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>
        /// TODO: Pull parsing into this file instead of relying on CMP
        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.ItemType == 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 \"" + (!ExcludeFields[(int)Field.MachineName] ? 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 = (!ExcludeFields[(int)Field.SampleOf] && 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.ItemType == ItemType.Rom
                && (((Rom)rom).Size == 0 || ((Rom)rom).Size == -1)))
            {
                return true;
            }

            try
            {
                string state = "";

                // Pre-process the item name
                ProcessItemName(rom, true);

                switch (rom.ItemType)
                {
                    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 " + (!ExcludeFields[(int)Field.Name] ? ((Rom)rom).Name : "")
                            + (!ExcludeFields[(int)Field.Size] && ((Rom)rom).Size != -1 ? " size " + ((Rom)rom).Size : "")
                            + (!ExcludeFields[(int)Field.Date] && !String.IsNullOrWhiteSpace(((Rom)rom).Date) ? " date " + ((Rom)rom).Date : "")
                            + (!ExcludeFields[(int)Field.CRC] && !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;
        }
    }
}