From 8339dc12642776552238786138a754030d957e9c Mon Sep 17 00:00:00 2001
From: Matt Nadareski <mnadareski@outlook.com>
Date: Wed, 24 Aug 2016 16:29:49 -0700
Subject: [PATCH] [ArchiveTools] V1 of TGZ write (untested, unused)

---
 SabreTools.Helper/Tools/ArchiveTools.cs | 91 +++++++++++++++++++++++++
 1 file changed, 91 insertions(+)

diff --git a/SabreTools.Helper/Tools/ArchiveTools.cs b/SabreTools.Helper/Tools/ArchiveTools.cs
index f7cf1711..9df4699d 100644
--- a/SabreTools.Helper/Tools/ArchiveTools.cs
+++ b/SabreTools.Helper/Tools/ArchiveTools.cs
@@ -569,6 +569,85 @@ namespace SabreTools.Helper
 			return rom;
 		}
 
+		/// <summary>
+		/// Write an input file to a torrent GZ file
+		/// </summary>
+		/// <param name="input">File to write from</param>
+		/// <param name="outdir">Directory to write archive to</param>
+		/// <param name="logger">Logger object for file and console output</param>
+		/// <returns>True if the write was a success, false otherwise</returns>
+		public static bool WriteTorrentGZ(string input, string outdir, Logger logger)
+		{
+			// Check that the input file exists
+			if (!File.Exists(input))
+			{
+				logger.Warning("File " + input + " does not exist!");
+				return false;
+			}
+			input = Path.GetFullPath(input);
+
+			// Make sure the output directory exists
+			if (!Directory.Exists(outdir))
+			{
+				Directory.CreateDirectory(outdir);
+			}
+			outdir = Path.GetFullPath(outdir);
+
+			// Now get the Rom info for the file so we have hashes and size
+			Rom rom = RomTools.GetSingleFileInfo(input);
+
+			// Now, check to make sure the output file doesn't already exist
+			string outfile = Path.Combine(outdir, rom.SHA1 + ".gz");
+			if (File.Exists(outfile))
+			{
+				return true;
+			}
+
+			// Rename the input file based on the SHA-1
+			string tempname = Path.Combine(Path.GetDirectoryName(input), rom.SHA1);
+			File.Move(input, tempname);
+
+			// If it doesn't exist, create the output file and then write
+			using (FileStream inputstream = new FileStream(tempname, FileMode.Open))
+			using (GZipStream output = new GZipStream(File.OpenWrite(outfile), CompressionMode.Compress))
+			{
+				inputstream.CopyTo(output);
+			}
+
+			// Name the original input file correctly again
+			File.Move(tempname, input);
+
+			// Now that it's renamed, inject the header info
+			using (BinaryReader br = new BinaryReader(File.Open(outfile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)))
+			using (BinaryWriter bw = new BinaryWriter(File.Open(outfile, FileMode.Open, FileAccess.Write, FileShare.ReadWrite)))
+			using (StreamWriter sw = new StreamWriter(new MemoryStream()))
+			{
+				// Copy the first part of the file to the memory stream
+				sw.Write(br.ReadBytes(3)); //0x1F (ID1), 0x8B (ID2), 0x08 (Compression method - Deflate)
+
+				// Now write TGZ info
+				byte[] data = new byte[] { 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1c, 0x0 } // Flags with FEXTRA set (1), MTIME (4), XFLAG (1), OS (1), FEXTRA-LEN (2, Mirrored)
+								.Concat(StringToByteArray(rom.MD5)) // MD5
+								.Concat(StringToByteArray(rom.CRC)) // CRC
+								.Concat(BitConverter.GetBytes(rom.Size).Reverse().ToArray()) // Long size (Mirrored)
+							.ToArray();
+				sw.Write(data);
+
+				// Finally, copy the rest of the data from the original file
+				br.BaseStream.Seek(10, SeekOrigin.Begin);
+				while (br.BaseStream.Position < br.BaseStream.Length)
+				{
+					sw.Write(br.ReadByte());
+				}
+
+				// Now write the new file over the original
+				sw.BaseStream.Seek(0, SeekOrigin.Begin);
+				sw.BaseStream.CopyTo(bw.BaseStream);
+			}
+
+			return true;
+		}
+
 		/// <summary>
 		/// Returns the archive type of an input file
 		/// </summary>
@@ -634,5 +713,17 @@ namespace SabreTools.Helper
 
 			return outtype;
 		}
+
+		/// <summary>
+		/// http://stackoverflow.com/questions/311165/how-do-you-convert-byte-array-to-hexadecimal-string-and-vice-versa
+		/// </summary>
+		public static byte[] StringToByteArray(String hex)
+		{
+			int NumberChars = hex.Length;
+			byte[] bytes = new byte[NumberChars / 2];
+			for (int i = 0; i < NumberChars; i += 2)
+				bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
+			return bytes;
+		}
 	}
 }