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

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

namespace SabreTools.Library.DatFiles
{
	/// <summary>
	/// Represents parsing and writing of a DosCenter DAT
	/// </summary>
	internal class DosCenter : DatFile
	{
		/// <summary>
		/// Constructor designed for casting a base DatFile
		/// </summary>
		/// <param name="datFile">Parent DatFile to copy from</param>
		public DosCenter(DatFile datFile)
			: base(datFile, cloneHeader: false)
		{
		}

		/// <summary>
		/// Parse a DosCenter 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>
		public override void ParseFile(
			// Standard Dat parsing
			string filename,
			int sysid,
			int srcid,

			// Miscellaneous
			bool keep,
			bool clean,
			bool remUnicode)
		{
			// ClrMamePro and DosCenter parsing are identical so it just calls one implementation
			new ClrMamePro(this).ParseFile(filename, sysid, srcid, keep, clean, remUnicode);
		}


		/// <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 override bool WriteToFile(string outfile, bool ignoreblanks = false)
		{
			try
			{
				Globals.Logger.User("Opening file for writing: {0}", outfile);
				FileStream fs = Utilities.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 the header
				WriteHeader(sw);

				// 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;
						}

						List<string> newsplit = rom.MachineName.Split('\\').ToList();

						// 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, rom);
						}

						// 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;
					}
				}

				// Write the file footer out
				WriteFooter(sw);

				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 DAT header 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 WriteHeader(StreamWriter sw)
		{
			try
			{
				string header = "DOSCenter (\n" +
							"\tName: " + Name + "\n" +
							"\tDescription: " + Description + "\n" +
							"\tVersion: " + Version + "\n" +
							"\tDate: " + Date + "\n" +
							"\tAuthor: " + Author + "\n" +
							"\tHomepage: " + Homepage + "\n" +
							"\tComment: " + Comment + "\n" +
							")\n";

				// Write the header out
				sw.Write(header);
				sw.Flush();
			}
			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 = "game (\n\tname \"" + rom.MachineName + ".zip\"\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>
		/// <param name="rom">DatItem object to be output</param>
		/// <returns>True if the data was written, false on error</returns>
		private bool WriteEndGame(StreamWriter sw, DatItem rom)
		{
			try
			{
				string state = (String.IsNullOrWhiteSpace(rom.SampleOf) ? "" : "\tsampleof \"" + rom.SampleOf + "\"\n") + ")\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.Disk:
					case ItemType.Release:
					case ItemType.Sample:
						// We don't output these at all for DosCenter
						break;
					case ItemType.Rom:
						state += "\tfile ( name " + ((Rom)rom).Name
							+ (((Rom)rom).Size != -1 ? " size " + ((Rom)rom).Size : "")
							+ (!String.IsNullOrWhiteSpace(((Rom)rom).Date) ? " date " + ((Rom)rom).Date : "")
							+ (!String.IsNullOrWhiteSpace(((Rom)rom).CRC) ? " crc " + ((Rom)rom).CRC.ToLowerInvariant() : "")
							+ " )\n";
						break;
				}

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

			return true;
		}

		/// <summary>
		/// Write out DAT footer 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 WriteFooter(StreamWriter sw)
		{
			try
			{
				string footer = ")\n";

				// Write the footer out
				sw.Write(footer);
				sw.Flush();
			}
			catch (Exception ex)
			{
				Globals.Logger.Error(ex.ToString());
				return false;
			}

			return true;
		}
	}
}