using System;
using System.Collections.Generic;
using System.Linq;

using SabreTools.Library.Data;
using SabreTools.Library.DatItems;
using SabreTools.Library.Tools;

#if MONO
using System.IO;
#else
using Alphaleonis.Win32.Filesystem;

using BinaryWriter = System.IO.BinaryWriter;
using EndOfStreamException = System.IO.EndOfStreamException;
using FileStream = System.IO.FileStream;
using MemoryStream = System.IO.MemoryStream;
using SeekOrigin = System.IO.SeekOrigin;
using Stream = System.IO.Stream;
#endif
using ROMVault2.SupportedFiles.Zip;
using SevenZip;
using SharpCompress.Archives;
using SharpCompress.Archives.SevenZip;
using SharpCompress.Common;
using SharpCompress.Readers;

namespace SabreTools.Library.FileTypes
{
	/// <summary>
	/// Represents a Torrent7zip archive for reading and writing
	/// </summary>
	/// TODO: Torrent 7-zip: https://sourceforge.net/p/t7z/code/HEAD/tree/
	public class SevenZipArchive : BaseArchive
	{
		#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)
		{
			_archiveType = ArchiveType.SevenZip;
		}

		#endregion

		#region Extraction

		/// <summary>
		/// Attempt to extract a file as an archive
		/// </summary>
		/// <param name="outDir">Output directory for archive extraction</param>
		/// <returns>True if the extraction was a success, false otherwise</returns>
		public override bool ExtractAll(string outDir)
		{
			bool encounteredErrors = true;

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

				// Extract all files to the temp directory
				SharpCompress.Archives.SevenZip.SevenZipArchive sza = SharpCompress.Archives.SevenZip.SevenZipArchive.Open(Utilities.TryOpenRead(_filename));
				foreach (SevenZipArchiveEntry entry in sza.Entries)
				{
					entry.WriteToDirectory(outDir, new ExtractionOptions { PreserveFileTime = true, ExtractFullPath = true, Overwrite = true });
				}
				encounteredErrors = false;
				sza.Dispose();
			}
			catch (EndOfStreamException)
			{
				// Catch this but don't count it as an error because SharpCompress is unsafe
			}
			catch (InvalidOperationException)
			{
				encounteredErrors = true;
			}
			catch (Exception)
			{
				// Don't log file open errors
				encounteredErrors = true;
			}

			return encounteredErrors;
		}

		/// <summary>
		/// Attempt to extract a file from an archive
		/// </summary>
		/// <param name="entryName">Name of the entry to be extracted</param>
		/// <param name="outDir">Output directory for archive extraction</param>
		/// <returns>Name of the extracted file, null on error</returns>
		public override string ExtractEntry(string entryName, string outDir)
		{
			// Try to extract a stream using the given information
			(MemoryStream ms, string realEntry) = ExtractEntryStream(entryName);

			// If the memory stream and the entry name are both non-null, we write to file
			if (ms != null && realEntry != null)
			{
				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 = Utilities.TryCreate(realEntry);
				if (fs != null)
				{
					ms.Seek(0, SeekOrigin.Begin);
					byte[] zbuffer = new byte[_bufferSize];
					int zlen;
					while ((zlen = ms.Read(zbuffer, 0, _bufferSize)) > 0)
					{
						fs.Write(zbuffer, 0, zlen);
						fs.Flush();
					}

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

			return realEntry;
		}

		/// <summary>
		/// Attempt to extract a stream from an archive
		/// </summary>
		/// <param name="entryName">Name of the entry to be extracted</param>
		/// <param name="realEntry">Output representing the entry name that was found</param>
		/// <returns>MemoryStream representing the entry, null on error</returns>
		public override (MemoryStream, string) ExtractEntryStream(string entryName)
		{
			MemoryStream ms = new MemoryStream();
			string realEntry = null;

			try
			{
				SharpCompress.Archives.SevenZip.SevenZipArchive sza = SharpCompress.Archives.SevenZip.SevenZipArchive.Open(_filename, new ReaderOptions { LeaveStreamOpen = false, });
				foreach (SevenZipArchiveEntry entry in sza.Entries)
				{
					if (entry != null && !entry.IsDirectory && entry.Key.Contains(entryName))
					{
						// Write the file out
						realEntry = entry.Key;
						entry.WriteTo(ms);
						break;
					}
				}
				sza.Dispose();
			}
			catch (Exception ex)
			{
				Globals.Logger.Error(ex.ToString());
				ms = null;
				realEntry = null;
			}

			return (ms, realEntry);
		}

		#endregion

		#region Information

		/// <summary>
		/// Generate a list of DatItem objects from the header values in an archive
		/// </summary>
		/// <param name="omitFromScan">Hash representing the hashes that should be skipped</param>
		/// <param name="date">True if entry dates should be included, false otherwise (default)</param>
		/// <returns>List of DatItem objects representing the found data</returns>
		/// <remarks>TODO: All instances of Hash.DeepHashes should be made into 0x0 eventually</remarks>
		public override List<Rom> GetArchiveFileInfo(Hash omitFromScan = Hash.DeepHashes, bool date = false)
		{
			List<Rom> found = new List<Rom>();
			string gamename = Path.GetFileNameWithoutExtension(_filename);

			try
			{
				SharpCompress.Archives.SevenZip.SevenZipArchive sza = SharpCompress.Archives.SevenZip.SevenZipArchive.Open(Utilities.TryOpenRead(_filename));
				foreach (SevenZipArchiveEntry entry in sza.Entries.Where(e => e != null && !e.IsDirectory))
				{
					// If secure hashes are disabled, do a quickscan
					if (omitFromScan == Hash.SecureHashes)
					{
						found.Add(new Rom
						{
							Type = ItemType.Rom,
							Name = entry.Key,
							Size = entry.Size,
							CRC = entry.Crc.ToString("X").ToLowerInvariant(),
							Date = (date && entry.LastModifiedTime != null ? entry.LastModifiedTime?.ToString("yyyy/MM/dd hh:mm:ss") : null),

							MachineName = gamename,
						});
					}
					// Otherwise, use the stream directly
					else
					{
						Stream entryStream = entry.OpenEntryStream();
						Rom sevenZipEntryRom = (Rom)Utilities.GetStreamInfo(entryStream, entry.Size, omitFromScan: omitFromScan);
						sevenZipEntryRom.Name = entry.Key;
						sevenZipEntryRom.MachineName = gamename;
						sevenZipEntryRom.Date = (date && entry.LastModifiedTime != null ? entry.LastModifiedTime?.ToString("yyyy/MM/dd hh:mm:ss") : null);
						found.Add(sevenZipEntryRom);
						entryStream.Dispose();
					}
				}

				// Dispose of the archive
				sza.Dispose();
			}
			catch (Exception)
			{
				// Don't log file open errors
				return null;
			}

			return found;
		}

		/// <summary>
		/// Generate a list of empty folders in an archive
		/// </summary>
		/// <param name="input">Input file to get data from</param>
		/// <returns>List of empty folders in the archive</returns>
		public override List<string> GetEmptyFolders()
		{
			List<string> empties = new List<string>();

			try
			{
				SharpCompress.Archives.SevenZip.SevenZipArchive sza = SharpCompress.Archives.SevenZip.SevenZipArchive.Open(_filename, new ReaderOptions { LeaveStreamOpen = false });
				List<SevenZipArchiveEntry> sevenZipEntries = sza.Entries.OrderBy(e => e.Key, new NaturalSort.NaturalReversedComparer()).ToList();
				string lastSevenZipEntry = null;
				foreach (SevenZipArchiveEntry entry in sevenZipEntries)
				{
					if (entry != null)
					{
						// If the current is a superset of last, we skip it
						if (lastSevenZipEntry != null && lastSevenZipEntry.StartsWith(entry.Key))
						{
							// No-op
						}
						// If the entry is a directory, we add it
						else if (entry.IsDirectory)
						{
							empties.Add(entry.Key);
							lastSevenZipEntry = entry.Key;
						}
					}
				}
			}
			catch (Exception ex)
			{
				Globals.Logger.Error(ex.ToString());
			}

			return empties;
		}

		/// <summary>
		/// Check whether the input file is a standardized format
		/// </summary>
		/// TODO: Finish reading T7z information
		public override bool IsTorrent()
		{
			bool ist7z = false;

			if (File.Exists(_filename))
			{
				try
				{
					Stream fread = Utilities.TryOpenRead(_filename);
					uint ar, offs = 0;
					fread.Seek(0, SeekOrigin.Begin);
					byte[] buffer = new byte[128];
					ar = (uint)fread.Read(buffer, 0, 4 + Constants.Torrent7ZipSignature.Length + 4);
					if (ar < (4 + Constants.Torrent7ZipSignature.Length + 4))
					{
						if (ar >= Constants.Torrent7ZipSignature.Length + 4)
						{
							ar -= (uint)(Constants.Torrent7ZipSignature.Length + 4);
						}
						if (ar <= Constants.Torrent7ZipHeader.Length)
						{
							ar = (uint)Constants.Torrent7ZipHeader.Length;
						}
						// memset(buffer+offs+ar,0,crcsz-ar)
					}

					fread.Dispose();
				}
				catch
				{
					Globals.Logger.Warning("File '{0}' could not be opened", _filename);
					ist7z = false;
				}
			}

			return ist7z;
		}

		#endregion

		#region Writing

		/// <summary>
		/// Write an input file to a torrent7z archive
		/// </summary>
		/// <param name="inputFile">Input filename to be moved</param>
		/// <param name="outDir">Output directory to build to</param>
		/// <param name="rom">DatItem representing the new information</param>
		/// <param name="date">True if the date from the DAT should be used if available, false otherwise (default)</param>
		/// <param name="romba">True if files should be output in Romba depot folders, false otherwise</param>
		/// <returns>True if the archive was written properly, false otherwise</returns>
		public override bool Write(string inputFile, string outDir, Rom rom, bool date = false, bool romba = false)
		{
			// Get the file stream for the file and write out
			return Write(Utilities.TryOpenRead(inputFile), outDir, rom, date: date);
		}

		/// <summary>
		/// Write an input file to a torrent7z archive
		/// </summary>
		/// <param name="inputStream">Input stream to be moved</param>
		/// <param name="outDir">Output directory to build to</param>
		/// <param name="rom">DatItem representing the new information</param>
		/// <param name="date">True if the date from the DAT should be used if available, false otherwise (default)</param>
		/// <param name="romba">True if files should be output in Romba depot folders, false otherwise</param>
		/// <returns>True if the archive was written properly, false otherwise</returns>
		public override bool Write(Stream inputStream, string outDir, Rom rom, bool date = false, bool romba = false)
		{
			bool success = false;
			string tempFile = Path.Combine(outDir, "tmp" + Guid.NewGuid().ToString());

			// If either input is null or empty, return
			if (inputStream == null || rom == null || rom.Name == null)
			{
				return success;
			}

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

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

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

			// Set internal variables
			SevenZipBase.SetLibraryPath("7za.dll");
			SevenZipExtractor oldZipFile = null;
			SevenZipCompressor zipFile;

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

				// If the archive doesn't exist, create it and put the single file
				if (!File.Exists(archiveFileName))
				{
					zipFile = new SevenZipCompressor()
					{
						ArchiveFormat = OutArchiveFormat.SevenZip,
						CompressionLevel = CompressionLevel.Normal,
					};

					// Create the temp directory
					string tempPath = Path.Combine(Path.GetTempPath(), new Guid().ToString());
					if (!Directory.Exists(tempPath))
					{
						Directory.CreateDirectory(tempPath);
					}

					// Create a stream dictionary
					Dictionary<string, Stream> dict = new Dictionary<string, Stream>();
					dict.Add(rom.Name, inputStream);

					// Now add the stream
					zipFile.CompressStreamDictionary(dict, tempFile);
				}

				// Otherwise, sort the input files and write out in the correct order
				else
				{
					// Open the old archive for reading
					using (oldZipFile = new SevenZipExtractor(archiveFileName))
					{
						// Map all inputs to index
						Dictionary<string, int> inputIndexMap = new Dictionary<string, int>();

						// If the old one doesn't contain the new file, then add it
						if (!oldZipFile.ArchiveFileNames.Contains(rom.Name.Replace('\\', '/')))
						{
							inputIndexMap.Add(rom.Name.Replace('\\', '/'), -1);
						}

						// Then add all of the old entries to it too
						for (int i = 0; i < oldZipFile.FilesCount; i++)
						{
							inputIndexMap.Add(oldZipFile.ArchiveFileNames[i], i);
						}

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

						// Otherwise, process the old zipfile
						zipFile = new SevenZipCompressor()
						{
							ArchiveFormat = OutArchiveFormat.SevenZip,
							CompressionLevel = CompressionLevel.Normal,
						};

						// Get the order for the entries with the new file
						List<string> keys = inputIndexMap.Keys.ToList();
						keys.Sort(ZipFile.TorrentZipStringCompare);

						// 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)
							{
								// Create a stream dictionary
								Dictionary<string, Stream> dict = new Dictionary<string, Stream>();
								dict.Add(rom.Name, inputStream);

								// Now add the stream
								zipFile.CompressStreamDictionary(dict, tempFile);
							}

							// Otherwise, copy the file from the old archive
							else
							{
								Stream oldZipFileEntryStream = new MemoryStream();
								oldZipFile.ExtractFile(index, oldZipFileEntryStream);
								oldZipFileEntryStream.Seek(0, SeekOrigin.Begin);

								// Create a stream dictionary
								Dictionary<string, Stream> dict = new Dictionary<string, Stream>();
								dict.Add(oldZipFile.ArchiveFileNames[index], oldZipFileEntryStream);

								// Now add the stream
								zipFile.CompressStreamDictionary(dict, tempFile);
								oldZipFileEntryStream.Dispose();
							}

							// After the first file, make sure we're in append mode
							zipFile.CompressionMode = CompressionMode.Append;
						}
					}
				}

				success = true;
			}
			catch (Exception ex)
			{
				Console.WriteLine(ex);
				success = false;
			}
			finally
			{
				inputStream?.Dispose();
			}

			// If the old file exists, delete it and replace
			if (File.Exists(archiveFileName))
			{
				Utilities.TryDeleteFile(archiveFileName);
			}
			File.Move(tempFile, archiveFileName);

			// Now make the file T7Z
			// TODO: Add ACTUAL T7Z compatible code

			BinaryWriter bw = new BinaryWriter(Utilities.TryOpenReadWrite(archiveFileName));
			bw.Seek(0, SeekOrigin.Begin);
			bw.Write(Constants.Torrent7ZipHeader);
			bw.Seek(0, SeekOrigin.End);

			using (oldZipFile = new SevenZipExtractor(Utilities.TryOpenReadWrite(archiveFileName)))
			{

				// Get the correct signature to use (Default 0, Unicode 1, SingleFile 2, StripFileNames 4)
				byte[] tempsig = Constants.Torrent7ZipSignature;
				if (oldZipFile.FilesCount > 1)
				{
					tempsig[16] = 0x2;
				}
				else
				{
					tempsig[16] = 0;
				}

				bw.Write(tempsig);
				bw.Flush();
				bw.Dispose();
			}

			return true;
		}

		/// <summary>
		/// Write a set of input files to a torrent7z archive (assuming the same output archive name)
		/// </summary>
		/// <param name="inputFiles">Input files to be moved</param>
		/// <param name="outDir">Output directory to build to</param>
		/// <param name="rom">DatItem representing the new information</param>
		/// <param name="date">True if the date from the DAT should be used if available, false otherwise (default)</param>
		/// <param name="romba">True if files should be output in Romba depot folders, false otherwise</param>
		/// <returns>True if the archive was written properly, false otherwise</returns>
		public override bool Write(List<string> inputFiles, string outDir, List<Rom> roms, bool date = false, bool romba = false)
		{
			bool success = false;
			string tempFile = Path.Combine(outDir, "tmp" + Guid.NewGuid().ToString());

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

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

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

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

			// Set internal variables
			SevenZipBase.SetLibraryPath("7za.dll");
			SevenZipExtractor oldZipFile;
			SevenZipCompressor zipFile;

			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))
				{
					zipFile = new SevenZipCompressor()
					{
						ArchiveFormat = OutArchiveFormat.SevenZip,
						CompressionLevel = CompressionLevel.Normal,
					};

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

					// Sort the keys in TZIP order
					List<string> keys = inputIndexMap.Keys.ToList();
					keys.Sort(ZipFile.TorrentZipStringCompare);

					// Create the temp directory
					string tempPath = Path.Combine(Path.GetTempPath(), new Guid().ToString());
					if (!Directory.Exists(tempPath))
					{
						Directory.CreateDirectory(tempPath);
					}

					// Now add all of the files in order
					foreach (string key in keys)
					{
						string newkey = Path.Combine(tempPath, key);

						File.Move(inputFiles[inputIndexMap[key]], newkey);
						zipFile.CompressFiles(tempFile, newkey);
						File.Move(newkey, inputFiles[inputIndexMap[key]]);

						// After the first file, make sure we're in append mode
						zipFile.CompressionMode = CompressionMode.Append;
					}

					Utilities.CleanDirectory(tempPath);
					Utilities.TryDeleteDirectory(tempPath);
				}

				// Otherwise, sort the input files and write out in the correct order
				else
				{
					// Open the old archive for reading
					using (oldZipFile = new SevenZipExtractor(archiveFileName))
					{
						// Map all inputs to index
						Dictionary<string, int> inputIndexMap = new Dictionary<string, int>();
						for (int i = 0; i < inputFiles.Count; i++)
						{
							// If the old one contains the new file, then just skip out
							if (oldZipFile.ArchiveFileNames.Contains(roms[i].Name.Replace('\\', '/')))
							{
								continue;
							}

							inputIndexMap.Add(roms[i].Name.Replace('\\', '/'), -(i + 1));
						}

						// Then add all of the old entries to it too
						for (int i = 0; i < oldZipFile.FilesCount; i++)
						{
							inputIndexMap.Add(oldZipFile.ArchiveFileNames[i], i);
						}

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

						// Otherwise, process the old zipfile
						zipFile = new SevenZipCompressor()
						{
							ArchiveFormat = OutArchiveFormat.SevenZip,
							CompressionLevel = CompressionLevel.Normal,
						};

						// Get the order for the entries with the new file
						List<string> keys = inputIndexMap.Keys.ToList();
						keys.Sort(ZipFile.TorrentZipStringCompare);

						// 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)
							{
								FileStream inputStream = Utilities.TryOpenRead(inputFiles[-index - 1]);

								// Create a stream dictionary
								Dictionary<string, Stream> dict = new Dictionary<string, Stream>();
								dict.Add(key, inputStream);

								// Now add the stream
								zipFile.CompressStreamDictionary(dict, tempFile);
							}

							// Otherwise, copy the file from the old archive
							else
							{
								Stream oldZipFileEntryStream = new MemoryStream();
								oldZipFile.ExtractFile(index, oldZipFileEntryStream);
								oldZipFileEntryStream.Seek(0, SeekOrigin.Begin);

								// Create a stream dictionary
								Dictionary<string, Stream> dict = new Dictionary<string, Stream>();
								dict.Add(oldZipFile.ArchiveFileNames[index], oldZipFileEntryStream);

								// Now add the stream
								zipFile.CompressStreamDictionary(dict, tempFile);
								oldZipFileEntryStream.Dispose();
							}

							// After the first file, make sure we're in append mode
							zipFile.CompressionMode = CompressionMode.Append;
						}
					}
				}

				success = true;
			}
			catch (Exception ex)
			{
				Console.WriteLine(ex);
				success = false;
			}

			// If the old file exists, delete it and replace
			if (File.Exists(archiveFileName))
			{
				Utilities.TryDeleteFile(archiveFileName);
			}
			File.Move(tempFile, archiveFileName);

			// Now make the file T7Z
			// TODO: Add ACTUAL T7Z compatible code

			BinaryWriter bw = new BinaryWriter(Utilities.TryOpenReadWrite(archiveFileName));
			bw.Seek(0, SeekOrigin.Begin);
			bw.Write(Constants.Torrent7ZipHeader);
			bw.Seek(0, SeekOrigin.End);

			using (oldZipFile = new SevenZipExtractor(Utilities.TryOpenReadWrite(archiveFileName)))
			{
				// Get the correct signature to use (Default 0, Unicode 1, SingleFile 2, StripFileNames 4)
				byte[] tempsig = Constants.Torrent7ZipSignature;
				if (oldZipFile.FilesCount > 1)
				{
					tempsig[16] = 0x2;
				}
				else
				{
					tempsig[16] = 0;
				}

				bw.Write(tempsig);
				bw.Flush();
				bw.Dispose();
			}

			return true;
		}

		#endregion
	}
}