Nanook.QueenBee.Parser.PakEditor.createBlankFile C# (CSharp) Method

        private PakHeaderItem createBlankFile(string newQbFilename, QbKey itemType, bool filenameInHeader)
        {
            //update the filename in the collection
            List<PakHeaderItem> hd = new List<PakHeaderItem>(_pakHeaders.Values);

            PakHeaderItem newHdr = new PakHeaderItem();
            newHdr.FileLength = 0; // (uint)(new FileInfo(localFilename)).Length;
            newHdr.FileOffset = hd[0].FileOffset + (uint)(filenameInHeader ? PakHeaderItem.FullHeaderLength : 0x20);
            newHdr.Flags = (PakHeaderFlags)(filenameInHeader ? PakHeaderFlags.Filename : 0);
            newHdr.HeaderStart = 0;
            newHdr.IsStoredInPak = true;
            newHdr.Filename = newQbFilename;
            newHdr.FileType = itemType;
            hd.Insert(0, newHdr);

            //update the filename in the collection
            bool pastNew = false;
            Dictionary<string, PakHeaderItem> p = new Dictionary<string, PakHeaderItem>(_pakHeaders.Count);

            bool hasFoundMatch = filenameInHeader;

            foreach (PakHeaderItem ph in hd)
            {
                //small hack to determine which items need to be filled - Find another header with
                if (!hasFoundMatch && ((ph.Flags & PakHeaderFlags.Filename) != PakHeaderFlags.Filename) && ph != newHdr)
                {
                    newHdr.SetFilename(newQbFilename, itemType, _pakFormat.FileExtension, ph);
                    hasFoundMatch = true;
                }

                if (pastNew)
                    ph.HeaderStart += (uint)(filenameInHeader ? PakHeaderItem.FullHeaderLength : 0x20);
                else if (ph != newHdr)
                    ph.FileOffset += (uint)(filenameInHeader ? PakHeaderItem.FullHeaderLength : 0x20);
                else // (ph == newHdr)
                    pastNew = true;

                p.Add(ph.Filename.ToLower(), ph);
            }

            if (!hasFoundMatch)
                newHdr.SetFilename(newQbFilename, itemType, _pakFormat.FileExtension, null);

            _pakFileLength += (uint)(filenameInHeader ? PakHeaderItem.FullHeaderLength : PakHeaderItem.FullHeaderLength - PakHeaderItem.FileNameMaxLength);

            _pakHeaders = p;

            string newPakFilename = string.Format("{0}_{1}", _pakFilename, Guid.NewGuid().ToString("N"));
            using (FileStream fsO = File.Open(newPakFilename, FileMode.CreateNew))
            {
                using (BinaryEndianWriter bw = new BinaryEndianWriter(fsO))
                {
                    writeHeaderItem(bw, newHdr);
                    using (FileStream fsI = File.OpenRead(_pakFilename))
                        copyData(fsI, fsO, new FileInfo(_pakFilename).Length);
                }
            }

            File.Delete(_pakFilename);
            File.Move(newPakFilename, _pakFilename);

            return newHdr;
        }