Imports System.Reflection
Imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
Imports System.Runtime.Remoting.Channels.Http

'case 1012
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.IO.Compression
Imports System.IO


'Imports System.Configuration

''' <summary>
''' This is the client-side DataPortal as described in
''' Chapter 5.
''' </summary>
Public Class DataPortal

  Private Shared mPortalRemote As Boolean = False
    Public Shared mIsRemote As Boolean = False
    Private Shared mInitialized As Boolean = False
    Public Shared mPortalString As String = ""


#Region " Data Access methods "

  ''' <summary>
  ''' Called by a factory method in a business class to create 
  ''' a new object, which is loaded with default
  ''' values from the database.
  ''' </summary>
  ''' <param name="Criteria">Object-specific criteria.</param>
  ''' <returns>A new object, populated with default values.</returns>
  Public Shared Function Create(ByVal Criteria As Object) As Object

        Dim obj As Object
        Dim method As MethodInfo = GetMethod(GetObjectType(Criteria), "DataPortal_Create")

        Dim forceLocal As Boolean = RunLocal(method)

        'If IsTransactionalMethod(method) Then
        '        'obj = ServicedPortal(forceLocal).Create(Criteria, _
        '        '  New Server.DataPortalContext(GetPrincipal, mPortalRemote AndAlso Not forceLocal))

        'Else
        obj = Portal(forceLocal).Create(Criteria, _
          New Server.DataPortalContext(GetPrincipal, mPortalRemote AndAlso Not forceLocal))
        'End If

        If mPortalRemote AndAlso Not forceLocal Then
            Serialization.SerializationNotification.OnDeserialized(obj)
        End If
        Return obj

  End Function

  ''' <summary>
  ''' Called by a factory method in a business class to retrieve
  ''' an object, which is loaded with values from the database.
  ''' </summary>
  ''' <param name="Criteria">Object-specific criteria.</param>
  ''' <returns>An object populated with values from the database.</returns>
    Public Shared Function Fetch(ByVal Criteria As Object) As Object
        Init()
        Dim obj As Object

        Dim method As MethodInfo = GetMethod(GetObjectType(Criteria), "DataPortal_Fetch")

        Dim forceLocal As Boolean = RunLocal(method)

        obj = Portal(forceLocal).Fetch(Criteria, _
          New Server.DataPortalContext(GetPrincipal, mPortalRemote AndAlso Not forceLocal))


        'If mPortalRemote AndAlso Not forceLocal Then
        '    Serialization.SerializationNotification.OnDeserialized(obj)
        'End If

        If mPortalRemote Then
            obj = Decompress(DirectCast(obj, Byte()))
        End If

        Return obj

    End Function

  ''' <summary>
  ''' Called by the <see cref="M:CSLA.BusinessBase.Save" /> method to
  ''' insert, update or delete an object in the database.
  ''' </summary>
  ''' <remarks>
  ''' Note that this method returns a reference to the updated business object.
  ''' If the server-side DataPortal is running remotely, this will be a new and
  ''' different object from the original, and all object references MUST be updated
  ''' to use this new object.
  ''' </remarks>
  ''' <param name="obj">A reference to the business object to be updated.</param>
  ''' <returns>A reference to the updated business object.</returns>
  Public Shared Function Update(ByVal obj As Object) As Object

    Dim updated As Object

    Dim method As MethodInfo = GetMethod(obj.GetType, "DataPortal_Update")

    Dim forceLocal As Boolean = RunLocal(method)

        Dim canCompress As Boolean = True


        'case 1012
        If mPortalRemote AndAlso canCompress Then
            'It's going to the server remotely so compress it
            'Note servicebank can't be compressed due to transaction object not being serializable
            If (obj.GetType().ToString() <> "GZTW.AyaNova.BLL.ServiceBank") Then
                obj = Compress(obj)
            Else
                canCompress = False
            End If

        End If


        updated = Portal(forceLocal).Update(obj, _
          New Server.DataPortalContext(GetPrincipal, mPortalRemote))

        'case 1012
        If mPortalRemote AndAlso canCompress Then
            'It came from the server compressed so decompress it
            Return Decompress(DirectCast(updated, Byte()))
        Else
            Return updated
        End If

        Return updated

    End Function

  ''' <summary>
  ''' Called by a <c>Shared</c> method in the business class to cause
  ''' immediate deletion of a specific object from the database.
  ''' </summary>
  ''' <param name="Criteria">Object-specific criteria.</param>
  Public Shared Sub Delete(ByVal Criteria As Object)

    Dim method As MethodInfo = GetMethod(GetObjectType(Criteria), "DataPortal_Delete")

    Dim forceLocal As Boolean = RunLocal(method)

        'If IsTransactionalMethod(method) Then
        '  ServicedPortal(forceLocal).Delete(Criteria, _
        '    New Server.DataPortalContext(GetPrincipal, mPortalRemote AndAlso Not forceLocal))

        'Else
        Portal(forceLocal).Delete(Criteria, _
          New Server.DataPortalContext(GetPrincipal, mPortalRemote AndAlso Not forceLocal))
        ' End If

    End Sub

#End Region

#Region "Compression" 'case 1012
    Private Shared bSerializer As New BinaryFormatter
    Public Shared Function Compress(ByVal obj As Object) As Byte()
        Dim ms3 As New MemoryStream
        Dim cmp3 As New GZipStream(ms3, CompressionMode.Compress, False)
        bSerializer.Serialize(cmp3, obj)
        cmp3.Flush()
        cmp3.Close()
        Return ms3.ToArray()
    End Function
    Public Shared Function Decompress(ByVal bytes() As Byte) As Object
        Dim ms4 As New MemoryStream(bytes)
        Dim cmp4 As New GZipStream(ms4, CompressionMode.Decompress)
        Dim o As Object = bSerializer.Deserialize(cmp4)
        Return o
    End Function
#End Region

#Region " Server-side DataPortal "

  Private Shared mPortal As Server.DataPortal
    '    Private Shared mServicedPortal As Server.ServicedDataPortal.DataPortal
    Private Shared mRemotePortal As Server.DataPortal
    '  Private Shared mRemoteServicedPortal As Server.ServicedDataPortal.DataPortal

    Private Shared Function Portal(ByVal forceLocal As Boolean) As Server.DataPortal

        If Not forceLocal AndAlso mPortalRemote Then
            ' return remote instance
            If mRemotePortal Is Nothing Then
                mRemotePortal = CType(Activator.GetObject(GetType(Server.DataPortal), mPortalString), _
                  Server.DataPortal)
            End If
            Return mRemotePortal

        Else
            ' return local instance
            If mPortal Is Nothing Then
                mPortal = New Server.DataPortal()
            End If
            Return mPortal
        End If

    End Function

    'Private Shared Function ServicedPortal(ByVal forceLocal As Boolean) As Server.ServicedDataPortal.DataPortal


    '    If Not forceLocal AndAlso mPortalRemote Then
    '        ' return remote instance
    '        If mRemoteServicedPortal Is Nothing Then
    '            mRemoteServicedPortal = _
    '              CType(Activator.GetObject(GetType(Server.ServicedDataPortal.DataPortal), _
    '                                        SERVICED_PORTAL_SERVER), _
    '              Server.ServicedDataPortal.DataPortal)
    '        End If
    '        Return mRemoteServicedPortal

    '    Else
    '        ' return local instance
    '        If mServicedPortal Is Nothing Then
    '            mServicedPortal = New Server.ServicedDataPortal.DataPortal()
    '        End If
    '        Return mServicedPortal
    '    End If

    'End Function

    'Private Shared Function PORTAL_SERVER() As String
    '      Return "XXX" 'System.CXXXonfiguration.ConfigurationManager.AppSettings("PortalServer")
    'End Function

    'Private Shared Function SERVICED_PORTAL_SERVER() As String
    '      Return "" 'System.CXXXonfiguration.ConfigurationManager.AppSettings("ServicedPortalServer")
    'End Function

#End Region

#Region " Security "

    'Private Shared Function AUTHENTICATION() As String
    '      Return "CSLA" 'System.CXXXonfiguration.ConfigurationManager.AppSettings("Authentication")
    'End Function

  Private Shared Function GetPrincipal() As System.Security.Principal.IPrincipal
        'If AUTHENTICATION() = "Windows" Then
        '  ' Windows integrated security 
        '  Return Nothing

        'Else
        ' we assume using the CSLA framework security
        Return System.Threading.Thread.CurrentPrincipal
        'End If
  End Function

#End Region

#Region " Helper methods "

    'Private Shared Function IsTransactionalMethod(ByVal Method As MethodInfo) As Boolean

    '  Return Attribute.IsDefined(Method, GetType(TransactionalAttribute))

    '  'Dim attrib() As Object = Method.GetCustomAttributes(GetType(TransactionalAttribute), True)
    '  'Return (UBound(attrib) > -1)

    'End Function

  Private Shared Function RunLocal(ByVal Method As MethodInfo) As Boolean

    Return Attribute.IsDefined(Method, GetType(RunLocalAttribute))

  End Function

  Private Shared Function GetMethod(ByVal ObjectType As Type, ByVal method As String) As MethodInfo
    Return ObjectType.GetMethod(method, BindingFlags.FlattenHierarchy Or BindingFlags.Instance Or BindingFlags.Public Or BindingFlags.NonPublic)
  End Function

  Private Shared Function GetObjectType(ByVal criteria As Object) As Type

    If criteria.GetType.IsSubclassOf(GetType(CriteriaBase)) Then
      ' get the type of the actual business object
      ' from CriteriaBase (using the new scheme)
      Return CType(criteria, CriteriaBase).ObjectType

    Else
      ' get the type of the actual business object
      ' based on the nested class scheme in the book
      Return criteria.GetType.DeclaringType
    End If

  End Function

    Private Shared Sub Init()
        If Not mInitialized Then
            mPortalRemote = mIsRemote
            If mIsRemote = True AndAlso Not ChannelServices.RegisteredChannels.Length > 0 Then


                ' create and register our custom HTTP channel
                ' that uses the binary formatter
                Dim properties As New Hashtable()
                properties("name") = "HttpBinary"

                'If AUTHENTICATION() = "Windows" Then
                '    ' make sure we pass the user's Windows credentials
                '    ' to the server
                '    properties("useDefaultCredentials") = True
                'End If

                Dim formatter As New BinaryClientFormatterSinkProvider()

                Dim channel As New HttpChannel(properties, formatter, Nothing)

                ChannelServices.RegisterChannel(channel)


                '' register the data portal types as being remote
                'If Len(PORTAL_SERVER) > 0 Then
                '  RemotingConfiguration.RegisterWellKnownClientType( _
                '    GetType(Server.DataPortal), PORTAL_SERVER)
                'End If
                'If Len(SERVICED_PORTAL_SERVER) > 0 Then
                '  RemotingConfiguration.RegisterWellKnownClientType( _
                '    GetType(Server.ServicedDataPortal.DataPortal), SERVICED_PORTAL_SERVER)
                'End If
            End If
        End If

    End Sub
    Shared Sub New()
        ' see if we need to configure remoting at all
        'body moved to init sub

    End Sub

#End Region

End Class