using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.IO;

using System.Linq;

using System.Text.RegularExpressions;

using System.Threading;

using SimpleJSON;

using Debug = UnityEngine.Debug;



namespace SkywardRay.FileBrowser {

	public class SfbFileSystem {

		public bool IsFake { get; private set; }

		private Dictionary<string, SfbFileSystemEntry> entries = new Dictionary<string, SfbFileSystemEntry>();

		public SfbFileSystemEntry root;



#if !UNITY_WEBGL && !UNITY_WEBPLAYER

		private SfbFileSystemThread thread;

#endif



		public SfbFileSystem (bool isFake) {

			IsFake = isFake;



			entries.Add("/", new SfbFileSystemEntry("/", false, SfbFileSystemEntryType.Root));

			root = entries["/"];



			if (isFake == false) {

				ReadLogicalDrives();

			}



#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			thread = new SfbFileSystemThread();

#endif

		}



		public void Update () {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			thread.MainThreadUpdate();

#endif

		}



		public void AddEntry (SfbFileSystemEntry entry) {

			if (entry.parent == null) {

				if (entry.type == SfbFileSystemEntryType.LogicalDrive) {

					entry.parent = root;

					root.AddChild(entry);

				}

				else {

					string s = GetParentPath(entry.path);

					if (entries.ContainsKey(s)) {

						entry.parent = entries[s];

						entries[s].AddChild(entry);

					}

				}

			}



			var children = entries.Where(a => GetParentPath(a.Key) == entry.path).Select(b => b.Value);

			foreach (var child in children) {

				entry.AddChild(child);

			}



			if (!entries.ContainsKey(entry.path)) {

				entries.Add(entry.path, entry);

			}

		}



		public void RemoveEntry (SfbFileSystemEntry entry) {

			entry.children.RemoveAll(a => a == entry);

			if (entry.parent != null) {

				entry.parent.RemoveChild(entry);

			}

			else {

				string s = GetParentPath(entry.path);

				Debug.Log(entries.ContainsKey(s));

			}

			entries.Remove(entry.path);

		}



		public void DeleteEntryOnDiskAndRemove (SfbFileSystemEntry entry) {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			if (IsFake) {

				return;

			}

			if (!File.Exists(entry.path) && !Directory.Exists(entry.path)) {

				return;

			}



			FileAttributes attr = File.GetAttributes(entry.path);



			if ((attr & FileAttributes.Directory) == FileAttributes.Directory) {

				Directory.Delete(entry.path, true);

			}

			else {

				File.Delete(entry.path);

			}



			RemoveEntry(entry);

#endif

		}



		public void NewDirectory (string path) {

			if (DirectoryExists(path)) {

				return;

			}

			path = GetNormalizedPath(path);

			if (!IsFake) {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

				Directory.CreateDirectory(path);

#endif

			}

			AddEntry(new SfbFileSystemEntry(path, false, SfbFileSystemEntryType.Folder));

		}



		public void NewDirectory (string parentPath, string name) {

			parentPath = GetNormalizedPath(parentPath);



			NewDirectory(parentPath + "/" + name);

		}



		public static bool RealDirectoryExists (string path) {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			return Directory.Exists(path) && (new DirectoryInfo(path).Attributes & FileAttributes.ReparsePoint) != FileAttributes.ReparsePoint;

#else

			return false;

#endif

		}



		public bool DirectoryExists (string path) {

			if (IsFake) {

				return entries.ContainsKey(path);

			}



			return RealDirectoryExists(path);

		}



		public bool DirectoryExists (SfbFileSystemEntry entry) {

			return entries.ContainsKey(entry.path) && entries[entry.path] == entry;

		}



		public bool FileExists (string path) {

			if (IsFake) {

				return !entries.ContainsKey(path);

			}

			if (entries.ContainsKey(path)) {

				return true;

			}



#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			return File.Exists(path);

#else

			return false;

#endif

		}



		public bool FileExists (SfbFileSystemEntry entry) {

			if (entry.type == SfbFileSystemEntryType.File) {

				return false;

			}



			return entries.ContainsKey(entry.path) && entries[entry.path] == entry;

		}



		public SfbFileSystemEntry GetDirectory (string path) {

			if (!entries.ContainsKey(path)) {

				if (IsFake) {

					return null;

				}



				return ReadDirectory(path);

			}



			return entries[path];

		}



		public SfbFileSystemEntry GetFile (string path) {

			if (!entries.ContainsKey(path)) {

				return IsFake ? null : ReadFile(path);

			}



			return entries[path];

		}



		public List<SfbFileSystemEntry> GetDirectoryContents (SfbFileSystemEntry entry) {

			if (!entries.ContainsKey(entry.path)) {

				return new List<SfbFileSystemEntry>();

			}



			if (entry.type == SfbFileSystemEntryType.Root) {

				if (root.children.Count == 0) {

					ReadLogicalDrives();

				}

				return root.children;

			}



			return entry.children;

		}



		public List<SfbFileSystemEntry> GetDirectoryContents (SfbFileSystemEntry entry, SfbFileSortingOrder sortingOrder) {

			switch (sortingOrder) {

				case SfbFileSortingOrder.FolderThenFileThenName:

					return GetDirectoryContents(entry).OrderByDescending(a => a.type).ThenBy(b => b.name).ToList();

			}



			return null;

		}



		public static char[] GetInvalidFileNameChars () {

//#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			return Path.GetInvalidFileNameChars();

//#else

//			return new char[0];

//#endif

		}



		public static string GetExtension (string path) {

//#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			return Path.GetExtension(path);

//#else

//			return "";

//#endif

		}



		public static string GetFileName (string path) {

			string s = path;

			if (s.EndsWith("/")) {

				s = path.Remove(s.Length - 1);

			}

			s = Regex.Match(s, @"([^/]*$)").Groups[1].Value;



			if (s == "" || Regex.IsMatch(s, @"[a-zA-Z]:")) {

				s += "/";

			}



			return s;

		}



		public static string GetParentPath (string path) {

			if (path.EndsWith("/")) {

				path = path.Remove(path.Length - 1);

			}

			path = Regex.Replace(path, @"[^/]*$", "");

			if (path == "") {

				path = "/";

			}

			return GetNormalizedPath(path);

		}



		public static string GetNormalizedPath (string path) {

			path = path.Replace('\\', '/');



			if (path.EndsWith("/")) {

				path = path.Remove(path.Length - 1);

			}



			if (path == "" || Regex.IsMatch(path, @"[a-zA-Z]:$")) {

				path += "/";

			}



			return path;

		}



		public static SfbFileSystem CreateFromJSON (string json) {

			var N = JSON.Parse(json);

			var fileSystem = new SfbFileSystem(true);



			if (N["fileSystem"] != null && N["fileSystem"]["root"] != null) {

				ParseJSONInto(N["fileSystem"]["root"], "/", fileSystem);

			}

			else {

				Debug.Log("No root found: " + N.ToString(""));

			}



			return fileSystem;

		}



		public static void ParseJSONInto (JSONNode N, string parentPath, SfbFileSystem fileSystem) {

			if (N["contents"] == null || N["contents"].Count == 0) {

				return;

			}



			foreach (var child in N["contents"].Childs) {

				if (child["logicalDrive"] != null) {

					if (child["logicalDrive"]["name"] == null) {

						return;

					}



					var path = parentPath + child["logicalDrive"]["name"].Value + "/";



					fileSystem.AddEntry(new SfbFileSystemEntry(path, false, SfbFileSystemEntryType.LogicalDrive));

					ParseJSONInto(child["logicalDrive"], path, fileSystem);

				}

				if (child["folder"] != null) {

					if (child["folder"]["name"] == null) {

						return;

					}



					var path = parentPath + child["folder"]["name"].Value + "/";

					var hidden = child["folder"]["hidden"] != null && child["folder"]["hidden"].AsBool;



					fileSystem.AddEntry(new SfbFileSystemEntry(path, hidden, SfbFileSystemEntryType.Folder));

					ParseJSONInto(child["folder"], path, fileSystem);

				}

				if (child["file"] != null) {

					if (child["file"]["name"] == null || child["file"]["extension"] == null) {

						return;

					}



					var path = parentPath + child["file"]["name"].Value + "." + child["file"]["extension"].Value;

					var hidden = child["file"]["hidden"] != null && child["file"]["hidden"].AsBool;



					fileSystem.AddEntry(new SfbFileSystemEntry(path, hidden, SfbFileSystemEntryType.File));

				}

			}

		}



		public SfbFileSystemEntry GetParentDirectory (string path) {

			if (entries.ContainsKey(path) && entries[path].parent != null) {

				return entries[path].parent;

			}



			if (path.EndsWith("/")) {

				path = path.Remove(path.Length - 1);

			}

			path = Regex.Replace(path, @"[^/]*$", "");

			if (path == "") {

				path = "/";

			}



			if (entries.ContainsKey(path)) {

				return entries[path];

			}

			if (IsFake) {

				return null;

			}



			return ReadDirectory(path);

		}



		private SfbFileSystemEntry ReadFile (string path) {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			if (IsFake) {

				return null;

			}

			string normalizedPath = GetNormalizedPath(path);

			if (!File.Exists(normalizedPath)) {

				return null;

			}

			SfbFileSystemEntry entry;



			if (!entries.ContainsKey(normalizedPath)) {

				bool hidden = (File.GetAttributes(normalizedPath) & FileAttributes.Hidden) != 0;

				entry = new SfbFileSystemEntry(normalizedPath, hidden, SfbFileSystemEntryType.File);

				AddEntry(entry);

			}

			else {

				entry = entries[normalizedPath];

			}

			return entry;

#else

			return null;

#endif

		}



		private SfbFileSystemEntry ReadDirectory (string path) {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			if (IsFake) {

				return null;

			}

			string normalizedPath = GetNormalizedPath(path);

			SfbFileSystemEntry entry;



			if (!entries.ContainsKey(normalizedPath)) {

				bool hidden = (new DirectoryInfo(normalizedPath).Attributes & FileAttributes.Hidden) != 0;

				entry = new SfbFileSystemEntry(normalizedPath, hidden, SfbFileSystemEntryType.Folder);

				AddEntry(entry);

			}

			else {

				entry = entries[normalizedPath];

			}

			return entry;

#else

			return null;

#endif

		}



		private void ReadLogicalDrives () {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			if (IsFake) {

				return;

			}



			var drives = new List<string>();

			foreach (string drive in Environment.GetLogicalDrives()) {

				bool accessible = true;

				try {

					Directory.GetFileSystemEntries(drive);

				}

				catch (Exception) {

					accessible = false;

				}

				if (accessible) {

					string normalizedPath = drive.Replace('\\', '/');

					drives.Add(normalizedPath);

				}

			}



			var remove = root.children.Select(a => a.path).Except(drives);

			foreach (var s in remove) {

				RemoveEntry(entries[s]);

			}



			foreach (var drive in drives) {

				if (entries.ContainsKey(drive)) {

					continue;

				}



				var entry = new SfbFileSystemEntry(drive, false, SfbFileSystemEntryType.LogicalDrive);

				AddEntry(entry);

			}



			root.readContents = true;

#endif

		}



		public SfbFileSystemEntry CreateNewFileAndAddEntry (string path) {

			if (entries.ContainsKey(path)) {

				Debug.LogWarning("File already exists");

				return null;

			}



			SfbFileSystemEntry entry = new SfbFileSystemEntry(path, false, SfbFileSystemEntryType.File);



#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			if (!IsFake) {

				try {

					File.Create(path);

				}

				catch (Exception e) {

					Debug.LogException(e);

					Debug.LogError("Could not create file");

					return null;

				}

			}

#endif



			AddEntry(entry);

			return entry;

		}



		public void ReadFileOrBackupFromDisk (SfbFileSystemEntry fileSystemEntry, string backupExtension) {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			if (string.IsNullOrEmpty(backupExtension)) {

				Debug.LogError("Cannot read backup file bacause no backup extension was set.");

				return;

			}

			if (fileSystemEntry.type != SfbFileSystemEntryType.File) {

				return;

			}



			if (!backupExtension.StartsWith(".")) {

				backupExtension = "." + backupExtension;

			}



			if (!File.Exists(fileSystemEntry.path)) {

				if (File.Exists(fileSystemEntry.path + backupExtension)) {

					fileSystemEntry.SetContents(File.ReadAllBytes(fileSystemEntry.path + backupExtension));

				}



				return;

			}



			fileSystemEntry.ReadContentsFromDisk();

#endif

		}



		public void CreateBackup (string path, string backupExtension) {

#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			if (string.IsNullOrEmpty(backupExtension)) {

				Debug.LogError("Cannot write backup file bacause no backup extension was set.");

				return;

			}

			if (!backupExtension.StartsWith(".")) {

				backupExtension = "." + backupExtension;

			}

			if (!File.Exists(path)) {

				return;

			}

			string backupPath = path + backupExtension;



			try {

				if (File.Exists(backupPath)) {

					File.Move(backupPath, backupPath + ".temp");

				}



				File.Move(path, backupPath);



				if (File.Exists(backupPath + ".temp")) {

					File.Delete(backupPath + ".temp");

				}



				var backupEntry = GetFile(backupPath) ?? new SfbFileSystemEntry(backupPath, false, SfbFileSystemEntryType.File);

				AddEntry(backupEntry);

			}

			catch (Exception e) {

				Debug.LogException(e);

			}

#endif

		}



		public void WriteBytesToDisk (string path, byte[] bytes) {

			path = GetNormalizedPath(path);



			var entry = GetFile(path) ?? new SfbFileSystemEntry(path, false, SfbFileSystemEntryType.File);



			entry.SetContents(bytes);

			entry.WriteContentsToDisk();

		}



		private bool IsUpdatingDirectoryContents;

		public void AsyncUpdateDirectoryContents (SfbFileSystemEntry fileSystemEntry) {

			if (IsFake) {

				fileSystemEntry.readContents = true;

				return;

			}



#if !UNITY_WEBGL && !UNITY_WEBPLAYER

			if (fileSystemEntry.readContents || IsUpdatingDirectoryContents) {

				return;

			}

			if (fileSystemEntry.type == SfbFileSystemEntryType.Root) {

				ReadLogicalDrives();

				return;

			}



			thread.AsyncReadDirectoryContents(fileSystemEntry.path, AsyncRecieveDirectoryContents);

			IsUpdatingDirectoryContents = true;

#endif

		}



		private void AsyncRecieveDirectoryContents (string path, SfbFileSystemEntry[] contents) {

			path = GetNormalizedPath(path);

			if (!entries.ContainsKey(path)) {

				Debug.Log("entry does not exist");

				return;

			}

			var directory = entries[path];



			foreach (var entry in contents) {

				if (entries.ContainsKey(entry.path)) {

					directory.AddChild(entries[entry.path]);

					continue;

				}



				directory.AddChild(entry);

				entries.Add(entry.path, entry);

			}



			directory.ReadLastWriteTime();

			directory.readContents = true;

			IsUpdatingDirectoryContents = false;

		}

	}

}