using System;
using Newtonsoft.Json;
using System.Collections.Generic;
using static ShiftOS.Objects.ShiftFS.Utils;
using System.Text;
using System.Threading;

namespace ShiftOS.Objects.ShiftFS
{

    public enum Permissions
    {
        User,
        Administrator,
        Superuser,
        All
    }
    public class File
    {
        public string Name;
        public byte[] Data;
        public bool ReadAccessToLowUsers;
        public Permissions permissions;
        public System.IO.Stream GetStream()
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                return new System.IO.MemoryStream(Data);
            }
            else if (ReadAccessToLowUsers == true)
            {
                return new System.IO.MemoryStream(Data, false);
            }
            return null;
        }

        public File(string name, byte[] data, bool ReadAccess_to_low_users, Permissions perm)
        {
            Name = name;
            Data = data;
            permissions = perm;
            ReadAccessToLowUsers = ReadAccess_to_low_users;
        }
    }
    public class Directory
    {
        public string Name;
        public List<File> Files = new List<File>();
        public List<Directory> Subdirectories = new List<Directory>();
        public bool ReadAccessToLowUsers;
        public Permissions permissions;
        public void AddFile(File file)
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                Files.Add(file);
            }
        }
        public void RemoveFile(string name)
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                Files.Remove(Files.Find(x => x.Name == name));
            }
        }
        public void RemoveFile(File file)
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                Files.Remove(file);
            }
        }
        public File FindFileByName(string name)
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                return Files.Find(x => x.Name == name);
            }
            return null;
        }
        public void AddDirectory(Directory dir)
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                Subdirectories.Add(dir);
            }
        }
        public void RemoveDirectory(string name)
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                Subdirectories.Remove(Subdirectories.Find(x => x.Name == name));
            }
        }
        public void RemoveDirectory(Directory dir)
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                Subdirectories.Remove(dir);
            }
        }
        public Directory FindDirectoryByName(string name)
        {
            if ((int)CurrentUser >= (int)permissions || permissions == Permissions.All)
            {
                return Subdirectories.Find(x => x.Name == name);
            }
            return null;
        }
    }

    public static class Utils
    {
        public static Permissions CurrentUser { get; set; }

        public static List<Directory> Mounts { get; set; }

        static Utils()
        {
            if (Mounts == null)
                Mounts = new List<Directory>();

        }

        public static void Mount(string json)
        {
            var dir = JsonConvert.DeserializeObject<Directory>(json);
            Mounts.Add(dir);
        }

        public static void MountPersistent(string mfsFile)
        {
            var dir = JsonConvert.DeserializeObject<Directory>(ReadAllText(mfsFile));
            Mounts.Add(dir);
            string oldJson = JsonConvert.SerializeObject(dir);
            var t = new Thread(new ThreadStart(() =>
            {
                while (Mounts != null)
                {
                    if (oldJson != JsonConvert.SerializeObject(dir))
                    {
                        oldJson = JsonConvert.SerializeObject(dir);
                        WriteAllText(mfsFile, oldJson);
                    }
                }
            }));
            t.IsBackground = true;
            t.Start();
        }


        public static void CreateDirectory(string path)
        {
            if (!DirectoryExists(path))
            {
                string[] pathlist = path.Split('/');
                int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
                var dir = Mounts[vol];
                for (int i = 1; i <= pathlist.Length - 2; i++)
                {
                    dir = dir.FindDirectoryByName(pathlist[i]);
                }
                dir.AddDirectory(new Directory
                {
                    Name = pathlist[pathlist.Length - 1],
                    permissions = CurrentUser,
                });
            }
            else
            {
                throw new Exception("The directory \"" + path + "\" already exists.");
            }
        }

        public static byte[] ReadAllBytes(string path)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 2; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }
            var file = dir.FindFileByName(pathlist[pathlist.Length - 1]);

            return file.Data;

        }

        public static void WriteAllText(string path, string contents)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 2; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }

            if (!FileExists(path))
            {
                dir.AddFile(new File(pathlist[pathlist.Length - 1], Encoding.UTF8.GetBytes(contents), false, Permissions.All));
            }
            else
            {
                var f = dir.FindFileByName(pathlist[pathlist.Length - 1]);
                f.Data = Encoding.UTF8.GetBytes(contents);
            }

        }


        public static void Delete(string path)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 2; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }

            if (FileExists(path))
            {
                dir.RemoveFile(pathlist[pathlist.Length - 1]);
            }
            else
            {
                dir.RemoveDirectory(pathlist[pathlist.Length - 1]);
            }

        }


        public static void WriteAllBytes(string path, byte[] contents)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 2; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }

            if (!FileExists(path))
            {
                dir.AddFile(new File(pathlist[pathlist.Length - 1], contents, false, Permissions.All));
            }
            else
            {
                var f = dir.FindFileByName(pathlist[pathlist.Length - 1]);
                f.Data = contents;
            }

        }



        public static string ExportMount(int index)
        {
            var dir = Mounts[index];
            return JsonConvert.SerializeObject(dir, Formatting.Indented);
        }

        public static bool DirectoryExists(string path)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 1; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }
            return dir != null;

        }

        public static bool FileExists(string path)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 2; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }
            return dir.FindFileByName(pathlist[pathlist.Length - 1]) != null;

        }

        public static Directory GetDirectoryInfo(string path)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 1; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }
            if (path.EndsWith("/"))
                path = path.Remove(path.Length - 1, 1);
            return dir;
        }

        public static string ReadAllText(string path)
        {
            return Encoding.UTF8.GetString(ReadAllBytes(path));
        }

    

    public static File GetFileInfo(string path)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 2; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }
            return dir.FindFileByName(pathlist[pathlist.Length - 1]);

        }

        public static string[] GetDirectories(string path)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for(int i = 1; i <= pathlist.Length - 1; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }
            if (path.EndsWith("/"))
                path = path.Remove(path.Length - 1, 1);

            List<string> paths = new List<string>();

            foreach(var subdir in dir.Subdirectories)
            {
                paths.Add(path + "/" + subdir.Name);
            }
            paths.Sort();
            return paths.ToArray();
        }

        public static string[] GetFiles(string path)
        {
            string[] pathlist = path.Split('/');
            int vol = Convert.ToInt32(pathlist[0].Replace(":", ""));
            var dir = Mounts[vol];
            for (int i = 1; i <= pathlist.Length - 1; i++)
            {
                dir = dir.FindDirectoryByName(pathlist[i]);
            }
            if (path.EndsWith("/"))
                path = path.Remove(path.Length - 1, 1);

            List<string> paths = new List<string>();

            foreach (var subdir in dir.Files)
            {
                paths.Add(path + "/" + subdir.Name);
            }
            paths.Sort();
            return paths.ToArray();
        }

        public static void WriteAllText(string v, object p)
        {
            throw new NotImplementedException();
        }
    }
}