Imports System.Collections.Generic
Imports System.Net
Imports System.IO
Imports System.Text.RegularExpressions

#Region "FTP client class"
''' <summary>
''' A wrapper class for .NET 2.0 FTP
''' </summary>
''' <remarks>
''' This class does not hold open an FTP connection but 
''' instead is stateless: for each FTP request it 
''' connects, performs the request and disconnects.
''' </remarks>
Public Class FTPclient

#Region "CONSTRUCTORS"
    ''' <summary>
    ''' Blank constructor
    ''' </summary>
    ''' <remarks>Hostname, username and password must be set manually</remarks>
    Sub New()
    End Sub

    ''' <summary>
    ''' Constructor just taking the hostname
    ''' </summary>
    ''' <param name="Hostname">in either ftp://ftp.host.com or ftp.host.com form</param>
    ''' <remarks></remarks>
    Sub New(ByVal Hostname As String)
        _hostname = Hostname
    End Sub

    ''' <summary>
    ''' Constructor taking hostname, username and password
    ''' </summary>
    ''' <param name="Hostname">in either ftp://ftp.host.com or ftp.host.com form</param>
    ''' <param name="Username">Leave blank to use 'anonymous' but set password to your email</param>
    ''' <param name="Password"></param>
    ''' <remarks></remarks>
    Sub New(ByVal Hostname As String, ByVal Username As String, ByVal Password As String)
        _hostname = Hostname
        _username = Username
        _password = Password
    End Sub
#End Region

#Region "Directory functions"
    ''' <summary>
    ''' Return a simple directory listing
    ''' </summary>
    ''' <param name="directory">Directory to list, e.g. /pub</param>
    ''' <returns>A list of filenames and directories as a List(of String)</returns>
    ''' <remarks>For a detailed directory listing, use ListDirectoryDetail</remarks>
    Public Function ListDirectory(Optional ByVal directory As String = "") As List(Of String)
        'return a simple list of filenames in directory
        Dim ftp As Net.FtpWebRequest = GetRequest(GetDirectory(directory))
        'Set request to do simple list
        ftp.Method = Net.WebRequestMethods.Ftp.ListDirectory

        Dim str As String = GetStringResponse(ftp)
        'replace CRLF to CR, remove last instance
        str = str.Replace(vbCrLf, vbCr).TrimEnd(Chr(13))
        'split the string into a list
        Dim result As New List(Of String)
        result.AddRange(str.Split(Chr(13)))
        Return result
    End Function

    ''' <summary>
    ''' Return a detailed directory listing
    ''' </summary>
    ''' <param name="directory">Directory to list, e.g. /pub/etc</param>
    ''' <returns>An FTPDirectory object</returns>
    Public Function ListDirectoryDetail(Optional ByVal directory As String = "") As FTPdirectory
        Dim ftp As Net.FtpWebRequest = GetRequest(GetDirectory(directory))
        'Set request to do simple list
        ftp.Method = Net.WebRequestMethods.Ftp.ListDirectoryDetails

        Dim str As String = GetStringResponse(ftp)
        'replace CRLF to CR, remove last instance
        str = str.Replace(vbCrLf, vbCr).TrimEnd(Chr(13))
        'split the string into a list
        Return New FTPdirectory(str, _lastDirectory)
    End Function

#End Region

#Region "Upload: File transfer TO ftp server"
    ''' <summary>
    ''' Copy a local file to the FTP server
    ''' </summary>
    ''' <param name="localFilename">Full path of the local file</param>
    ''' <param name="targetFilename">Target filename, if required</param>
    ''' <returns></returns>
    ''' <remarks>If the target filename is blank, the source filename is used
    ''' (assumes current directory). Otherwise use a filename to specify a name
    ''' or a full path and filename if required.</remarks>
    Public Function Upload(ByVal localFilename As String, Optional ByVal targetFilename As String = "") As Boolean
        '1. check source
        If Not File.Exists(localFilename) Then
            Throw New ApplicationException("File " & localFilename & " not found")
        End If
        'copy to FI
        Dim fi As New FileInfo(localFilename)
        Return Upload(fi, targetFilename)
    End Function

    ''' <summary>
    ''' Upload a local file to the FTP server
    ''' </summary>
    ''' <param name="fi">Source file</param>
    ''' <param name="targetFilename">Target filename (optional)</param>
    ''' <returns></returns>
    Public Function Upload(ByVal fi As FileInfo, Optional ByVal targetFilename As String = "") As Boolean
        'copy the file specified to target file: target file can be full path or just filename (uses current dir)

        '1. check target
        Dim target As String
        If targetFilename.Trim = "" Then
            'Blank target: use source filename & current dir
            target = Me.CurrentDirectory & fi.Name
        ElseIf targetFilename.Contains("/") Then
            'If contains / treat as a full path
            target = AdjustDir(targetFilename)
        Else
            'otherwise treat as filename only, use current directory
            target = CurrentDirectory & targetFilename
        End If

        Dim URI As String = Hostname & target
        'perform copy
        Dim ftp As Net.FtpWebRequest = GetRequest(URI)

        'Set request to upload a file in binary
        ftp.Method = Net.WebRequestMethods.Ftp.UploadFile
        ftp.UseBinary = True

        'Notify FTP of the expected size
        ftp.ContentLength = fi.Length

        'create byte array to store: ensure at least 1 byte!
        Const BufferSize As Integer = 2048
        Dim content(BufferSize - 1) As Byte, dataRead As Integer

        'open file for reading 
        Using fs As FileStream = fi.OpenRead()
            Try
                'open request to send
                Using rs As Stream = ftp.GetRequestStream
                    Do
                        dataRead = fs.Read(content, 0, BufferSize)
                        rs.Write(content, 0, dataRead)
                    Loop Until dataRead < BufferSize
                    rs.Close()
                End Using
            Catch ex As Exception

            Finally
                'ensure file closed
                fs.Close()
            End Try

        End Using

        ftp = Nothing
        Return True

    End Function
#End Region

#Region "Download: File transfer FROM ftp server"
    ''' <summary>
    ''' Copy a file from FTP server to local
    ''' </summary>
    ''' <param name="sourceFilename">Target filename, if required</param>
    ''' <param name="localFilename">Full path of the local file</param>
    ''' <returns></returns>
    ''' <remarks>Target can be blank (use same filename), or just a filename
    ''' (assumes current directory) or a full path and filename</remarks>
    Public Function Download(ByVal sourceFilename As String, ByVal localFilename As String, Optional ByVal PermitOverwrite As Boolean = False) As Boolean
        '2. determine target file
        Dim fi As New FileInfo(localFilename)
        Return Me.Download(sourceFilename, fi, PermitOverwrite)
    End Function

    'Version taking an FtpFileInfo
    Public Function Download(ByVal file As FTPfileInfo, ByVal localFilename As String, Optional ByVal PermitOverwrite As Boolean = False) As Boolean
        Return Me.Download(file.FullName, localFilename, PermitOverwrite)
    End Function

    'Another version taking FtpFileInfo and FileInfo
    Public Function Download(ByVal file As FTPfileInfo, ByVal localFI As FileInfo, Optional ByVal PermitOverwrite As Boolean = False) As Boolean
        Return Me.Download(file.FullName, localFI, PermitOverwrite)
    End Function

    'Version taking string/FileInfo
    Public Function Download(ByVal sourceFilename As String, ByVal targetFI As FileInfo, Optional ByVal PermitOverwrite As Boolean = False) As Boolean
        '1. check target
        If targetFI.Exists And Not (PermitOverwrite) Then Throw New ApplicationException("Target file already exists")

        '2. check source
        Dim target As String
        If sourceFilename.Trim = "" Then
            Throw New ApplicationException("File not specified")
        ElseIf sourceFilename.Contains("/") Then
            'treat as a full path
            target = AdjustDir(sourceFilename)
        Else
            'treat as filename only, use current directory
            target = CurrentDirectory & sourceFilename
        End If

        Dim URI As String = Hostname & target

        '3. perform copy
        Dim ftp As Net.FtpWebRequest = GetRequest(URI)

        'Set request to download a file in binary mode
        ftp.Method = Net.WebRequestMethods.Ftp.DownloadFile
        ftp.UseBinary = True

        'open request and get response stream
        Using response As FtpWebResponse = CType(ftp.GetResponse, FtpWebResponse)
            Using responseStream As Stream = response.GetResponseStream
                'loop to read & write to file
                Using fs As FileStream = targetFI.OpenWrite
                    Try
                        Dim buffer(2047) As Byte
                        Dim read As Integer = 0
                        Do
                            read = responseStream.Read(buffer, 0, buffer.Length)
                            fs.Write(buffer, 0, read)
                        Loop Until read = 0
                        responseStream.Close()
                        fs.Flush()
                        fs.Close()
                    Catch ex As Exception
                        'catch error and delete file only partially downloaded
                        fs.Close()
                        'delete target file as it's incomplete
                        targetFI.Delete()
                        Throw
                    End Try
                End Using
                responseStream.Close()
            End Using
            response.Close()
        End Using

        Return True
    End Function
#End Region

#Region "Other functions: Delete rename etc."
    ''' <summary>
    ''' Delete remote file
    ''' </summary>
    ''' <param name="filename">filename or full path</param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Function FtpDelete(ByVal filename As String) As Boolean
        'Determine if file or full path
        Dim URI As String = Me.Hostname & GetFullPath(filename)

        Dim ftp As Net.FtpWebRequest = GetRequest(URI)
        'Set request to delete
        ftp.Method = Net.WebRequestMethods.Ftp.DeleteFile
        Try
            'get response but ignore it
            Dim str As String = GetStringResponse(ftp)
        Catch ex As Exception
            Return False
        End Try
        Return True
    End Function

    ''' <summary>
    ''' Determine if file exists on remote FTP site
    ''' </summary>
    ''' <param name="filename">Filename (for current dir) or full path</param>
    ''' <returns></returns>
    ''' <remarks>Note this only works for files</remarks>
    Public Function FtpFileExists(ByVal filename As String) As Boolean
        'Try to obtain filesize: if we get error msg containing "550"
        'the file does not exist
        Try
            Dim size As Long = GetFileSize(filename)
            Return True

        Catch ex As Exception
            'only handle expected not-found exception
            If TypeOf ex Is System.Net.WebException Then
                'file does not exist/no rights error = 550
                If ex.Message.Contains("550") Then
                    'clear 
                    Return False
                Else
                    Throw
                End If
            Else
                Throw
            End If
        End Try
    End Function

    ''' <summary>
    ''' Determine size of remote file
    ''' </summary>
    ''' <param name="filename"></param>
    ''' <returns></returns>
    ''' <remarks>Throws an exception if file does not exist</remarks>
    Public Function GetFileSize(ByVal filename As String) As Long
        Dim path As String
        If filename.Contains("/") Then
            path = AdjustDir(filename)
        Else
            path = Me.CurrentDirectory & filename
        End If
        Dim URI As String = Me.Hostname & path
        Dim ftp As Net.FtpWebRequest = GetRequest(URI)
        'Try to get info on file/dir?
        ftp.Method = Net.WebRequestMethods.Ftp.GetFileSize
        Dim tmp As String = Me.GetStringResponse(ftp)
        Return GetSize(ftp)
    End Function

    Public Function FtpRename(ByVal sourceFilename As String, ByVal newName As String) As Boolean
        'Does file exist?
        Dim source As String = GetFullPath(sourceFilename)
        If Not FtpFileExists(source) Then
            Throw New FileNotFoundException("File " & source & " not found")
        End If

        'build target name, ensure it does not exist
        Dim target As String = GetFullPath(newName)
        If target = source Then
            Throw New ApplicationException("Source and target are the same")
        ElseIf FtpFileExists(target) Then
            Throw New ApplicationException("Target file " & target & " already exists")
        End If

        'perform rename
        Dim URI As String = Me.Hostname & source

        Dim ftp As Net.FtpWebRequest = GetRequest(URI)
        'Set request to delete
        ftp.Method = Net.WebRequestMethods.Ftp.Rename
        ftp.RenameTo = target
        Try
            'get response but ignore it
            Dim str As String = GetStringResponse(ftp)
        Catch ex As Exception
            Return False
        End Try
        Return True
    End Function

    Public Function FtpCreateDirectory(ByVal dirpath As String) As Boolean
        'perform create
        Dim URI As String = Me.Hostname & AdjustDir(dirpath)
        Dim ftp As Net.FtpWebRequest = GetRequest(URI)
        'Set request to MkDir
        ftp.Method = Net.WebRequestMethods.Ftp.MakeDirectory
        Try
            'get response but ignore it
            Dim str As String = GetStringResponse(ftp)
        Catch ex As Exception
            Return False
        End Try
        Return True
    End Function

    Public Function FtpDeleteDirectory(ByVal dirpath As String) As Boolean
        'perform remove
        Dim URI As String = Me.Hostname & AdjustDir(dirpath)
        Dim ftp As Net.FtpWebRequest = GetRequest(URI)
        'Set request to RmDir
        ftp.Method = Net.WebRequestMethods.Ftp.RemoveDirectory
        Try
            'get response but ignore it
            Dim str As String = GetStringResponse(ftp)
        Catch ex As Exception
            Return False
        End Try
        Return True
    End Function
#End Region

#Region "private supporting fns"
    'Get the basic FtpWebRequest object with the
    'common settings and security
    Private Function GetRequest(ByVal URI As String) As FtpWebRequest
        'create request
        Dim result As FtpWebRequest = CType(FtpWebRequest.Create(URI), FtpWebRequest)
        'Set the login details
        result.Credentials = GetCredentials()
        'Do not keep alive (stateless mode)
        result.KeepAlive = False
        Return result
    End Function


    ''' <summary>
    ''' Get the credentials from username/password
    ''' </summary>
    Private Function GetCredentials() As Net.ICredentials
        Return New Net.NetworkCredential(Username, Password)
    End Function

    ''' <summary>
    ''' returns a full path using CurrentDirectory for a relative file reference
    ''' </summary>
    Private Function GetFullPath(ByVal file As String) As String
        If file.Contains("/") Then
            Return AdjustDir(file)
        Else
            Return Me.CurrentDirectory & file
        End If
    End Function

    ''' <summary>
    ''' Amend an FTP path so that it always starts with /
    ''' </summary>
    ''' <param name="path">Path to adjust</param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Private Function AdjustDir(ByVal path As String) As String
        Return CStr(IIf(path.StartsWith("/"), "", "/")) & path
    End Function

    Private Function GetDirectory(Optional ByVal directory As String = "") As String
        Dim URI As String
        If directory = "" Then
            'build from current
            URI = Hostname & Me.CurrentDirectory
            _lastDirectory = Me.CurrentDirectory
        Else
            If Not directory.StartsWith("/") Then Throw New ApplicationException("Directory should start with /")
            URI = Me.Hostname & directory
            _lastDirectory = directory
        End If
        Return URI
    End Function

    'stores last retrieved/set directory
    Private _lastDirectory As String = ""

    ''' <summary>
    ''' Obtains a response stream as a string
    ''' </summary>
    ''' <param name="ftp">current FTP request</param>
    ''' <returns>String containing response</returns>
    ''' <remarks>FTP servers typically return strings with CR and
    ''' not CRLF. Use respons.Replace(vbCR, vbCRLF) to convert
    ''' to an MSDOS string</remarks>
    Private Function GetStringResponse(ByVal ftp As FtpWebRequest) As String
        'Get the result, streaming to a string
        Dim result As String = ""
        Using response As FtpWebResponse = CType(ftp.GetResponse, FtpWebResponse)
            Dim size As Long = response.ContentLength
            Using datastream As Stream = response.GetResponseStream
                Using sr As New StreamReader(datastream)
                    result = sr.ReadToEnd()
                    sr.Close()
                End Using
                datastream.Close()
            End Using
            response.Close()
        End Using
        Return result
    End Function

    ''' <summary>
    ''' Gets the size of an FTP request
    ''' </summary>
    ''' <param name="ftp"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Private Function GetSize(ByVal ftp As FtpWebRequest) As Long
        Dim size As Long
        Using response As FtpWebResponse = CType(ftp.GetResponse, FtpWebResponse)
            size = response.ContentLength
            response.Close()
        End Using
        Return size
    End Function
#End Region

#Region "Properties"
    Private _hostname As String
    ''' <summary>
    ''' Hostname
    ''' </summary>
    ''' <value></value>
    ''' <remarks>Hostname can be in either the full URL format
    ''' ftp://ftp.myhost.com or just ftp.myhost.com
    ''' </remarks>
    Public Property Hostname() As String
        Get
            If _hostname.StartsWith("ftp://") Then
                Return _hostname
            Else
                Return "ftp://" & _hostname
            End If
        End Get
        Set(ByVal value As String)
            _hostname = value
        End Set
    End Property
    Private _username As String
    ''' <summary>
    ''' Username property
    ''' </summary>
    ''' <value></value>
    ''' <remarks>Can be left blank, in which case 'anonymous' is returned</remarks>
    Public Property Username() As String
        Get
            Return IIf(_username = "", "anonymous", _username)
        End Get
        Set(ByVal value As String)
            _username = value
        End Set
    End Property
    Private _password As String
    Public Property Password() As String
        Get
            Return _password
        End Get
        Set(ByVal value As String)
            _password = value
        End Set
    End Property

    ''' <summary>
    ''' The CurrentDirectory value
    ''' </summary>
    ''' <remarks>Defaults to the root '/'</remarks>
    Private _currentDirectory As String = "/"
    Public Property CurrentDirectory() As String
        Get
            'return directory, ensure it ends with /
            Return _currentDirectory & CStr(IIf(_currentDirectory.EndsWith("/"), "", "/"))
        End Get
        Set(ByVal value As String)
            If Not value.StartsWith("/") Then Throw New ApplicationException("Directory should start with /")
            _currentDirectory = value
        End Set
    End Property


#End Region

End Class
#End Region

#Region "FTP file info class"
    ''' <summary>
    ''' Represents a file or directory entry from an FTP listing
    ''' </summary>
    ''' <remarks>
    ''' This class is used to parse the results from a detailed
    ''' directory list from FTP. It supports most formats of
    ''' </remarks>
    Public Class FTPfileInfo
        'Stores extended info about FTP file

#Region "Properties"
        Public ReadOnly Property FullName() As String
            Get
                Return Path & Filename
            End Get
        End Property
        Public ReadOnly Property Filename() As String
            Get
                Return _filename
            End Get
        End Property
        Public ReadOnly Property Path() As String
            Get
                Return _path
            End Get
        End Property
        Public ReadOnly Property FileType() As DirectoryEntryTypes
            Get
                Return _fileType
            End Get
        End Property
        Public ReadOnly Property Size() As Long
            Get
                Return _size
            End Get
        End Property
        Public ReadOnly Property FileDateTime() As Date
            Get
                Return _fileDateTime
            End Get
        End Property
        Public ReadOnly Property Permission() As String
            Get
                Return _permission
            End Get
        End Property
        Public ReadOnly Property Extension() As String
            Get
                Dim i As Integer = Me.Filename.LastIndexOf(".")
                If i >= 0 And i < (Me.Filename.Length - 1) Then
                    Return Me.Filename.Substring(i + 1)
                Else
                    Return ""
                End If
            End Get
        End Property
        Public ReadOnly Property NameOnly() As String
            Get
                Dim i As Integer = Me.Filename.LastIndexOf(".")
                If i > 0 Then
                    Return Me.Filename.Substring(0, i)
                Else
                    Return Me.Filename
                End If
            End Get
        End Property
        Private _filename As String
        Private _path As String
        Private _fileType As DirectoryEntryTypes
        Private _size As Long
        Private _fileDateTime As Date
        Private _permission As String

#End Region

        ''' <summary>
        ''' Identifies entry as either File or Directory
        ''' </summary>
        Public Enum DirectoryEntryTypes
            File
            Directory
        End Enum

        ''' <summary>
        ''' Constructor taking a directory listing line and path
        ''' </summary>
        ''' <param name="line">The line returned from the detailed directory list</param>
        ''' <param name="path">Path of the directory</param>
        ''' <remarks></remarks>
        Sub New(ByVal line As String, ByVal path As String)
            'parse line
            Dim m As Match = GetMatchingRegex(line)
            If m Is Nothing Then
                'failed
                Throw New ApplicationException("Unable to parse line: " & line)
            Else
                _filename = m.Groups("name").Value
                _path = path
                _size = CLng(m.Groups("size").Value)
                _permission = m.Groups("permission").Value
                Dim _dir As String = m.Groups("dir").Value
                If (_dir <> "" And _dir <> "-") Then
                    _fileType = DirectoryEntryTypes.Directory
                Else
                    _fileType = DirectoryEntryTypes.File
                End If

                Try
                    _fileDateTime = Date.Parse(m.Groups("timestamp").Value)
                Catch ex As Exception
                    _fileDateTime = Nothing
                End Try

            End If
        End Sub

        Private Function GetMatchingRegex(ByVal line As String) As Match
            Dim rx As Regex, m As Match
            For i As Integer = 0 To _ParseFormats.Length - 1
                rx = New Regex(_ParseFormats(i))
                m = rx.Match(line)
                If m.Success Then Return m
            Next
            Return Nothing
        End Function

#Region "Regular expressions for parsing LIST results"
        ''' <summary>
        ''' List of REGEX formats for different FTP server listing formats
        ''' </summary>
        ''' <remarks>
        ''' The first three are various UNIX/LINUX formats, fourth is for MS FTP
        ''' in detailed mode and the last for MS FTP in 'DOS' mode.
        ''' I wish VB.NET had support for Const arrays like C# but there you go
        ''' </remarks>
        Private Shared _ParseFormats As String() = { _
            "(?<dir>[\-d])(?<permission>([\-r][\-w][\-xs]){3})\s+\d+\s+\w+\s+\w+\s+(?<size>\d+)\s+(?<timestamp>\w+\s+\d+\s+\d{4})\s+(?<name>.+)", _
            "(?<dir>[\-d])(?<permission>([\-r][\-w][\-xs]){3})\s+\d+\s+\d+\s+(?<size>\d+)\s+(?<timestamp>\w+\s+\d+\s+\d{4})\s+(?<name>.+)", _
            "(?<dir>[\-d])(?<permission>([\-r][\-w][\-xs]){3})\s+\d+\s+\d+\s+(?<size>\d+)\s+(?<timestamp>\w+\s+\d+\s+\d{1,2}:\d{2})\s+(?<name>.+)", _
            "(?<dir>[\-d])(?<permission>([\-r][\-w][\-xs]){3})\s+\d+\s+\w+\s+\w+\s+(?<size>\d+)\s+(?<timestamp>\w+\s+\d+\s+\d{1,2}:\d{2})\s+(?<name>.+)", _
            "(?<dir>[\-d])(?<permission>([\-r][\-w][\-xs]){3})(\s+)(?<size>(\d+))(\s+)(?<ctbit>(\w+\s\w+))(\s+)(?<size2>(\d+))\s+(?<timestamp>\w+\s+\d+\s+\d{2}:\d{2})\s+(?<name>.+)", _
            "(?<timestamp>\d{2}\-\d{2}\-\d{2}\s+\d{2}:\d{2}[Aa|Pp][mM])\s+(?<dir>\<\w+\>){0,1}(?<size>\d+){0,1}\s+(?<name>.+)"}
#End Region
    End Class
#End Region

#Region "FTP Directory class"
    ''' <summary>
    ''' Stores a list of files and directories from an FTP result
    ''' </summary>
    ''' <remarks></remarks>
    Public Class FTPdirectory
        Inherits List(Of FTPfileInfo)

        Sub New()
            'creates a blank directory listing
        End Sub

        ''' <summary>
        ''' Constructor: create list from a (detailed) directory string
        ''' </summary>
        ''' <param name="dir">directory listing string</param>
        ''' <param name="path"></param>
        ''' <remarks></remarks>
        Sub New(ByVal dir As String, ByVal path As String)
            For Each line As String In dir.Replace(vbLf, "").Split(CChar(vbCr))
                'parse
                If line <> "" Then Me.Add(New FTPfileInfo(line, path))
            Next
        End Sub

        ''' <summary>
        ''' Filter out only files from directory listing
        ''' </summary>
        ''' <param name="ext">optional file extension filter</param>
        ''' <returns>FTPdirectory listing</returns>
        Public Function GetFiles(Optional ByVal ext As String = "") As FTPdirectory
            Return Me.GetFileOrDir(FTPfileInfo.DirectoryEntryTypes.File, ext)
        End Function

        ''' <summary>
        ''' Returns a list of only subdirectories
        ''' </summary>
        ''' <returns>FTPDirectory list</returns>
        ''' <remarks></remarks>
        Public Function GetDirectories() As FTPdirectory
            Return Me.GetFileOrDir(FTPfileInfo.DirectoryEntryTypes.Directory)
        End Function

        'internal: share use function for GetDirectories/Files
        Private Function GetFileOrDir(ByVal type As FTPfileInfo.DirectoryEntryTypes, Optional ByVal ext As String = "") As FTPdirectory
            Dim result As New FTPdirectory()
            For Each fi As FTPfileInfo In Me
                If fi.FileType = type Then
                    If ext = "" Then
                        result.Add(fi)
                    ElseIf ext = fi.Extension Then
                        result.Add(fi)
                    End If
                End If
            Next
            Return result

        End Function

        Public Function FileExists(ByVal filename As String) As Boolean
            For Each ftpfile As FTPfileInfo In Me
                If ftpfile.Filename = filename Then
                    Return True
                End If
            Next
            Return False
        End Function

        Private Const slash As Char = "/"

        Public Shared Function GetParentDirectory(ByVal dir As String) As String
            Dim tmp As String = dir.TrimEnd(slash)
            Dim i As Integer = tmp.LastIndexOf(slash)
            If i > 0 Then
                Return tmp.Substring(0, i - 1)
            Else
                Throw New ApplicationException("No parent for root")
            End If
        End Function
    End Class
#End Region