using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Compress;
using Compress.SevenZip;
using SabreTools.Core.Tools;
using SabreTools.Hashing;
using SabreTools.Matching.Compare;

namespace SabreTools.FileTypes.Archives
{
    /// <summary>
    /// Represents a Torrent7zip archive for reading and writing
    /// </summary>
    public class SevenZipArchive : BaseArchive
    {
        /* Torrent7z Header Format
            http://cpansearch.perl.org/src/BJOERN/Compress-Deflate7-1.0/7zip/DOC/7zFormat.txt

            00-05		Local file header signature (0x37, 0x7A, 0xBC, 0xAF, 0x27, 0x1C) SevenZipSignature
            06-07		ArchiveVersion (0x00, 0x03)
            The rest is unknown
        */

        #region Constructors

        /// <summary>
        /// Create a new TorrentSevenZipArchive with no base file
        /// </summary>
        public SevenZipArchive()
            : base()
        {
        }

        /// <summary>
        /// Create a new TorrentSevenZipArchive from the given file
        /// </summary>
        /// <param name="filename">Name of the file to use as an archive</param>
        /// <param name="read">True for opening file as read, false for opening file as write</param>
        public SevenZipArchive(string filename)
            : base(filename)
        {
        }

        #endregion

        #region Extraction

        /// <inheritdoc/>
        public override bool CopyAll(string outDir)
        {
            bool encounteredErrors = true;

            // If we have an invalid file
            if (Filename == null)
                return true;

            try
            {
                // Create the temp directory
                Directory.CreateDirectory(outDir);

                // Extract all files to the temp directory
                var zf = new SevenZ();
                ZipReturn zr = zf.ZipFileOpen(Filename, -1, true);
                if (zr != ZipReturn.ZipGood)
                    throw new Exception(CompressUtils.ZipErrorMessageText(zr));

                for (int i = 0; i < zf.LocalFilesCount() && zr == ZipReturn.ZipGood; i++)
                {
                    // Open the read stream
                    zr = zf.ZipFileOpenReadStream(i, out Stream? readStream, out ulong streamsize);

                    // Create the rest of the path, if needed
                    if (!string.IsNullOrEmpty(Path.GetDirectoryName(zf.GetLocalFile(i).Filename)))
                        Directory.CreateDirectory(Path.Combine(outDir, Path.GetDirectoryName(zf.GetLocalFile(i).Filename)!));

                    // If the entry ends with a directory separator, continue to the next item, if any
                    if (zf.GetLocalFile(i).Filename!.EndsWith(Path.DirectorySeparatorChar.ToString())
                        || zf.GetLocalFile(i).Filename!.EndsWith(Path.AltDirectorySeparatorChar.ToString())
                        || zf.GetLocalFile(i).Filename!.EndsWith(Path.PathSeparator.ToString()))
                    {
                        zf.ZipFileCloseReadStream();
                        continue;
                    }

                    FileStream writeStream = File.Create(Path.Combine(outDir, zf.GetLocalFile(i).Filename!));

                    // If the stream is smaller than the buffer, just run one loop through to avoid issues
                    if (streamsize < _bufferSize)
                    {
                        byte[] ibuffer = new byte[streamsize];
                        int ilen = readStream!.Read(ibuffer, 0, (int)streamsize);
                        writeStream.Write(ibuffer, 0, ilen);
                        writeStream.Flush();
                    }
                    // Otherwise, we do the normal loop
                    else
                    {
                        int realBufferSize = (streamsize < _bufferSize ? (int)streamsize : _bufferSize);
                        byte[] ibuffer = new byte[realBufferSize];
                        int ilen;
                        while ((ilen = readStream!.Read(ibuffer, 0, realBufferSize)) > 0)
                        {
                            writeStream.Write(ibuffer, 0, ilen);
                            writeStream.Flush();
                        }
                    }

                    zr = zf.ZipFileCloseReadStream();
                    writeStream.Dispose();
                }

                zf.ZipFileClose();
                encounteredErrors = false;
            }
            catch (EndOfStreamException ex)
            {
                // Catch this but don't count it as an error because SharpCompress is unsafe
                _logger.Verbose(ex);
            }
            catch (InvalidOperationException ex)
            {
                _logger.Warning(ex);
                encounteredErrors = true;
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
                encounteredErrors = true;
            }

            return encounteredErrors;
        }

        /// <inheritdoc/>
        public override string? CopyToFile(string entryName, string outDir)
        {
            // Try to extract a stream using the given information
            (Stream? stream, string? realEntry) = GetEntryStream(entryName);
            if (stream == null || realEntry == null)
                return null;

            // If the stream and the entry name are both non-null, we write to file
            realEntry = Path.Combine(outDir, realEntry);

            // Create the output subfolder now
            Directory.CreateDirectory(Path.GetDirectoryName(realEntry)!);

            // Now open and write the file if possible
            FileStream fs = File.Create(realEntry);
            if (fs != null)
            {
                if (stream.CanSeek)
                    stream.Seek(0, SeekOrigin.Begin);

                byte[] zbuffer = new byte[_bufferSize];
                int zlen;
                while ((zlen = stream.Read(zbuffer, 0, _bufferSize)) > 0)
                {
                    fs.Write(zbuffer, 0, zlen);
                    fs.Flush();
                }

                stream?.Dispose();
                fs?.Dispose();
            }
            else
            {
                stream?.Dispose();
                fs?.Dispose();
                realEntry = null;
            }

            return realEntry;
        }

        /// <inheritdoc/>
        public override (Stream?, string?) GetEntryStream(string entryName)
        {
            // If we have an invalid file
            if (Filename == null)
                return (null, null);

            try
            {
                Stream? stream = null;
                string? realEntry = null;

                var zf = new SevenZ();
                ZipReturn zr = zf.ZipFileOpen(Filename, -1, true);
                if (zr != ZipReturn.ZipGood)
                    throw new Exception(CompressUtils.ZipErrorMessageText(zr));

                for (int i = 0; i < zf.LocalFilesCount() && zr == ZipReturn.ZipGood; i++)
                {
                    // Get the entry
                    var entry = zf.GetLocalFile(i);

                    // Skip invalid entries
                    if (entry.Filename == null)
                        continue;

                    // Skip directory entries
                    if (entry.IsDirectory)
                        continue;

                    // Skip non-matching keys
                    if (!entry.Filename.Contains(entryName))
                        continue;

                    // Open the entry stream
                    realEntry = entry.Filename;
                    zr = zf.ZipFileOpenReadStream(i, out stream, out ulong streamsize);
                    break;
                }

                zf.ZipFileClose();
                return (stream, realEntry);
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
                return (null, null);
            }
        }

        #endregion

        #region Information

        /// <inheritdoc/>
        public override List<BaseFile>? GetChildren()
        {
            List<BaseFile> found = [];

            // If we have an invalid file
            if (Filename == null)
                return null;

            string? gamename = Path.GetFileNameWithoutExtension(Filename);

            try
            {
                var zf = new SevenZ();
                ZipReturn zr = zf.ZipFileOpen(Filename, -1, true);
                if (zr != ZipReturn.ZipGood)
                    throw new Exception(CompressUtils.ZipErrorMessageText(zr));

                for (int i = 0; i < zf.LocalFilesCount(); i++)
                {
                    // If the entry is a directory (or looks like a directory), we don't want to open it
                    if (zf.GetLocalFile(i).IsDirectory
                        || zf.GetLocalFile(i).Filename!.EndsWith(Path.DirectorySeparatorChar.ToString())
                        || zf.GetLocalFile(i).Filename!.EndsWith(Path.AltDirectorySeparatorChar.ToString())
                        || zf.GetLocalFile(i).Filename!.EndsWith(Path.PathSeparator.ToString()))
                    {
                        continue;
                    }

                    // Open the read stream
                    zr = zf.ZipFileOpenReadStream(i, out Stream? readStream, out ulong streamsize);

                    // If we get a read error, log it and continue
                    if (zr != ZipReturn.ZipGood)
                    {
                        _logger.Warning($"An error occurred while reading archive {Filename}: Zip Error - {zr}");
                        zr = zf.ZipFileCloseReadStream();
                        continue;
                    }

                    // Create a blank item for the entry
                    BaseFile zipEntryRom = new();

                    // Perform a quickscan, if flagged to
                    if (_hashTypes.Length == 1 && _hashTypes[0] == HashType.CRC32)
                    {
                        zipEntryRom.Size = (long)zf.GetLocalFile(i).UncompressedSize;
                        zipEntryRom.CRC = zf.GetLocalFile(i).CRC;
                    }
                    // Otherwise, use the stream directly
                    else
                    {
                        zipEntryRom = GetInfo(readStream, size: (long)zf.GetLocalFile(i).UncompressedSize, hashes: _hashTypes, keepReadOpen: true);
                    }

                    // Fill in common details and add to the list
                    zipEntryRom.Filename = zf.GetLocalFile(i).Filename;
                    zipEntryRom.Parent = gamename;
                    found.Add(zipEntryRom);
                }

                // Dispose of the archive
                zr = zf.ZipFileCloseReadStream();
                zf.ZipFileClose();
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
                return null;
            }

            return found;
        }

        /// <inheritdoc/>
        public override List<string> GetEmptyFolders()
        {
            List<string> empties = [];

            // If we have an invalid file
            if (Filename == null)
                return empties;

            try
            {
                var zf = new SevenZ();
                ZipReturn zr = zf.ZipFileOpen(Filename, -1, true);
                if (zr != ZipReturn.ZipGood)
                    throw new Exception(CompressUtils.ZipErrorMessageText(zr));

                List<(string, bool)> zipEntries = [];
                for (int i = 0; i < zf.LocalFilesCount(); i++)
                {
                    zipEntries.Add((zf.GetLocalFile(i).Filename!, zf.GetLocalFile(i).IsDirectory));
                }

                zipEntries = zipEntries.OrderBy(p => p.Item1, new NaturalReversedComparer()).ToList();
                string? lastZipEntry = null;
                foreach ((string, bool) entry in zipEntries)
                {
                    // If the current is a superset of last, we skip it
                    if (lastZipEntry != null && lastZipEntry.StartsWith(entry.Item1))
                    {
                        // No-op
                    }
                    // If the entry is a directory, we add it
                    else
                    {
                        if (entry.Item2)
                            empties.Add(entry.Item1);

                        lastZipEntry = entry.Item1;
                    }
                }
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
            }

            return empties;
        }

        /// <inheritdoc/>
        public override bool IsTorrent()
        {
            // If we have an invalid file
            if (Filename == null)
                return false;

            SevenZ zf = new();
            ZipReturn zr = zf.ZipFileOpen(Filename, -1, true);
            if (zr != ZipReturn.ZipGood)
                throw new Exception(CompressUtils.ZipErrorMessageText(zr));

            return zf.ZipStatus == ZipStatus.Trrnt7Zip;
        }

        #endregion

        #region Writing

        /// <inheritdoc/>
        public override bool Write(string inputFile, string outDir, BaseFile? baseFile)
        {
            // Get the file stream for the file and write out
            return Write(File.OpenRead(inputFile), outDir, baseFile);
        }

        /// <inheritdoc/>
        public override bool Write(Stream? inputStream, string outDir, BaseFile? baseFile)
        {
            bool success = false;
            string tempFile = Path.Combine(outDir, $"tmp{Guid.NewGuid()}");

            // If either input is null or empty, return
            if (inputStream == null || baseFile == null || baseFile.Filename == null)
                return success;

            // If the stream is not readable, return
            if (!inputStream.CanRead)
                return success;

            // Seek to the beginning of the stream
            if (inputStream.CanSeek)
                inputStream.Seek(0, SeekOrigin.Begin);

            // Get the output archive name from the first rebuild rom
            string archiveFileName = Path.Combine(outDir, TextHelper.RemovePathUnsafeCharacters(baseFile.Parent) + (baseFile.Parent?.EndsWith(".7z") ?? false ? string.Empty : ".7z"));

            // Set internal variables
            Stream? writeStream = null;
            SevenZ oldZipFile = new();
            SevenZ zipFile = new();
            ZipReturn zipReturn = ZipReturn.ZipGood;

            try
            {
                // If the full output path doesn't exist, create it
                if (!Directory.Exists(Path.GetDirectoryName(archiveFileName)))
                    Directory.CreateDirectory(Path.GetDirectoryName(archiveFileName)!);

                // If the archive doesn't exist, create it and put the single file
                if (!File.Exists(archiveFileName))
                {
                    if (inputStream.CanSeek)
                        inputStream.Seek(0, SeekOrigin.Begin);

                    zipReturn = zipFile.ZipFileCreate(tempFile);

                    // Open the input file for reading
                    ulong istreamSize = (ulong)(inputStream.Length);

                    DateTime dt = DateTime.Now;
                    if (UseDates && !string.IsNullOrEmpty(baseFile.Date) && DateTime.TryParse(baseFile.Date!.Replace('\\', '/'), out dt))
                    {
                        long msDosDateTime = DateTimeHelper.ConvertToMsDosTimeFormat(dt);
                        TimeStamps ts = new() { ModTime = msDosDateTime };
                        zipFile.ZipFileOpenWriteStream(false, false, baseFile.Filename.Replace('\\', '/'), istreamSize, 0, out writeStream, ts);
                    }
                    else
                    {
                        zipFile.ZipFileOpenWriteStream(false, true, baseFile.Filename.Replace('\\', '/'), istreamSize, 0, out writeStream, null);
                    }

                    // Copy the input stream to the output
                    if (writeStream != null)
                    {
                        byte[] ibuffer = new byte[_bufferSize];
                        int ilen;
                        while ((ilen = inputStream.Read(ibuffer, 0, _bufferSize)) > 0)
                        {
                            writeStream.Write(ibuffer, 0, ilen);
                            writeStream.Flush();
                        }
                    }

                    zipFile.ZipFileCloseWriteStream(baseFile.CRC!);
                }

                // Otherwise, sort the input files and write out in the correct order
                else
                {
                    // Open the old archive for reading
                    oldZipFile.ZipFileOpen(archiveFileName, -1, true);

                    // Map all inputs to index
                    Dictionary<string, int> inputIndexMap = [];
                    List<string> oldZipFileContents = [];
                    for (int i = 0; i < oldZipFile.LocalFilesCount(); i++)
                    {
                        oldZipFileContents.Add(oldZipFile.GetLocalFile(i).Filename!);
                    }

                    // If the old one doesn't contain the new file, then add it
                    if (!oldZipFileContents.Contains(baseFile.Filename.Replace('\\', '/')))
                        inputIndexMap.Add(baseFile.Filename.Replace('\\', '/'), -1);

                    // Then add all of the old entries to it too
                    for (int i = 0; i < oldZipFile.LocalFilesCount(); i++)
                    {
                        inputIndexMap.Add(oldZipFile.GetLocalFile(i).Filename!, i);
                    }

                    // If the number of entries is the same as the old archive, skip out
                    if (inputIndexMap.Keys.Count <= oldZipFile.LocalFilesCount())
                    {
                        success = true;
                        return success;
                    }

                    // Otherwise, process the old zipfile
                    zipFile.ZipFileCreate(tempFile);

                    // Get the order for the entries with the new file
                    List<string> keys = [.. inputIndexMap.Keys];
                    keys.Sort(CompressUtils.TrrntZipStringCompare);

                    // Copy over all files to the new archive
                    foreach (string key in keys)
                    {
                        // Get the index mapped to the key
                        int index = inputIndexMap[key];

                        // If we have the input file, add it now
                        if (index < 0)
                        {
                            // Open the input file for reading
                            ulong istreamSize = (ulong)(inputStream.Length);

                            DateTime dt = DateTime.Now;
                            if (UseDates && !string.IsNullOrEmpty(baseFile.Date) && DateTime.TryParse(baseFile.Date!.Replace('\\', '/'), out dt))
                            {
                                long msDosDateTime = DateTimeHelper.ConvertToMsDosTimeFormat(dt);
                                TimeStamps ts = new() { ModTime = msDosDateTime };
                                zipFile.ZipFileOpenWriteStream(false, false, baseFile.Filename.Replace('\\', '/'), istreamSize, 0, out writeStream, ts);
                            }
                            else
                            {
                                zipFile.ZipFileOpenWriteStream(false, true, baseFile.Filename.Replace('\\', '/'), istreamSize, 0, out writeStream, null);
                            }

                            // Copy the input stream to the output
                            if (writeStream != null)
                            {
                                byte[] ibuffer = new byte[_bufferSize];
                                int ilen;
                                while ((ilen = inputStream.Read(ibuffer, 0, _bufferSize)) > 0)
                                {
                                    writeStream.Write(ibuffer, 0, ilen);
                                    writeStream.Flush();
                                }
                            }

                            zipFile.ZipFileCloseWriteStream(baseFile.CRC!);
                        }

                        // Otherwise, copy the file from the old archive
                        else
                        {
                            // Instantiate the streams
                            oldZipFile.ZipFileOpenReadStream(index, out Stream? zreadStream, out ulong istreamSize);
                            zipFile.ZipFileOpenWriteStream(false, true, oldZipFile.GetLocalFile(index).Filename!, istreamSize, 0, out writeStream, null);

                            // Copy the input stream to the output
                            if (writeStream != null)
                            {
                                byte[] ibuffer = new byte[_bufferSize];
                                int ilen;
                                while ((ilen = zreadStream!.Read(ibuffer, 0, _bufferSize)) > 0)
                                {
                                    writeStream.Write(ibuffer, 0, ilen);
                                    writeStream.Flush();
                                }
                            }

                            oldZipFile.ZipFileCloseReadStream();
                            zipFile.ZipFileCloseWriteStream(oldZipFile.GetLocalFile(index).CRC!);
                        }
                    }
                }

                // Close the output zip file
                zipFile.ZipFileClose();
                oldZipFile.ZipFileClose();

                success = true;
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
                success = false;
            }
            finally
            {
            }

            // If the old file exists, delete it and replace
            if (File.Exists(archiveFileName))
                File.Delete(archiveFileName);

            File.Move(tempFile, archiveFileName);

            return true;
        }

        /// <inheritdoc/>
        public override bool Write(List<string> inputFiles, string outDir, List<BaseFile>? baseFiles)
        {
            bool success = false;
            string tempFile = Path.Combine(outDir, $"tmp{Guid.NewGuid()}");

            // If either list of roms is null or empty, return
            if (inputFiles == null || baseFiles == null || inputFiles.Count == 0 || baseFiles.Count == 0)
                return false;

            // If the number of inputs is less than the number of available roms, return
            if (inputFiles.Count < baseFiles.Count)
                return false;

            // If one of the files doesn't exist, return
            foreach (string file in inputFiles)
            {
                if (!File.Exists(file))
                    return false;
            }

            // Get the output archive name from the first rebuild rom
            string archiveFileName = Path.Combine(outDir, TextHelper.RemovePathUnsafeCharacters(baseFiles[0].Parent) + (baseFiles[0].Parent?.EndsWith(".7z") ?? false ? string.Empty : ".7z"));

            // Set internal variables
            Stream? writeStream = null;
            SevenZ oldZipFile = new();
            SevenZ zipFile = new();
            ZipReturn zipReturn = ZipReturn.ZipGood;

            try
            {
                // If the full output path doesn't exist, create it
                if (!Directory.Exists(Path.GetDirectoryName(archiveFileName)))
                    Directory.CreateDirectory(Path.GetDirectoryName(archiveFileName)!);

                // If the archive doesn't exist, create it and put the single file
                if (!File.Exists(archiveFileName))
                {
                    zipReturn = zipFile.ZipFileCreate(tempFile);

                    // Map all inputs to index
                    Dictionary<string, int> inputIndexMap = [];
                    for (int i = 0; i < inputFiles.Count; i++)
                    {
                        inputIndexMap.Add(baseFiles[i]?.Filename?.Replace('\\', '/') ?? string.Empty, i);
                    }

                    // Sort the keys in TZIP order
                    List<string> keys = [.. inputIndexMap.Keys];
                    keys.Sort(CompressUtils.TrrntZipStringCompare);

                    // Now add all of the files in order
                    foreach (string key in keys)
                    {
                        // Get the index mapped to the key
                        int index = inputIndexMap[key];

                        // Open the input file for reading
                        Stream freadStream = File.OpenRead(inputFiles[index]);
                        ulong istreamSize = (ulong)new FileInfo(inputFiles[index]).Length;

                        DateTime dt = DateTime.Now;
                        if (UseDates && !string.IsNullOrEmpty(baseFiles[index].Date) && DateTime.TryParse(baseFiles[index].Date?.Replace('\\', '/'), out dt))
                        {
                            long msDosDateTime = DateTimeHelper.ConvertToMsDosTimeFormat(dt);
                            TimeStamps ts = new() { ModTime = msDosDateTime };
                            zipFile.ZipFileOpenWriteStream(false, false, baseFiles[index].Filename!.Replace('\\', '/')!, istreamSize, 0, out writeStream, ts);
                        }
                        else
                        {
                            zipFile.ZipFileOpenWriteStream(false, true, baseFiles[index].Filename!.Replace('\\', '/'), istreamSize, 0, out writeStream, null);
                        }

                        // Copy the input stream to the output
                        byte[] ibuffer = new byte[_bufferSize];
                        int ilen;
                        while ((ilen = freadStream.Read(ibuffer, 0, _bufferSize)) > 0)
                        {
                            writeStream!.Write(ibuffer, 0, ilen);
                            writeStream.Flush();
                        }

                        freadStream.Dispose();
                        zipFile.ZipFileCloseWriteStream(baseFiles[index].CRC!);
                    }
                }

                // Otherwise, sort the input files and write out in the correct order
                else
                {
                    // Open the old archive for reading
                    oldZipFile.ZipFileOpen(archiveFileName, -1, true);

                    // Map all inputs to index
                    Dictionary<string, int> inputIndexMap = new();
                    for (int i = 0; i < inputFiles.Count; i++)
                    {
                        List<string> oldZipFileContents = [];
                        for (int j = 0; j < oldZipFile.LocalFilesCount(); j++)
                        {
                            oldZipFileContents.Add(oldZipFile.GetLocalFile(j).Filename!);
                        }

                        // If the old one contains the new file, then just skip out
                        if (oldZipFileContents.Contains(baseFiles[i].Filename!.Replace('\\', '/')))
                            continue;

                        inputIndexMap.Add(baseFiles[i].Filename!.Replace('\\', '/'), -(i + 1));
                    }

                    // Then add all of the old entries to it too
                    for (int i = 0; i < oldZipFile.LocalFilesCount(); i++)
                    {
                        inputIndexMap.Add(oldZipFile.GetLocalFile(i).Filename!, i);
                    }

                    // If the number of entries is the same as the old archive, skip out
                    if (inputIndexMap.Keys.Count <= oldZipFile.LocalFilesCount())
                    {
                        success = true;
                        return success;
                    }

                    // Otherwise, process the old zipfile
                    zipFile.ZipFileCreate(tempFile);

                    // Get the order for the entries with the new file
                    List<string> keys = [.. inputIndexMap.Keys];
                    keys.Sort(CompressUtils.TrrntZipStringCompare);

                    // Copy over all files to the new archive
                    foreach (string key in keys)
                    {
                        // Get the index mapped to the key
                        int index = inputIndexMap[key];

                        // If we have the input file, add it now
                        if (index < 0)
                        {
                            // Open the input file for reading
                            Stream freadStream = File.OpenRead(inputFiles[-index - 1]);
                            ulong istreamSize = (ulong)(new FileInfo(inputFiles[-index - 1]).Length);

                            DateTime dt = DateTime.Now;
                            if (UseDates && !string.IsNullOrEmpty(baseFiles[-index - 1].Date) && DateTime.TryParse(baseFiles[-index - 1].Date?.Replace('\\', '/'), out dt))
                            {
                                long msDosDateTime = DateTimeHelper.ConvertToMsDosTimeFormat(dt);
                                TimeStamps ts = new() { ModTime = msDosDateTime };
                                zipFile.ZipFileOpenWriteStream(false, false, baseFiles[-index - 1].Filename!.Replace('\\', '/'), istreamSize, 0, out writeStream, ts);
                            }
                            else
                            {
                                zipFile.ZipFileOpenWriteStream(false, true, baseFiles[-index - 1].Filename!.Replace('\\', '/'), istreamSize, 0, out writeStream, null);
                            }

                            // Copy the input stream to the output
                            byte[] ibuffer = new byte[_bufferSize];
                            int ilen;
                            while ((ilen = freadStream.Read(ibuffer, 0, _bufferSize)) > 0)
                            {
                                writeStream!.Write(ibuffer, 0, ilen);
                                writeStream.Flush();
                            }

                            freadStream.Dispose();
                            zipFile.ZipFileCloseWriteStream(baseFiles[-index - 1].CRC!);
                        }

                        // Otherwise, copy the file from the old archive
                        else
                        {
                            // Instantiate the streams
                            oldZipFile.ZipFileOpenReadStream(index, out Stream? zreadStream, out ulong istreamSize);
                            zipFile.ZipFileOpenWriteStream(false, true, oldZipFile.GetLocalFile(index).Filename!, istreamSize, 0, out writeStream, null);

                            // Copy the input stream to the output
                            byte[] ibuffer = new byte[_bufferSize];
                            int ilen;
                            while ((ilen = zreadStream!.Read(ibuffer, 0, _bufferSize)) > 0)
                            {
                                writeStream!.Write(ibuffer, 0, ilen);
                                writeStream.Flush();
                            }

                            zipFile.ZipFileCloseWriteStream(oldZipFile.GetLocalFile(index).CRC!);
                        }
                    }
                }

                // Close the output zip file
                zipFile.ZipFileClose();
                oldZipFile.ZipFileClose();

                success = true;
            }
            catch (Exception ex)
            {
                _logger.Error(ex);
                success = false;
            }

            // If the old file exists, delete it and replace
            if (File.Exists(archiveFileName))
                File.Delete(archiveFileName);

            File.Move(tempFile, archiveFileName);

            return true;
        }

        #endregion
    }
}