using LightlessSync.LightlessConfiguration;
using LightlessSync.Services;
using Microsoft.Extensions.Logging;
using Microsoft.Win32.SafeHandles;
using System.Collections.Concurrent;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Threading.Channels;
using static LightlessSync.Utils.FileSystemHelper;

namespace LightlessSync.FileCache;

public sealed class FileCompactor : IDisposable
{
    public const uint FSCTL_DELETE_EXTERNAL_BACKING = 0x90314U;
    public const ulong WOF_PROVIDER_FILE = 2UL;

    private readonly ConcurrentDictionary<string, byte> _pendingCompactions;
    private readonly ILogger<FileCompactor> _logger;
    private readonly LightlessConfigService _lightlessConfigService;
    private readonly DalamudUtilService _dalamudUtilService;

    private readonly Channel<string> _compactionQueue;
    private readonly CancellationTokenSource _compactionCts = new();
    private readonly Task _compactionWorker;
    
    private readonly WOF_FILE_COMPRESSION_INFO_V1 _efInfo = new()
    {
        Algorithm = (int)CompressionAlgorithm.XPRESS8K,
        Flags = 0
    };
    private enum CompressionAlgorithm 
    {
        NO_COMPRESSION = -2,
        LZNT1 = -1,
        XPRESS4K = 0,
        LZX = 1,
        XPRESS8K = 2,
        XPRESS16K = 3
    }

    public FileCompactor(ILogger<FileCompactor> logger, LightlessConfigService lightlessConfigService, DalamudUtilService dalamudUtilService)
    {
        _pendingCompactions = new(StringComparer.OrdinalIgnoreCase);
        _logger = logger;
        _lightlessConfigService = lightlessConfigService;
        _dalamudUtilService = dalamudUtilService;

        _compactionQueue = Channel.CreateUnbounded<string>(new UnboundedChannelOptions
        {
            SingleReader = true,
            SingleWriter = false
        });

        _compactionWorker = Task.Factory.StartNew(() => ProcessQueueAsync(_compactionCts.Token), _compactionCts.Token, TaskCreationOptions.LongRunning,TaskScheduler.Default).Unwrap();
    }

    public bool MassCompactRunning { get; private set; }
    public string Progress { get; private set; } = string.Empty;

    public void CompactStorage(bool compress)
    {
        MassCompactRunning = true;
        try
        {
            var allFiles = Directory.EnumerateFiles(_lightlessConfigService.Current.CacheFolder).ToList();
            int total = allFiles.Count;
            int current = 0;

            foreach (var file in allFiles)
            {
                current++;
                Progress = $"{current}/{total}";

                try
                {
                    if (compress)
                        CompactFile(file);
                    else
                        DecompressFile(file);
                }
                catch (IOException ioEx)
                {
                    _logger.LogDebug(ioEx, "File {file} locked or busy, skipping", file);
                }
                catch (Exception ex)
                {
                    _logger.LogWarning(ex, "Error compacting/decompressing file {file}", file);
                }
            }
        }
        finally
        {
            MassCompactRunning = false;
            Progress = string.Empty;
        }
    }

    /// <summary>
    /// Write all bytes into a directory async
    /// </summary>
    /// <param name="filePath">Bytes will be writen to this filepath</param>
    /// <param name="bytes">Bytes that have to be written</param>
    /// <param name="token">Cancellation Token for interupts</param>
    /// <returns>Writing Task</returns>
    public async Task WriteAllBytesAsync(string filePath, byte[] bytes, CancellationToken token)
    {
        var dir = Path.GetDirectoryName(filePath);
        if (!string.IsNullOrEmpty(dir) && !Directory.Exists(dir))
            Directory.CreateDirectory(dir);

        await File.WriteAllBytesAsync(filePath, bytes, token).ConfigureAwait(false);

        if (_lightlessConfigService.Current.UseCompactor)
            EnqueueCompaction(filePath);
    }

    /// <summary>
    /// Gets the File size for an BTRFS or NTFS file system for the given FileInfo
    /// </summary>
    /// <param name="path">Amount of blocks used in the disk</param>
    public long GetFileSizeOnDisk(FileInfo fileInfo)
    {
        var fsType = GetFilesystemType(fileInfo.FullName, _dalamudUtilService.IsWine);

        if (fsType == FilesystemType.NTFS && !_dalamudUtilService.IsWine)
        {
            var blockSize = GetBlockSizeForPath(fileInfo.FullName, _logger, _dalamudUtilService.IsWine);
            var losize = GetCompressedFileSizeW(fileInfo.FullName, out uint hosize);
            var size = (long)hosize << 32 | losize;
            return ((size + blockSize - 1) / blockSize) * blockSize;
        }

        if (fsType == FilesystemType.Btrfs)
        {
            try
            {
                var realPath = fileInfo.FullName.Replace("\"", "\\\"", StringComparison.Ordinal);
                var psi = new ProcessStartInfo("stat", $"-c %b \"{realPath}\"")
                {
                    RedirectStandardOutput = true,
                    RedirectStandardError = true,
                    UseShellExecute = false,
                    CreateNoWindow = true
                };

                using var proc = Process.Start(psi) ?? throw new InvalidOperationException("Could not start stat");
                var outp = proc.StandardOutput.ReadToEnd();
                var err = proc.StandardError.ReadToEnd();
                proc.WaitForExit();

                if (proc.ExitCode != 0)
                    throw new InvalidOperationException($"stat failed: {err}");

                if (!long.TryParse(outp.Trim(), out var blocks))
                    throw new InvalidOperationException($"invalid stat output: {outp}");

                // st_blocks are always 512-byte on Linux enviroment. 
                return blocks * 512L;
            }
            catch (Exception ex)
            {
                _logger.LogDebug(ex, "Failed stat size for {file}, fallback to Length", fileInfo.FullName);
            }
        }

        return fileInfo.Length;
    }

    /// <summary>
    /// Compressing the given path with BTRFS or NTFS file system.
    /// </summary>
    /// <param name="path">Path of the decompressed/normal file</param>
    private void CompactFile(string filePath)
    {
        var fi = new FileInfo(filePath);
        if (!fi.Exists)
        {
            _logger.LogTrace("Skip compact: missing {file}", filePath);
            return;
        }

        var fsType = GetFilesystemType(filePath, _dalamudUtilService.IsWine);
        _logger.LogTrace("Detected filesystem {fs} for {file} (isWine={wine})", fsType, filePath, _dalamudUtilService.IsWine);
        var oldSize = fi.Length;

        int blockSize = GetBlockSizeForPath(fi.FullName, _logger, _dalamudUtilService.IsWine);
        if (oldSize < Math.Max(blockSize, 8 * 1024))
        {
            _logger.LogTrace("Skip compact: {file} < block {block}", filePath, blockSize);
            return;
        }

        if (fsType == FilesystemType.NTFS && !_dalamudUtilService.IsWine)
        {
            if (!IsWOFCompactedFile(filePath))
            {
                _logger.LogDebug("NTFS compact XPRESS8K: {file}", filePath);
                if (WOFCompressFile(filePath))
                {
                    var newSize = GetFileSizeOnDisk(fi);
                    _logger.LogDebug("NTFS compressed {file} {old} -> {new}", filePath, oldSize, newSize);
                }
                else
                {
                    _logger.LogWarning("NTFS compression failed or unavailable for {file}", filePath);
                }
            }
            else
            {
                _logger.LogTrace("Already NTFS-compressed: {file}", filePath);
            }
            return;
        }

        if (fsType == FilesystemType.Btrfs)
        {
            if (!IsBtrfsCompressedFile(filePath))
            {
                _logger.LogDebug("Btrfs compress zstd: {file}", filePath);
                if (BtrfsCompressFile(filePath))
                {
                    var newSize = GetFileSizeOnDisk(fi);
                    _logger.LogDebug("Btrfs compressed {file} {old} -> {new}", filePath, oldSize, newSize);
                }
                else
                {
                    _logger.LogWarning("Btrfs compression failed or unavailable for {file}", filePath);
                }
            }
            else
            {
                _logger.LogTrace("Already Btrfs-compressed: {file}", filePath);
            }
            return;
        }

        _logger.LogTrace("Skip compact: unsupported FS for {file}", filePath);
    }

    /// <summary>
    /// Decompressing the given path with BTRFS file system or NTFS file system.
    /// </summary>
    /// <param name="path">Path of the compressed file</param>
    private void DecompressFile(string path)
    {
        _logger.LogDebug("Decompress request: {file}", path);
        var fsType = GetFilesystemType(path, _dalamudUtilService.IsWine);

        if (fsType == FilesystemType.NTFS && !_dalamudUtilService.IsWine)
        {
            try
            {
                bool flowControl = DecompressWOFFile(path, out FileStream fs);
                if (!flowControl)
                {
                    return;
                }
            }
            catch (Exception ex)
            {
                _logger.LogWarning(ex, "NTFS decompress error {file}", path);
            }
        }

        if (fsType == FilesystemType.Btrfs)
        {
            try
            {
                bool flowControl = DecompressBtrfsFile(path);
                if (!flowControl)
                {
                    return;
                }
            }
            catch (Exception ex)
            {
                _logger.LogWarning(ex, "Btrfs decompress error {file}", path);
            }
        }
    }

    /// <summary>
    /// Decompress an BTRFS File
    /// </summary>
    /// <param name="path">Path of the compressed file</param>
    /// <returns>Decompessing state</returns>
    private bool DecompressBtrfsFile(string path)
    {
        try
        {
            var opts = GetMountOptionsForPath(path);
            if (opts.Contains("compress", StringComparison.OrdinalIgnoreCase))
            {
                _logger.LogWarning("Cannot safely decompress {file}: mount options include compression ({opts})", path, opts);
                return false;
            }

            string realPath = ToLinuxPathIfWine(path, _dalamudUtilService.IsWine);
            var psi = new ProcessStartInfo
            {
                FileName = _dalamudUtilService.IsWine ? "/bin/bash" : "btrfs",
                Arguments = _dalamudUtilService.IsWine
                    ? $"-c \"btrfs filesystem defragment -- '{EscapeSingle(realPath)}'\""
                    : $"filesystem defragment -- \"{realPath}\"",
                RedirectStandardOutput = true,
                RedirectStandardError = true,
                UseShellExecute = false,
                CreateNoWindow = true,
                WorkingDirectory = "/"
            };

            using var proc = Process.Start(psi);
            if (proc == null)
            {
                _logger.LogWarning("Failed to start btrfs defragment for {file}", path);
                return false;
            }

            var stdout = proc.StandardOutput.ReadToEnd();
            var stderr = proc.StandardError.ReadToEnd();
            proc.WaitForExit();

            if (proc.ExitCode != 0)
            {
                _logger.LogWarning("btrfs defragment failed for {file}: {err}", path, stderr);
                return false;
            }

            if (!string.IsNullOrWhiteSpace(stdout))
                _logger.LogTrace("btrfs defragment output {file}: {out}", path, stdout.Trim());

            _logger.LogInformation("Btrfs rewritten uncompressed: {file}", path);
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "Btrfs decompress error {file}", path);
        }

        return true;
    }

    /// <summary>
    /// Decompress an NTFS File
    /// </summary>
    /// <param name="path">Path of the compressed file</param>
    /// <returns>Decompessing state</returns>
    private bool DecompressWOFFile(string path, out FileStream fs)
    {
        fs = new FileStream(path, FileMode.Open, FileAccess.ReadWrite, FileShare.Read);
        var handle = fs.SafeFileHandle;

        if (handle.IsInvalid)
        {
            _logger.LogWarning("Invalid handle: {file}", path);
            return false;
        }

        if (!DeviceIoControl(handle, FSCTL_DELETE_EXTERNAL_BACKING,
                             IntPtr.Zero, 0, IntPtr.Zero, 0,
                             out _, IntPtr.Zero))
        {
            int err = Marshal.GetLastWin32Error();

            if (err == 342)
            {
                _logger.LogTrace("File {file} not externally backed (already decompressed)", path);
            }
            else
            {
                _logger.LogWarning("DeviceIoControl failed for {file} with Win32 error {err}", path, err);
            }
        }
        else
        {
            _logger.LogTrace("Successfully decompressed NTFS file {file}", path);
        }

        return true;
    }

    private static string EscapeSingle(string p) => p.Replace("'", "'\\'", StringComparison.Ordinal);

    private static string ToLinuxPathIfWine(string path, bool isWine)
    {
        if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            return path;

        if (!IsProbablyWine() && !isWine)
            return path;

        string realPath = path;
        if (path.StartsWith("Z:\\", StringComparison.OrdinalIgnoreCase)) 
            realPath = "/" + path[3..].Replace('\\', '/');
        else if (path.StartsWith("C:\\", StringComparison.OrdinalIgnoreCase))
            realPath = Path.Combine(Environment.GetEnvironmentVariable("HOME") ?? "/home", path[3..].Replace('\\', '/')).Replace('\\', '/');

        return realPath;
    }

    /// <summary>
    /// Compress an WOF File
    /// </summary>
    /// <param name="path">Path of the decompressed/normal file</param>
    /// <returns>Compessing state</returns>
    private bool WOFCompressFile(string path)
    {
        FileStream? fs = null;
        int size = Marshal.SizeOf<WOF_FILE_COMPRESSION_INFO_V1>();
        IntPtr efInfoPtr = Marshal.AllocHGlobal(size);

        try
        {
            Marshal.StructureToPtr(_efInfo, efInfoPtr, fDeleteOld: false);
            ulong length = (ulong)size;

            const int maxRetries = 3;

            for (int attempt = 0; attempt < maxRetries; attempt++)
            {
                try
                {
                    fs = new FileStream(path, FileMode.Open, FileAccess.ReadWrite, FileShare.Read);
                    break;
                }
                catch (IOException)
                {
                    if (attempt == maxRetries - 1)
                    {
                        _logger.LogWarning("File still in use after {attempts} attempts, skipping compression for {file}", maxRetries, path);
                        return false;
                    }

                    int delay = 150 * (attempt + 1);
                    _logger.LogTrace("File in use, retrying in {delay}ms for {file}", delay, path);
                    Thread.Sleep(delay);
                }
            }

            if (fs == null)
            {
                _logger.LogWarning("Failed to open {file} for compression; skipping", path);
                return false;
            }

            var handle = fs.SafeFileHandle;

            if (handle.IsInvalid)
            {
                _logger.LogWarning("Invalid file handle for {file}", path);
                return false;
            }

            int ret = WofSetFileDataLocation(handle, WOF_PROVIDER_FILE, efInfoPtr, length);

            // 0x80070158 is WOF error whenever compression fails in an non-fatal way.
            if (ret != 0 && ret != unchecked((int)0x80070158))
            {
                _logger.LogWarning("Failed to compact {file}: {ret}", path, ret.ToString("X"));
                return false;
            }

            return true;
        }
        catch (DllNotFoundException)
        {
            _logger.LogTrace("WofUtil.dll not available; skipping NTFS compaction for {file}", path);
            return false;
        }
        catch (EntryPointNotFoundException)
        {
            _logger.LogTrace("WOF entrypoint missing (Wine/older OS); skipping NTFS compaction for {file}", path);
            return false;
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "Error compacting file {path}", path);
            return false;
        }
        finally
        {
            fs?.Dispose();

            if (efInfoPtr != IntPtr.Zero)
            {
                Marshal.FreeHGlobal(efInfoPtr);
            }
        }
    }

    /// <summary>
    /// Checks if an File is compacted with WOF compression
    /// </summary>
    /// <param name="path">Path of the file</param>
    /// <returns>State of the file</returns>
    private static bool IsWOFCompactedFile(string filePath)
    {
        try
        {
            uint buf = (uint)Marshal.SizeOf<WOF_FILE_COMPRESSION_INFO_V1>();
            int result = WofIsExternalFile(filePath, out int isExternal, out _, out var info, ref buf);
            if (result != 0 || isExternal == 0)
                return false;

            return info.Algorithm == (int)CompressionAlgorithm.XPRESS8K
                || info.Algorithm == (int)CompressionAlgorithm.XPRESS4K
                || info.Algorithm == (int)CompressionAlgorithm.XPRESS16K
                || info.Algorithm == (int)CompressionAlgorithm.LZX
                || info.Algorithm == (int)CompressionAlgorithm.LZNT1
                || info.Algorithm == (int)CompressionAlgorithm.NO_COMPRESSION;
        }
        catch
        {
            return false;
        }
    }

    /// <summary>
    /// Checks if an File is compacted with Btrfs compression
    /// </summary>
    /// <param name="path">Path of the file</param>
    /// <returns>State of the file</returns>
    private bool IsBtrfsCompressedFile(string path)
    {
        try
        {
            bool isWine = _dalamudUtilService?.IsWine ?? false;
            string realPath = isWine ? ToLinuxPathIfWine(path, isWine) : path;

            var psi = new ProcessStartInfo
            {
                FileName = isWine ? "/bin/bash" : "filefrag",
                Arguments = isWine
                    ? $"-c \"filefrag -v '{EscapeSingle(realPath)}'\""
                    : $"-v \"{realPath}\"",
                RedirectStandardOutput = true,
                RedirectStandardError = true,
                UseShellExecute = false,
                CreateNoWindow = true,
                WorkingDirectory = "/"
            };

            using var proc = Process.Start(psi);
            if (proc == null)
            {
                _logger.LogWarning("Failed to start filefrag for {file}", path);
                return false;
            }

            string stdout = proc.StandardOutput.ReadToEnd();
            string stderr = proc.StandardError.ReadToEnd();
            proc.WaitForExit();

            if (proc.ExitCode != 0 && !string.IsNullOrWhiteSpace(stderr))
            {
                _logger.LogTrace("filefrag exited with code {code}: {stderr}", proc.ExitCode, stderr);
            }

            bool compressed = stdout.Contains("flags: compressed", StringComparison.OrdinalIgnoreCase);
            _logger.LogTrace("Btrfs compression check for {file}: {compressed}", path, compressed);
            return compressed;
        }
        catch (Exception ex)
        {
            _logger.LogDebug(ex, "Failed to detect Btrfs compression for {file}", path);
            return false;
        }
    }

    /// <summary>
    /// Compress an Btrfs File
    /// </summary>
    /// <param name="path">Path of the decompressed/normal file</param>
    /// <returns>Compessing state</returns>
    private bool BtrfsCompressFile(string path)
    {
        try
        {
            bool isWine = _dalamudUtilService?.IsWine ?? false;
            string realPath = isWine ? ToLinuxPathIfWine(path, isWine) : path;

            if (isWine && IsProbablyWine())
            {
                if (path.StartsWith("Z:\\", StringComparison.OrdinalIgnoreCase))
                {
                    realPath = "/" + path[3..].Replace('\\', '/');
                }
                else if (path.StartsWith("C:\\", StringComparison.OrdinalIgnoreCase))
                {
                    string linuxHome = Environment.GetEnvironmentVariable("HOME") ?? "/home";
                    realPath = Path.Combine(linuxHome, path[3..].Replace('\\', '/')).Replace('\\', '/');
                }

                _logger.LogTrace("Detected Wine environment. Converted path for compression: {realPath}", realPath);
            }

            const int maxRetries = 3;
            for (int attempt = 0; attempt < maxRetries; attempt++)
            {
                try
                {
                    using var fs = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
                    break;
                }
                catch (IOException)
                {
                    if (attempt == maxRetries - 1)
                    {
                        _logger.LogWarning("File still in use after {attempts} attempts; skipping btrfs compression for {file}", maxRetries, path);
                        return false;
                    }

                    int delay = 150 * (attempt + 1);
                    _logger.LogTrace("File busy, retrying in {delay}ms for {file}", delay, path);
                    Thread.Sleep(delay);
                }
            }

            string command = $"btrfs filesystem defragment -czstd -- \"{realPath}\"";
            var psi = new ProcessStartInfo
            {
                FileName = isWine ? "/bin/bash" : "btrfs",
                Arguments = isWine ? $"-c \"{command}\"" : $"filesystem defragment -czstd -- \"{realPath}\"",
                RedirectStandardOutput = true,
                RedirectStandardError = true,
                UseShellExecute = false,
                CreateNoWindow = true,
                WorkingDirectory = "/"
            };

            using var proc = Process.Start(psi);
            if (proc == null)
            {
                _logger.LogWarning("Failed to start btrfs defragment for compression of {file}", path);
                return false;
            }

            string stdout = proc.StandardOutput.ReadToEnd();
            string stderr = proc.StandardError.ReadToEnd();

            try 
            { 
                proc.WaitForExit(); 
            }
            catch (Exception ex)
            {
                _logger.LogTrace(ex, "Process.WaitForExit threw under Wine for {file}", path);
            }

            if (proc.ExitCode != 0)
            {
                _logger.LogWarning("btrfs defragment failed for {file}: {stderr}", path, stderr);
                return false;
            }

            if (!string.IsNullOrWhiteSpace(stdout))
                _logger.LogTrace("btrfs defragment output for {file}: {stdout}", path, stdout.Trim());

            _logger.LogInformation("Compressed btrfs file successfully: {file}", path);
            return true;
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "Error running btrfs defragment for {file}", path);
            return false;
        }
    }

    private void EnqueueCompaction(string filePath)
    {
        if (!_pendingCompactions.TryAdd(filePath, 0))
            return;

        var fsType = GetFilesystemType(filePath, _dalamudUtilService.IsWine);
        if (fsType != FilesystemType.NTFS && fsType != FilesystemType.Btrfs)
        {
            _logger.LogTrace("Skip enqueue (unsupported fs) {fs} {file}", fsType, filePath);
            _pendingCompactions.TryRemove(filePath, out _);
            return;
        }

        if (!_compactionQueue.Writer.TryWrite(filePath))
        {
            _pendingCompactions.TryRemove(filePath, out _);
            _logger.LogDebug("Failed to enqueue compaction {file}", filePath);
        }
    }

    private async Task ProcessQueueAsync(CancellationToken token)
    {
        try
        {
            while (await _compactionQueue.Reader.WaitToReadAsync(token).ConfigureAwait(false))
            {
                while (_compactionQueue.Reader.TryRead(out var filePath))
                {
                    try
                    {
                        if (token.IsCancellationRequested)
                        {
                            return;
                        }

                        if (!_lightlessConfigService.Current.UseCompactor)
                        {
                            continue;
                        }

                        if (!File.Exists(filePath))
                        {
                            _logger.LogTrace("Skip compact (missing) {file}", filePath);
                            continue;
                        }

                        CompactFile(filePath);
                    }
                    catch (OperationCanceledException) 
                    {
                        return;
                    }
                    catch (Exception ex)
                    {
                        _logger.LogWarning(ex, "Error compacting file {file}", filePath);
                    }
                    finally
                    {
                        _pendingCompactions.TryRemove(filePath, out _);
                    }
                }
            }
        }
        catch (OperationCanceledException)
        {
            _logger.LogDebug("Compaction queue cancelled");
        }
    }

    [StructLayout(LayoutKind.Sequential, Pack = 1)]
    private struct WOF_FILE_COMPRESSION_INFO_V1
    {
        public int Algorithm;
        public ulong Flags;
    }

    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern bool DeviceIoControl(SafeFileHandle hDevice, uint dwIoControlCode, IntPtr lpInBuffer, uint nInBufferSize, IntPtr lpOutBuffer, uint nOutBufferSize, out uint lpBytesReturned, IntPtr lpOverlapped);

    [DllImport("kernel32.dll")]
    private static extern uint GetCompressedFileSizeW([In, MarshalAs(UnmanagedType.LPWStr)] string lpFileName, [Out, MarshalAs(UnmanagedType.U4)] out uint lpFileSizeHigh);

    [DllImport("WofUtil.dll")]
    private static extern int WofIsExternalFile([MarshalAs(UnmanagedType.LPWStr)] string Filepath, out int IsExternalFile, out uint Provider, out WOF_FILE_COMPRESSION_INFO_V1 Info, ref uint BufferLength);

    [DllImport("WofUtil.dll", SetLastError = true)]
    private static extern int WofSetFileDataLocation(SafeFileHandle FileHandle, ulong Provider, IntPtr ExternalFileInfo, ulong Length);

    public void Dispose()
    {
        _compactionQueue.Writer.TryComplete();
        _compactionCts.Cancel();
        try
        {
            _compactionWorker.Wait(TimeSpan.FromSeconds(5));
        }
        catch 
        { 
            //ignore on catch ^^
        }
        finally
        {
            _compactionCts.Dispose();
        }

        GC.SuppressFinalize(this);
    }
}