Imports System.IO

Friend Class FileFunctions
    Friend Shared Sub CopyDirectory(ByVal sourceDir As String, ByVal destinationDir As String, Optional ByVal recursive As Boolean = True)
        Dim dir = New DirectoryInfo(sourceDir)
        If Not dir.Exists Then Throw New DirectoryNotFoundException($"Source directory not found: {dir.FullName}")
        Dim dirs As DirectoryInfo() = dir.GetDirectories()
        Directory.CreateDirectory(destinationDir)

        For Each file As FileInfo In dir.GetFiles()
            Dim targetFilePath As String = Path.Combine(destinationDir, file.Name)
            file.CopyTo(targetFilePath, True)
        Next

        If recursive Then

            For Each subDir As DirectoryInfo In dirs
                Dim newDestinationDir As String = Path.Combine(destinationDir, subDir.Name)
                CopyDirectory(subDir.FullName, newDestinationDir, True)
            Next
        End If
    End Sub

End Class