/*
    Tesses.VirtualFilesystem a library for virtual filesystems in .NET
    Copyright (C) 2023  Mike Nolan

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Tesses.VirtualFilesystem
{
    public sealed class NonExistantPointer : EntryPointer
    {
        public override bool IsNonExistantPointer => true;
        public NonExistantPointer(IVirtualFilesystem fs,UnixPath path) : base(fs,path)
        {

        }

        public override bool Exists => false;
        public override string Name { get => Path.Name; set {} }

        public override void Delete()
        {
            
        }
    }
    public abstract class EntryPointer
    {
        public virtual bool IsNonExistantPointer {get{return false;}}
        public virtual bool IsFilePointer {get{return false;}}
        public virtual bool IsDirectoryPointer {get{return false;}}

        public virtual bool IsSymlinkPointer {get{return false;}}
        public EntryPointer this[UnixPath path]
        {
            get{
                return _fs.OpenEntry(Path / path);
            }
        }
        public DirectoryPointer AsDirectoryPointer()
        {
            return new DirectoryPointer(_fs,Path);
        }
         public FilePointer AsFilePointer()
        {
            return new FilePointer(_fs,Path);
        }
        public SymlinkPointer AsSymlinkPointer()
        {
            return new SymlinkPointer(_fs,Path);
        }
        internal EntryPointer(IVirtualFilesystem fs)
        {
            _fs=fs;
        }
        internal EntryPointer(IVirtualFilesystem fs,UnixPath path) : this(fs)
        {
            Path = path;
        }
        protected IVirtualFilesystem _fs;
        
        public IVirtualFilesystem Filesystem {get{return _fs;}}
         public UnixPath Path {get;set;}="/";
        public abstract string Name {get;set;}

         public UnixPath WithPath(UnixPath path)
         {
            return Path / path;
         }
        public DirectoryPointer Up()
        {
            return new DirectoryPointer(_fs,_fs.UpPath(Path));
        }
        public abstract void Delete();
        public abstract bool Exists {get;}
    }

    public sealed class SymlinkPointer : EntryPointer
    {
        public override bool IsSymlinkPointer => true;
        public SymlinkPointer(IVirtualFilesystem fs,UnixPath path) : base(fs,path)
        {

        }
        private void _setName(string name)
        {
            UnixPath oldPath = Path;
            UnixPath target= Target;
            Delete();
            Path.Name = name;
            Target= target;
            
        }
        public override string Name { get => Path.Name; set => _setName(value); }

        public override bool Exists => _fs.SymlinkExists(Path);

        public override void Delete()
        {
            if(Exists)
            _fs.DeleteFile(Path);
        }

        public UnixPath Target {
            get{
                return _fs.ReadLink(Path);
            }
            set{
                Delete();
                _fs.CreateSymlink(value,Path);
            }
        }
        public EntryPointer TargetPointer
        {
            get
            {
                return _fs.OpenEntry(Target);
            }
        }
    }

    public sealed class FilePointer : EntryPointer
    {
        public override bool IsFilePointer => true;
        public FilePointer(IVirtualFilesystem fs,UnixPath path) : base(fs,path)
        {
        
        }
        public Stream Create()
        {
            return _fs.Open(Path,FileMode.Create,FileAccess.Write,FileShare.Inheritable);
        }
        public Stream OpenRead()
        {
            return _fs.Open(Path,FileMode.Open,FileAccess.Read,FileShare.Read);
        }
        public Stream OpenWrite()
        {
            return _fs.Open(Path,FileMode.OpenOrCreate,FileAccess.Write,FileShare.Inheritable);
        }

        public void WriteAllText(string text,Encoding encoding)
        {
            using(var f = Create())
                StreamHelper.WriteAllText(f,text,encoding);
        }
        public void WriteAllText(string text)
        {
            WriteAllText(text,Encoding.UTF8);
        }
        public string ReadAllText(Encoding encoding)
        {
            using(var f = OpenRead())
                return StreamHelper.ReadAllText(f,encoding);
        }
        public override bool Exists => _fs.FileExists(Path);
        public void WriteAllBytes(byte[] data)
        {
            using(var f = Create())
                StreamHelper.WriteAllBytes(f,data);
        }
        public byte[] ReadAllBytes()
        {
            using(var f = OpenRead())
                return StreamHelper.ReadAllBytes(f);
        }
        public override void Delete()
        {
            _fs.DeleteFile(Path);
        }   
        public override string Name
        {
            get
            {
                return Path.Name;
            }
            set
            {
                UnixPath old = new UnixPath(Path);
                Path.Name = value;
                _fs.MoveFile(old,Path);
            }
        }
    }
    public class DirectoryPointer : EntryPointer, IEnumerable<EntryPointer>
    {

        public override bool IsDirectoryPointer => true;
        public DirectoryPointer(IVirtualFilesystem fs) : base(fs)
        {
        
        }
        public DirectoryPointer(IVirtualFilesystem fs,UnixPath path) : this(fs)
        {
          
            Path = path;
        }
        public void Create()
        {
            _fs.CreateDirectory(Path);
        }
        public override void Delete()
        {
            _fs.DeleteDirectory(Path);
        }
        public void DeleteRecursive()
        {
            _fs.DeleteDirectory(Path,true);
        }
        
         public IVirtualFilesystem SubDirectoryFilesystem {get{return _fs.GetSubdirFilesystem(Path);}}

         public DirectoryPointer[] Directories 
         {
            get{
                return EnumerateDirectories().ToArray();
            }
         }
         public FilePointer[] Files
         {
            get{
                return EnumerateFiles().ToArray();
            }
         }
         public SymlinkPointer[] Symlinks
         {
            get{
                return EnumerateSymlinks().ToArray();
            }
         }
         public EntryPointer[] Entries
         {
            get {
                return EnumerateEntries().ToArray();
            }
         }

         public IEnumerable<DirectoryPointer> EnumerateDirectories()
         {
            foreach(var item in _fs.EnumerateDirectories(Path))
            {
                yield return new DirectoryPointer(_fs,item);
            }
         }
         public IEnumerable<FilePointer> EnumerateFiles()
         {
            foreach(var item in _fs.EnumerateFiles(Path))
            {
                yield return new FilePointer(_fs,item);
            }
            
         }
         public IEnumerable<SymlinkPointer> EnumerateSymlinks()
         {
            foreach(var item in _fs.EnumerateSymlinks(Path))
            {
                yield return new SymlinkPointer(_fs,item);
            }
         }
        public static DirectoryPointer operator/(DirectoryPointer pointer,string path)
        {
             return new DirectoryPointer(pointer._fs,pointer.Path / path);
        }
        public static DirectoryPointer operator/(DirectoryPointer pointer,UnixPath path)
        {
            return new DirectoryPointer(pointer._fs,pointer.Path / path);
        }
        public IEnumerable<EntryPointer> EnumerateEntries()
        {
            foreach(var item in _fs.EnumerateFileSystemEntries(Path))
            {
                yield return _fs.OpenEntry(item);
            }
        }

        public IEnumerator<EntryPointer> GetEnumerator()
        {
            return EnumerateEntries().GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return EnumerateEntries().GetEnumerator();
        }

        public override bool Exists {get{return _fs.DirectoryExists(Path);}}

        public override string Name
        {
            get
            {
                return Path.Name;
            }
            set
            {
                UnixPath old = new UnixPath(Path);
                Path.Name = value;
                _fs.MoveDirectory(old,Path);
            }
        }


    }
    public static class StreamHelper
    {
        public static string ReadAllText(Stream strm,Encoding enc)
        {
            using(var sr = new StreamReader(strm,enc))
            {
                return sr.ReadToEnd();
            }
        }
        public static string ReadAllText(Stream strm)
        {
            return ReadAllText(strm,Encoding.UTF8);
        }
        public static byte[] ReadAllBytes(Stream strm)
        {
            MemoryStream ms=new MemoryStream();
            strm.CopyTo(ms);
            return ms.ToArray();
        }
        public static void WriteAllBytes(Stream strm,byte[] data)
        {
            using(MemoryStream ms = new MemoryStream(data))
                ms.CopyTo(strm);
        }
        
        public static void WriteAllText(Stream strm,string text,Encoding enc)
        {
            using(var sw = new StreamWriter(strm,enc))
            {
                sw.Write(text);
            }
        }
        public static void WriteAllText(Stream strm,string text)
        {
            WriteAllText(strm,text,Encoding.UTF8);
        }
        public static string[] ReadAllLines(Stream strm,Encoding enc)
        {
            List<string> ls = new List<string>();
            using(var sr = new StreamReader(strm,enc))
            {
                string line;
                while((line=sr.ReadLine()) != null)
                {
                    ls.Add(line);
                }
            }
            return ls.ToArray();
        }
        public static string[] ReadAllLines(Stream strm)
        {
            return ReadAllLines(strm,Encoding.UTF8);
        }
        public static void WriteAllLines(Stream strm,IEnumerable<string> lines,Encoding enc)
        {
            using(var sw = new StreamWriter(strm,enc))
            {
                foreach(var line in lines)
                {
                    sw.WriteLine(line);
                }
            }
        }
        public static void WriteAllLines(Stream strm,IEnumerable<string> lines)
        {
            WriteAllLines(strm,lines,Encoding.UTF8);
        }
    
        
    }
    public interface IVirtualFilesystem : IDisposable
    {
        
        IVirtualFilesystem GetSubdirFilesystem(UnixPath path);
        EntryPointer OpenEntry(UnixPath path);
        FilePointer OpenFile(UnixPath path);
        SymlinkPointer OpenSymlink(UnixPath path);
        DirectoryPointer OpenDirectory();
        DirectoryPointer OpenDirectory(UnixPath path);
        UnixPath UpPath(UnixPath path);
        UnixPath ConvertPathToUnixPath(string path);
        string ConvertPathFromUnixPath(UnixPath path);
        Stream Open(UnixPath path,FileMode mode,FileAccess access,FileShare share);
        Task<Stream> OpenAsync(UnixPath path,FileMode mode,FileAccess access,FileShare share,CancellationToken token=default(CancellationToken));
        void CreateDirectory(UnixPath directory);
        Task CreateDirectoryAsync(UnixPath directory,CancellationToken token=default(CancellationToken));

        IEnumerable<UnixPath> EnumerateFileSystemEntries(UnixPath path);
        IEnumerable<UnixPath> EnumerateFiles(UnixPath path);
        IEnumerable<UnixPath> EnumerateDirectories(UnixPath path);

        IEnumerable<UnixPath> EnumerateSymlinks(UnixPath path);

        IAsyncEnumerable<UnixPath> EnumerateFilesAsync(UnixPath path,CancellationToken token=default(CancellationToken));

        IAsyncEnumerable<UnixPath> EnumerateDirectoriesAsync(UnixPath path,CancellationToken token=default(CancellationToken));
        IAsyncEnumerable<UnixPath> EnumerateSymlinksAsync(UnixPath path,CancellationToken token=default(CancellationToken));
        IAsyncEnumerable<UnixPath> EnumerateFileSystemEntriesAsync(UnixPath path,CancellationToken token =default(CancellationToken));

        bool DirectoryExists(UnixPath path);

        Task<bool> DirectoryExistsAsync(UnixPath path,CancellationToken token=default(CancellationToken));

        bool FileExists(UnixPath path);

        Task<bool> FileExistsAsync(UnixPath path,CancellationToken token=default(CancellationToken));

        void DeleteFile(UnixPath path);
        void DeleteDirectory(UnixPath path);

        void DeleteDirectory(UnixPath path,bool recursive);
        void CreateSymlink(UnixPath src,UnixPath dest);

        void CreateHardlink(UnixPath src,UnixPath dest);

        UnixPath ReadLink(UnixPath file);

        Task<UnixPath> ReadLinkAsync(UnixPath file,CancellationToken token=default(CancellationToken));
        bool SymlinkExists(UnixPath file);
        Task<bool> SymlinkExistsAsync(UnixPath file,CancellationToken token=default(CancellationToken));
        Task CreateSymlinkAsync(UnixPath src,UnixPath dest,CancellationToken token=default(CancellationToken));
        Task CreateHardlinkAsync(UnixPath src,UnixPath dest,CancellationToken token=default(CancellationToken));
        Task<bool> SameFileSystemAsync(UnixPath src,UnixPath dest,CancellationToken token=default(CancellationToken));
        bool SameFileSystem(UnixPath src,UnixPath dest);
        bool CanHandleSymlinks(UnixPath path);

        Task DeleteFileAsync(UnixPath path,CancellationToken token=default(CancellationToken));
        Task DeleteDirectoryAsync(UnixPath path,CancellationToken token=default(CancellationToken));
          Task DeleteDirectoryAsync(UnixPath path,bool recursive,CancellationToken token=default(CancellationToken));
        bool CanWatch(UnixPath path);

        IVirtualWatcher WatchDirectory(UnixPath dir);

        void MoveFile(UnixPath src,UnixPath dest);

        void MoveDirectory(UnixPath src,UnixPath dest);

        Task MoveFileAsync(UnixPath src,UnixPath dest);
        Task MoveDirectoryAsync(UnixPath src,UnixPath dest);

        DateTime GetCreationTime(UnixPath path);

        DateTime GetLastAccessTime(UnixPath path);
        DateTime GetLastWriteTime(UnixPath path);

        void SetCreationTime(UnixPath path,DateTime time);
        void SetLastAccessTime(UnixPath path,DateTime time);
        void SetLastWriteTime(UnixPath path,DateTime time);

        void SetAttributes(UnixPath path,FileAttributes attributes);

        FileAttributes GetAttributes(UnixPath path);

         Task<DateTime> GetCreationTimeAsync(UnixPath path,CancellationToken token=default(CancellationToken));

        Task<DateTime> GetLastAccessTimeAsync(UnixPath path,CancellationToken token=default(CancellationToken));
        Task<DateTime> GetLastWriteTimeAsync(UnixPath path,CancellationToken token=default(CancellationToken));

        Task SetCreationTimeAsync(UnixPath path,DateTime time,CancellationToken token=default(CancellationToken));
        Task SetLastAccessTimeAsync(UnixPath path,DateTime time,CancellationToken token=default(CancellationToken));
        Task SetLastWriteTimeAsync(UnixPath path,DateTime time,CancellationToken token=default(CancellationToken));

        Task SetAttributesAsync(UnixPath path,FileAttributes attributes,CancellationToken token=default(CancellationToken));

        Task<FileAttributes> GetAttributesAsync(UnixPath path,CancellationToken token=default(CancellationToken));

       
    }
    
    public interface IVirtualWatcher : IDisposable
    {
        
        event EventHandler<VirtualWatcherChangedArgs> Changed;
        event EventHandler<VirtualWatcherChangedArgs> Created;

        event EventHandler<VirtualWatcherChangedArgs> Deleted;

        event EventHandler<VirtualWatcherRenamedEventArgs> Renamed;

        event EventHandler<ErrorEventArgs> Error;


         /// <summary>
        /// Implementation-defined buffer size for storing events.
        /// </summary>
        int InternalBufferSize { get; set; }

        /// <summary>
        /// Implementation-defined filters for filtering events.
        /// </summary>
        NotifyFilters NotifyFilter { get; set; }

        /// <summary>
        /// True to enable raising events, false to never raise them. Default false.
        /// </summary>
        bool EnableRaisingEvents { get; set; }
        
        /// <summary>
        /// File name and extension filter. Use <c>"*"</c> to specify variable length placeholder, <c>"?"</c>
        /// for a single character placeholder. Default is <c>"*.*"</c> for all files.
        /// </summary>
        string Filter { get; set; }

        /// <summary>
        /// True to watch all subdirectories in <see cref="Path"/>, false to only watch entries directly
        /// in <see cref="Path"/>.
        /// </summary>
        bool IncludeSubdirectories { get; set; }

    }
    
    public class VirtualWatcherRenamedEventArgs : VirtualWatcherChangedArgs
    {
        public VirtualWatcherRenamedEventArgs(IVirtualFilesystem fs,WatcherChangeTypes changeTypes,UnixPath newPath,UnixPath oldPath) : base(fs,changeTypes,newPath)
        {
            OldFullPath = oldPath;
            OldName = oldPath.Name;
        }
        public UnixPath OldFullPath {get;}
        public string OldName {get;}
    }
    public class VirtualWatcherChangedArgs : EventArgs
    {
        public VirtualWatcherChangedArgs(IVirtualFilesystem fs,WatcherChangeTypes changeTypes,UnixPath path)
        {
            FullPath=path;
            Name = path.Name;
            Filesystem = fs;
            ChangeType = changeTypes;
        }
        public IVirtualFilesystem Filesystem {get;}
        public WatcherChangeTypes ChangeType {get;}

        public UnixPath FullPath { get; }

        public string Name {get;}

    }
    /*    
      public class UnixPathList : UnixPath, IReadOnlyCollection<UnixPath>
    {

        private string tostr(int i,UnixPath[] paths)
        {
            if(i == 0)
            {
                return paths[0].ToString();
            }
            else
            {
                var p = paths[i];
                if(!string.IsNullOrWhiteSpace(p._scheme))
                {
                    return $"{p._scheme}://[{tostr(i-1,paths)}]{p._path}";
                }
                else 
                {
                    return $"[{tostr(i - 1, paths)}]{p._path}";
                }


            }

        }

        private bool LastIsRoot
        {
            get
            {
                if (Count > 0)
                {
                    return _paths[_paths.Length - 1].IsRoot;
                }
                return false;
            }
        }
        public UnixPathList ParentPL
        {
            get
            {
                if (LastIsRoot)
                {
                    List<UnixPath> paths = new List<UnixPath>();
                    for (int i = 0; i < Count - 2; i++)
                    {
                        paths.Add(new UnixPath(this[i]));
                    }
                    if (Count > 1)
                    {
                        paths.Add(this[Count - 2].Parent);
                    }
                    return new UnixPathList(paths);
                }
                else
                {
                    List<UnixPath> paths = new List<UnixPath>();
                    for (int i = 0; i < Count - 1; i++)
                    {
                        paths.Add(new UnixPath(this[i]));
                    }
                    if (Count > 0)
                    {
                        paths.Add(this[Count - 1].Parent);
                    }
                    return new UnixPathList(paths);
                }
            }
        }
        UnixPath[] _paths;
        public UnixPathList(params UnixPath[] paths)
        {
            _paths = paths;
            if (_paths.Length > 0)
            {
                _path = _paths[0]._path;
                _parts = _paths[0]._parts;
                _scheme = _paths[0]._scheme;
            }
        }

        public UnixPathList(IEnumerable<UnixPath> paths) : this(paths.ToArray())
        {

        }

        public static UnixPathList Parse(string path)
        {
            List<UnixPath> paths = new List<UnixPath>();
            Parse(path, paths);
            return new UnixPathList(paths);
        }
        private static void Parse(string path, List<UnixPath> paths)
        {

            string scheme = "";
            if (path.Contains("://"))
            {
                var res = path.Split(new string[] { "://" }, 2, StringSplitOptions.None);
                scheme = res[0] + "://";
                path = res[1];
            }
            if (path[0] == '[')
            {
                int br = 1;
                int i = 1;
                for (; i < path.Length; i++)
                {
                    if (path[i] == '[') br++;
                    if (path[i] == ']') br--;
                    if (br <= 0) break;
                }
                Parse(path.Substring(1, i - 1), paths);
                paths.Add(scheme + path.Substring(i + 1));

            }
            else
            {
                paths.Add(scheme + path);
            }


        }

        public IEnumerator<UnixPath> GetEnumerator()
        {
            return _G().GetEnumerator();

        }
        private IEnumerable<UnixPath> _G()
        {
            foreach(UnixPath p in _paths)
            {
                yield return p;
            }
        }


        IEnumerator IEnumerable.GetEnumerator()
        {
            return _G().GetEnumerator();
        }

        public UnixPath this[int i]
        {
            get
            {
                return _paths[i];
            }
            set
            {
                _paths[i] = value;
            }
        }
        public int Count { get { return _paths.Length; } }

        public override string AsText
        {
            get
            {
                if (Count < 2)
                {
                    return ToString();
                }
                else
                {
                    
                    return tostr(Count-1,_paths);
                }
            }
        }
        private string GetFs()
        {
            return "";
        }
    }*/
    public class Special
    {
        
        public static UnixPath CurDir {get{return UnixPath.FromLocal(Environment.CurrentDirectory);} set{Environment.CurrentDirectory = value.ToLocal();}}
        public static UnixPath Root {get;} = new UnixPath();
        public static UnixPath Home {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.UserProfile);}}
       
        public static UnixPath Videos {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.MyVideos);}}
        public static UnixPath Pictures {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.MyPictures);}}

        public static UnixPath Documents {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.MyDocuments);}}

        public static UnixPath LocalAppData {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.LocalApplicationData);}}
        public static UnixPath RoamingAppData {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.ApplicationData);}}

        public static UnixPath Music {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.MyMusic);}}

        public static UnixPath DesktopFolder {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.DesktopDirectory);}}

        public static UnixPath PublicVideos {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonVideos);}}
        public static UnixPath PublicPictures {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonPictures);}}

        public static UnixPath PublicDocuments {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonDocuments);}}

        public static UnixPath PublicAppData {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonApplicationData);}}


        public static UnixPath PublicStart {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonStartMenu);}}

        public static UnixPath PublicTemplates {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonTemplates);}}

        public static UnixPath Start {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.StartMenu);}}
        public static UnixPath Templates {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.Templates);}}


        public static UnixPath ProgramFiles {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.ProgramFiles);}}

        public static UnixPath ProgramFilesX86 {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.ProgramFilesX86);}}

        public static UnixPath Programs {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.Programs);}}


        
        public static UnixPath CommonProgramFiles {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonProgramFiles);}}

        public static UnixPath CommonProgramFilesX86 {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonProgramFilesX86);}}

        public static UnixPath CommonPrograms {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonPrograms);}}

        
        public static UnixPath PublicDesktopFolder {get {return UnixPath.FromSpecialDirectory(Environment.SpecialFolder.CommonDesktopDirectory);}}
    }
    public class UnixPath
    {
        public string ToLocal()
        {
            if(Environment.OSVersion.Platform == PlatformID.Win32NT)
            {
                // /mnt/driveLetter/
                if(Parts[0] != "mnt")
                {
                    return "";
                }else{
                    List<string> p = new List<string>();
                    for(int i = 0;i<Parts.Length;i++)
                    {
                        if(i == 0)
                        {
                            p.Add($"{Parts[i].ToUpper()}:");
                        }else{
                            p.Add(Parts[i]);
                        }
                    }
                    return string.Join("\\",p);
                }

            }   
            else
            {
                return Path;
            }
        }
        public static UnixPath FromSpecialDirectory(Environment.SpecialFolder specialFolder)
        {
            return UnixPath.FromLocal(Environment.GetFolderPath(specialFolder));
        }
        public static UnixPath FromLocal(string path)
        {
            if(Environment.OSVersion.Platform == PlatformID.Win32NT)
            {
                string[] p = path.Split(new char[]{':'},2,StringSplitOptions.None);
                List<string> paths=new List<string>();
                paths.Add("mnt");
                paths.Add(p[0].ToLower());
                foreach(var path0 in p[1].Split('\\'))
                {
                    paths.Add(path0);
                }
                return new UnixPath(paths);
            }   
            else
            {
                return path;
            }
        }
       
        public UnixPath()
        {
            
            _parts = new string[0];
        }
        public UnixPath(IEnumerable<string> pathParts)
        {
            UnixPath path = new UnixPath();
            foreach (var item in pathParts)
            {
                path /= new UnixPath(item);
            }
            _parts = path._parts;
            
        }
        public UnixPath(UnixPath path1, UnixPath path2)
        {
           
            List<string> pathParts = new List<string>();
            pathParts.AddRange(path1.Parts);
            pathParts.AddRange(path2.Parts);
            _parts = pathParts.ToArray();
        }
        public UnixPath(UnixPath path1)
        {
            _parts = path1._parts.ToArray();
          
            
        }
        public UnixPath(params string[] pathParts) : this((IEnumerable<string>)pathParts)
        {


        }


        public UnixPath(UnixPath path, params string[] pathParts) : this(path, new UnixPath(pathParts))
        {

        }
        public UnixPath(string path)
        {
           
            _parts=path.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
        }



        public static DirectoryPointer operator/(IVirtualFilesystem fs,UnixPath path)
        {
            return new DirectoryPointer(fs,path);
        }
        public static UnixPath operator /(UnixPath path, string path2)
        {
            return new UnixPath(path, path2);
        }
        public static UnixPath operator /(UnixPath path1, UnixPath path2)
        {

            return new UnixPath(
                path1, path2
            );
        }
        public static UnixPath operator +(UnixPath path1, string path2)
        {
            return path1 + new UnixPath(path2);
        }
        public static UnixPath operator +(UnixPath path1, UnixPath path2)
        {
            List<string> p = new List<string>();
            StringBuilder b = new StringBuilder();
            for (int i = 0; i < path1._parts.Length - 1; i++)
            {
                p.Add(path1._parts[i]);
            }
            if (path1._parts.Length - 1 >= 0)
            {
                b.Append(path1._parts[path1._parts.Length - 1]);
            }
            if (path2._parts.Length > 0)
            {
                b.Append(path2._parts[0]);
            }
            if (b.Length > 0)
            {
                p.Add(b.ToString());
            }
            for (int i = 1; i < path2._parts.Length; i++)
            {
                p.Add(path2._parts[i]);
            }

            var path = new UnixPath(p.ToArray());
            
            return path;
        }
        public static implicit operator UnixPath(string path)
        {
            

            return new UnixPath(path);
        }
        public static implicit operator UnixPath(string[] path)
        {
            return new UnixPath((IEnumerable<string>)path);
        }
        public bool MyPathEquals(UnixPath path)
        {
            if(path.Parts.Length != Parts.Length) return false;

            for(int i = 0;i<Parts.Length;i++)
            {
                if(Parts[i] != path.Parts[i]) return false;
            }

            return true;
        }
        
       
        public string Path =>$"/{string.Join("/",_parts)}";

        public string Name { get { if (_parts.Length == 0) return ""; return _parts[_parts.Length - 1]; } set{
            if(_parts.Length > 0) _parts[_parts.Length-1] = value;

        } }
        public bool IsRoot
        {
            get
            {
                return _parts.Length == 0;
            }
        }
        public bool ParentIsRoot
        {
            get
            {
                return _parts.Length <= 1;
            }
        }
        public UnixPath Parent
        {
            get
            {
                var p = new UnixPath();
                if (!ParentIsRoot)
                {
                    p._parts=_parts.Take(_parts.Length - 1).ToArray();
                }
                return p;
            }
        }
        internal string[] _parts;
        public string[] Parts { get { return _parts; } }
        public virtual string AsText
        {
            get { return ToString(); }
        }
        public override string ToString()
        {
           
                return Path;
          
        }
    }

}