using System;
using System.Collections.Generic;
using System.IO;

namespace CMLeonOS
{
    public class FileSystem
    {
        private string currentDirectory;

        public FileSystem()
        {
            currentDirectory = @"0:\";
        }

        public string CurrentDirectory
        {
            get { return currentDirectory; }
        }

        public void ChangeDirectory(string path)
        {
            if (string.IsNullOrEmpty(path))
            {
                currentDirectory = @"0:\";
                return;
            }

            string fullPath = GetFullPath(path);
            
            try
            {
                if (Directory.Exists(fullPath))
                {
                    currentDirectory = fullPath;
                }
                else
                {
                    Console.WriteLine($"Directory not found: {path}");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error changing directory: {ex.Message}");
            }
        }

        public void MakeDirectory(string path)
        {
            string fullPath = GetFullPath(path);
            
            try
            {
                if (!Directory.Exists(fullPath))
                {
                    Directory.CreateDirectory(fullPath);
                    Console.WriteLine($"Directory created: {path}");
                }
                else
                {
                    Console.WriteLine($"Directory already exists: {path}");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error creating directory: {ex.Message}");
            }
        }

        public void ListFiles(string path = ".")
        {
            string fullPath = GetFullPath(path);
            
            try
            {
                if (Directory.Exists(fullPath))
                {
                    // 列出当前目录下的文件和子目录
                    Console.WriteLine($"Contents of {path}:");
                    
                    // 列出子目录
                    try
                    {
                        var dirs = Directory.GetDirectories(fullPath);
                        foreach (var dir in dirs)
                        {
                            // 使用Path.GetFileName获取目录名，避免Substring可能导致的问题
                            string dirName = Path.GetFileName(dir);
                            Console.WriteLine($"[DIR]  {dirName}");
                        }
                    }
                    catch
                    {
                        // 可能没有权限或其他错误
                    }
                    
                    // 列出文件
                    try
                    {
                        var files = Directory.GetFiles(fullPath);
                        foreach (var file in files)
                        {
                            // 使用Path.GetFileName获取文件名，避免Substring可能导致的问题
                            string fileName = Path.GetFileName(file);
                            Console.WriteLine($"[FILE] {fileName}");
                        }
                    }
                    catch
                    {
                        // 可能没有权限或其他错误
                    }
                }
                else
                {
                    Console.WriteLine($"Directory not found: {path}");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error listing files: {ex.Message}");
            }
        }

        public void CreateFile(string path, string content = "")
        {
            string fullPath = GetFullPath(path);
            
            try
            {
                // 创建或覆盖文件
                File.WriteAllText(fullPath, content);
                Console.WriteLine($"File created: {path}");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error creating file: {ex.Message}");
            }
        }

        public void WriteFile(string path, string content)
        {
            string fullPath = GetFullPath(path);
            
            try
            {
                if (File.Exists(fullPath))
                {
                    File.WriteAllText(fullPath, content);
                    Console.WriteLine($"File written: {path}");
                }
                else
                {
                    Console.WriteLine($"File not found: {path}");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error writing file: {ex.Message}");
            }
        }

        public string ReadFile(string path)
        {
            string fullPath = GetFullPath(path);
            
            try
            {
                if (File.Exists(fullPath))
                {
                    return File.ReadAllText(fullPath);
                }
                else
                {
                    Console.WriteLine($"File not found: {path}");
                    return "";
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error reading file: {ex.Message}");
                return "";
            }
        }

        public void DeleteFile(string path)
        {
            string fullPath = GetFullPath(path);
            
            try
            {
                if (File.Exists(fullPath))
                {
                    File.Delete(fullPath);
                    Console.WriteLine($"File deleted: {path}");
                }
                else
                {
                    Console.WriteLine($"File not found: {path}");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error deleting file: {ex.Message}");
            }
        }

        public void DeleteDirectory(string path)
        {
            string fullPath = GetFullPath(path);
            
            try
            {
                if (Directory.Exists(fullPath))
                {
                    try
                    {
                        // 尝试删除目录
                        Directory.Delete(fullPath);
                        Console.WriteLine($"Directory deleted: {path}");
                    }
                    catch
                    {
                        // 目录可能不为空
                        Console.WriteLine($"Directory not empty: {path}");
                    }
                }
                else
                {
                    Console.WriteLine($"Directory not found: {path}");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error deleting directory: {ex.Message}");
            }
        }

        private string GetFullPath(string path)
        {
            if (path.StartsWith(@"0:\"))
            {
                return path;
            }
            else if (path == ".")
            {
                return currentDirectory;
            }
            else if (path == "..")
            {
                if (currentDirectory == @"0:\")
                {
                    return @"0:\";
                }
                else
                {
                    int lastSlash = currentDirectory.LastIndexOf('\\');
                    if (lastSlash == 2) // 0:\
                    {
                        return @"0:\";
                    }
                    else
                    {
                        return currentDirectory.Substring(0, lastSlash);
                    }
                }
            }
            else
            {
                if (currentDirectory == @"0:\")
                {
                    return $@"0:\{path}";
                }
                else
                {
                    return $@"{currentDirectory}\{path}";
                }
            }
        }
    }
}