using LightlessSync.LightlessConfiguration;
using LightlessSync.Services;
using LightlessSync.Services.Compactor;
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;
    public const int _maxRetries = 3;

    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 List<Task> _workers = [];
    private readonly SemaphoreSlim _globalGate;

    //Limit btrfs gate on half of threads given to compactor.
    private static readonly SemaphoreSlim _btrfsGate = new(4, 4);
    private readonly BatchFilefragService _fragBatch;

    private readonly WOF_FILE_COMPRESSION_INFO_V1 _efInfo = new()
    {
        Algorithm = (int)CompressionAlgorithm.XPRESS8K,
        Flags = 0
    };

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

    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 = false,
            SingleWriter = false
        });

        int workers = Math.Clamp(Math.Min(Environment.ProcessorCount / 2, 4), 1, 8);
        _globalGate = new SemaphoreSlim(workers, workers);
        int workerCount = Math.Max(workers * 2, workers);

        for (int i = 0; i < workerCount; i++)
        {
            _workers.Add(Task.Factory.StartNew(
                () => ProcessQueueWorkerAsync(_compactionCts.Token),
                _compactionCts.Token,
                TaskCreationOptions.LongRunning,
                TaskScheduler.Default).Unwrap());
        }

        _fragBatch = new BatchFilefragService(
            useShell: _dalamudUtilService.IsWine,
            log: _logger,
            batchSize: 64,
            flushMs: 25, 
            runDirect: RunProcessDirect,
            runShell: RunProcessShell
         );

        _logger.LogInformation("FileCompactor started with {workers} workers", workerCount);
    }

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

    /// <summary>
    /// Compact the storage of the Cache Folder
    /// </summary>
    /// <param name="compress">Used to check if files needs to be compressed</param>
    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
                {
                    // Compress or decompress files
                    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)
        {
            (bool flowControl, long value) = GetFileSizeNTFS(fileInfo);
            if (!flowControl)
            {
                return value;
            }
        }

        if (fsType == FilesystemType.Btrfs)
        {
            (bool flowControl, long value) = GetFileSizeBtrfs(fileInfo);
            if (!flowControl)
            {
                return value;
            }
        }

        return fileInfo.Length;
    }

    /// <summary>
    /// Get File Size in an Btrfs file system (Linux/Wine).
    /// </summary>
    /// <param name="fileInfo">File that you want the size from.</param>
    /// <returns>Succesful check and value of the filesize.</returns>
    /// <exception cref="InvalidOperationException">Fails on the Process in StartProcessInfo</exception>
    private (bool flowControl, long value) GetFileSizeBtrfs(FileInfo fileInfo)
    {
        try
        {
            bool isWindowsProc = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
            var (_, linuxPath) = ResolvePathsForBtrfs(fileInfo.FullName);

            var (ok, output, err, code) =
                isWindowsProc
                    ? RunProcessShell($"stat -c='%b' {QuoteSingle(linuxPath)}", workingDir: null, 10000)
                    : RunProcessDirect("stat", ["-c='%b'", linuxPath], workingDir: null, 10000);

            if (ok && long.TryParse(output.Trim(), out long blocks))
                return (false, blocks * 512L); // st_blocks are always 512B units

            _logger.LogDebug("Btrfs size probe failed for {linux} (stat {code}, err {err}). Falling back to Length.", linuxPath, code, err);
            return (false, fileInfo.Length);
        }
        catch (Exception ex)
        {
            _logger.LogDebug(ex, "Failed Btrfs size probe for {file}, using Length", fileInfo.FullName);
            return (false, fileInfo.Length);
        }
    }

    /// <summary>
    /// Get File Size in an NTFS file system (Windows).
    /// </summary>
    /// <param name="fileInfo">File that you want the size from.</param>
    /// <returns>Succesful check and value of the filesize.</returns>
    private (bool flowControl, long value) GetFileSizeNTFS(FileInfo fileInfo)
    {
        try
        {
            var blockSize = GetBlockSizeForPath(fileInfo.FullName, _logger, _dalamudUtilService.IsWine);
            var losize = GetCompressedFileSizeW(fileInfo.FullName, out uint hosize);
            var size = (long)hosize << 32 | losize;
            return (flowControl: false, value: ((size + blockSize - 1) / blockSize) * blockSize);
        }
        catch (Exception ex)
        {
            _logger.LogDebug(ex, "Failed stat size for {file}, fallback to Length", fileInfo.FullName);
        }

        return (flowControl: true, value: default);
    }

    /// <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 compaction: missing {file}", filePath);
            return;
        }

        var fsType = GetFilesystemType(filePath, _dalamudUtilService.IsWine);
        var oldSize = fi.Length;
        int blockSize = GetBlockSizeForPath(fi.FullName, _logger, _dalamudUtilService.IsWine);

        // We skipping small files (128KiB) as they slow down the system a lot for BTRFS. as BTRFS has a different blocksize it requires an different calculation.
        long minSizeBytes = fsType == FilesystemType.Btrfs
            ? Math.Max(blockSize * 2L, 128 * 1024L)
            : Math.Max(blockSize, 8 * 1024L);

        if (oldSize < minSizeBytes)
        {
            _logger.LogTrace("Skip compaction: {file} ({size} B) < threshold ({th} B)", filePath, oldSize, minSizeBytes);
            return;
        }

        if (fsType == FilesystemType.NTFS && !_dalamudUtilService.IsWine)
        {
            if (!IsWOFCompactedFile(filePath))
            {
                _logger.LogDebug("NTFS compaction 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 compression 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);
                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 on Wine/Linux
    /// </summary>
    /// <param name="path">Path of the compressed file</param>
    /// <returns>Decompressing state</returns>
    private bool DecompressBtrfsFile(string path)
    {
        return RunWithBtrfsGate(() =>
        {
            try
            {
                bool isWine = _dalamudUtilService?.IsWine ?? false;
                string linuxPath = isWine ? ToLinuxPathIfWine(path, isWine) : path;

                var opts = GetMountOptionsForPath(linuxPath);
                bool hasCompress = opts.Contains("compress", StringComparison.OrdinalIgnoreCase);
                bool hasCompressForce = opts.Contains("compress-force", StringComparison.OrdinalIgnoreCase);

                if (hasCompressForce)
                {
                    _logger.LogWarning("Cannot safely decompress {file}: mount options contains compress-force ({opts}).", linuxPath, opts);
                    return false;
                }

                if (hasCompress)
                {
                    var setCmd = $"btrfs property set -- {QuoteDouble(linuxPath)} compression none";
                    var (okSet, _, errSet, codeSet) = isWine
                        ? RunProcessShell(setCmd)
                        : RunProcessDirect("btrfs", ["property", "set", "--", linuxPath, "compression", "none"]);

                    if (!okSet)
                    {
                        _logger.LogWarning("Failed to set 'compression none' on {file}, please check drive options (exit code is: {code}): {err}", linuxPath, codeSet, errSet);
                        return false;
                    }
                    _logger.LogTrace("Set per-file 'compression none' on {file}", linuxPath);
                }

                if (!IsBtrfsCompressedFile(linuxPath))
                {
                    _logger.LogTrace("{file} is not compressed, skipping decompression completely", linuxPath);
                    return true;
                }

                var (ok, stdout, stderr, code) = isWine
                    ? RunProcessShell($"btrfs filesystem defragment -- {QuoteDouble(linuxPath)}")
                    : RunProcessDirect("btrfs", ["filesystem", "defragment", "--", linuxPath]);

                if (!ok)
                {
                    _logger.LogWarning("btrfs defragment (decompress) failed for {file} (exit code is: {code}): {stderr}",
                        linuxPath, code, stderr);
                    return false;
                }

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

                _logger.LogInformation("Decompressed (rewritten uncompressed) Btrfs file: {file}", linuxPath);
                return true;
            }
            catch (Exception ex)
            {
                _logger.LogWarning(ex, "Error rewriting {file} for Btrfs decompression", path);
                return false;
            }
        });
    }

    /// <summary>
    /// Decompress an NTFS File
    /// </summary>
    /// <param name="path">Path of the compressed file</param>
    /// <returns>Decompressing state</returns>
    private bool DecompressWOFFile(string path)
    {
        //Check if its already been compressed
        if (TryIsWofExternal(path, out bool isExternal, out int algo))
        {
            if (!isExternal)
            {
                _logger.LogTrace("Already decompressed file: {file}", path);
                return true;
            }
            var compressString = ((CompressionAlgorithm)algo).ToString();
            _logger.LogTrace("WOF compression (algo={algo}) detected for {file}", compressString, path);
        }

        //This will attempt to start WOF thread.
        return WithFileHandleForWOF(path, FileAccess.ReadWrite, h =>
        {
            if (!DeviceIoControl(h, FSCTL_DELETE_EXTERNAL_BACKING,
                                 IntPtr.Zero, 0, IntPtr.Zero, 0,
                                 out uint _, IntPtr.Zero))
            {
                int err = Marshal.GetLastWin32Error();
                // 342 error code means its been decompressed after the control, we handle it as it succesfully been decompressed.
                if (err == 342)
                {
                    _logger.LogTrace("Successfully decompressed NTFS file {file}", path);
                    return true;
                }

                _logger.LogWarning("DeviceIoControl failed for {file} with Win32 error {err}", path, err);
                return false;
            }

            _logger.LogTrace("Successfully decompressed NTFS file {file}", path);
            return true;
        });
    }

    /// <summary>
    /// Converts to Linux Path if its using Wine (diferent pathing system in Wine)
    /// </summary>
    /// <param name="path">Path that has to be converted</param>
    /// <param name="isWine">Extra check if using the wine enviroment</param>
    /// <returns>Converted path to be used in Linux</returns>
    private string ToLinuxPathIfWine(string path, bool isWine, bool preferShell = true)
    {
        if (!isWine || !IsProbablyWine())
            return path;

        if (path.StartsWith("Z:\\", StringComparison.OrdinalIgnoreCase))
            return ("/" + path[3..].Replace('\\', '/')).Replace("//", "/", StringComparison.Ordinal);

        if (path.StartsWith("C:\\", StringComparison.OrdinalIgnoreCase))
        {
            const string usersPrefix = "C:\\Users\\";
            var p = path.Replace('/', '\\');

            if (p.StartsWith(usersPrefix, StringComparison.OrdinalIgnoreCase))
            {
                int afterUsers = usersPrefix.Length;
                int slash = p.IndexOf('\\', afterUsers);
                if (slash > 0 && slash + 1 < p.Length)
                {
                    var rel = p[(slash + 1)..].Replace('\\', '/');
                    var home = Environment.GetEnvironmentVariable("HOME");
                    if (string.IsNullOrEmpty(home))
                    {
                        var linuxUser = Environment.GetEnvironmentVariable("USER") ?? Environment.UserName;
                        home = "/home/" + linuxUser;
                    }
                    return (home!.TrimEnd('/') + "/" + rel).Replace("//", "/", StringComparison.Ordinal);
                }
            }

            try
            {
                (bool ok, string stdout, string stderr, int code) = preferShell
                        ? RunProcessShell($"winepath -u {QuoteSingle(path)}", timeoutMs: 5000, workingDir: "/")
                        : RunProcessDirect("winepath", ["-u", path], workingDir: "/", timeoutMs: 5000);

                if (ok)
                {
                    var outp = (stdout ?? "").Trim();
                    if (!string.IsNullOrEmpty(outp) && outp.StartsWith('/'))
                        return outp.Replace("//", "/", StringComparison.Ordinal);
                }
                else
                {
                    _logger.LogTrace("winepath failed for {path} (exit {code}): {err}", path, code, stderr);
                }
            }
            catch (Exception ex)
            {
                _logger.LogTrace(ex, "winepath invocation failed for {path}", path);
            }
        }

        return path.Replace('\\', '/').Replace("//", "/", StringComparison.Ordinal);
    }

    /// <summary>
    /// Compress an File using the WOF methods (NTFS)
    /// </summary>
    /// <param name="path">Path of the decompressed/normal file</param>
    /// <returns>Compessing state</returns>
    private bool WOFCompressFile(string path)
    {
        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;

            return WithFileHandleForWOF(path, FileAccess.ReadWrite, h =>
            {
                int ret = WofSetFileDataLocation(h, WOF_PROVIDER_FILE, efInfoPtr, length);

                // 0x80070158 is the being "already compressed/unsupported" style return
                if (ret != 0 && ret != unchecked((int)0x80070158))
                {
                    _logger.LogWarning("Failed to compact {file}: {ret}", path, ret.ToString("X"));
                    return false;
                }

                return true;
            });
        }
        catch (DllNotFoundException ex)
        {
            _logger.LogTrace(ex, "WofUtil not available; skipping NTFS compaction for {file}", path);
            return false;
        }
        catch (EntryPointNotFoundException ex)
        {
            _logger.LogTrace(ex, "WOF entrypoint missing on this system (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
        {
            if (efInfoPtr != IntPtr.Zero)
                Marshal.FreeHGlobal(efInfoPtr);
        }
    }

    /// <summary>
    /// Checks if an File is compacted with WOF compression (NTFS)
    /// </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 any WOF compression with an WOF backing (NTFS)
    /// </summary>
    /// <param name="path">Path of the file</param>
    /// <returns>State of the file, if its an external (no backing) and which algorithm if detected</returns>
    private static bool TryIsWofExternal(string path, out bool isExternal, out int algorithm)
    {
        isExternal = false;
        algorithm = 0;
        try
        {
            uint buf = (uint)Marshal.SizeOf<WOF_FILE_COMPRESSION_INFO_V1>();
            int hr = WofIsExternalFile(path, out int ext, out _, out var info, ref buf);
            if (hr == 0 && ext != 0)
            {
                isExternal = true;
                algorithm = info.Algorithm;
            }
            return true;
        }
        catch (DllNotFoundException) 
        {
            return false; 
        }
        catch (EntryPointNotFoundException) 
        { 
            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)
    {
        return RunWithBtrfsGate(() =>
        {
            try
            {
                bool windowsProc = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
                string linuxPath = windowsProc ? ResolveLinuxPathForWine(path) : path;

                var task = _fragBatch.IsCompressedAsync(linuxPath, _compactionCts.Token);

                if (task.Wait(TimeSpan.FromSeconds(5), _compactionCts.Token) && task.IsCompletedSuccessfully)
                    return task.Result;

                _logger.LogTrace("filefrag batch timed out for {file}", linuxPath);
                return false;
            }
            catch (OperationCanceledException)
            {
                return false;
            }
            catch (Exception ex)
            {
                _logger.LogDebug(ex, "filefrag batch check failed 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)
    {
        return RunWithBtrfsGate(() => {
            try
            {
                var (winPath, linuxPath) = ResolvePathsForBtrfs(path);
                bool isWindowsProc = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);

                if (IsBtrfsCompressedFile(linuxPath))
                {
                    _logger.LogTrace("Already Btrfs compressed: {file} (linux={linux})", winPath, linuxPath);
                    return true;
                }

                if (!ProbeFileReadableForBtrfs(winPath, linuxPath))
                {
                    _logger.LogTrace("Probe failed; cannot open file for compress: {file} (linux={linux})", winPath, linuxPath);
                    return false;
                }

                (bool ok, string stdout, string stderr, int code) =
                    isWindowsProc
                        ? RunProcessShell($"btrfs filesystem defragment -clzo -- {QuoteSingle(linuxPath)}")
                        : RunProcessDirect("btrfs", ["filesystem", "defragment", "-clzo", "--", linuxPath]);

                if (!ok)
                {
                    _logger.LogWarning("btrfs defragment failed for {file} (linux={linux}) exit {code}: {stderr}",
                        winPath, linuxPath, code, stderr);
                    return false;
                }

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

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

    /// <summary>
    /// Attempt opening file stream for WOF functions
    /// </summary>
    /// <param name="path">File that has to be accessed</param>
    /// <param name="access">Permissions for the file</param>
    /// <param name="body">Access of the file stream for the WOF function to handle.</param>
    /// <returns>State of the attempt for the file</returns>
    private bool WithFileHandleForWOF(string path, FileAccess access, Func<SafeFileHandle, bool> body)
    {
        const FileShare share = FileShare.ReadWrite | FileShare.Delete;

        for (int attempt = 0; attempt < _maxRetries; attempt++)
        {
            try
            {
                using var fs = new FileStream(path, FileMode.Open, access, share);

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

                return body(handle);
            }
            catch (IOException ex)
            {
                if (attempt == _maxRetries - 1)
                {
                    _logger.LogWarning(ex, "File still in use after {attempts} attempts, skipping {file}", _maxRetries, path);
                    return false;
                }

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

        return false;
    }

    /// <summary>
    /// Runs an nonshell process meant for Linux enviroments
    /// </summary>
    /// <param name="fileName">File that has to be excuted</param>
    /// <param name="args">Arguments meant for the file/command</param>
    /// <param name="workingDir">Working directory used to execute the file with/without arguments</param>
    /// <param name="timeoutMs">Timeout timer for the process</param>
    /// <returns>State of the process, output of the process and error with exit code</returns>
    private (bool ok, string stdout, string stderr, int exitCode) RunProcessDirect(string fileName, IEnumerable<string> args, string? workingDir = null, int timeoutMs = 60000)
    {
        var psi = new ProcessStartInfo(fileName)
        {
            RedirectStandardOutput = true,
            RedirectStandardError = true,
            UseShellExecute = false,
            CreateNoWindow = true
        };
        if (!string.IsNullOrEmpty(workingDir)) psi.WorkingDirectory = workingDir;
        foreach (var a in args) psi.ArgumentList.Add(a);
        EnsureUnixPathEnv(psi);

        using var proc = Process.Start(psi);
        if (proc is null) return (false, "", "failed to start process", -1);

        var (success, so2, se2) = CheckProcessResult(proc, timeoutMs, _compactionCts.Token);
        if (!success)
        {
            return (false, so2, se2, -1);
        }

        int code;
        try { code = proc.ExitCode; } catch { code = -1; }
        return (code == 0, so2, se2, code);
    }

    /// <summary>
    /// Runs an shell using '/bin/bash'/ command meant for Linux/Wine enviroments
    /// </summary>
    /// <param name="command">Command that has to be excuted</param>
    /// <param name="timeoutMs">Timeout timer for the process</param>
    /// <returns>State of the process, output of the process and error with exit code</returns>
    private (bool ok, string stdout, string stderr, int exitCode) RunProcessShell(string command, string? workingDir = null, int timeoutMs = 60000)
    {
        
        var psi = new ProcessStartInfo("/bin/bash")
        {
            RedirectStandardOutput = true,
            RedirectStandardError = true,
            UseShellExecute = false,
            CreateNoWindow = true
        };
        if (!string.IsNullOrEmpty(workingDir)) psi.WorkingDirectory = workingDir;

        // Use a Login shell so PATH includes /usr/sbin etc. AKA -lc for login shell
        psi.ArgumentList.Add("-lc");
        psi.ArgumentList.Add(QuoteDouble(command));
        EnsureUnixPathEnv(psi);

        using var proc = Process.Start(psi);
        if (proc is null) return (false, "", "failed to start /bin/bash", -1);

        var (success, so2, se2) = CheckProcessResult(proc, timeoutMs, _compactionCts.Token);
        if (!success)
        {
            return (false, so2, se2, -1);
        }

        int code;
        try { code = proc.ExitCode; } catch { code = -1; }
        return (code == 0, so2, se2, code);
    }

    /// <summary>
    /// Checking the process result for shell or direct processes
    /// </summary>
    /// <param name="proc">Process</param>
    /// <param name="timeoutMs">How long when timeout is gotten</param>
    /// <param name="token">Cancellation Token</param>
    /// <returns>Multiple variables</returns>
    private (bool success, string testy, string testi) CheckProcessResult(Process proc, int timeoutMs, CancellationToken token)
    {
        var outTask = proc.StandardOutput.ReadToEndAsync(token);
        var errTask = proc.StandardError.ReadToEndAsync(token);
        var bothTasks = Task.WhenAll(outTask, errTask);

        //On wine, we dont wanna use waitforexit as it will be always broken and giving an error.
        if (_dalamudUtilService.IsWine)
        {
            var finished = Task.WhenAny(bothTasks, Task.Delay(timeoutMs, token)).GetAwaiter().GetResult();
            if (finished != bothTasks)
            {
                try 
                { 
                    proc.Kill(entireProcessTree: true);
                    Task.WaitAll([outTask, errTask], 1000, token);
                } 
                catch 
                {
                    // ignore this 
                }
                var so = outTask.IsCompleted ? outTask.Result : "";
                var se = errTask.IsCompleted ? errTask.Result : "timeout";
                return (false, so, se);
            }

            var stderr = errTask.Result;
            var ok = string.IsNullOrWhiteSpace(stderr);
            return (ok, outTask.Result, stderr);
        }

        // On linux, we can use it as we please
        if (!proc.WaitForExit(timeoutMs))
        {
            try
            {
                proc.Kill(entireProcessTree: true);
                Task.WaitAll([outTask, errTask], 1000, token);
            }
            catch
            {
                // ignore this 
            }
            return (false, outTask.IsCompleted ? outTask.Result : "", "timeout");
        }

        Task.WaitAll(outTask, errTask);
        return (true, outTask.Result, errTask.Result);
    }

    /// <summary>
    /// Enqueues the compaction/decompation of an filepath.
    /// </summary>
    /// <param name="filePath">Filepath that will be enqueued</param>
    private void EnqueueCompaction(string filePath)
    {
        // Safe-checks
        if (string.IsNullOrWhiteSpace(filePath))
            return;

        if (!_lightlessConfigService.Current.UseCompactor)
            return;

        if (!File.Exists(filePath))
            return;

        if (!_pendingCompactions.TryAdd(filePath, 0))
            return;

        bool enqueued = false;
        try
        {
            bool isWine = _dalamudUtilService?.IsWine ?? false;
            var fsType = GetFilesystemType(filePath, isWine);

            // If under Wine, we should skip NTFS because its not Windows but might return NTFS.
            if (fsType == FilesystemType.NTFS && isWine)
            {
                _logger.LogTrace("Skip enqueue (NTFS under Wine) {file}", filePath);
                return;
            }

            // Unknown file system should be skipped.
            if (fsType != FilesystemType.NTFS && fsType != FilesystemType.Btrfs)
            {
                _logger.LogTrace("Skip enqueue (unsupported fs) {fs} {file}", fsType, filePath);
                return;
            }

            // Channel got closed, skip enqueue on file
            if (!_compactionQueue.Writer.TryWrite(filePath))
            {
                _logger.LogTrace("Skip enqueue: compaction channel is/got closed {file}", filePath);
                return;
            }

            enqueued = true;
            _logger.LogTrace("Queued compaction for {file} (fs={fs})", filePath, fsType);
        }
        finally
        {
            if (!enqueued)
                _pendingCompactions.TryRemove(filePath, out _);
        }
    }

    /// <summary>
    /// Process the queue with, meant for a worker/thread
    /// </summary>
    /// <param name="token">Cancellation token for the worker whenever it needs to be stopped</param>
    private async Task ProcessQueueWorkerAsync(CancellationToken token)
    {
        try
        {
            while (await _compactionQueue.Reader.WaitToReadAsync(token).ConfigureAwait(false))
            {
                while (_compactionQueue.Reader.TryRead(out var filePath))
                {
                    try
                    {
                        token.ThrowIfCancellationRequested();
                        await _globalGate.WaitAsync(token).ConfigureAwait(false);

                        try
                        {
                            if (_lightlessConfigService.Current.UseCompactor && File.Exists(filePath))
                                CompactFile(filePath);
                        }
                        finally
                        {
                            _globalGate.Release();
                        }
                    }
                    catch (OperationCanceledException) { return; }
                    catch (Exception ex)
                    {
                        _logger.LogWarning(ex, "Error compacting file {file}", filePath);
                    }
                    finally
                    {
                        _pendingCompactions.TryRemove(filePath, out _);
                    }
                }
            }
        }
        catch (OperationCanceledException) 
        { 
            // Shutting down worker, this exception is expected
        }
    }

    /// <summary>
    /// Resolves linux path from wine pathing
    /// </summary>
    /// <param name="windowsPath">Windows path given from Wine</param>
    /// <returns>Linux path to be used in Linux</returns>
    private string ResolveLinuxPathForWine(string windowsPath)
    {
        var (ok, outp, _, _) = RunProcessShell($"winepath -u {QuoteSingle(windowsPath)}", null, 5000);
        if (ok && !string.IsNullOrWhiteSpace(outp)) return outp.Trim();
        return ToLinuxPathIfWine(windowsPath, isWine: true);
    }

    /// <summary>
    /// Ensures the Unix pathing to be included into the process start
    /// </summary>
    /// <param name="psi">Process</param>
    private static void EnsureUnixPathEnv(ProcessStartInfo psi)
    {
        if (!psi.Environment.TryGetValue("PATH", out var p) || string.IsNullOrWhiteSpace(p))
            psi.Environment["PATH"] = "/usr/sbin:/usr/bin:/bin";
        else if (!p.Contains("/usr/sbin", StringComparison.Ordinal))
            psi.Environment["PATH"] = "/usr/sbin:/usr/bin:/bin:" + p;
    }

    /// <summary>
    /// Resolves paths for Btrfs to be used on wine or linux and windows in case
    /// </summary>
    /// <param name="path">Path given t</param>
    /// <returns></returns>
    private (string windowsPath, string linuxPath) ResolvePathsForBtrfs(string path)
    {
        bool isWindowsProc = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);

        if (!isWindowsProc)
            return (path, path);

        var (ok, outp, _, _) = RunProcessShell($"winepath -u {QuoteSingle(path)}", workingDir: null, 5000);
        var linux = (ok && !string.IsNullOrWhiteSpace(outp)) ? outp.Trim() : ToLinuxPathIfWine(path, isWine: true);

        return (path, linux);
    }

    /// <summary>
    /// Probes file if its readable to be used
    /// </summary>
    /// <param name="winePath">Windows path</param>
    /// <param name="linuxPath">Linux path</param>
    /// <returns>Succesfully probed or not</returns>
    private bool ProbeFileReadableForBtrfs(string winePath, string linuxPath)
    {
        try
        {
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                using var _ = new FileStream(winePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
            }
            else
            {
                using var _ = new FileStream(linuxPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
            }
            return true;
        }
        catch { return false; }
    }

    /// <summary>
    /// Running functions into the Btrfs Gate/Threading.
    /// </summary>
    /// <typeparam name="T">Type of the function that wants to be run inside Btrfs Gate</typeparam>
    /// <param name="body">Body of the function</param>
    /// <returns>Task</returns>
    private T RunWithBtrfsGate<T>(Func<T> body)
    {
        bool acquired = false;
        try
        {
            _btrfsGate.Wait(_compactionCts.Token);
            acquired = true;
            return body();
        }
        finally
        {
            if (acquired) _btrfsGate.Release();
        }
    }


    [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);

    private static string QuoteSingle(string s) => "'" + s.Replace("'", "'\\''", StringComparison.Ordinal) + "'";

    private static string QuoteDouble(string s) => "\"" + s.Replace("\\", "\\\\", StringComparison.Ordinal).Replace("\"", "\\\"", StringComparison.Ordinal).Replace("$", "\\$", StringComparison.Ordinal).Replace("`", "\\`", StringComparison.Ordinal) + "\"";

    public void Dispose()
    {
        _fragBatch?.Dispose();
        _compactionQueue.Writer.TryComplete();
        _compactionCts.Cancel();

        try
        {
            Task.WaitAll([.. _workers.Where(t => t != null)], TimeSpan.FromSeconds(5));
        }
        catch 
        { 
            // Ignore this catch on the dispose
        }
        finally
        {
            _compactionCts.Dispose();
        }

        GC.SuppressFinalize(this);
    }
}