DearFTP/DearFTP/Connection/Commands/DeleteCommand.cs

using DearFTP.Utils;
using System;
using System.IO;
using System.Linq;

namespace DearFTP.Connection.Commands
{
    class DeleteCommand : ICommand
    {
        public string[] Aliases { get; } = new string[]
        {
            "DELE",
            "RMD",
            "XRMD"
        };

        public void Execute(Session session, FtpStream stream, string alias, string argument)
        {
            (NavigablePath navigablePath, string path, bool isDirectory) = session.NavigablePath.GetSystemFilePath(argument);

            if (navigablePath == null)
            {
                stream.Send(ResponseCode.FileUnavailable, "File does not exist.");
                return;
            }

            if (navigablePath.CurrentDirectory == "/")
            {
                stream.Send(ResponseCode.FileUnavailable, "Operation not allowed: can't remove a share.");
                return;
            }

            if (!session.WritablesShares.Contains(navigablePath.CurrentShare))
            {
                stream.Send(ResponseCode.FileUnavailable, "You don't have write access to this file.");
                return;
            }

            if (isDirectory)
            {
                if (alias.ToUpper() == "RMD")
                {
                    Directory.Delete(path, true);

                    stream.Send(ResponseCode.FileActionOK, "Directory successfully deleted.");
                }
                else
                {
                    stream.Send(ResponseCode.ArgumentsError, "Path is a directory and not a file.");
                }
            }
            else
            {
                if (alias.ToUpper() == "DELE")
                {
                    File.Delete(path);

                    stream.Send(ResponseCode.FileActionOK, "File successfully deleted");
                }
                else
                {
                    stream.Send(ResponseCode.ArgumentsError, "Path is a file and not a directory.");
                }
            }
        }
    }
}