Script Task: How To Compare Files On FTP With Existing Files In Local Folder Before Transfer!

In the first step of my SSIS package I need to get files from FTP and dump it/them in a local directory, but it's more than that, the logic is like this:
1. If no file(s) found, stop executing and send email saying no file(s) found;
2. If file(s) found, then compare it/them with existing files in our archive folder; if file(s) already exist in archive folder, stop executing and send email saying file(s) already existed, if file(s) not in archive folder yet, then transfer it/them to the local directory for processing.

I know i have to use a script task to do this and i did some research and found examples for each of the above 2 steps and not both combined, so that's why I need some help here to get the logic incorporated right.

Thanks for the help in advance and i apologize for the long lines of code!

example for step 1:
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' Microsoft SQL Server Integration Services Script Task
' Write scripts using Microsoft Visual Basic
' The ScriptMain class is the entry point of the Script Task.

Imports System
Imports System.Data
Imports System.Math
Imports Microsoft.SqlServer.Dts.Runtime
Imports Microsoft.SqlServer.Dts.Pipeline.Wrapper
Imports Microsoft.SqlServer.Dts.Runtime.Wrapper
Imports Microsoft.VisualBasic.FileIO.FileSystem
Imports System.IO.FileSystemInfo

Public Class ScriptMain

' The execution engine calls this method when the task executes.
' To access the object model, use the Dts object. Connections, variables, events,
' and logging features are available as static members of the Dts class.
' Before returning from this method, set the value of Dts.TaskResult to indicate success or failure.
'
' To open Code and Text Editor Help, press F1.
' To open Object Browser, press Ctrl+Alt+J.

Public Sub Main()

Dim cDataFileName As String
Dim cFileType As String
Dim cFileFlgVar As String
WriteVariable("SCFileFlg", False)
WriteVariable("OOFileFlg", False)
WriteVariable("INFileFlg", False)
WriteVariable("IAFileFlg", False)
WriteVariable("RCFileFlg", False)
cDataFileName = ReadVariable("DataFileName").ToString
cFileType = Left(Right(cDataFileName, 4), 2)
cFileFlgVar = cFileType.ToUpper + "FileFlg"
WriteVariable(cFileFlgVar, True)
Dts.TaskResult = Dts.Results.Success
End Sub
Private Sub WriteVariable(ByVal varName As String, ByVal varValue As Object)
Try
Dim vars As Variables
Dts.VariableDispenser.LockForWrite(varName)
Dts.VariableDispenser.GetVariables(vars)
Try
vars(varName).Value = varValue
Catch ex As Exception
Throw ex
Finally
vars.Unlock()
End Try
Catch ex As Exception
Throw ex
End Try
End Sub
Private Function ReadVariable(ByVal varName As String) As Object
Dim result As Object
Try
Dim vars As Variables
Dts.VariableDispenser.LockForRead(varName)
Dts.VariableDispenser.GetVariables(vars)
Try
result = vars(varName).Value
Catch ex As Exception
Throw ex
Finally
vars.Unlock()
End Try
Catch ex As Exception
Throw ex
End Try
Return result
End Function
End Class

example for step 2:
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' Microsoft SQL Server Integration Services Script Task

' Write scripts using Microsoft Visual Basic

' The ScriptMain class is the entry point of the Script Task.

Imports System

Imports System.Data

Imports System.Math

Imports Microsoft.SqlServer.Dts.Runtime

Public Class ScriptMain

' The execution engine calls this method when the task executes.

' To access the object model, use the Dts object. Connections, variables, events,

' and logging features are available as static members of the Dts class.

' Before returning from this method, set the value of Dts.TaskResult to indicate success or failure.

'

' To open Code and Text Editor Help, press F1.

' To open Object Browser, press Ctrl+Alt+J.

Public Sub Main()

Try

'Create the connection to the ftp server

Dim cm As ConnectionManager = Dts.Connections.Add("FTP")

'Set the properties like username & password

cm.Properties("ServerName").SetValue(cm, "ftp.name.com")

cm.Properties("ServerUserName").SetValue(cm, "username")

cm.Properties("ServerPassword").SetValue(cm, "password")

cm.Properties("ServerPort").SetValue(cm, "21")

cm.Properties("Timeout").SetValue(cm, "0") 'The 0 setting will make it not timeout

cm.Properties("ChunkSize").SetValue(cm, "1000") '1000 kb

cm.Properties("Retries").SetValue(cm, "1")

'create the FTP object that sends the files and pass it the connection created above.

Dim ftp As FtpClientConnection = New FtpClientConnection(cm.AcquireConnection(Nothing))

'Connects to the ftp server

ftp.Connect()

'ftp.SetWorkingDirectory("..")

ftp.SetWorkingDirectory("directoryname")

Dim folderNames() As String

Dim fileNames() As String

ftp.GetListing(folderNames, fileNames)

Dim maxname As String = ""

For Each filename As String In fileNames

' whatever operation you need to do to find the correct file...

Next

Dim files(0) As String

files(0) = maxname

ftp.ReceiveFiles(files, "C: emp", True, True)

' Close the ftp connection

ftp.Close()





'Set the filename you retreive for use in data flow

Dts.Variables.Item("FILENAME").Value = maxname

Catch ex As Exception

Dts.TaskResult = Dts.Results.Failure

End Try

Dts.TaskResult = Dts.Results.Success

End Sub

End Class