Imports DigitalData.Modules.Logging
Imports DigitalData.Modules.EDMI.API.EDMIServiceReference
Imports System.ServiceModel
Imports System.IO

Public Class Client
    Private ReadOnly _logger As Logger
    Private ReadOnly _channelFactory As ChannelFactory(Of IEDMIServiceChannel)
    Private _channel As IEDMIServiceChannel

    Public Class StreamedFile
        Public Stream As MemoryStream
        Public FileName As String
    End Class

    Public Class FileList
        Public Datatable As DataTable
    End Class

    ''' <summary>
    ''' Creates a new EDMIAPI object
    ''' </summary>
    ''' <param name="LogConfig">LogConfig object</param>
    ''' <param name="ServiceAdress">The full service url to connect to</param>
    Public Sub New(LogConfig As LogConfig, ServiceAdress As String)
        _logger = LogConfig.GetLogger()

        Try
            Dim oBinding = Channel.GetBinding()
            Dim oAddress = New EndpointAddress(ServiceAdress)
            Dim oFactory = New ChannelFactory(Of IEDMIServiceChannel)(oBinding, oAddress)

            _channelFactory = oFactory
        Catch ex As Exception
            _logger.Error(ex)
        End Try
    End Sub

    Public Sub New(LogConfig As LogConfig, IPAddress As String, PortNumber As Integer)
        _logger = LogConfig.GetLogger()

        Try
            Dim oBinding = Channel.GetBinding()
            Dim oAddress = New EndpointAddress($"net.tcp://{IPAddress}:{PortNumber}/DigitalData/Services/Main")
            Dim oFactory = New ChannelFactory(Of IEDMIServiceChannel)(oBinding, oAddress)

            _channelFactory = oFactory
        Catch ex As Exception
            _logger.Error(ex)
        End Try
    End Sub

    ''' <summary>
    ''' Connect to the service
    ''' </summary>
    ''' <returns>True if connection was successful, false otherwise</returns>
    Public Function Connect() As Boolean
        Try
            _channel = GetChannel()

            _logger.Debug("Opening channel..")
            _channel.Open()

            _logger.Info("Connection to Service established!")
            Return True
        Catch ex As Exception
            _logger.Error(ex)
            Return False
        End Try
    End Function

    ''' <summary>
    ''' Imports a file by filename
    ''' </summary>
    ''' <returns>A document object</returns>
    Public Async Function ImportFileAsync(FilePath As String, DocumentType As String, ObjectStoreId As Long, Optional RetentionDays As Integer = 0) As Task(Of Long)
        Try
            Dim oFileInfo As New FileInfo(FilePath)
            If oFileInfo.Exists = False Then
                Throw New FileNotFoundException("Cannot import non-existing file.", FilePath)
            End If

            Using oStream As New FileStream(FilePath, FileMode.Open)
                Dim oContents(oStream.Length) As Byte
                Dim oBytesRead = Await oStream.ReadAsync(oContents, 0, oStream.Length)
                Dim oData As New DocumentImportRequest() With {
                    .FileName = oFileInfo.Name,
                    .Contents = oContents,
                    .DocumentType = DocumentType,
                    .ObjectStoreId = ObjectStoreId,
                    .RetentionDays = RetentionDays
                }

                Dim oResponse = Await _channel.ImportFileAsync(oData)

                Return oResponse.ObjectId
            End Using
        Catch ex As Exception
            _logger.Error(ex)
            Throw ex
        End Try
    End Function

    Public Async Function GetFileByObjectIdAsync(ObjectId As Long) As Task(Of StreamedFile)
        Try
            Dim oData As New DocumentStreamRequest() With {.ObjectId = ObjectId}
            Dim oResponse As DocumentStreamResponse = Await _channel.GetFileByObjectIdAsync(oData)
            Dim oMemoryStream As New MemoryStream()
            oResponse.FileContents.CopyTo(oMemoryStream)
            oMemoryStream.Position = 0

            Return New StreamedFile() With {
                .Stream = oMemoryStream,
                .FileName = oResponse.FileName
            }
        Catch ex As Exception
            _logger.Error(ex)
            Throw ex
        End Try
    End Function

    Public Async Function ListFilesForUserAsync() As Task(Of FileList)
        Try
            Dim oResponse As DocumentListResponse = Await _channel.ListFilesForUserAsync(New ListFilesForUserRequest())
            Return New FileList() With {
                .Datatable = oResponse.Datatable
            }
        Catch ex As Exception
            _logger.Error(ex)
            Throw ex
        End Try
    End Function

    ''' <summary>
    ''' Aborts the channel and creates a new connection
    ''' </summary>
    Private Sub Reconnect()
        _logger.Warn("Connection faulted. Trying to reconnect..")

        Try
            _channel.Abort()
            _channel = GetChannel()
            _channel.Open()
        Catch ex As Exception
            _logger.Error(ex)
        End Try
    End Sub

    ''' <summary>
    ''' Creates a channel and adds a Faulted-Handler
    ''' </summary>
    ''' <returns>A channel object</returns>
    Private Function GetChannel() As IEDMIServiceChannel
        Try
            _logger.Debug("Creating channel..")
            Dim oChannel = _channelFactory.CreateChannel()

            AddHandler oChannel.Faulted, AddressOf Reconnect

            Return oChannel
        Catch ex As Exception
            _logger.Error(ex)
            Throw ex
        End Try
    End Function
End Class