Imports System
Imports System.Net
Imports System.Net.Sockets
Imports System.IO
Imports System.Threading

'-------- The following code is a modified version of a VB sample code "NetworkStreamSampleVBReceiver". --------'
'---------------- The orginal script was downloaded from www.winsocketdotnetworkprogramming.com ----------------'
'------------ The name of the process has changed from "NetworkStreamSampleVBReceiver" to SWAsrvapp ------------'

' This sample demonstrates how To use the NetworkStream Class To
' perform IO between 2 sockets. When using TCP Sockets you have to 
' build a listening Socket application that will receive a connection
' from another application. In Socket terminology the application that
' receives a connection is know as a server and the peer that connects
' to a server is know as a client. 
' 
' The focus of this sample is not on Sockets but on network streams. We 
' call this application a NetworkStreamServer because it is designed to
' receive a Socket connection and perform IO using a NetworkStream.
' 
' To run this sample, simply just run the program without parameters and
' it will listen for a client connection on TCP port 5150. If you want to
' use a different port than 5150 then you can optionally supply a command
' line parameter "/port <port number>" and the listening socket will use
' your port instead.

Module Module1
    ' The main entry point for the application.
    Sub Main()

        Console.Title = "SWA Data Streamer on 2366 with starttime request"

        ' The following are default values, change accordingly
        Dim ServerName As String = "0.0.0.0" ' "127.0.0.1"
        Dim Port As Integer = 2366 ' 5150

        Dim ClientAddress As String
        Dim ClientPort As Integer

        ' Specify a file to read from (MODIFIED)
        Dim pathSource As String

        ' Specify a file to write the report (MODIFIED)
        Dim reporttext As StreamWriter = My.Computer.FileSystem.OpenTextFileWriter("Reports\Recent\SWA_DataStreamerOnrequest_Report_" + System.DateTime.UtcNow.ToString("yyyyMMddTHHmmssZ") + ".txt", False, System.Text.Encoding.ASCII)
        reporttext.AutoFlush = True

        Dim chosenfileid As Integer = -10

        Dim intialfilelistarray() As String

checkagainforthefirstfile:
        intialfilelistarray = createfilelist()
        pathSource = ""

        If intialfilelistarray.Length = 0 Then
            Console.ForegroundColor = ConsoleColor.Yellow  '(MODIFIED)
            Console.Clear()
            Console.WriteLine("No cached data or live stream detected. Waiting for new data from the server! ")  '(MODIFIED)
            reporttext.WriteLine("No cached data or live stream detected. Waiting for new data from the server! ")  '(MODIFIED)
            Thread.Sleep(5000)
            GoTo checkagainforthefirstfile
            'Console.ForegroundColor = ConsoleColor.White '(MODIFIED)
            'reporttext.Close()
            'Exit Sub
        End If
        Console.Clear()



        Dim ServerSocket As Socket = Nothing
        Dim ListeningSocket As Socket = Nothing

        Try
            ' Setup a listening Socket to await a connection from a peer socket.
            ListeningSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP)

            Dim ListeningEndPoint As IPEndPoint = New IPEndPoint(IPAddress.Parse(ServerName), Port)

            ListeningSocket.Bind(ListeningEndPoint)
            Console.ForegroundColor = ConsoleColor.Green  '(MODIFIED)
            Console.WriteLine("Bind is OK!")  '(MODIFIED)
            reporttext.WriteLine("Bind is OK!")  '(MODIFIED)
            ListeningSocket.Listen(5)
            Console.WriteLine("Listen is OK!")  '(MODIFIED)
            reporttext.WriteLine("Listen is OK!")  '(MODIFIED)
            Console.ForegroundColor = ConsoleColor.Cyan  '(MODIFIED)
            Console.WriteLine("Awaiting a TCP connection on IP: " + ListeningEndPoint.Address.ToString() + " Port: " + ListeningEndPoint.Port.ToString() + "...")
            reporttext.WriteLine("Awaiting a TCP connection on IP: " + ListeningEndPoint.Address.ToString() + " Port: " + ListeningEndPoint.Port.ToString() + "...")
            'Console.WriteLine("Waiting for the client ro connect...")  '(MODIFIED)
            ServerSocket = ListeningSocket.Accept()
            Console.ForegroundColor = ConsoleColor.Green  '(MODIFIED)
            Console.WriteLine("Accept is OK!")  '(MODIFIED)
            reporttext.WriteLine("Accept is OK!")  '(MODIFIED)
            'Dim proc As New System.Diagnostics.Process()  '(MODIFIED)
            'proc = Process.Start("SWA_datastreamer_onrequestLAUNCHER.bat", "")  '(MODIFIED)

            Dim streamerLAUNCHERproc As New System.Diagnostics.Process()
            Dim streamerLAUNCHERprocinfo As New ProcessStartInfo("SWA_datastreamer_onrequestLAUNCHER.bat")
            streamerLAUNCHERprocinfo.WindowStyle = ProcessWindowStyle.Minimized
            streamerLAUNCHERproc = Process.Start(streamerLAUNCHERprocinfo)

            Dim Clientip As IPEndPoint = ServerSocket.RemoteEndPoint  '(MODIFIED)
            ClientAddress = Clientip.Address.ToString
            ClientPort = Clientip.Port
            Console.ForegroundColor = ConsoleColor.Cyan  '(MODIFIED)
            Console.WriteLine("Received a connection from IPaddress: " + CStr(ClientAddress) + " on port No.: " + CStr(ClientPort))  '(MODIFIED)
            reporttext.WriteLine("Received a connection from IPaddress: " + CStr(ClientAddress) + " on port No.: " + CStr(ClientPort))  '(MODIFIED)
        Catch e As SocketException
            Console.ForegroundColor = ConsoleColor.DarkRed  '(MODIFIED)
            Console.WriteLine("Failure to create Sockets: " + e.Message)
            reporttext.WriteLine("Failure to create Sockets: " + e.Message)
            reporttext.Close()
            Exit Sub
        Finally
            ' Close the listening socket - we do not plan to handle any
            ' additional connections.
            ListeningSocket.Close()
        End Try



        '''''''''''.....................................................................................'''''''''''
        '''trying to read the timespan requested   (the variables have "initial" tag in them)
        '''
        Dim ServerNetworkStream As NetworkStream = Nothing
        Dim InitialBytestotext As String = ""
        Dim InitialBytestotext_date As String = ""
        Dim InitialBytestotext_time As String = ""
        Try
            Try
                ' Setup a network stream on the server Socket
                'Console.WriteLine("Instantiate the reading NetworkStream object...")
                ServerNetworkStream = New NetworkStream(ServerSocket, True)
            Catch e As Exception
                Throw New Exception("Failed to create a Network Stream with error: " + e.Message)
            End Try

            Try
                Dim BytesInitialRead As Integer = 0
                Dim ReadInitialBuffer(4096) As Byte

                'Console.WriteLine("Reading...")
                'Do
                BytesInitialRead = ServerNetworkStream.Read(ReadInitialBuffer, 0, ReadInitialBuffer.GetUpperBound(0))
                'Console.WriteLine("We read " + BytesInitialRead.ToString() + " byte(s) from a peer socket.")
                For i = 0 To BytesInitialRead - 1
                    InitialBytestotext += ChrW(CInt(ReadInitialBuffer(i).ToString()))
                    'Console.WriteLine("The byte #" + i.ToString() + " contains " + ReadInitialBuffer(i).ToString())
                Next
                'Console.WriteLine(InitialBytestotext)



                Dim requestedstartdate As String = ""
                Dim requestedstarttime As String = ""
                If Right(Left(InitialBytestotext, 9), 1) = "T" And Right(Left(InitialBytestotext, 16), 1) = "Z" Then  '''''checks the validity of time/date format
                    requestedstartdate = Left(InitialBytestotext, 8)
                    requestedstarttime = Right(Left(InitialBytestotext, 15), 6)
                    Console.ForegroundColor = ConsoleColor.White
                    Console.WriteLine("")
                    Console.WriteLine("StartDate:  " & requestedstartdate)
                    Console.WriteLine("StartTime:  " & requestedstarttime)
                    Console.WriteLine("")
                    reporttext.WriteLine("")
                    reporttext.WriteLine("StartDate:  " & requestedstartdate)
                    reporttext.WriteLine("StartTime:  " & requestedstarttime)
                    reporttext.WriteLine("")
                Else
                    Console.ForegroundColor = ConsoleColor.Yellow  '(MODIFIED)
                    Console.WriteLine("The starting date/time format is not correct! Please enter it as yyyymmddThhmmssZ")  '(MODIFIED)
                    reporttext.WriteLine("The starting date/time format is not correct! Please enter it as yyyymmddThhmmssZ")  '(MODIFIED)
                    Console.ForegroundColor = ConsoleColor.White '(MODIFIED)
                    reporttext.Close()
                    Exit Sub
                End If


                ''''' does the selection to the nearest file
                intialfilelistarray = createfilelist()  'update the list of files
                Dim filenamedate As String = ""
                Dim filenametime As String = ""

                For iii = 0 To intialfilelistarray.Length - 1
                    'Console.WriteLine(Left(Right(intialfilelistarray(iii).ToString, 20), 16))

                    filenamedate = Left(Right(intialfilelistarray(iii).ToString, 20), 8)
                    filenametime = Left(Right(intialfilelistarray(iii).ToString, 11), 6)
                    'Console.WriteLine(filenamedate + filenametime)
                    'Console.WriteLine(requestedstartdate + requestedstarttime)
                    If CLng(filenamedate + filenametime) >= CLng(requestedstartdate + requestedstarttime) Then
                        'Console.WriteLine("true")
                        chosenfileid = iii - 1
                        Exit For
                    Else
                        'Console.WriteLine("False")

                    End If

                Next


                '''''
                'Console.WriteLine(chosenfileid)

                If chosenfileid = -1 Then
                    chosenfileid = 0    '''''if the requested time was before the oldest file, it will choose the oldest file anyway
                End If

                If chosenfileid = -10 Then
                    chosenfileid = intialfilelistarray.Length - 1    '''''if the requested time was after the latest file, it will choose the latest file anyway
                End If

                'Console.WriteLine(chosenfileid)

                InitialBytestotext = ""
                'Loop Until BytesInitialRead > 0
            Catch e As Exception
                Throw New Exception("Failed to read from a network stream with error: " + e.Message)
            End Try
        Catch e As Exception
            Console.WriteLine(e.Message)
            reporttext.WriteLine(e.Message)
        Finally
            ' We are finished with the NetworkStream, so we will close it.
            ' Note: the ServerSocket will be closed by the NetworkStream.
            '''''''ServerNetworkStream.Close()
        End Try

        '''''''''''.....................................................................................'''''''''''





        ' Let's create a network stream to communicate over the connected Socket.
        'Dim ServerNetworkStream As NetworkStream = Nothing
        Dim bytecounter As Integer = 0  '(MODIFIED)
        Dim sizeofthelatestpacketinbytes As Integer = 0




        Try
            Try
                ' Setup a network stream on the server Socket
                'Console.ForegroundColor = ConsoleColor.Cyan  '(MODIFIED)
                'Console.WriteLine("Instantiate a NetworkStream object...")
                ServerNetworkStream = New NetworkStream(ServerSocket, True)
            Catch e As Exception
                Console.ForegroundColor = ConsoleColor.DarkRed  '(MODIFIED)
                Throw New Exception("Failed to create a Network Stream with error: " + e.Message)
            End Try


            Try
                Dim Buffer(1) As Byte
                'Console.ForegroundColor = ConsoleColor.Cyan  '(MODIFIED)
                'Console.WriteLine("Sending the buffered bytes...")  '(MODIFIED)

                '---------------------------------------------------------------------------------------------------------------------------------------------'
                '-------- This part of the code was copy pasted from https://msdn.microsoft.com/en-us/library/system.io.filestream.read(v=vs.110).aspx--------'


                Dim totalbytesread As Integer = 0
                Dim nonewpackettimer As Integer = 0
                Dim sleeptime As Integer = 1000 ' in miliseconds
                Dim nonewpackettimeoute As Integer = 10 * 3600000 ' in miliseconds

                Dim streammode As String
                streammode = "cached" ' cached is when the files are being streamed, and it changes to live when streaming is from the latest file, which is being topped up by new bytes

                Console.ForegroundColor = ConsoleColor.Green
                Console.WriteLine("  ")
                Console.WriteLine("Client is connected!")
                Console.WriteLine("  ")
                reporttext.WriteLine("  ")
                reporttext.WriteLine("Client is connected!")
                reporttext.WriteLine("  ")
                Console.ForegroundColor = ConsoleColor.White
                Console.WriteLine("-----------------------------------------------------------------------")
                Console.Write("   Pktsize  ")
                reporttext.WriteLine("-----------------------------------------------------------------------")
                reporttext.Write("   Pktsize  ")
                Console.ForegroundColor = ConsoleColor.Cyan
                Console.Write(vbTab & "Streaming DateTime(UTC)")
                reporttext.Write(vbTab & "Streaming DateTime(UTC)")
                Console.ForegroundColor = ConsoleColor.Yellow
                Console.WriteLine(vbTab & "Pktsource")
                reporttext.WriteLine(vbTab & "Pktsource")
                Console.ForegroundColor = ConsoleColor.White
                Console.WriteLine("-----------------------------------------------------------------------")
                reporttext.WriteLine("-----------------------------------------------------------------------")

streamtosocket:

                'Check if the socket is still connected (Modified)
                Try
                    Dim nullbuffer(0) As Byte
                    ServerSocket.Send(nullbuffer, 0, 0)
                    'Console.WriteLine(" ServerSocket.Blocking.ToString()" + ServerSocket.Blocking.ToString())
                Catch e As SocketException
                    Throw New Exception("Client disconnected!")
                End Try
                '



                'Check how many files are created (maybe new ones are added)
                Dim filelistarray() As String
                filelistarray = createfilelist()
                Dim ii As Integer
                For ii = 0 To filelistarray.Length - 1

                    If (pathSource = filelistarray(ii)) And (ii < filelistarray.Length - 1) Then
                        If streammode = "cached" Then
                            pathSource = filelistarray(ii + 1)
                            totalbytesread = 0
                            nonewpackettimer = 0
                            sleeptime = 1000
                            Console.ForegroundColor = ConsoleColor.Cyan
                            Console.Write(vbTab & System.DateTime.UtcNow.ToString("yyyy/MM/dd HH:mm:ss"))
                            reporttext.Write(vbTab & System.DateTime.UtcNow.ToString("yyyy/MM/dd HH:mm:ss"))
                            Console.ForegroundColor = ConsoleColor.Yellow
                            Console.Write(vbTab & "file No.{0} : " & Left(Right(filelistarray(ii).ToString, 20), 16), ii + 1)
                            reporttext.Write(vbTab & "file No.{0} : " & Left(Right(filelistarray(ii).ToString, 20), 16), ii + 1)
                            'Console.WriteLine("Streaming cached file No. {0} ...", ii + 1)
                            Exit For
                        ElseIf streammode = "live" Then
                            Console.WriteLine("")
                            Console.WriteLine(vbTab & "New cache file created.")
                            Console.Write(vbTab)
                            reporttext.WriteLine("")
                            reporttext.WriteLine(vbTab & "New cache file created.")
                            reporttext.Write(vbTab)
                            streammode = "cached"  ' this is to make sure that last bits of the live stream from the the current streaming file is sent, before going to the next new file to stream
                            Exit For
                        End If

                    Else
                        If pathSource = "" Then
                            pathSource = filelistarray(chosenfileid) 'instead of first file, it will chose the file based on the requested start date/time
                            Exit For
                        End If
                        If (ii = filelistarray.Length - 1) And (nonewpackettimer <= sleeptime) Then
                            Console.Write(vbTab & System.DateTime.UtcNow.ToString("yyyy/MM/dd HH:mm:ss"))
                            reporttext.Write(vbTab & System.DateTime.UtcNow.ToString("yyyy/MM/dd HH:mm:ss"))
                            Console.ForegroundColor = ConsoleColor.Yellow
                            Console.Write(vbTab & "live...")
                            reporttext.Write(vbTab & "live...")
                            'Console.WriteLine("Streaming live packets ...")
                            sleeptime = 3000
                            streammode = "live"
                        End If

                    End If
                Next


                Try

                    Using fsSource As FileStream = New FileStream(pathSource, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)

                        fsSource.Position = totalbytesread
                        ' Read the source file into a byte array.
                        Dim bytes() As Byte = New Byte((fsSource.Length) - 1) {}
                        Dim numBytesToRead As Integer = CType(fsSource.Length, Integer)
                        Dim numBytesRead As Integer = 0


                        numBytesToRead -= totalbytesread


                        Dim initiallength As Long = fsSource.Length



                        If numBytesToRead > 0 Then
                            'Console.WriteLine("Data packets consisting of {0} Bytes are being sent ... ", numBytesToRead.ToString)
                            sizeofthelatestpacketinbytes = numBytesToRead
                            nonewpackettimer = 0 ' rests the timeout timer to zero if new packet arrives
                        End If


                        While (numBytesToRead > 0)
                            ' Read may return anything from 0 to numBytesToRead.
                            Dim n As Integer = fsSource.Read(bytes, numBytesRead, numBytesToRead)

                            ' Break when the end of the file is reached.
                            If (n = 0) Then
                                Exit While
                            End If
                            numBytesRead = (numBytesRead + n)
                            numBytesToRead = (numBytesToRead - n)

                            ''''
                            ' send the byte array to the socket
                            ' For i = 1 To n
                            ' Buffer(0) = bytes(i - 1)

                            'ServerNetworkStream.Write(Buffer, 0, Buffer.GetUpperBound(0))

                            'bytecounter += 1  '(MODIFIED)
                            '  Next
                            ''''

                            ServerNetworkStream.Write(bytes, 0, numBytesRead)
                            Console.ForegroundColor = ConsoleColor.White
                            Console.WriteLine("")
                            Console.Write("   {0}  ", numBytesRead.ToString)
                            reporttext.WriteLine("")
                            reporttext.Write("   {0}  ", numBytesRead.ToString)
                            'Console.WriteLine("{0} Bytes sent to IPaddress {1} ", numBytesRead.ToString, CStr(ClientAddress))

                            Console.ForegroundColor = ConsoleColor.Cyan

                        End While


                        numBytesToRead = bytes.Length
                        totalbytesread = fsSource.Seek(0, SeekOrigin.Current)


                        Thread.Sleep(sleeptime)
                        nonewpackettimer += sleeptime

                        'If fsSource2.Length <> initiallength Then

                        'GoTo sendtosocket
                        ' End If

                    End Using

                Catch ioEx As FileNotFoundException
                    Console.WriteLine(ioEx.Message)
                    reporttext.WriteLine(ioEx.Message)
                End Try
                '---------------------------------------------------------------------------------------------------------------------------------------------'
                '---------------------------------------------------------------------------------------------------------------------------------------------'
                If nonewpackettimer < nonewpackettimeoute Then
                    GoTo streamtosocket
                Else
                    Console.ForegroundColor = ConsoleColor.Yellow  '(MODIFIED)
                    Console.WriteLine("Timeout!")
                    Console.WriteLine("No new incoming packets for " + CStr(Math.Floor(nonewpackettimer / 60000)) + " minute(s) and " + CStr((nonewpackettimer / 60000 - Math.Floor(nonewpackettimer / 60000)) * 60) + " second(s).")  '(MODIFIED)
                    reporttext.WriteLine("Timeout!")
                    reporttext.WriteLine("No new incoming packets for " + CStr(Math.Floor(nonewpackettimer / 60000)) + " minute(s) and " + CStr((nonewpackettimer / 60000 - Math.Floor(nonewpackettimer / 60000)) * 60) + " second(s).")  '(MODIFIED)
                End If


                Console.ForegroundColor = ConsoleColor.Yellow  '(MODIFIED)
                Console.WriteLine("We sent " + CStr(bytecounter) + " bytes to IPaddress: " + CStr(ClientAddress))  '(MODIFIED)
                reporttext.WriteLine("We sent " + CStr(bytecounter) + " bytes to IPaddress: " + CStr(ClientAddress))  '(MODIFIED)
                Console.ForegroundColor = ConsoleColor.Green  '(MODIFIED)
                Console.WriteLine("Transfer completed.")  '(MODIFIED)
                reporttext.WriteLine("Transfer completed.")  '(MODIFIED)
            Catch e As Exception
                ServerNetworkStream.Close()
                Console.ForegroundColor = ConsoleColor.Yellow  '(MODIFIED)
                Console.WriteLine("We sent " + CStr(bytecounter - sizeofthelatestpacketinbytes) + " bytes to IPaddress: " + CStr(ClientAddress))  '(MODIFIED) 
                reporttext.WriteLine("We sent " + CStr(bytecounter - sizeofthelatestpacketinbytes) + " bytes to IPaddress: " + CStr(ClientAddress))  '(MODIFIED) 
                Console.ForegroundColor = ConsoleColor.Red  '(MODIFIED)
                Throw New Exception("Failed to send NetworkStream with error: " + e.Message)

            End Try


        Catch e As Exception
            Console.ForegroundColor = ConsoleColor.Red
            Console.WriteLine(e.Message)
            reporttext.WriteLine(e.Message)
        Finally
            ' We are finished with the NetworkStream, so we will close it.
            ' Note: the ServerSocket will be closed by the NetworkStream.
            ServerNetworkStream.Close()
        End Try
        Console.ForegroundColor = ConsoleColor.White
    End Sub





    Function createfilelist()

        '-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------'
        '-------- This part of the code was copy pasted from https://docs.microsoft.com/en-us/dotnet/api/microsoft.visualbasic.myservices.filesystemproxy.getfiles?view=netframework-4.7.1--------'
        Dim foundfilecounter As Integer = 0
        For Each foundFile As String In My.Computer.FileSystem.GetFiles(
         My.Computer.FileSystem.CurrentDirectory,
         FileIO.SearchOption.SearchTopLevelOnly, "Data\Recent\IncomingSWAdata_*.dat")
            foundfilecounter += 1
        Next

        Dim foundfilearray(foundfilecounter - 1) As String
        foundfilecounter = 0

        For Each foundFile As String In My.Computer.FileSystem.GetFiles(
         My.Computer.FileSystem.CurrentDirectory,
         FileIO.SearchOption.SearchTopLevelOnly, "Data\Recent\IncomingSWAdata_*.dat")
            foundfilearray(foundfilecounter) = foundFile
            foundfilecounter += 1
        Next
        '-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------'
        '-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------'

        Return foundfilearray

    End Function


End Module