using System;
using System.Collections.Generic;
using System.IO;
using Godot;
using TBL.GodotSharp.IO.File;
using Zio;

namespace TBL.GodotSharp.Content.FileSystem
{
    /// <summary>
    /// Godot 文件系统
    /// </summary>
    public class GodotFileSystem : Zio.FileSystems.FileSystem
    {
        /// <summary>
        /// 根目录
        /// </summary>
        private readonly string _rootPath;

        /// <summary>
        /// 目录工具
        /// </summary>
        private readonly Godot.Directory _directoryTool;

        public GodotFileSystem(string rootPath)
        {
            _rootPath = rootPath;
            _directoryTool = new Godot.Directory();
        }

        private string GetFullPath(UPath uPath) => $"{_rootPath}{uPath}";

        protected override void CreateDirectoryImpl(UPath path)
        {
            _directoryTool.MakeDirRecursive(GetFullPath(path));
        }

        protected override bool DirectoryExistsImpl(UPath path) => _directoryTool.DirExists(GetFullPath(path));
        
        protected override bool FileExistsImpl(UPath path) => _directoryTool.FileExists(GetFullPath(path));
        
        protected override Stream OpenFileImpl(UPath path, FileMode mode, FileAccess access, FileShare share)
        {
            if (mode == FileMode.Open && access == FileAccess.Read)
            {
                return new GodotFileStream(GetFullPath(path), Godot.File.ModeFlags.Read);
            }

            throw new FileNotFoundException();
        }
        
        protected override IEnumerable<UPath> EnumeratePathsImpl(
            UPath path, 
            string searchPattern, 
            SearchOption searchOption, 
            SearchTarget searchTarget
            )
        {
            var directoryTool = new Godot.Directory();
            var err = directoryTool.Open(GetFullPath(path));
            if (err != Error.Ok)
                throw new IOException($"{err}");
            directoryTool.ListDirBegin();

            var searchPatternMatcher = SearchPattern.Parse(ref path, ref searchPattern);
            
            for (var current = directoryTool.GetNext();; current = directoryTool.GetNext())
            {
                if (string.IsNullOrEmpty(current))
                    break;
                if (current == ".." || current == ".")
                    continue;
                if ((searchTarget == SearchTarget.Both || searchTarget == SearchTarget.File) &&
                    !directoryTool.CurrentIsDir() && searchPatternMatcher.Match(current))
                    yield return System.IO.Path.Combine(path.FullName, current);
                if ((searchTarget == SearchTarget.Both || searchTarget == SearchTarget.Directory) &&
                    directoryTool.CurrentIsDir() && searchPatternMatcher.Match(current))
                    yield return System.IO.Path.Combine(path.FullName, current);
                if (directoryTool.CurrentIsDir() && searchOption == SearchOption.AllDirectories)
                {
                    foreach (var sub in EnumeratePathsImpl(System.IO.Path.Combine(path.FullName, current), 
                                 searchPattern, searchOption, searchTarget))
                    {
                        yield return sub;
                    }
                }
            }
            directoryTool.ListDirEnd();
        }

        protected override void MoveDirectoryImpl(UPath srcPath, UPath destPath)
        {
            throw new NotImplementedException();
        }

        protected override void DeleteDirectoryImpl(UPath path, bool isRecursive)
        {
            throw new NotImplementedException();
        }

        protected override void CopyFileImpl(UPath srcPath, UPath destPath, bool overwrite)
        {
            throw new NotImplementedException();
        }

        protected override void ReplaceFileImpl(UPath srcPath, UPath destPath, UPath destBackupPath, bool ignoreMetadataErrors)
        {
            throw new NotImplementedException();
        }

        protected override long GetFileLengthImpl(UPath path)
        {
            throw new NotImplementedException();
        }

        protected override void MoveFileImpl(UPath srcPath, UPath destPath)
        {
            throw new NotImplementedException();
        }

        protected override void DeleteFileImpl(UPath path)
        {
            throw new NotImplementedException();
        }

        protected override FileAttributes GetAttributesImpl(UPath path)
        {
            throw new NotImplementedException();
        }

        protected override void SetAttributesImpl(UPath path, FileAttributes attributes)
        {
            throw new NotImplementedException();
        }

        protected override DateTime GetCreationTimeImpl(UPath path)
        {
            throw new NotImplementedException();
        }

        protected override void SetCreationTimeImpl(UPath path, DateTime time)
        {
            throw new NotImplementedException();
        }

        protected override DateTime GetLastAccessTimeImpl(UPath path)
        {
            throw new NotImplementedException();
        }

        protected override void SetLastAccessTimeImpl(UPath path, DateTime time)
        {
            throw new NotImplementedException();
        }

        protected override DateTime GetLastWriteTimeImpl(UPath path)
        {
            throw new NotImplementedException();
        }

        protected override void SetLastWriteTimeImpl(UPath path, DateTime time)
        {
            throw new NotImplementedException();
        }

        protected override IEnumerable<FileSystemItem> EnumerateItemsImpl(UPath path, SearchOption searchOption, SearchPredicate searchPredicate)
        {
            throw new NotImplementedException();
        }

        protected override IFileSystemWatcher WatchImpl(UPath path)
        {
            throw new NotImplementedException();
        }

        protected override string ConvertPathToInternalImpl(UPath path)
        {
            throw new NotImplementedException();
        }

        protected override UPath ConvertPathFromInternalImpl(string innerPath)
        {
            throw new NotImplementedException();
        }
    }
}