webRtcTransporter.UseKeepAlive = false;
                    _webRtcTransporter.ComponentName = "File System Active WebRTC Transporter";
                    await _webRtcTransporter.Connect();

                    IsWebRtcAvailable = true;

                    LogManager.Log("FileSystem via WebRTC is ready.");
                }
                catch (Exception ex)
                {
                    IsWebRtcAvailable = false;
                    LogManager.Log(ex, "Error initializing FileSystem via WebRTC.");
                    NotificationProvider.PushErrorReportingSnackbar(ex, "PPC Module Error", "Could not initialize the remote file system fast channel.");
                }
            }
        }

        #endregion

        #region Public Methods

        /// <summary>
        /// Gets a folder by the specified path.
        /// </summary>
        /// <param name="path">The path.</param>
        /// <returns></returns>
        public async Task<IFileSystemContainer> GetFolder(string path)
        {
            try
            {
                LogManager.Log($"Retrieving remote folder '{path}'...");

                var response = await _machineProvider.MachineOperator.SendGenericRequest<GetFileSystemItemRequest, GetFileSystemItemResponse>(new GetFileSystemItemRequest()
                {
                    Path = path,
                }, new TransportRequestConfig()
                {
                    Timeout = TimeSpan.FromSeconds(30),
                });

                return FileSystemItem.FromDTO(response.FileSystemItem) as IFileSystemContainer;
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error retrieving remote folder.");
            }
        }

        /// <summary>
        /// Gets the specified special folder.
        /// </summary>
        /// <param name="specialFolder">The special folder.</param>
        /// <returns></returns>
        public async Task<IFileSystemContainer> GetSpecialFolder(Environment.SpecialFolder specialFolder)
        {
            try
            {
                LogManager.Log($"Retrieving remote special folder '{specialFolder}'...");

                var response = await _machineProvider.MachineOperator.SendGenericRequest<GetFileSystemItemRequest, GetFileSystemItemResponse>(new GetFileSystemItemRequest()
                {
                    SpecialFolder = specialFolder
                }, new TransportRequestConfig()
                {
                    Timeout = TimeSpan.FromSeconds(30),
                });

                return FileSystemItem.FromDTO(response.FileSystemItem) as IFileSystemContainer;
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error retrieving remote special folder.");
            }
        }

        /// <summary>
        /// Gets the ThisPC (the root path of the PC).
        /// </summary>
        /// <returns></returns>
        public async Task<IFileSystemContainer> GetThisPC()
        {
            try
            {
                LogManager.Log("Retrieving remote root directory (This PC)...");

                var response = await _machineProvider.MachineOperator.SendGenericRequest<GetFileSystemItemRequest, GetFileSystemItemResponse>(new GetFileSystemItemRequest()
                {
                    //No parameters at all
                }, new TransportRequestConfig()
                {
                    Timeout = TimeSpan.FromSeconds(30),
                });

                return FileSystemItem.FromDTO(response.FileSystemItem) as IFileSystemContainer;
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error retrieving remote root directory.");
            }
        }

        /// <summary>
        /// Downloads the specified file or folder item.
        /// </summary>
        /// <param name="item">The file or folder.</param>
        /// <param name="localTargetFolderOrFile">The local target folder or file.</param>
        /// <param name="isSingleFile">Indicates whether the localTargetFolder is a file.</param>
        /// <returns></returns>
        public Task<FileSystemHandler> Download(FileSystemItem item, String localTargetFolderOrFile, bool isSingleFile = false)
        {
            AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_PPCFileSystemRead);

            LogManager.Log($"Downloading remote item '{item.Path}' to local path '{localTargetFolderOrFile}'...");

            String operationId = String.Empty;
            String destination = String.Empty;
            long downloadLength = 0;
            bool aborted = false;

            FileSystemHandler handler = null;

            if (isSingleFile)
            {
                destination = localTargetFolderOrFile;
            }
            else
            {
                destination = Path.Combine(localTargetFolderOrFile, item.Name);
            }

            handler = new FileSystemHandler(item.Type == FileSystemItemType.Folder ? FileSystemHandlerType.FolderDownload : FileSystemHandlerType.FileDownload, item, destination, async () =>
            {
                if (!aborted)
                {
                    LogManager.Log($"Download aborted by user for '{item.Name}'. Aborting download...");

                    aborted = true;
                    try
                    {
                        LogManager.Log("Sending abort download operation request...");

                        var response = await _machineProvider.MachineOperator.SendGenericRequest<AbortOperationRequest, AbortOperationResponse>(
                        new AbortOperationRequest()
                        {
                            OperationId = operationId
                        }, new TransportRequestConfig() { Timeout = TimeSpan.FromSeconds(30) });

                        LogManager.Log($"Download operation for '{item.Name} 'aborted successfully.");
                    }
                    catch (Exception ex)
                    {
                        LogManager.Log(ex, $"Error aborting the download operation for '{item.Name}'.");
                    }
                    finally
                    {
                        handler.RaiseAborted();
                    }
                }
            });

            _activeHandlers.Add(handler);

            ThreadFactory.StartNew(async () =>
            {
                try
                {
                    if (item.Type == FileSystemItemType.File)
                    {
                        LogManager.Log("Download item identified as a file. Sending file download request...");

                        var response = await _machineProvider.MachineOperator.SendGenericRequest<FileDownloadRequest, FileDownloadResponse>(
                            new FileDownloadRequest()
                            {
                                Path = item.Path
                            }, new TransportRequestConfig() { Timeout = TimeSpan.FromSeconds(20) });

                        LogManager.Log($"File download response received:\n{response.ToJsonString()}");

                        operationId = response.OperationId;
                        downloadLength = response.Length;
                        handler.OperationId = operationId;
                    }
                    else if (item.Type == FileSystemItemType.Folder)
                    {
                        LogManager.Log("Download item identified as a folder. Sending folder download request...");

                        var response = await _machineProvider.MachineOperator.SendGenericRequest<FolderDownloadRequest, FolderDownloadResponse>(
                            new FolderDownloadRequest()
                            {
                                Path = item.Path
                            }, new TransportRequestConfig() { Timeout = TimeSpan.FromSeconds(60) });

                        LogManager.Log($"folder download response received:\n{response.ToJsonString()}");

                        operationId = response.OperationId;
                        downloadLength = response.Length;
                        handler.OperationId = operationId;
                    }
                    else
                    {
                        throw new NotSupportedException("The requested file system item is not supported for downloading.");
                    }
                }
                catch (Exception ex)
                {
                    LogManager.Log(ex, $"Error downloading remote item '{item.Path}'.");
                    _activeHandlers.Remove(handler);
                    handler.RaiseFailed(ex);
                    return;
                }

                long position = 0;
                bool webRtcFailed = false;
                int webRtcRetries = WEB_RTC_MAX_RETRIES;
                long dynamicMaxChunkSizeSignalR = MAX_CHUNK_SIZE;
                long dynamicMaxChunkSizeWebRTC = MIN_CHUNK_SIZE_WEB_RTC;
                bool isWebRTCChunkSizeFixed = false;

                var tempFile = TemporaryManager.CreateFile();
                LogManager.Log($"Generated temporary local file '{tempFile}'...");
                LogManager.Log("Starting chunks download...");
                LogManager.Log($"WebRTC active: {(IsWebRtcAvailable && EnableWebRTC).ToStringYesNo()}.");

                while (position < downloadLength && !aborted)
                {
                    if (handler.IsPaused)
                    {
                        Thread.Sleep(1000);
                        continue;
                    }

                    try
                    {
                        ChunkDownloadResponse response = null;
                        ChunkDownloadRequest request = new ChunkDownloadRequest()
                        {
                            MaxChunkSize = MAX_CHUNK_SIZE,
                            OperationId = operationId,
                            Position = position,
                        };

                        if (_webRtcTransporter != null && _webRtcTransporter.State == TransportComponentState.Connected && EnableWebRTC && !webRtcFailed && _machineProvider.ConnectionType == MachineConnectionTypes.SignalR)
                        {
                            try
                            {
                                request.MaxChunkSize = dynamicMaxChunkSizeWebRTC;

                                response = await _webRtcTransporter.SendGenericRequest<ChunkDownloadRequest, ChunkDownloadResponse>(request, new TransportRequestConfig()
                                {
                                    Timeout = TimeSpan.FromSeconds(2),
                                    Priority = QueuePriority.Low
                                });

                                if (!isWebRTCChunkSizeFixed)
                                {
                                    dynamicMaxChunkSizeWebRTC = Math.Min(dynamicMaxChunkSizeWebRTC + 1024, MAX_CHUNK_SIZE_WEB_RTC);
                                }

                                webRtcRetries = WEB_RTC_MAX_RETRIES;
                            }
                            catch (Exception ex)
                            {
                                webRtcRetries--;

                                dynamicMaxChunkSizeWebRTC = Math.Max(dynamicMaxChunkSizeWebRTC - 1024, MIN_CHUNK_SIZE_WEB_RTC);
                                isWebRTCChunkSizeFixed = true;

                                if (webRtcRetries == 0)
                                {
                                    webRtcFailed = true;
                                    LogManager.Log(ex, $"WebRTC chunk download for '{item.Name}' failed after {WEB_RTC_MAX_RETRIES} retries with exception:\n{ex.FlattenMessage()}\nFalling back to SignalR download...");
                                }

                                continue;
                            }
                        }
                        else
                        {
                            request.MaxChunkSize = dynamicMaxChunkSizeSignalR;

                            Stopwatch watch = new Stopwatch();
                            watch.Start();

                            response = await _machineProvider.MachineOperator.SendGenericRequest<ChunkDownloadRequest, ChunkDownloadResponse>(request, new TransportRequestConfig()
                            {
                                Timeout = TimeSpan.FromSeconds(30),
                                Priority = QueuePriority.Low
                            });

                            watch.Stop();

                            if (watch.Elapsed.TotalSeconds < 1)
                            {
                                dynamicMaxChunkSizeSignalR += 1024 * 10;
                            }
                            else if (watch.Elapsed.TotalSeconds > 1)
                            {
                                dynamicMaxChunkSizeSignalR -= 1024 * 10;
                            }

                            dynamicMaxChunkSizeSignalR = Math.Max(dynamicMaxChunkSizeSignalR, MIN_CHUNK_SIZE);
                        }

                        using (FileStream fs = new FileStream(tempFile, FileMode.Append))
                        {
                            fs.Write(response.Data, 0, response.Data.Length);
                        }

                        position += response.Data.Length;
                        handler.InvalidateProgress(position, downloadLength);
                    }
                    catch (Exception ex)
                    {
                        LogManager.Log(ex, $"Download failed for '{item.Name}'.");
                        _activeHandlers.Remove(handler);
                        tempFile.Delete();
                        handler.RaiseFailed(ex);
                        return;
                    }
                }

                if (!aborted)
                {
                    LogManager.Log($"Chunks completed for '{item.Name}'.");

                    try
                    {
                        if (item.Type == FileSystemItemType.File)
                        {
                            LogManager.Log("Copying temporary file to destination directory...");
                            File.Copy(tempFile, destination, true);

                            LogManager.Log("Removing temporary file...");
                            tempFile.Delete();
                        }
                        else if (item.Type == FileSystemItemType.Folder)
                        {
                            LogManager.Log("Extracting temporary zip file to destination directory...");

                            using (Ionic.Zip.ZipFile zip = new Ionic.Zip.ZipFile(tempFile))
                            {
                                zip.ExtractAll(destination, Ionic.Zip.ExtractExistingFileAction.OverwriteSilently);
                            }

                            LogManager.Log("Removing temporary zip file...");
                            tempFile.Delete();
                        }

                        LogManager.Log($"Download completed successfully for '{item.Name}'.");
                        handler.RaiseCompleted();
                    }
                    catch (Exception ex)
                    {
                        LogManager.Log(ex, $"Download failed on the final stage for {item.Name}.");
                        handler.RaiseFailed(ex);
                    }
                }
                else
                {
                    tempFile.Delete();
                }

                _activeHandlers.Remove(handler);
            });

            return Task.FromResult(handler);
        }

        /// <summary>
        /// Uploads the specified local file or folder.
        /// </summary>
        /// <param name="localSourcePath">The local source path.</param>
        /// <param name="remoteFolder">The remote folder.</param>
        /// <returns></returns>
        /// <exception cref="System.IO.FileNotFoundException">Could not locate the local file or directory to upload.</exception>
        public Task<FileSystemHandler> Upload(String localSourcePath, FileSystemItem remoteFolder)
        {
            String destination = Path.Combine(remoteFolder.Path, Path.GetFileName(localSourcePath));
            return Upload(localSourcePath, destination);
        }

        /// <summary>
        /// Uploads the specified local file or folder.
        /// </summary>
        /// <param name="localSourcePath">The local source path.</param>
        /// <param name="remotePath">The remote destination path.</param>
        /// <param name="forRemoteUpgrade">Indicates whether this upload operation is performed for a remote upgrade.</param>
        /// <returns></returns>
        /// <exception cref="FileNotFoundException">Could not locate the local file or directory to upload.</exception>
        public Task<FileSystemHandler> Upload(String localSourcePath, String remotePath, bool forRemoteUpgrade = false)
        {
            if (!forRemoteUpgrade)
            {
                AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_PPCFileSystemWrite);
            }
            else
            {
                AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_RemoteUpgradeOnline);
            }

            String operationId = String.Empty;
            String destination = remotePath;
            bool isFolder = false;
            bool aborted = false;

            FileSystemItem sourceItem = null;

            if (Directory.Exists(localSourcePath))
            {
                LogManager.Log($"Uploading local folder '{localSourcePath}' to remote path '{destination}'...");
                sourceItem = new FolderItem() { Path = localSourcePath };
                isFolder = true;
            }
            else if (File.Exists(localSourcePath))
            {
                LogManager.Log($"Uploading local file '{localSourcePath}' to remote path '{destination}'...");
                sourceItem = new FileItem() { Path = localSourcePath };
                isFolder = false;
            }
            else
            {
                throw LogManager.Log(new FileNotFoundException("Could not locate the local file or directory to upload."), "Error uploading local item to remote location.");
            }

            FileSystemHandler handler = null;

            handler = new FileSystemHandler(isFolder ? FileSystemHandlerType.FolderUpload : FileSystemHandlerType.FileUpload, sourceItem, destination, async () =>
            {
                if (!aborted)
                {
                    LogManager.Log($"Upload aborted by user for item '{sourceItem.Name}'. Aborting upload...");

                    aborted = true;
                    try
                    {
                        LogManager.Log("Sending upload operation abort request...");
                        var response = await _machineProvider.MachineOperator.SendGenericRequest<AbortOperationRequest, AbortOperationResponse>(
                        new AbortOperationRequest()
                        {
                            OperationId = operationId
                        }, new TransportRequestConfig() { Timeout = TimeSpan.FromSeconds(30) });

                        LogManager.Log($"Upload operation successfully aborted for item '{sourceItem.Name}'.");
                    }
                    catch (Exception ex)
                    {
                        LogManager.Log(ex, $"Error aborting the upload operation for item '{sourceItem.Name}'.");
                    }
                    finally
                    {
                        handler.RaiseAborted();
                    }
                }
            });

            _activeHandlers.Add(handler);

            ThreadFactory.StartNew(async () =>
            {
                try
                {
                    if (!isFolder)
                    {
                        LogManager.Log("Upload item identified as a file. Sending file upload request...");

                        var response = await _machineProvider.MachineOperator.SendGenericRequest<FileUploadRequest, FileUploadResponse>(
                            new FileUploadRequest()
                            {
                                Path = destination
                            }, new TransportRequestConfig() { Timeout = TimeSpan.FromSeconds(20) });

                        LogManager.Log($"File upload response received:\n{response.ToJsonString()}");

                        operationId = response.OperationId;
                        handler.OperationId = operationId;
                    }
                    else
                    {
                        LogManager.Log("Upload item identified as a folder. Sending file upload request...");

                        var response = await _machineProvider.MachineOperator.SendGenericRequest<FolderUploadRequest, FolderUploadResponse>(
                            new FolderUploadRequest()
                            {
                                Path = destination
                            }, new TransportRequestConfig() { Timeout = TimeSpan.FromSeconds(20) });

                        LogManager.Log($"Folder upload response received:\n{response.ToJsonString()}");

                        operationId = response.OperationId;
                        handler.OperationId = operationId;
                    }

                    if (isFolder)
                    {
                        var originalPath = localSourcePath;
                        localSourcePath = TemporaryManager.CreateImaginaryFile().Path;
                        LogManager.Log($"Compressing local folder to temporary zip file '{localSourcePath}'...");
                        ZipFile.CreateFromDirectory(originalPath, localSourcePath);
                    }


                    long position = 0;
                    bool webRtcFailed = false;
                    int webRtcRetries = WEB_RTC_MAX_RETRIES;
                    long dynamixMaxChunkSizeSignalR = MAX_CHUNK_SIZE;
                    long dynamicMaxChunkSizeWebRTC = MIN_CHUNK_SIZE_WEB_RTC;
                    bool isWebRTCChunkSizeFixed = false;

                    LogManager.Log("Starting chunks download...");
                    LogManager.Log($"WebRTC active: {(IsWebRtcAvailable && EnableWebRTC).ToStringYesNo()}.");

                    using (FileStream fs = new FileStream(localSourcePath, FileMode.Open))
                    {
                        while (position < fs.Length && !aborted)
                        {
                            fs.Position = position;

                            if (handler.IsPaused)
                            {
                                Thread.Sleep(1000);
                                continue;
                            }

                            try
                            {
                                ChunkUploadResponse response = null;
                                ChunkUploadRequest request = new ChunkUploadRequest()
                                {
                                    OperationId = operationId,
                                };

                                if (_webRtcTransporter != null && _webRtcTransporter.State == TransportComponentState.Connected && EnableWebRTC && !webRtcFailed && _machineProvider.ConnectionType == MachineConnectionTypes.SignalR)
                                {
                                    try
                                    {
                                        byte[] data = new byte[Math.Min(dynamicMaxChunkSizeWebRTC, fs.Length - fs.Position)];
                                        fs.Read(data, 0, data.Length);
                                        request.Data = data;
                                        request.IsCompleted = fs.Position == fs.Length;

                                        response = await _webRtcTransporter.SendGenericRequest<ChunkUploadRequest, ChunkUploadResponse>(request, new TransportRequestConfig()
                                        {
                                            Timeout = request.IsCompleted ? TimeSpan.FromSeconds(120) : TimeSpan.FromSeconds(2),
                                            Priority = QueuePriority.Low
                                        });

                                        if (!isWebRTCChunkSizeFixed)
                                        {
                                            dynamicMaxChunkSizeWebRTC = Math.Min(dynamicMaxChunkSizeWebRTC + 1024, MAX_CHUNK_SIZE_WEB_RTC);
                                        }

                                        webRtcRetries = WEB_RTC_MAX_RETRIES;
                                    }
                                    catch (Exception ex)
                                    {
                                        webRtcRetries--;

                                        dynamicMaxChunkSizeWebRTC = Math.Max(dynamicMaxChunkSizeWebRTC - 1024, MIN_CHUNK_SIZE_WEB_RTC);
                                        isWebRTCChunkSizeFixed = true;

                                        if (webRtcRetries == 0)
                                        {
                                            webRtcFailed = true;
                                            LogManager.Log(ex, $"WebRTC chunk upload for '{sourceItem.Name}' failed after {WEB_RTC_MAX_RETRIES} retries with exception:\n{ex.FlattenMessage()}\nFalling back to SignalR upload...");
                                        }

                                        continue;
                                    }
                                }
                                else
                                {
                                    byte[] data = new byte[Math.Min(dynamixMaxChunkSizeSignalR, fs.Length - fs.Position)];
                                    fs.Read(data, 0, data.Length);
                                    request.Data = data;
                                    request.IsCompleted = fs.Position == fs.Length;

                                    Stopwatch watch = new Stopwatch();
                                    watch.Start();

                                    response = await _machineProvider.MachineOperator.SendGenericRequest<ChunkUploadRequest, ChunkUploadResponse>(request, new TransportRequestConfig()
                                    {
                                        Timeout = request.IsCompleted ? TimeSpan.FromSeconds(120) : TimeSpan.FromSeconds(30),
                                        Priority = QueuePriority.Low
                                    });

                                    watch.Stop();

                                    if (watch.Elapsed.TotalSeconds < 1)
                                    {
                                        dynamixMaxChunkSizeSignalR += 1024 * 10;
                                    }
                                    else if (watch.Elapsed.TotalSeconds > 1)
                                    {
                                        dynamixMaxChunkSizeSignalR -= 1024 * 10;
                                    }

                                    dynamixMaxChunkSizeSignalR = Math.Max(dynamixMaxChunkSizeSignalR, MIN_CHUNK_SIZE);
                                }

                                position = fs.Position;
                                handler.InvalidateProgress(position, fs.Length);
                            }
                            catch (Exception ex)
                            {
                                LogManager.Log(ex, $"Upload failed for '{sourceItem.Name}'.");

                                _activeHandlers.Remove(handler);
                                handler.RaiseFailed(ex);

                                if (isFolder)
                                {
                                    try
                                    {
                                        fs.Dispose();
                                        LogManager.Log("Removing temporary zip file...");
                                        File.Delete(localSourcePath);
                                    }
                                    catch { }
                                }

                                return;
                            }
                        }

                        if (!aborted)
                        {
                            LogManager.Log($"Upload for '{sourceItem.Name}' completed successfully.");
                            handler.RaiseCompleted();
                        }

                        if (isFolder)
                        {
                            try
                            {
                                LogManager.Log("Removing temporary zip file...");
                                File.Delete(localSourcePath);
                            }
                            catch { }
                        }
                    }
                }
                catch (Exception ex)
                {
                    LogManager.Log(ex, $"Error uploading local item '{sourceItem.Name}'.");
                    _activeHandlers.Remove(handler);
                    handler.RaiseFailed(ex);
                    return;
                }

                _activeHandlers.Remove(handler);
            });

            return Task.FromResult(handler);
        }

        /// <summary>
        /// Copies the specified remote file or folder to the specified target remote folder.
        /// </summary>
        /// <param name="source">The remote source file or folder.</param>
        /// <param name="target">The remote target folder.</param>
        /// <returns></returns>
        /// <exception cref="System.NotSupportedException">
        /// The source file system item is not supported for copying.
        /// or
        /// The target file system item is not a valid container.
        /// </exception>
        public async Task Copy(FileSystemItem source, FileSystemItem target)
        {
            AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_PPCFileSystemWrite);

            try
            {
                LogManager.Log($"Copying remote item '{source.Path}' to '{target.Path}'...");

                if (source.Type == FileSystemItemType.Drive)
                {
                    throw new NotSupportedException("The source file system item is not supported for copying.");
                }
                if (target.Type == FileSystemItemType.File)
                {
                    throw new NotSupportedException("The target file system item is not a valid container.");
                }

                await _machineProvider.MachineOperator.SendGenericRequest<CopyRequest, CopyResponse>(new CopyRequest()
                {

                    Source = source.Path,
                    Destination = Path.Combine(target.Path, source.Name)

                }, new TransportRequestConfig()
                {
                    Timeout = TimeSpan.FromSeconds(120),
                });
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error performing copy operation on remote file system.");
            }
        }

        /// <summary>
        /// Moves the specified remote file or folder to the remote target folder.
        /// </summary>
        /// <param name="source">The remote source file or folder.</param>
        /// <param name="target">The remote target folder.</param>
        /// <returns></returns>
        /// <exception cref="System.NotSupportedException">
        /// The source file system item is not supported for copying.
        /// or
        /// The target file system item is not a valid container.
        /// </exception>
        public async Task Move(FileSystemItem source, FileSystemItem target)
        {
            AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_PPCFileSystemWrite);

            try
            {
                LogManager.Log($"Moving remote item '{source.Path}' to '{target.Path}'...");

                if (source.Type == FileSystemItemType.Drive)
                {
                    throw new NotSupportedException("The source file system item is not supported for moving.");
                }
                if (target.Type == FileSystemItemType.File)
                {
                    throw new NotSupportedException("The target file system item is not a valid container.");
                }

                await _machineProvider.MachineOperator.SendGenericRequest<MoveRequest, MoveResponse>(new MoveRequest()
                {

                    Source = source.Path,
                    Destination = Path.Combine(target.Path, source.Name)

                }, new TransportRequestConfig()
                {
                    Timeout = TimeSpan.FromSeconds(120),
                });
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error performing move operation on the remote file system item.");
            }
        }

        /// <summary>
        /// Renames the specified file or folder.
        /// </summary>
        /// <param name="source">The remote source file or folder.</param>
        /// <param name="newName">The new name.</param>
        /// <returns></returns>
        /// <exception cref="System.NotSupportedException">The source file system item is not supported for copying.</exception>
        /// <exception cref="System.ArgumentException">The new name contains invalid characters.</exception>
        public async Task Rename(FileSystemItem source, string newName)
        {
            AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_PPCFileSystemWrite);

            try
            {
                LogManager.Log($"Renaming remote item '{source.Path}' to '{newName}'...");

                if (source.Type == FileSystemItemType.Drive)
                {
                    throw new NotSupportedException("The source file system item is not supported for renaming.");
                }
                if (newName.ToList().Exists(x => Path.GetInvalidFileNameChars().Contains(x)))
                {
                    throw new ArgumentException("The new name contains invalid characters.");
                }

                await _machineProvider.MachineOperator.SendGenericRequest<MoveRequest, MoveResponse>(new MoveRequest()
                {
                    Source = source.Path,
                    Destination = Path.Combine(Path.GetDirectoryName(source.Path), newName)
                });
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error performing rename operation on the remote file system item.");
            }
        }

        /// <summary>
        /// Deletes the specified file or folder.
        /// </summary>
        /// <param name="item">The remote file or folder.</param>
        /// <returns></returns>
        /// <exception cref="System.NotSupportedException">The source file system item is not supported for deletion.</exception>
        public async Task Delete(FileSystemItem item)
        {
            AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_PPCFileSystemWrite);

            try
            {
                LogManager.Log($"Deleting remote item '{item.Path}'...");

                if (item.Type == FileSystemItemType.Drive)
                {
                    throw new NotSupportedException("The source file system item is not supported for deletion.");
                }

                await _machineProvider.MachineOperator.SendGenericRequest<DeleteRequest, DeleteResponse>(new DeleteRequest()
                {
                    Path = item.Path
                }, new TransportRequestConfig() { Timeout = TimeSpan.FromSeconds(120) });
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error performing delete operation on the remote file system item.");
            }
        }

        /// <summary>
        /// Creates a new folder at the specified remote parent.
        /// </summary>
        /// <param name="parent">The remote parent path.</param>
        /// <param name="folderName">Name of the new folder.</param>
        /// <returns></returns>
        public async Task<FolderItem> CreateFolder(FileSystemItem parent, string folderName)
        {
            AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_PPCFileSystemWrite);

            try
            {
                LogManager.Log($"Creating new folder '{folderName}' on the remote path '{parent.Path}'...");

                var response = await _machineProvider.MachineOperator.SendGenericRequest<CreateFolderRequest, CreateFolderResponse>(new CreateFolderRequest()
                {
                    Path = parent.Path,
                    FolderName = folderName,
                });

                return FileSystemItem.FromDTO(response.FolderItem) as FolderItem;
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error creating new folder on the remote file system location.");
            }
        }

        /// <summary>
        /// Performs a disk space optimization.
        /// </summary>
        /// <returns></returns>
        public async Task<PerformDiskSpaceOptimizationResponse> PerformDiskSpaceOptimization()
        {
            AuthenticationProvider.ThrowIfNoPermission(Permissions.FSE_PPCFileSystemRead);

            try
            {
                LogManager.Log("Performing disk space optimization on the remote file system.");

                var response = await _machineProvider.MachineOperator.SendGenericRequest<PerformDiskSpaceOptimizationRequest, PerformDiskSpaceOptimizationResponse>(new PerformDiskSpaceOptimizationRequest()
                {

                }, new TransportRequestConfig()
                {
                    Timeout = TimeSpan.FromMinutes(5)
                });

                return response;
            }
            catch (Exception ex)
            {
                throw LogManager.Log(ex, "Error occurred while trying to perform the disk space optimization on the remote file system.");
            }
        }

        #endregion
    }
}