Imports System.IO
Imports System.Object
Imports System.Text
Imports System.Net
Imports System.Net.Sockets
Imports System.UInt16


Public Class ClientSocket

    Const m_nHeaderSize = 12
    Private m_bIsConnected As Boolean

    Public ReadOnly Property IsConnected() As Boolean
        Get
            Return m_bIsConnected
        End Get
    End Property

    Public Delegate Sub ProcessPacket(ByVal contents() As Byte, ByVal nPacketCMD As Byte, ByVal errorCode As Int16)
    Public Delegate Sub ProcessDisconnect()

    Private m_TCPSocket As TcpClient

    Private m_RecvCallBack As AsyncCallback
    Private m_ReceivedData() As Byte
    Private m_nReceived As Int32

    Private m_ProcessTable As Hashtable
    Private m_DisconnectProcess As ProcessDisconnect

    Private m_MainLoop As Object

    Private Class AsyncReceived

    End Class


    Public Sub New()

        m_TCPSocket = New TcpClient()
        m_ProcessTable = New Hashtable()

        ReDim m_ReceivedData(65535)

    End Sub

    Public Sub Connect(ByVal HostName As String, ByVal Port As Integer, _
        ByVal mainLoop As Object, ByVal disconnProcess As ProcessDisconnect)

        Try

            m_MainLoop = mainLoop

            m_DisconnectProcess = disconnProcess
            m_TCPSocket.Connect(HostName, Port)

            m_RecvCallBack = New AsyncCallback(AddressOf Me.RecvCallBack)

            ' 비동기 입력 예약
            Recv()

            m_bIsConnected = True

        Catch

            If False = m_DisconnectProcess.Equals(Nothing) Then
                m_DisconnectProcess.Invoke()
            End If

            m_bIsConnected = False

        End Try

    End Sub


    Public Sub AddProcess(ByVal packetCommand As Byte, ByVal fnProcess As ProcessPacket)
        If False = fnProcess.Equals(Nothing) Then
            m_ProcessTable.Add(packetCommand, fnProcess)
        End If
    End Sub


    Public Sub Close()
        m_TCPSocket.Close()
    End Sub


    Public Sub Send(ByVal packetCommand As Byte, ByVal contents() As Byte)

        Dim nPacketLength As Int16 = contents.GetLength(0) + m_nHeaderSize
        Dim Packet(nPacketLength) As Byte

        Packet(0) = CByte(255)
        Packet(1) = packetCommand
        Array.Copy(BitConverter.GetBytes(nPacketLength), 0, Packet, 2, 2)

        ' Wrap Header
        EncryptHeader(Packet, 1, m_nHeaderSize - 1, 0, 0)

        Array.Copy(contents, 0, Packet, m_nHeaderSize, contents.GetLength(0))

        Try

            m_TCPSocket.GetStream.Write(Packet, 0, nPacketLength)

        Catch

            If False = m_DisconnectProcess.Equals(Nothing) And True = m_bIsConnected Then
                m_DisconnectProcess.Invoke()
            End If

            m_bIsConnected = False

        End Try

    End Sub


    Private Sub Recv()

        Dim asyncReceived As AsyncReceived = New AsyncReceived()
        m_TCPSocket.GetStream.BeginRead(m_ReceivedData, m_nReceived, _
            m_ReceivedData.GetUpperBound(0) - m_nReceived, m_RecvCallBack, asyncReceived)

    End Sub


    Private Sub RecvCallBack(ByVal ar As IAsyncResult)

        Try
            ' 받은 데이터를 처리한다.
            m_nReceived += m_TCPSocket.GetStream.EndRead(ar)

        Catch ex As Exception

            If False = m_DisconnectProcess.Equals(Nothing) And True = m_bIsConnected Then
                m_DisconnectProcess.Invoke()
            End If

            m_bIsConnected = False

        End Try

        Dim nProcessed As Int32 = 0
        Dim nPacketCommand As Byte = 0
        Dim nPacketLength As Int16 = 0
        Dim nCopy As Int32 = 0

        While m_nHeaderSize <= m_nReceived - nProcessed

            ' 헤더를 분석한다
            If 255 <> m_ReceivedData(nProcessed) Then
                Exit While
            End If

            ' 길이를 분석한다
            DecryptHeader(m_ReceivedData, nProcessed + 1, m_nHeaderSize - 1, 0, 0)

            nPacketCommand = m_ReceivedData(nProcessed + 1)
            nPacketLength = BitConverter.ToInt16(m_ReceivedData, nProcessed + 2)

            ' 아직 덜 받았으면 루프를 탈출한다.
            If m_nReceived < nProcessed + nPacketLength Then
                EncryptHeader(m_ReceivedData, nProcessed + 1, m_nHeaderSize - 1, 0, 0)
                Exit While
            End If

            Dim process As ProcessPacket = m_ProcessTable(nPacketCommand)
            If False = process.Equals(Nothing) Then

                Dim contents(nPacketLength - m_nHeaderSize - 1) As Byte

                Array.Copy(m_ReceivedData, nProcessed + m_nHeaderSize, _
                    contents, 0, nPacketLength - m_nHeaderSize)

                Dim params() As Object = {contents, nPacketCommand, BitConverter.ToInt16(m_ReceivedData, nProcessed + 8)}
                m_MainLoop.Invoke(process, params)

            End If

            nProcessed += nPacketLength

        End While

        ' 아직 처리하지 않은 부분을 앞으로 복사한다.
        If 0 <> nProcessed Then

            Array.Copy(m_ReceivedData, nProcessed, m_ReceivedData, 0, m_nReceived - nProcessed)
            m_nReceived -= nProcessed

        End If

        Try
            ' 다시 Recv를 Pending한다.
            Recv()

        Catch ex As Exception

            If False = m_DisconnectProcess.Equals(Nothing) And True = m_bIsConnected Then
                m_DisconnectProcess.Invoke()
            End If

            m_bIsConnected = False

        End Try

    End Sub


    ' 암호화 관련 코드
    Private Sub EncryptHeader(ByRef Data() As Byte, ByVal nStartPos As Integer, ByVal nLength As Integer, _
        ByVal nPageVer As Integer, ByVal nPageNum As Integer)

        If Data.GetLength(0) < nLength Then
            Exit Sub
        End If

        Dim Pos As Integer = 0

        For Pos = nStartPos To nLength + nStartPos - 1

            Data(Pos) = Data(Pos) Xor m_XORTable(nPageVer, nPageNum, (Pos - nStartPos) Mod BIT_COUNT)
            Data(Pos) = Int(Int(Data(Pos) And &H80) / (2 ^ 7)) Or Int(Int(Data(Pos) * 2) And &HFE)

        Next

    End Sub

    Private Sub DecryptHeader(ByRef Data() As Byte, ByVal nStartPos As Integer, ByVal nLength As Integer, _
        ByVal nPageVer As Integer, ByVal nPageNum As Integer)

        If Data.GetLength(0) < nLength Then
            Exit Sub
        End If

        Dim Pos As Integer = 0

        For Pos = nStartPos To nLength + nStartPos - 1

            Data(Pos) = Int(Int((Data(Pos) And &H1) * (2 ^ 7)) And &H80) Or (Int(Data(Pos) / 2) And &H7F)
            Data(Pos) = Data(Pos) Xor m_XORTable(nPageVer, nPageNum, (Pos - nStartPos) Mod BIT_COUNT)

        Next

    End Sub


    Dim BIT_COUNT As Integer = 40
    Dim CODE_PAGE As Integer = 10

    Dim m_XORTable(,,) As Byte = {{{ _
     &H82, &H53, &H43, &H4C, &H2B, _
     &HD, &H37, &HD7, &HD9, &HD8, _
     &H1B, &H6D, &HA0, &HC3, &H2B, _
     &HEE, &H45, &H88, &H1A, &HA6, _
     &H18, &H1D, &H9D, &H38, &H2A, _
     &H55, &H3, &H1D, &HCD, &HA6, _
     &H73, &H7, &HED, &H8D, &HC5, _
     &HDB, &HA3, &HBD, &HB6, &HD5}, _
 _
     {&H34, &HB5, &HB2, &H3D, &H7D, _
     &H43, &H8C, &HC0, &H21, &H25, _
     &HCD, &HB6, &H53, &H76, &HCE, _
     &H5D, &HD4, &H87, &HCA, &H84, _
     &H81, &HCB, &H5E, &H4, &HBA, _
     &H69, &H3E, &H65, &HDE, &H21, _
     &H8A, &H63, &H62, &H71, &H90, _
     &H87, &HA, &H52, &H28, &H44}, _
 _
     {&HA3, &H49, &HDC, &HEA, &H9, _
     &HB7, &H1, &HA4, &HA1, &H11, _
     &H11, &H8E, &H80, &H35, &H5B, _
     &HDD, &H38, &HD5, &H4E, &H36, _
     &HC, &HA2, &HBB, &H5, &H36, _
     &H57, &H2E, &H98, &HBE, &H88, _
     &H3C, &H28, &H43, &H63, &HA0, _
     &HE9, &HE1, &H6D, &H51, &HCB}, _
 _
     {&H4D, &H62, &H84, &H43, &H89, _
     &HC7, &H89, &H83, &H65, &H29, _
     &H53, &H95, &H7C, &HC0, &HA1, _
     &HC, &HDB, &HD7, &H4, &HD8, _
     &H6A, &HD1, &H73, &H1D, &H21, _
     &H67, &H86, &H8D, &HA4, &HA0, _
     &H34, &HBD, &H31, &H20, &H61, _
     &HE, &HE9, &H63, &HB4, &HC0}, _
 _
     {&HC7, &H36, &H1B, &H41, &H23, _
     &H9C, &HD1, &H8C, &H25, &H53, _
     &H42, &H2E, &H45, &H6D, &H42, _
     &H7B, &H4E, &H5B, &HEB, &H24, _
     &H33, &H74, &H52, &H28, &HC6, _
     &H2A, &HC3, &H16, &H60, &HA5, _
     &H45, &H35, &HDB, &H9A, &H54, _
     &H97, &HE2, &HEE, &H9B, &HDE}, _
 _
     {&HE0, &HC3, &H84, &H41, &HED, _
     &H45, &H4C, &H69, &HD9, &H28, _
     &H55, &H27, &H8E, &H3A, &H3C, _
     &H8E, &H84, &H97, &H14, &HE6, _
     &H58, &H51, &H26, &HD, &HE2, _
     &H9E, &H66, &H7C, &HD, &H1, _
     &H7D, &H17, &H4C, &H8, &HDD, _
     &H97, &H1C, &H7B, &HCE, &H5D}, _
 _
     {&H54, &H37, &H7C, &HC, &H8E, _
     &H27, &H7A, &H78, &H2E, &HE6, _
     &H6D, &H25, &H62, &H62, &H98, _
     &H20, &H2E, &H23, &H15, &H61, _
     &H7D, &H97, &H50, &H7, &H20, _
     &H7A, &H4, &H29, &H62, &H90, _
     &H6B, &HE9, &HE6, &H22, &H72, _
     &H38, &H56, &HC9, &H6, &H2E}, _
 _
     {&H3B, &H47, &H8, &H2D, &H21, _
     &H42, &H7, &H69, &H4A, &H57, _
     &H8B, &H79, &HE7, &H56, &H27, _
     &H23, &H24, &H85, &H47, &H74, _
     &H75, &H85, &HA9, &HEB, &H10, _
     &HCB, &H17, &H85, &H4B, &H5E, _
     &H20, &H78, &HD0, &H7D, &H86, _
     &H5E, &H14, &H7E, &H64, &H50}, _
 _
     {&H69, &H52, &H4A, &HBD, &H8C, _
     &H9B, &HD6, &H63, &HBD, &H26, _
     &H86, &H32, &H95, &HA4, &H2, _
     &H9B, &H1, &H14, &H49, &H78, _
     &H88, &H57, &H3A, &H1, &H4A, _
     &HBC, &H50, &HCD, &H31, &H39, _
     &H71, &H30, &H5B, &H9C, &H4D, _
     &H21, &H67, &H82, &HE8, &H5C}, _
 _
     {&H66, &H10, &HA9, &H7D, &HD2, _
     &H36, &HE2, &HB1, &H28, &H20, _
     &HD5, &HE7, &HD5, &HE, &HD4, _
     &HC, &H2C, &H77, &H80, &HE, _
     &HA6, &H37, &HBE, &H61, &HAD, _
     &HD6, &H17, &H65, &H13, &H70, _
     &HAE, &H40, &H3B, &H52, &HEE, _
     &H53, &H84, &HEB, &H4, &HD}}, _
 _
     {{&H49, &H8C, &H77, &HC0, &HC0, _
     &H64, &H54, &HB, &H22, &HBD, _
     &H82, &H93, &H9A, &H23, &H8D, _
     &HE4, &HC8, &H9D, &HB3, &H50, _
     &H44, &HB1, &HE2, &H9E, &H15, _
     &H7A, &HA1, &HC, &H24, &HE3, _
     &H1E, &HA, &HA, &H73, &H6A, _
     &HA5, &H8B, &H3A, &H53, &H33}, _
 _
     {&HB0, &HE6, &HB7, &H51, &H70, _
     &HDA, &HD6, &H29, &HAA, &H10, _
     &HB5, &H8A, &H38, &H37, &H4E, _
     &H7A, &H3B, &H74, &H7B, &H63, _
     &H41, &H7C, &H21, &H65, &H5E, _
     &H26, &H95, &H44, &H75, &HA3, _
     &H74, &HDD, &HB4, &H33, &H9E, _
     &H54, &H3C, &H95, &H5E, &H34}, _
 _
     {&H10, &H19, &H43, &H64, &H78, _
     &H2B, &HA6, &H60, &H7D, &HCD, _
     &HA9, &H28, &HB8, &H85, &HE, _
     &H66, &HC7, &H3C, &H28, &HDC, _
     &HA1, &H4D, &H60, &H9B, &HC7, _
     &HD3, &H74, &H93, &HE6, &HC3, _
     &H97, &H76, &H12, &HA4, &HCB, _
     &HB9, &H22, &H51, &HB9, &H79}, _
 _
     {&H5C, &H68, &HDB, &HE6, &H59, _
     &H57, &H95, &HCD, &HAE, &HCA, _
     &H67, &HB8, &H37, &H90, &HBA, _
     &H54, &H98, &H95, &H73, &H8E, _
     &H47, &HC1, &H40, &HBA, &H80, _
     &H26, &H10, &HAA, &H60, &H64, _
     &HD8, &H69, &HC7, &HD, &H2B, _
     &H28, &HA6, &HBA, &H1, &H4A}, _
 _
     {&HEE, &H28, &H65, &HC4, &H9D, _
     &H41, &H8D, &H91, &H6C, &H91, _
     &H7E, &H80, &HC3, &HD1, &HAE, _
     &HB6, &H92, &H41, &H66, &H13, _
     &H72, &H20, &H26, &HA1, &H72, _
     &H5, &H29, &H8, &H88, &H30, _
     &H40, &H6D, &H5A, &H41, &H1, _
     &H7A, &HDB, &H2C, &HEE, &HC3}, _
 _
     {&H5C, &H3, &H38, &HD8, &H95, _
     &HE7, &HB4, &H67, &H30, &H51, _
     &H21, &H68, &H78, &H89, &H68, _
     &HB, &HE3, &HB0, &H28, &HB3, _
     &HA9, &H38, &H18, &HE4, &H59, _
     &H43, &HC9, &H52, &H75, &H4, _
     &H15, &H7, &H97, &H14, &H7, _
     &H27, &HDA, &HE5, &HD9, &HDB}, _
 _
     {&HDB, &H8, &H27, &HA3, &H64, _
     &HDC, &H42, &HE3, &H3D, &HD, _
     &H26, &HA2, &HC3, &H5E, &H3E, _
     &HA7, &H47, &HE4, &H1C, &H73, _
     &H13, &H99, &H9E, &HBA, &HD3, _
     &H8, &H73, &H88, &H3, &H1, _
     &H24, &H2E, &H9, &HBD, &H3A, _
     &H6E, &H3C, &HB6, &HA2, &H22}, _
 _
     {&HE7, &H27, &H60, &H20, &H85, _
     &HDA, &HEA, &H84, &H86, &H41, _
     &H67, &H1C, &H83, &HBE, &H7A, _
     &H61, &H67, &H1, &H18, &H30, _
     &HC6, &H37, &HBC, &H51, &HBC, _
     &H78, &HA1, &H53, &H53, &H58, _
     &H9B, &H32, &H5, &H67, &H6B, _
     &HC7, &H3A, &H7C, &HA8, &HE5}, _
 _
     {&H70, &H10, &H29, &H88, &H94, _
     &HC0, &HEE, &H8D, &H52, &H20, _
     &HD9, &HC3, &H3C, &HB3, &H43, _
     &H74, &H83, &HC8, &HC5, &HAA, _
     &H90, &H58, &HC, &HD0, &HBC, _
     &H2A, &HED, &H4, &H5, &H8E, _
     &H27, &HDE, &H9C, &H37, &H57, _
     &H2A, &H93, &H63, &H1B, &H9E}, _
 _
     {&HC3, &H52, &HDB, &HE9, &H63, _
     &H9A, &H87, &H18, &H6D, &HBE, _
     &H1B, &H37, &H6A, &HEA, &H1, _
     &H2, &H1, &HB5, &H74, &H71, _
     &HA5, &H9A, &H9A, &H3A, &H11, _
     &H8B, &H62, &HD7, &HB0, &H6, _
     &HC, &HA0, &H10, &H9, &H97, _
     &H5A, &HEB, &HEA, &H18, &HB8}}}

End Class