using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;

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

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

using FileStream = System.IO.FileStream;
using StreamReader = System.IO.StreamReader;
using StreamWriter = System.IO.StreamWriter;
#endif
using NaturalSort;

namespace SabreTools.Library.DatFiles
{
	/// <summary>
	/// Represents parsing and writing of a MAME Listroms DAT
	/// </summary>
	public class Listroms : DatFile
	{
		/// <summary>
		/// Constructor designed for casting a base DatFile
		/// </summary>
		/// <param name="datFile">Parent DatFile to copy from</param>
		public Listroms(DatFile datFile)
		{
			this._datHeader = datFile._datHeader;
			this._items = datFile._items;
			this._sortedBy = datFile._sortedBy;
			this._datStats = datFile._datStats;
		}

		/// <summary>
		/// Parse a MAME Listroms DAT and return all found games and roms within
		/// </summary>
		/// <param name="filename">Name of the file to be parsed</param>
		/// <param name="sysid">System ID for the DAT</param>
		/// <param name="srcid">Source ID for the DAT</param>
		/// <param name="keep">True if full pathnames are to be kept, false otherwise (default)</param>
		/// <param name="clean">True if game names are sanitized, false otherwise (default)</param>
		/// <param name="remUnicode">True if we should remove non-ASCII characters from output, false otherwise (default)</param>
		/// <remarks>
		/// In a new style MAME listroms DAT, each game has the following format:
		/// 
		/// ROMs required for driver "005".
		/// Name                                   Size Checksum
		/// 1346b.cpu-u25                          2048 CRC(8e68533e) SHA1(a257c556d31691068ed5c991f1fb2b51da4826db)
		/// 6331.sound-u8                            32 BAD CRC(1d298cb0) SHA1(bb0bb62365402543e3154b9a77be9c75010e6abc) BAD_DUMP
		/// 16v8h-blue.u24                          279 NO GOOD DUMP KNOWN
		/// </remarks>
		public void Parse(
			// Standard Dat parsing
			string filename,
			int sysid,
			int srcid,

			// Miscellaneous
			bool keep,
			bool clean,
			bool remUnicode)
		{
			// Open a file reader
			Encoding enc = Style.GetEncoding(filename);
			StreamReader sr = new StreamReader(FileTools.TryOpenRead(filename), enc);

			string gamename = "";
			while (!sr.EndOfStream)
			{
				string line = sr.ReadLine().Trim();

				// If we have a blank line, we just skip it
				if (String.IsNullOrEmpty(line))
				{
					continue;
				}

				// If we have the descriptor line, ignore it
				else if (line == "Name                                   Size Checksum")
				{
					continue;
				}

				// If we have the beginning of a game, set the name of the game
				else if (line.StartsWith("ROMs required for"))
				{
					gamename = Regex.Match(line, @"^ROMs required for \S*? ""(.*?)""\.").Groups[1].Value;
				}

				// If we have a machine with no required roms (usually internal devices), skip it
				else if (line.StartsWith("No ROMs required for"))
				{
					continue;
				}

				// Otherwise, we assume we have a rom that we need to add
				else
				{
					// First, we preprocess the line so that the rom name is consistently correct
					string romname = "";
					string[] split = line.Split(new string[] { "    " }, StringSplitOptions.RemoveEmptyEntries);

					// If the line doesn't have the 4 spaces of padding, check for 3
					if (split.Length == 1)
					{
						split = line.Split(new string[] { "   " }, StringSplitOptions.RemoveEmptyEntries);
					}

					// If the split is still unsuccessful, log it and skip
					if (split.Length == 1)
					{
						Globals.Logger.Warning("Possibly malformed line: '{0}'", line);
					}

					romname = split[0];
					line = line.Substring(romname.Length);

					// Next we separate the ROM into pieces
					split = line.Split(new char[0], StringSplitOptions.RemoveEmptyEntries);

					// Standard Disks have 2 pieces (name, sha1)
					if (split.Length == 1)
					{
						Disk disk = new Disk()
						{
							Name = romname,
							SHA1 = Style.CleanListromHashData(split[0]),

							MachineName = gamename,
						};

						ParseAddHelper(disk, clean, remUnicode);
					}

					// Baddump Disks have 4 pieces (name, BAD, sha1, BAD_DUMP)
					else if (split.Length == 3 && line.EndsWith("BAD_DUMP"))
					{
						Disk disk = new Disk()
						{
							Name = romname,
							SHA1 = Style.CleanListromHashData(split[1]),
							ItemStatus = ItemStatus.BadDump,

							MachineName = gamename,
						};

						ParseAddHelper(disk, clean, remUnicode);
					}

					// Standard ROMs have 4 pieces (name, size, crc, sha1)
					else if (split.Length == 3)
					{
						if (!Int64.TryParse(split[0], out long size))
						{
							size = 0;
						}

						Rom rom = new Rom()
						{
							Name = romname,
							Size = size,
							CRC = Style.CleanListromHashData(split[1]),
							SHA1 = Style.CleanListromHashData(split[2]),

							MachineName = gamename,
						};

						ParseAddHelper(rom, clean, remUnicode);
					}

					// Nodump Disks have 5 pieces (name, NO, GOOD, DUMP, KNOWN)
					else if (split.Length == 4 && line.EndsWith("NO GOOD DUMP KNOWN"))
					{
						Disk disk = new Disk()
						{
							Name = romname,
							ItemStatus = ItemStatus.Nodump,

							MachineName = gamename,
						};

						ParseAddHelper(disk, clean, remUnicode);
					}

					// Baddump ROMs have 6 pieces (name, size, BAD, crc, sha1, BAD_DUMP)
					else if (split.Length == 5 && line.EndsWith("BAD_DUMP"))
					{
						if (!Int64.TryParse(split[0], out long size))
						{
							size = 0;
						}

						Rom rom = new Rom()
						{
							Name = romname,
							Size = size,
							CRC = Style.CleanListromHashData(split[2]),
							SHA1 = Style.CleanListromHashData(split[3]),
							ItemStatus = ItemStatus.BadDump,

							MachineName = gamename,
						};

						ParseAddHelper(rom, clean, remUnicode);
					}

					// Nodump ROMs have 6 pieces (name, size, NO, GOOD, DUMP, KNOWN)
					else if (split.Length == 5 && line.EndsWith("NO GOOD DUMP KNOWN"))
					{
						if (!Int64.TryParse(split[0], out long size))
						{
							size = 0;
						}

						Rom rom = new Rom()
						{
							Name = romname,
							Size = size,
							ItemStatus = ItemStatus.Nodump,

							MachineName = gamename,
						};

						ParseAddHelper(rom, clean, remUnicode);
					}

					// If we have something else, it's invalid
					else
					{
						Globals.Logger.Warning("Invalid line detected: '{0} {1}'", romname, line);
					}
				}
			}
		}


		/// <summary>
		/// Create and open an output file for writing direct from a dictionary
		/// </summary>
		/// <param name="outfile">Name of the file to write to</param>
		/// <param name="ignoreblanks">True if blank roms should be skipped on output, false otherwise (default)</param>
		/// <returns>True if the DAT was written correctly, false otherwise</returns>
		public bool WriteToFile(string outfile, bool ignoreblanks = false)
		{
			try
			{
				Globals.Logger.User("Opening file for writing: {0}", outfile);
				FileStream fs = FileTools.TryCreate(outfile);

				// If we get back null for some reason, just log and return
				if (fs == null)
				{
					Globals.Logger.Warning("File '{0}' could not be created for writing! Please check to see if the file is writable", outfile);
					return false;
				}

				StreamWriter sw = new StreamWriter(fs, new UTF8Encoding(false));

				// Write out each of the machines and roms
				string lastgame = null;

				// Get a properly sorted set of keys
				List<string> keys = Keys;
				keys.Sort(new NaturalComparer());

				foreach (string key in keys)
				{
					List<DatItem> roms = this[key];

					// Resolve the names in the block
					roms = DatItem.ResolveNames(roms);

					for (int index = 0; index < roms.Count; index++)
					{
						DatItem rom = roms[index];

						// There are apparently times when a null rom can skip by, skip them
						if (rom.Name == null || rom.MachineName == null)
						{
							Globals.Logger.Warning("Null rom found!");
							continue;
						}

						// If we have a different game and we're not at the start of the list, output the end of last item
						if (lastgame != null && lastgame.ToLowerInvariant() != rom.MachineName.ToLowerInvariant())
						{
							WriteEndGame(sw);
						}

						// If we have a new game, output the beginning of the new item
						if (lastgame == null || lastgame.ToLowerInvariant() != rom.MachineName.ToLowerInvariant())
						{
							WriteStartGame(sw, rom);
						}

						// If we have a "null" game (created by DATFromDir or something similar), log it to file
						if (rom.Type == ItemType.Rom
							&& ((Rom)rom).Size == -1
							&& ((Rom)rom).CRC == "null")
						{
							Globals.Logger.Verbose("Empty folder found: {0}", rom.MachineName);

							rom.Name = (rom.Name == "null" ? "-" : rom.Name);
							((Rom)rom).Size = Constants.SizeZero;
							((Rom)rom).CRC = ((Rom)rom).CRC == "null" ? Constants.CRCZero : null;
							((Rom)rom).MD5 = ((Rom)rom).MD5 == "null" ? Constants.MD5Zero : null;
							((Rom)rom).SHA1 = ((Rom)rom).SHA1 == "null" ? Constants.SHA1Zero : null;
							((Rom)rom).SHA256 = ((Rom)rom).SHA256 == "null" ? Constants.SHA256Zero : null;
							((Rom)rom).SHA384 = ((Rom)rom).SHA384 == "null" ? Constants.SHA384Zero : null;
							((Rom)rom).SHA512 = ((Rom)rom).SHA512 == "null" ? Constants.SHA512Zero : null;
						}

						// Now, output the rom data
						WriteDatItem(sw, rom, ignoreblanks);

						// Set the new data to compare against
						lastgame = rom.MachineName;
					}
				}

				Globals.Logger.Verbose("File written!" + Environment.NewLine);
				sw.Dispose();
				fs.Dispose();
			}
			catch (Exception ex)
			{
				Globals.Logger.Error(ex.ToString());
				return false;
			}

			return true;
		}

		/// <summary>
		/// Write out Game start using the supplied StreamWriter
		/// </summary>
		/// <param name="sw">StreamWriter to output to</param>
		/// <param name="rom">DatItem object to be output</param>
		/// <returns>True if the data was written, false on error</returns>
		private bool WriteStartGame(StreamWriter sw, DatItem rom)
		{
			try
			{
				// No game should start with a path separator
				if (rom.MachineName.StartsWith(Path.DirectorySeparatorChar.ToString()))
				{
					rom.MachineName = rom.MachineName.Substring(1);
				}

				string state = "ROMs required for driver \"" + rom.MachineName + "\".\n" +
							"Name                                   Size Checksum\n";

				sw.Write(state);
				sw.Flush();
			}
			catch (Exception ex)
			{
				Globals.Logger.Error(ex.ToString());
				return false;
			}

			return true;
		}

		/// <summary>
		/// Write out Game end using the supplied StreamWriter
		/// </summary>
		/// <param name="sw">StreamWriter to output to</param>
		/// <returns>True if the data was written, false on error</returns>
		private bool WriteEndGame(StreamWriter sw)
		{
			try
			{
				string state = "\n";

				sw.Write(state);
				sw.Flush();
			}
			catch (Exception ex)
			{
				Globals.Logger.Error(ex.ToString());
				return false;
			}

			return true;
		}

		/// <summary>
		/// Write out DatItem using the supplied StreamWriter
		/// </summary>
		/// <param name="sw">StreamWriter to output to</param>
		/// <param name="rom">DatItem object to be output</param>
		/// <param name="ignoreblanks">True if blank roms should be skipped on output, false otherwise (default)</param>
		/// <returns>True if the data was written, false on error</returns>
		private bool WriteDatItem(StreamWriter sw, DatItem rom, bool ignoreblanks = false)
		{
			// If we are in ignore blanks mode AND we have a blank (0-size) rom, skip
			if (ignoreblanks
				&& (rom.Type == ItemType.Rom
				&& (((Rom)rom).Size == 0 || ((Rom)rom).Size == -1)))
			{
				return true;
			}

			try
			{
				string state = "";
				switch (rom.Type)
				{
					case ItemType.Archive:
					case ItemType.BiosSet:
					case ItemType.Release:
					case ItemType.Sample:
						// We don't output these at all
						break;
					case ItemType.Disk:
						// The name is padded out to a particular length
						if (rom.Name.Length < 43)
						{
							state += rom.Name.PadRight(43, ' ');
						}
						else
						{
							state += rom.Name + "          ";
						}

						// If we have a baddump, put the first indicator
						if (((Disk)rom).ItemStatus == ItemStatus.BadDump)
						{
							state += " BAD";
						}

						// If we have a nodump, write out the indicator
						if (((Disk)rom).ItemStatus == ItemStatus.Nodump)
						{
							state += " NO GOOD DUMP KNOWN";
						}
						// Otherwise, write out the SHA-1 hash
						else
						{
							state += " SHA1(" + ((Disk)rom).SHA1 + ")";
						}

						// If we have a baddump, put the second indicator
						if (((Disk)rom).ItemStatus == ItemStatus.BadDump)
						{
							state += " BAD_DUMP";
						}

						state += "\n";
						break;
					case ItemType.Rom:
						// The name is padded out to a particular length
						if (rom.Name.Length < 40)
						{
							state += rom.Name.PadRight(43 - (((Rom)rom).Size.ToString().Length), ' ');
						}
						else
						{
							state += rom.Name + "          ";
						}

						// If we don't have a nodump, write out the size
						if (((Rom)rom).ItemStatus != ItemStatus.Nodump)
						{
							state += ((Rom)rom).Size;
						}

						// If we have a baddump, put the first indicator
						if (((Rom)rom).ItemStatus == ItemStatus.BadDump)
						{
							state += " BAD";
						}

						// If we have a nodump, write out the indicator
						if (((Rom)rom).ItemStatus == ItemStatus.Nodump)
						{
							state += " NO GOOD DUMP KNOWN";
						}
						// Otherwise, write out the CRC and SHA-1 hashes
						else
						{
							state += " CRC(" + ((Rom)rom).CRC + ")";
							state += " SHA1(" + ((Rom)rom).SHA1 + ")";
						}

						// If we have a baddump, put the second indicator
						if (((Rom)rom).ItemStatus == ItemStatus.BadDump)
						{
							state += " BAD_DUMP";
						}

						state += "\n";
						break;
				}

				sw.Write(state);
				sw.Flush();
			}
			catch (Exception ex)
			{
				Globals.Logger.Error(ex.ToString());
				return false;
			}

			return true;
		}
	}
}