Zugferd: fix

Interfaces/ZUGFeRDInterface/FileGroups.vb

@@ -3,7 +3,7 @@ Imports System.Text.RegularExpressions
 Imports DigitalData.Modules.Logging
 
 Public Class FileGroups
-    Private _logger As Logger
+    Private ReadOnly _logger As Logger
 
     Public Sub New(LogConfig As LogConfig)
         _logger = LogConfig.GetLogger()
@@ -25,7 +25,7 @@ Public Class FileGroups
             Dim oMessageId = GetMessageIdFromFileName(oFile.Name)
 
             If oMessageId Is Nothing Then
-                _logger.Warn("File {0} did not have the required filename-format!", oMessageId)
+                _logger.Warn("File {0} did not have the required filename-format!", oFile.Name)
                 Continue For
             End If
 

Jobs/Exceptions.vb

@@ -7,11 +7,13 @@ Public Class Exceptions
         Inherits ApplicationException
 
         Public ReadOnly File As FileInfo
+        Public ReadOnly MissingProperties As List(Of String)
 
-        Public Sub New(File As FileInfo)
+        Public Sub New(pFile As FileInfo, pMissingProperties As List(Of String))
-            MyBase.New($"Missing values in [{File.Name}]")
+            MyBase.New($"Missing values in [{pFile.Name}]")
 
-            Me.File = File
+            Me.File = pFile
+            Me.MissingProperties = pMissingProperties
         End Sub
     End Class
 

Jobs/Jobs.vbproj

@@ -97,6 +97,7 @@
     <Compile Include="ZUGFeRD\EmailFunctions.vb" />
     <Compile Include="ZUGFeRD\EmailStrings.vb" />
     <Compile Include="ZUGFeRD\FileFunctions.vb" />
+    <Compile Include="ZUGFeRD\HashFunctions.vb" />
     <Compile Include="ZUGFeRD\HistoryFunctions.vb" />
     <Compile Include="ZUGFeRD\ImportZUGFeRDFiles.vb" />
     <Compile Include="ZUGFeRD\WorkerArgs.vb" />

Jobs/My Project/AssemblyInfo.vb

@@ -13,7 +13,7 @@ Imports System.Runtime.InteropServices
 <Assembly: AssemblyCompany("Digital Data")>
 <Assembly: AssemblyProduct("Modules.Jobs")>
 <Assembly: AssemblyCopyright("Copyright © 2023")>
-<Assembly: AssemblyTrademark("2.1.0.0")>
+<Assembly: AssemblyTrademark("2.2.0.0")>
 
 <Assembly: ComVisible(False)>
 
@@ -30,5 +30,5 @@ Imports System.Runtime.InteropServices
 ' Sie können alle Werte angeben oder die standardmäßigen Build- und Revisionsnummern 
 ' übernehmen, indem Sie "*" eingeben:
 
-<Assembly: AssemblyVersion("2.1.0.0")>
+<Assembly: AssemblyVersion("2.2.0.0")>
-<Assembly: AssemblyFileVersion("2.1.0.0")>
+<Assembly: AssemblyFileVersion("2.2.0.0")>

Jobs/ZUGFeRD/FileFunctions.vb

@@ -5,7 +5,6 @@ Imports DigitalData.Modules.Base
 Imports DigitalData.Modules.Database
 Imports DigitalData.Modules.Interfaces
 Imports DigitalData.Modules.Logging
-Imports Microsoft.VisualBasic.FileIO
 
 Namespace ZUGFeRD
     Public Class FileFunctions
@@ -13,29 +12,31 @@ Namespace ZUGFeRD
         Private ReadOnly _logger As Logger
         Private ReadOnly _mssql As MSSQLServer
         Private ReadOnly _filesystem As FilesystemEx
+        Private ReadOnly _email As ZUGFeRD.EmailFunctions
 
-        Public Sub New(LogConfig As LogConfig, MSSQL As MSSQLServer)
+        Public Sub New(pLogConfig As LogConfig, pMSSQL As MSSQLServer)
-            _logConfig = LogConfig
+            _logConfig = pLogConfig
             _logger = _logConfig.GetLogger()
-            _mssql = MSSQL
+            _mssql = pMSSQL
-            _filesystem = New FilesystemEx(LogConfig)
+            _email = New EmailFunctions(pLogConfig, pMSSQL)
+            _filesystem = New FilesystemEx(pLogConfig)
         End Sub
 
         Public Sub MoveFiles(
-                         Args As WorkerArgs,
+                         pArgs As WorkerArgs,
-                         MessageId As String,
+                         pMessageId As String,
-                         Files As List(Of FileInfo),
+                         pFiles As List(Of FileInfo),
-                         AttachmentFiles As List(Of FileInfo),
+                         pAttachmentFiles As List(Of FileInfo),
-                         EmbeddedAttachments As List(Of PDFEmbeds.EmbeddedFile),
+                         pEmbeddedAttachments As List(Of PDFEmbeds.EmbeddedFile),
-                         MoveDirectory As String,
+                         pMoveDirectory As String,
-                         IsSuccess As Boolean)
+                         pIsSuccess As Boolean)
 
-            Dim oFinalMoveDirectory As String = MoveDirectory
+            Dim oFinalMoveDirectory As String = pMoveDirectory
             Dim oDateSubDirectoryName As String = Now.ToString("yyyy\\MM\\dd")
-            Dim oAttachmentDirectory As String = Path.Combine(oFinalMoveDirectory, Args.AttachmentsSubDirectory, oDateSubDirectoryName)
+            Dim oAttachmentDirectory As String = Path.Combine(oFinalMoveDirectory, pArgs.AttachmentsSubDirectory, oDateSubDirectoryName)
 
             ' Files will be moved to a subfolder for the current day if they are rejected
-            If Not IsSuccess Then
+            If Not pIsSuccess Then
                 oFinalMoveDirectory = Path.Combine(oFinalMoveDirectory, oDateSubDirectoryName)
             End If
 
@@ -48,7 +49,7 @@ Namespace ZUGFeRD
                 End Try
             End If
 
-            If Not Directory.Exists(oAttachmentDirectory) And AttachmentFiles.Count > 0 Then
+            If Not Directory.Exists(oAttachmentDirectory) And pAttachmentFiles.Count > 0 Then
                 Try
                     Directory.CreateDirectory(oAttachmentDirectory)
                 Catch ex As Exception
@@ -57,7 +58,7 @@ Namespace ZUGFeRD
             End If
 
             ' Filter out Attachments from `Files`
-            Dim oInvoiceFiles As List(Of FileInfo) = Files.Except(AttachmentFiles).ToList()
+            Dim oInvoiceFiles As List(Of FileInfo) = pFiles.Except(pAttachmentFiles).ToList()
 
             ' Move PDF/A Files
             For Each oFile In oInvoiceFiles
@@ -74,7 +75,7 @@ Namespace ZUGFeRD
             Next
 
             ' Move non-PDF/A Email Attachments/Files
-            For Each oFile In AttachmentFiles
+            For Each oFile In pAttachmentFiles
                 Try
                     Dim oFilePath = _filesystem.GetVersionedFilename(Path.Combine(oAttachmentDirectory, oFile.Name))
 
@@ -87,9 +88,9 @@ Namespace ZUGFeRD
             Next
 
             ' Write Embedded Files to disk
-            For Each oResult In EmbeddedAttachments
+            For Each oResult In pEmbeddedAttachments
                 Try
-                    Dim oFileName As String = $"{MessageId}~{oResult.FileName}"
+                    Dim oFileName As String = $"{pMessageId}~{oResult.FileName}"
                     Dim oFilePath As String = Path.Combine(oAttachmentDirectory, oFileName)
 
                     If Not File.Exists(oAttachmentDirectory) Then
@@ -108,6 +109,72 @@ Namespace ZUGFeRD
 
             _logger.Info("Finished moving files")
         End Sub
+
+        Public Function MoveAndRenameEmailToRejected(pArgs As WorkerArgs, pMessageId As String) As EmailData
+            _logger.Info("Moving Mail with MessageId [{0}] to Rejected folder", pMessageId)
+            _logger.Debug("Fetching Email Data")
+
+            Dim oEmailData = _email.GetEmailDataForMessageId(pMessageId)
+            _logger.Debug("Email Data fetched!")
+
+            Dim oSource = _email.GetOriginalEmailPath(pArgs.OriginalEmailDirectory, pMessageId)
+            _logger.Debug("Original email path: [{0}]", oSource)
+
+            Dim oDateSubDirectoryName As String = Now.ToString("yyyy-MM-dd")
+            Dim oDestination As String
+
+            Dim oRejectedDirectory As String = Path.Combine(pArgs.RejectedEmailDirectory, oDateSubDirectoryName)
+
+            ' Create the destination directory if it does not exist
+            _logger.Debug("Creating destination directory [{0}]", oRejectedDirectory)
+            If Not Directory.Exists(oRejectedDirectory) Then
+                Try
+                    Directory.CreateDirectory(oRejectedDirectory)
+                Catch ex As Exception
+                    _logger.Error(ex)
+                End Try
+            End If
+
+            If oSource = String.Empty Then
+                _logger.Warn("Original Email for [{0}] could not be found. Exiting.", pMessageId)
+                Return New EmailData()
+            End If
+
+            ' If oEmailData is Nothing, TBEDM_EMAIL_PROFILER_HISTORY for MessageId was not found. 
+            ' This only should happen when testing and db-tables are deleted frequently
+            If oEmailData Is Nothing Then
+                oDestination = _email.GetEmailPathWithSubjectAsName(oRejectedDirectory, pMessageId)
+            Else
+                oDestination = _email.GetEmailPathWithSubjectAsName(oRejectedDirectory, StringEx.ConvertTextToSlug(oEmailData.Subject))
+            End If
+
+            _logger.Debug("Destination for eml file is {0}", oDestination)
+
+            Dim oFinalFileName = _filesystem.GetVersionedFilename(oDestination)
+
+            _logger.Debug("Versioned filename for eml file is {0}", oFinalFileName)
+
+            If oEmailData Is Nothing Then
+                _logger.Warn("Could not get Email Data from Database. File {0} will not be moved!", oSource)
+                Return New EmailData()
+            End If
+
+            '---------------------------
+
+            Try
+                _logger.Info("Moving email from {0} to {1}", oSource, oFinalFileName)
+                File.Move(oSource, oFinalFileName)
+                oEmailData.Attachment = oFinalFileName
+            Catch ex As Exception
+                _logger.Warn("File {0} could not be moved! Original Filename will be used!", oSource)
+                _logger.Error(ex)
+                oEmailData.Attachment = oSource
+            End Try
+
+            _logger.Info("Email [{0}] moved to rejected folder!", pMessageId)
+
+            Return oEmailData
+        End Function
     End Class
 
 End Namespace

Jobs/ZUGFeRD/HashFunctions.vb

@@ -0,0 +1,123 @@
+Imports DigitalData.Modules.Base
+Imports DigitalData.Modules.Database
+Imports DigitalData.Modules.Jobs.Exceptions
+Imports DigitalData.Modules.Logging
+Imports System.Data
+Imports System.IO
+Imports System.Security.Cryptography
+
+Public Class HashFunctions
+    Inherits BaseClass
+
+    Private ReadOnly Database As MSSQLServer
+
+    Public Sub New(pLogConfig As LogConfig, pDatabase As MSSQLServer)
+        MyBase.New(pLogConfig)
+        Database = pDatabase
+    End Sub
+
+    ''' <summary>
+    ''' Generates the MD5 Checksum of a file and checks it against the histroy table TBEDM_ZUGFERD_HISTORY_IN
+    ''' </summary>
+    ''' <param name="pFilePath">The path of the file to be checked</param>
+    ''' <param name="pIgnoreRejectionStatus">Should the check take into account the rejection status of the file?</param>
+    ''' <returns>The MD5 Checksum of the file, or an empty string, if the Checksum could not be created</returns>
+    ''' <exception cref="MD5HashException">Throws, when the file should be rejected, ie. if it already exists in the table</exception>
+    Public Function GenerateAndCheck_MD5Sum(pFile As FileInfo, pMessageId As String, pIgnoreRejectionStatus As Boolean) As String
+        Dim oMD5CheckSum = CreateMD5(pFile.FullName)
+
+        ' Exit if MD5 could not be created
+        If oMD5CheckSum = String.Empty Then
+            Logger.Warn("MD5 Checksum is nothing for file [{0}]!", pFile.FullName)
+            Return oMD5CheckSum
+        End If
+
+        ' Check if Checksum exists in History Table
+        'Dim oCheckCommand = $"SELECT * FROM TBEDM_ZUGFERD_HISTORY_IN WHERE GUID = (SELECT MAX(GUID) FROM TBEDM_ZUGFERD_HISTORY_IN WHERE UPPER(MD5HASH) = UPPER('{oMD5CheckSum}'))"
+        'Dim oTable As DataTable = _firebird.GetDatatable(oCheckCommand, Firebird.TransactionMode.NoTransaction)
+
+        ' Check if Checksum exists in History Table
+        ' TODO: WHAT THE FUCK IS THIS
+        Dim oCheckCommand = $"SELECT * FROM TBEMLP_HISTORY WHERE GUID = (SELECT MAX(GUID) FROM TBEMLP_HISTORY WHERE UPPER(MD5HASH) = UPPER('{oMD5CheckSum}'))"
+        Dim oTable As DataTable = Database.GetDatatable(oCheckCommand, MSSQLServer.TransactionMode.NoTransaction)
+
+        ' If History entries could not be fetched, just return the MD5 Checksum
+        If IsNothing(oTable) Then
+            Logger.Warn("Be careful: oExistsDT is nothing for file [{0}]!", pFile.FullName)
+            Return oMD5CheckSum
+        End If
+
+        ' If Checksum does not exist in History entries, just return the MD5 Checksum
+        If oTable.Rows.Count = 0 Then
+            Logger.Debug("File [{0}] was not found in History!", pFile.FullName)
+            Return oMD5CheckSum
+        End If
+
+        ' ====================================================
+        ' Checksum exists in History entries, reject!
+        ' ====================================================
+
+        Dim oRejected As Boolean
+        Dim oHistoryId As Integer
+
+        ' Try to read Rejected Status and History Id
+        Try
+            Dim oRow As DataRow = oTable.Rows.Item(0)
+            oRejected = oRow.ItemEx("CUST_REJECTED", False)
+            oHistoryId = oRow.Item("GUID")
+
+        Catch ex As Exception
+            Logger.Warn("Error while converting REJECTED: " & ex.Message)
+            oRejected = False
+
+        End Try
+
+        ' Try to get the original filename from Attachment table
+        ' If this fails, falls back to the new filename (<msgid>~Attm<i>.ext)
+        Dim oSQL = $"SELECT EMAIL_ATTMT FROM TBEMLP_HISTORY_ATTACHMENT WHERE EMAIL_ATTMT_INDEX = '{pFile.Name}'"
+        Dim oEmailAttachment = Database.GetScalarValue(oSQL, MSSQLServer.TransactionMode.NoTransaction)
+        Dim oOriginalName = ObjectEx.NotNull(oEmailAttachment, pFile.Name)
+
+        Logger.Info("File with MessageId [{0}] and Filename [{1}] has already been processed.", pMessageId, oOriginalName)
+
+        ' If the file was already rejected, it is allowed to be processed again, 
+        ' even if the Checksum exists in the history entries (default case)
+        ' Which means, if it was not rejected before, it will be rejected in any case!
+        '
+        ' This logic can be overwritten by the IgnoreRejectionStatus parameter.
+        ' If it is set to true, the file will be rejected if the file exists in the history entries,
+        ' regardless of the rejected parameter.
+
+        If oRejected = True And pIgnoreRejectionStatus = True Then
+            Logger.Info("ZuGFeRDFile already has been processed, but Rejection Status will be ignored!")
+        ElseIf oRejected = False Then
+            Logger.Info("ZuGFeRDFile already has been processed. Will be rejected.")
+            Throw New MD5HashException($"There is already an identical invoice! - HistoryID [{oHistoryId}] - Case 1", oOriginalName)
+        Else
+            Logger.Info("ZuGFeRDFile already has been processed. Will be rejected.")
+            Throw New MD5HashException($"There is already an identical invoice! - HistoryID [{oHistoryId}] - Case 2", oOriginalName)
+        End If
+
+        Return oMD5CheckSum
+    End Function
+
+    Private Function CreateMD5(pFilename As String) As String
+        Try
+            Dim oMD5 As New MD5CryptoServiceProvider
+            Dim oHash As Byte()
+            Dim oHashString As String
+            Dim oResult As String = ""
+
+            Using oFileStream As New FileStream(pFilename, FileMode.Open, FileAccess.Read, FileShare.Read, 8192)
+                oHash = oMD5.ComputeHash(oFileStream)
+                oHashString = BitConverter.ToString(oHash)
+            End Using
+
+            oResult = oHashString.Replace("-", "")
+            Return oResult
+        Catch ex As Exception
+            Logger.Error(ex)
+            Return ""
+        End Try
+    End Function
+End Class

Jobs/ZUGFeRD/ImportZUGFeRDFiles.vb

@@ -37,6 +37,7 @@ Public Class ImportZUGFeRDFiles
     Private ReadOnly _email As ZUGFeRD.EmailFunctions
     Private ReadOnly _file As ZUGFeRD.FileFunctions
     Private ReadOnly _history As ZUGFeRD.HistoryFunctions
+    Private ReadOnly _hash As HashFunctions
     Private ReadOnly _embeds As PDFEmbeds
 
     Private ReadOnly _gdpictureLicenseKey As String
@@ -45,9 +46,13 @@ Public Class ImportZUGFeRDFiles
     Private _EmailOutAccountId As Integer
 
     Private Class ProcessFileResult
-        Public ZugferdFileCount As Integer
+        Public ZugferdFileFound As Boolean = False
-        Public MD5Hash As String = Nothing
 
+        Public ZugferdFileCount As Integer = 0
+        Public MD5Checksum As String = Nothing
+
+        Public EmailAttachmentFiles As New List(Of FileInfo)
+        Public EmbeddedAttachmentFiles As New List(Of PDFEmbeds.EmbeddedFile)
     End Class
 
     Private Class DatabaseConnections
@@ -64,6 +69,7 @@ Public Class ImportZUGFeRDFiles
         _file = New ZUGFeRD.FileFunctions(LogConfig, _mssql)
         _history = New ZUGFeRD.HistoryFunctions(LogConfig, _mssql)
         _embeds = New PDFEmbeds(LogConfig)
+        _hash = New HashFunctions(_logConfig, _mssql)
 
         _logger.Debug("Registering GDPicture License")
         If _mssql IsNot Nothing Then
@@ -152,147 +158,36 @@ Public Class ImportZUGFeRDFiles
                 Dim oEmbeddedAttachmentFiles As New List(Of PDFEmbeds.EmbeddedFile)
 
                 Dim oMessageId As String = oFileGroup.Key
-                Dim oMissingProperties As New List(Of String)
                 Dim oMD5CheckSum As String = String.Empty
 
                 _logger.Info("Start processing file group {0}", oMessageId)
 
-                ' TODO: Use this refactored function 
+                Dim oEmailDataBase = _email.GetEmailDataForMessageId(oMessageId)
-                ' ProcessFileGroup(oMessageId, oFileGroupFiles, oConnections, oArgs)
 
                 Try
                     For Each oFile In oFileGroupFiles
-                        ' 09.12.2021: oDocument is now an Object, because have different classes corresponding to the 
+                        Dim oResult As ProcessFileResult = ProcessFile(oMessageId, oEmailDataBase, oZUGFeRDCount, oFile, oConnections, oArgs)
-                        '   different versions of ZUGFeRD and the type is unknown at compile-time.
-                        ' 17.11.2022: oDocument is now a Tuple of (String, Object), to be able to return the filename
-                        '   of the extracted xml file.
-                        ' 21.12.2022: oDocument is now an object of type ZugferdResult to be able to save
-                        '   the new meta data, ie. the type of schema (zugferd version)
-                        Dim oDocument As ZUGFeRDInterface.ZugferdResult
 
-                        ' Start a global group counter for each file
+                        If oResult.ZugferdFileFound = False Then
-                        Dim oGlobalGroupCounter = 0
+                            _logger.Debug("Zugferd File found")
-                        ' Clear missing properties for the new file
+                            oMD5CheckSum = oResult.MD5Checksum
-                        oMissingProperties = New List(Of String)
+                            oZUGFeRDCount = oResult.ZugferdFileCount
-
+                            oEmailAttachmentFiles.AddRange(oResult.EmailAttachmentFiles)
-                        ' Only pdf files are allowed from here on
+                            oEmbeddedAttachmentFiles.AddRange(oResult.EmbeddedAttachmentFiles)
-                        If Not oFile.Name.ToUpper.EndsWith(".PDF") Then
-                            _logger.Debug("Skipping non-pdf file {0}", oFile.Name)
-                            oEmailAttachmentFiles.Add(oFile)
-
-                            ' Checking filesize for attachment files
-                            If _filesystem.TestFileSizeIsLessThanMaxFileSize(oFile.FullName, oArgs.MaxAttachmentSizeInMegaBytes) = False Then
-                                _logger.Warn("Filesize for File [{0}] exceeded limit of {1} MB", oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
-                                Throw New FileSizeLimitReachedException(oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
-                            End If
-
-                            Continue For
                         End If
 
-                        _logger.Info("Start processing file {0}", oFile.Name)
-
-                        ' Checking filesize for pdf files
-                        If _filesystem.TestFileSizeIsLessThanMaxFileSize(oFile.FullName, oArgs.MaxAttachmentSizeInMegaBytes) = False Then
-                            _logger.Warn("Filesize for File [{0}] exceeded limit of {1} MB", oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
-                            Throw New FileSizeLimitReachedException(oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
-                        End If
-
-                        Try
-                            oDocument = _zugferd.ExtractZUGFeRDFileWithGDPicture(oFile.FullName)
-
-                        Catch ex As ValidationException
-                            Throw ex
-
-                        Catch ex As ZUGFeRDExecption
-                            Select Case ex.ErrorType
-                                Case ZUGFeRDInterface.ErrorType.NoZugferd
-                                    _logger.Info("File [{0}] is not a valid ZUGFeRD document. Skipping.", oFile.Name)
-                                    oEmailAttachmentFiles.Add(oFile)
-                                    Continue For
-
-                                Case ZUGFeRDInterface.ErrorType.UnsupportedFormat
-                                    _logger.Info("File [{0}/{1}] is an unsupported ZUFeRD document format!", oFile.Name, ex.XmlFile)
-                                    Throw New UnsupportedFerdException(ex.XmlFile)
-
-                                Case ZUGFeRDInterface.ErrorType.NoValidZugferd
-                                    _logger.Info("File [{0}] is an Incorrectly formatted ZUGFeRD document!", oFile.Name)
-                                    Throw New InvalidFerdException()
-
-                                Case Else
-                                    _logger.Warn("Unexpected Error occurred while extracting ZUGFeRD Information from file {0}", oFile.Name)
-                                    Throw ex
-                            End Select
-                        End Try
-
-                        ' Check if there are more than one ZUGFeRD files
-                        If oZUGFeRDCount = 1 Then
-                            Throw New TooMuchFerdsException()
-                        End If
-
-                        ' Since extraction went well, increase the amount of ZUGFeRD files
-                        oZUGFeRDCount += 1
-
-                        ' Extract all attachments with the extensions specified in `AllowedExtensions`.
-                        ' If you need to extract and use embedded xml files, you need to filter out the zugferd-invoice.xml yourself.
-                        ' Right now the zugferd-invoice.xml is filtered out because `AllowedExtensions` does not contain `xml`.
-                        Dim oAttachments = oAttachmentExtractor.Extract(oFile.FullName, AllowedExtensions)
-                        If oAttachments Is Nothing Then
-                            _logger.Warn("Attachments for file [{0}] could not be extracted", oFile.FullName)
-                        Else
-                            oEmbeddedAttachmentFiles.AddRange(oAttachments)
-                        End If
-
-                        ' Check the Checksum and rejection status
-                        oMD5CheckSum = GenerateAndCheck_MD5Sum(oFile, oMessageId, oArgs.IgnoreRejectionStatus)
-
-                        ' Check the document against the configured property map and return:
-                        ' - a List of valid properties 
-                        ' - a List of missing properties
-
-                        Dim oPropertyMap = _zugferd.FilterPropertyMap(oArgs.PropertyMap, oDocument.Specification)
-                        Dim oCheckResult = _zugferd.PropertyValues.CheckPropertyValues(oDocument.SchemaObject, oPropertyMap, oMessageId)
-
-                        _logger.Info("Properties checked: [{0}] missing properties / [{1}] valid properties found.", oCheckResult.MissingProperties.Count, oCheckResult.ValidProperties.Count)
-
-                        If oCheckResult.MissingProperties.Count > 0 Then
-                            _logger.Warn("[{0}] missing properties found. Exiting.", oCheckResult.MissingProperties.Count)
-                            oMissingProperties = oCheckResult.MissingProperties
-                            Throw New MissingValueException(oFile)
-                        Else
-                            _logger.Debug("No missing properties found. Continuing.")
-
-                        End If
-
-                        DeleteExistingPropertyValues(oMessageId, oConnections)
-
-                        Dim oFirstProperty = oCheckResult.ValidProperties.FirstOrDefault()
-                        If oFirstProperty IsNot Nothing Then
-                            InsertPropertyValue(oMessageId, oConnections, New PropertyValues.ValidProperty() With {
-                                .MessageId = oMessageId,
-                                .Description = "ZUGFeRDSpezifikation",
-                                .GroupCounter = 0,
-                                .IsRequired = False,
-                                .Value = oDocument.Specification,
-                                .TableName = oFirstProperty.TableName,
-                                .TableColumn = "ZUGFERD_SPECIFICATION"
-                            })
-                        End If
-
-                        For Each oProperty In oCheckResult.ValidProperties
-                            InsertPropertyValue(oMessageId, oConnections, oProperty)
-                        Next
                     Next
 
                     'Check if there are no ZUGFeRD files
                     If oZUGFeRDCount = 0 Then
                         ' If NonZugferdDirectory is not set, a NoFerdsException will be thrown and a rejection will be generated
                         ' This is the default/initial behaviour.
-                        If oArgs.NonZugferdDirectory Is Nothing OrElse oArgs.NonZugferdDirectory = String.Empty Then
+                        If String.IsNullOrEmpty(oArgs.NonZugferdDirectory) Then
                             Throw New NoFerdsException()
                         End If
 
                         ' Also, if the directory is set but does not exist, still a rejection will be generated.
-                        If Not IO.Directory.Exists(oArgs.NonZugferdDirectory) Then
+                        If Not Directory.Exists(oArgs.NonZugferdDirectory) Then
                             Throw New NoFerdsException()
                         End If
 
@@ -302,12 +197,11 @@ Public Class ImportZUGFeRDFiles
 
                     End If
 
-                    'If no errors occurred...
+                    'If no errors occurred, update the history table for this MessageId
-                    'Log the History
+                    If String.IsNullOrEmpty(oMD5CheckSum) Then
-                    If oMD5CheckSum <> String.Empty Then
-                        _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "SUCCESS")
-                    Else
                         _history.Update_HistoryEntry(oMessageId, String.Empty, "SUCCESS (with empty MD5Hash)")
+                    Else
+                        _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "SUCCESS")
                     End If
 
                     oIsSuccess = True
@@ -326,7 +220,7 @@ Public Class ImportZUGFeRDFiles
                     Next
 
                     Dim oBody = String.Format(EmailStrings.EMAIL_VALIDATION_ERROR, oErrorList)
-                    Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+                    Dim oEmailData = _file.MoveAndRenameEmailToRejected(oArgs, oMessageId)
                     _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "ValidationException", _EmailOutAccountId, oArgs.NamePortal)
                     AddRejectedState(oMessageId, "ValidationException", "Die Rechnungsvalidierung ist fehlgeschlagen!", "", oSQLTransaction)
 
@@ -339,7 +233,7 @@ Public Class ImportZUGFeRDFiles
                     _history.Update_HistoryEntry(oMessageId, String.Empty, oMessage)
 
                     Dim oBody = String.Format(EmailStrings.EMAIL_MD5_ERROR, ex.FileName)
-                    Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+                    Dim oEmailData = _file.MoveAndRenameEmailToRejected(oArgs, oMessageId)
                     _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "MD5HashException", _EmailOutAccountId, oArgs.NamePortal)
                     AddRejectedState(oMessageId, "MD5HashException", "Die gesendete Rechnung wurde bereits verarbeitet!", "", oSQLTransaction)
 
@@ -350,7 +244,7 @@ Public Class ImportZUGFeRDFiles
                     ' That 's why we set it to String.Empty here.
                     _history.Update_HistoryEntry(oMessageId, String.Empty, "REJECTED - ZUGFeRD yes but unsupported format")
 
-                    Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+                    Dim oEmailData = _file.MoveAndRenameEmailToRejected(oArgs, oMessageId)
                     Dim oBody As String = String.Format(EmailStrings.EMAIL_UNSUPPORTED_DOCUMENT, oEmailData.Subject, ex.XmlFile)
 
                     _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "UnsupportedFerdException", _EmailOutAccountId, oArgs.NamePortal)
@@ -363,7 +257,7 @@ Public Class ImportZUGFeRDFiles
                     ' That 's why we set it to String.Empty here.
                     _history.Update_HistoryEntry(oMessageId, String.Empty, "REJECTED - ZUGFeRD yes but incorrect format")
 
-                    Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+                    Dim oEmailData = _file.MoveAndRenameEmailToRejected(oArgs, oMessageId)
                     Dim oBody = String.Format(EmailStrings.EMAIL_INVALID_DOCUMENT, oEmailData.Subject)
 
                     _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "InvalidFerdException", _EmailOutAccountId, oArgs.NamePortal)
@@ -374,7 +268,7 @@ Public Class ImportZUGFeRDFiles
 
                     _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - More than one ZUGFeRD-document in email")
 
-                    Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+                    Dim oEmailData = _file.MoveAndRenameEmailToRejected(oArgs, oMessageId)
                     Dim oBody = String.Format(EmailStrings.EMAIL_TOO_MUCH_FERDS, oEmailData.Subject)
 
                     _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "TooMuchFerdsException", _EmailOutAccountId, oArgs.NamePortal)
@@ -385,7 +279,7 @@ Public Class ImportZUGFeRDFiles
 
                     _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - no ZUGFeRD-Document in email")
 
-                    Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+                    Dim oEmailData = _file.MoveAndRenameEmailToRejected(oArgs, oMessageId)
                     Dim oBody = String.Format(EmailStrings.EMAIL_NO_FERDS, oEmailData.Subject)
 
                     _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "NoFerdsException", _EmailOutAccountId, oArgs.NamePortal)
@@ -395,14 +289,14 @@ Public Class ImportZUGFeRDFiles
                     _logger.Error(ex)
 
                     Dim oMessage As String = ""
-                    For Each prop In oMissingProperties
+                    For Each prop In ex.MissingProperties
                         oMessage &= $"- {prop}"
                     Next
 
                     _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, $"REJECTED - Missing Required Properties: [{oMessage}]")
 
-                    Dim oBody = _email.CreateBodyForMissingProperties(ex.File.Name, oMissingProperties)
+                    Dim oBody = _email.CreateBodyForMissingProperties(ex.File.Name, ex.MissingProperties)
-                    Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+                    Dim oEmailData = _file.MoveAndRenameEmailToRejected(oArgs, oMessageId)
                     _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "MissingValueException", _EmailOutAccountId, oArgs.NamePortal)
                     AddRejectedState(oMessageId, "MissingValueException", "Es fehlten ZugferdSpezifikationen", oMessage, oSQLTransaction)
 
@@ -411,7 +305,7 @@ Public Class ImportZUGFeRDFiles
 
                     _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - File size limit reached")
 
-                    Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+                    Dim oEmailData = _file.MoveAndRenameEmailToRejected(oArgs, oMessageId)
 
                     Dim oKey = FileSizeLimitReachedException.KEY_FILENAME
                     Dim oFileExceedingThreshold As String = IIf(ex.Data.Contains(oKey), ex.Data.Item(oKey), "")
@@ -522,405 +416,15 @@ Public Class ImportZUGFeRDFiles
         End Try
     End Sub
 
-#Region "=== REFACTOR"
+    Private Function ProcessFile(pMessageId As String, pEmailData As EmailData, pZugferdFiles As Integer, oFile As FileInfo, oConnections As DatabaseConnections, pArgs As WorkerArgs) As ProcessFileResult
-    Private Function ProcessFileGroup(oMessageId As String, pFiles As List(Of FileInfo), oConnections As DatabaseConnections, pArgs As WorkerArgs)
-        Dim oMissingProperties = New List(Of String)
-        Dim oEmailAttachmentFiles = New List(Of FileInfo)
-        Dim oEmbeddedAttachmentFiles = New List(Of PDFEmbeds.EmbeddedFile)
-        Dim oZUGFeRDCount = 0
-        Dim oMD5CheckSum As String = Nothing
-
-        ' Set the default Move Directory
-        Dim oMoveDirectory As String = pArgs.ErrorDirectory
-
-        ' Flag to save if the whole process was a success.
-        ' Will be set only at the end of the function if no error occurred.
-        Dim oIsSuccess As Boolean = False
-
-        ' Flag to save if the occurred error (if any) was expected
-        ' Used to determine if transactions should be committed or not
-        Dim oExpectedError As Boolean = True
-
-        Try
-            For Each oFile In pFiles
-                ' 09.12.2021: oDocument is now an Object, because have different classes corresponding to the 
-                '   different versions of ZUGFeRD and the type is unknown at compile-time.
-                ' 17.11.2022: oDocument is now a Tuple of (String, Object), to be able to return the filename
-                '   of the extracted xml file.
-                ' 21.12.2022: oDocument is now an object of type ZugferdResult to be able to save
-                '   the new meta data, ie. the type of schema (zugferd version)
-                Dim oDocument As ZUGFeRDInterface.ZugferdResult
-
-                ' Start a global group counter for each file
-                Dim oGlobalGroupCounter = 0
-                ' Clear missing properties for the new file
-                oMissingProperties = New List(Of String)
-
-                ' Only pdf files are allowed from here on
-                If Not oFile.Name.ToUpper.EndsWith(".PDF") Then
-                    _logger.Debug("Skipping non-pdf file {0}", oFile.Name)
-                    oEmailAttachmentFiles.Add(oFile)
-
-                    ' Checking filesize for attachment files
-                    If _filesystem.TestFileSizeIsLessThanMaxFileSize(oFile.FullName, pArgs.MaxAttachmentSizeInMegaBytes) = False Then
-                        _logger.Warn("Filesize for File [{0}] exceeded limit of {1} MB", oFile.Name, pArgs.MaxAttachmentSizeInMegaBytes)
-                        Throw New FileSizeLimitReachedException(oFile.Name, pArgs.MaxAttachmentSizeInMegaBytes)
-                    End If
-
-                    Continue For
-                End If
-
-                _logger.Info("Start processing file {0}", oFile.Name)
-
-                ' Checking filesize for pdf files
-                If _filesystem.TestFileSizeIsLessThanMaxFileSize(oFile.FullName, pArgs.MaxAttachmentSizeInMegaBytes) = False Then
-                    _logger.Warn("Filesize for File [{0}] exceeded limit of {1} MB", oFile.Name, pArgs.MaxAttachmentSizeInMegaBytes)
-                    Throw New FileSizeLimitReachedException(oFile.Name, pArgs.MaxAttachmentSizeInMegaBytes)
-                End If
-
-                Try
-                    oDocument = _zugferd.ExtractZUGFeRDFileWithGDPicture(oFile.FullName)
-
-                Catch ex As ValidationException
-                    Throw ex
-
-                Catch ex As ZUGFeRDExecption
-                    Select Case ex.ErrorType
-                        Case ZUGFeRDInterface.ErrorType.NoZugferd
-                            _logger.Info("File [{0}] is not a valid ZUGFeRD document. Skipping.", oFile.Name)
-                            oEmailAttachmentFiles.Add(oFile)
-                            Continue For
-
-                        Case ZUGFeRDInterface.ErrorType.UnsupportedFormat
-                            _logger.Info("File [{0}/{1}] is an unsupported ZUFeRD document format!", oFile.Name, ex.XmlFile)
-                            Throw New UnsupportedFerdException(ex.XmlFile)
-
-                        Case ZUGFeRDInterface.ErrorType.NoValidZugferd
-                            _logger.Info("File [{0}] is an Incorrectly formatted ZUGFeRD document!", oFile.Name)
-                            Throw New InvalidFerdException()
-
-                        Case Else
-                            _logger.Warn("Unexpected Error occurred while extracting ZUGFeRD Information from file {0}", oFile.Name)
-                            Throw ex
-                    End Select
-                End Try
-
-                ' Check if there are more than one ZUGFeRD files
-                If oZUGFeRDCount = 1 Then
-                    Throw New TooMuchFerdsException()
-                End If
-
-                ' Since extraction went well, increase the amount of ZUGFeRD files
-                oZUGFeRDCount += 1
-
-                ' Extract all attachments with the extensions specified in `AllowedExtensions`.
-                ' If you need to extract and use embedded xml files, you need to filter out the zugferd-invoice.xml yourself.
-                ' Right now the zugferd-invoice.xml is filtered out because `AllowedExtensions` does not contain `xml`.
-                Dim oAttachments = _embeds.Extract(oFile.FullName, AllowedExtensions)
-                If oAttachments Is Nothing Then
-                    _logger.Warn("Attachments for file [{0}] could not be extracted", oFile.FullName)
-                Else
-                    oEmbeddedAttachmentFiles.AddRange(oAttachments)
-                End If
-
-                ' Check the Checksum and rejection status
-                oMD5CheckSum = GenerateAndCheck_MD5Sum(oFile, oMessageId, pArgs.IgnoreRejectionStatus)
-
-                ' Check the document against the configured property map and return:
-                ' - a List of valid properties 
-                ' - a List of missing properties
-
-                Dim oPropertyMap = _zugferd.FilterPropertyMap(pArgs.PropertyMap, oDocument.Specification)
-                Dim oCheckResult = _zugferd.PropertyValues.CheckPropertyValues(oDocument.SchemaObject, oPropertyMap, oMessageId)
-
-                _logger.Info("Properties checked: [{0}] missing properties / [{1}] valid properties found.", oCheckResult.MissingProperties.Count, oCheckResult.ValidProperties.Count)
-
-                If oCheckResult.MissingProperties.Count > 0 Then
-                    _logger.Warn("[{0}] missing properties found. Exiting.", oCheckResult.MissingProperties.Count)
-                    oMissingProperties = oCheckResult.MissingProperties
-                    Throw New MissingValueException(oFile)
-                Else
-                    _logger.Debug("No missing properties found. Continuing.")
-
-                End If
-
-                DeleteExistingPropertyValues(oMessageId, oConnections)
-
-                Dim oFirstProperty = oCheckResult.ValidProperties.FirstOrDefault()
-                If oFirstProperty IsNot Nothing Then
-                    InsertPropertyValue(oMessageId, oConnections, New PropertyValues.ValidProperty() With {
-                        .MessageId = oMessageId,
-                        .Description = "ZUGFeRDSpezifikation",
-                        .GroupCounter = 0,
-                        .IsRequired = False,
-                        .Value = oDocument.Specification,
-                        .TableName = oFirstProperty.TableName,
-                        .TableColumn = "ZUGFERD_SPECIFICATION"
-                    })
-                End If
-
-                For Each oProperty In oCheckResult.ValidProperties
-                    InsertPropertyValue(oMessageId, oConnections, oProperty)
-                Next
-            Next
-
-            'Check if there are no ZUGFeRD files
-            If oZUGFeRDCount = 0 Then
-
-                ' If NonZugferdDirectory is not set, a NoFerdsException will be thrown and a rejection will be generated
-                ' This is the default/initial behaviour.
-                If pArgs.NonZugferdDirectory Is Nothing OrElse pArgs.NonZugferdDirectory = String.Empty Then
-                    Throw New NoFerdsException()
-                End If
-
-                ' Also, if the directory is set but does not exist, still a rejection will be generated.
-                If Not IO.Directory.Exists(pArgs.NonZugferdDirectory) Then
-                    Throw New NoFerdsException()
-                End If
-
-                ' Only if the directory is set and does exist, it will be used and any file groups which
-                ' do NOT CONTAIN ANY ZUGFERD DOCUMENTS, are moved to that directory.
-                Throw New NoFerdsAlternateException()
-
-            End If
-
-            'If no errors occurred...
-            'Log the History
-            If oMD5CheckSum <> String.Empty Then
-                _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "SUCCESS")
-            Else
-                _history.Update_HistoryEntry(oMessageId, String.Empty, "SUCCESS (with empty MD5Hash)")
-            End If
-
-            oIsSuccess = True
-            oMoveDirectory = pArgs.SuccessDirectory
-
-        Catch ex As ValidationException
-            _logger.Error(ex)
-
-            Dim oErrors = ex.ValidationErrors
-            Dim oMessage = "REJECTED - ZUGFeRD yes but formal validation failed!"
-            _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, oMessage)
-
-            Dim oErrorList As String = ""
-            For Each oError In oErrors
-                oErrorList += $"<li>Element '{oError.ElementName}' mit Wert '{oError.ElementValue}': {oError.ErrorMessage}</li>"
-            Next
-
-            Dim oBody = String.Format(EmailStrings.EMAIL_VALIDATION_ERROR, oErrorList)
-            Dim oEmailData = MoveAndRenameEmailToRejected(pArgs, oMessageId)
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "ValidationException", _EmailOutAccountId, pArgs.NamePortal)
-            AddRejectedState(oMessageId, "ValidationException", "Die Rechnungsvalidierung ist fehlgeschlagen!", "", oConnections.SQLServerTransaction)
-
-        Catch ex As MD5HashException
-            _logger.Error(ex)
-
-            ' When MD5HashException is thrown, we don't have a MD5Hash yet.
-            ' That 's why we set it to String.Empty here.
-            Dim oMessage = "REJECTED - Already processed (MD5Hash)"
-            _history.Update_HistoryEntry(oMessageId, String.Empty, oMessage)
-
-            Dim oBody = EmailStrings.EMAIL_MD5_ERROR
-            Dim oEmailData = MoveAndRenameEmailToRejected(pArgs, oMessageId)
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "MD5HashException", _EmailOutAccountId, pArgs.NamePortal)
-            AddRejectedState(oMessageId, "MD5HashException", "Die gesendete Rechnung wurde bereits verarbeitet!", "", oConnections.SQLServerTransaction)
-
-        Catch ex As UnsupportedFerdException
-            _logger.Error(ex)
-
-            ' When UnsupportedFerdException is thrown, we don't have a MD5Hash yet.
-            ' That 's why we set it to String.Empty here.
-            _history.Update_HistoryEntry(oMessageId, String.Empty, "REJECTED - ZUGFeRD yes but unsupported format")
-
-            Dim oEmailData = MoveAndRenameEmailToRejected(pArgs, oMessageId)
-            Dim oBody As String = String.Format(EmailStrings.EMAIL_UNSUPPORTED_DOCUMENT, oEmailData.Subject, ex.XmlFile)
-
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "UnsupportedFerdException", _EmailOutAccountId, pArgs.NamePortal)
-            AddRejectedState(oMessageId, "UnsupportedFerdException", "Nicht unterstütztes Datenformat", "", oConnections.SQLServerTransaction)
-
-        Catch ex As InvalidFerdException
-            _logger.Error(ex)
-
-            ' When InvalidFerdException is thrown, we don't have a MD5Hash yet.
-            ' That 's why we set it to String.Empty here.
-            _history.Update_HistoryEntry(oMessageId, String.Empty, "REJECTED - ZUGFeRD yes but incorrect format")
-
-            Dim oEmailData = MoveAndRenameEmailToRejected(pArgs, oMessageId)
-            Dim oBody = String.Format(EmailStrings.EMAIL_INVALID_DOCUMENT, oEmailData.Subject)
-
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "InvalidFerdException", _EmailOutAccountId, pArgs.NamePortal)
-            AddRejectedState(oMessageId, "InvalidFerdException", "Inkorrekte Formate", "", oConnections.SQLServerTransaction)
-
-        Catch ex As TooMuchFerdsException
-            _logger.Error(ex)
-
-            _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - More than one ZUGFeRD-document in email")
-
-            Dim oEmailData = MoveAndRenameEmailToRejected(pArgs, oMessageId)
-            Dim oBody = String.Format(EmailStrings.EMAIL_TOO_MUCH_FERDS, oEmailData.Subject)
-
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "TooMuchFerdsException", _EmailOutAccountId, pArgs.NamePortal)
-            AddRejectedState(oMessageId, "TooMuchFerdsException", "Email enthielt mehr als ein ZUGFeRD-Dokument", "", oConnections.SQLServerTransaction)
-
-        Catch ex As NoFerdsException
-            _logger.Error(ex)
-
-            _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - no ZUGFeRD-Document in email")
-
-            Dim oEmailData = MoveAndRenameEmailToRejected(pArgs, oMessageId)
-            Dim oBody = String.Format(EmailStrings.EMAIL_NO_FERDS, oEmailData.Subject)
-
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "NoFerdsException", _EmailOutAccountId, pArgs.NamePortal)
-            AddRejectedState(oMessageId, "NoFerdsException", " Email enthielt keine ZUGFeRD-Dokumente", "", oConnections.SQLServerTransaction)
-
-        Catch ex As MissingValueException
-            _logger.Error(ex)
-
-            Dim oMessage As String = ""
-            For Each prop In oMissingProperties
-                oMessage &= $"- {prop}"
-            Next
-
-            _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, $"REJECTED - Missing Required Properties: [{oMessage}]")
-
-            Dim oBody = _email.CreateBodyForMissingProperties(ex.File.Name, oMissingProperties)
-            Dim oEmailData = MoveAndRenameEmailToRejected(pArgs, oMessageId)
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "MissingValueException", _EmailOutAccountId, pArgs.NamePortal)
-            AddRejectedState(oMessageId, "MissingValueException", "Es fehlten ZugferdSpezifikationen", oMessage, oConnections.SQLServerTransaction)
-
-        Catch ex As FileSizeLimitReachedException
-            _logger.Error(ex)
-
-            _history.Update_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - File size limit reached")
-
-            Dim oEmailData = MoveAndRenameEmailToRejected(pArgs, oMessageId)
-
-            Dim oKey = FileSizeLimitReachedException.KEY_FILENAME
-            Dim oFileExceedingThreshold As String = IIf(ex.Data.Contains(oKey), ex.Data.Item(oKey), "")
-            Dim oFileWithoutMessageId = oFileExceedingThreshold.
-                Replace(oMessageId, "").
-                Replace("~", "")
-
-            Dim oBody = String.Format(EmailStrings.EMAIL_FILE_SIZE_REACHED, pArgs.MaxAttachmentSizeInMegaBytes, oFileWithoutMessageId)
-
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "FileSizeLimitReachedException", _EmailOutAccountId, pArgs.NamePortal)
-            AddRejectedState(oMessageId, "FileSizeLimitReachedException", "Erlaubte Dateigröße überschritten", "", oConnections.SQLServerTransaction)
-
-
-        Catch ex As NoFerdsAlternateException
-            ' TODO: Maybe dont even log this 'error', since it's not really an error and it might happen *A LOT*
-            _logger.Error(ex)
-            oMoveDirectory = pArgs.NonZugferdDirectory
-
-        Catch ex As OutOfMemoryException
-            _logger.Warn("OutOfMemory Error occurred: {0}", ex.Message)
-            _logger.Error(ex)
-
-            ' Send Email to Digital Data
-            Dim oBody = _email.CreateBodyForUnhandledException(oMessageId, ex)
-            Dim oEmailData As New EmailData With {
-                .From = pArgs.ExceptionEmailAddress,
-                .Subject = $"OutOfMemoryException im ZUGFeRD-Parser @ {oMessageId}"
-            }
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "OutOfMemoryException", _EmailOutAccountId, pArgs.NamePortal)
-
-            ' Rollback Transaction
-            oConnections.SQLServerTransaction.Rollback()
-
-            oMoveDirectory = DIRECTORY_DONT_MOVE
-
-            oExpectedError = False
-
-        Catch ex As Exception
-            _logger.Warn("Unknown Error occurred: {0}", ex.Message)
-            _logger.Error(ex)
-
-            ' Send Email to Digital Data
-            Dim oBody = _email.CreateBodyForUnhandledException(oMessageId, ex)
-            Dim oEmailData As New EmailData With {
-                .From = pArgs.ExceptionEmailAddress,
-                .Subject = $"UnhandledException im ZUGFeRD-Parser @ {oMessageId}"
-            }
-            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "UnhandledException", _EmailOutAccountId, pArgs.NamePortal)
-
-            ' Rollback Transaction
-            oConnections.SQLServerTransaction.Rollback()
-
-            oMoveDirectory = DIRECTORY_DONT_MOVE
-
-            oExpectedError = False
-
-        Finally
-            Try
-                ' If an application error occurred, dont move files so they will be processed again later
-                If oMoveDirectory = DIRECTORY_DONT_MOVE Then
-                    _logger.Info("Application Error occurred. Files for message Id {0} will not be moved.", oMessageId)
-                Else
-                    ' Move all files of the current group
-                    _file.MoveFiles(pArgs, oMessageId, pFiles, oEmailAttachmentFiles, oEmbeddedAttachmentFiles, oMoveDirectory, oIsSuccess)
-                End If
-                _logger.Info("Finished processing file group {0}", oMessageId)
-            Catch ex As Exception
-                ' Send Email to Digital Data
-                Dim oBody = _email.CreateBodyForUnhandledException(oMessageId, ex)
-                Dim oEmailData As New EmailData With {
-                    .From = pArgs.ExceptionEmailAddress,
-                    .Subject = $"FileMoveException im ZUGFeRD-Parser @ {oMessageId}"
-                }
-                _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "FileMoveException", _EmailOutAccountId, pArgs.NamePortal)
-
-                _logger.Warn("Could not move files!")
-                _logger.Error(ex)
-                Throw ex
-            End Try
-
-            Try
-                ' If everything went OK or an expected error occurred, 
-                ' finally commit all changes To the Database
-                ' ==================================================================
-                If oIsSuccess Or oExpectedError Then
-                    ' Commit Transaction
-                    oConnections.SQLServerTransaction.Commit()
-                End If
-
-                _logger.Info("FileGroup for MessageId [{0}] successfully processed!", oMessageId)
-            Catch ex As Exception
-                _logger.Error(ex)
-                _logger.Warn("Database Transactions were not committed successfully.")
-            End Try
-
-            Try
-                oConnections.SQLServerConnection.Close()
-            Catch ex As Exception
-                _logger.Error(ex)
-                _logger.Warn("Database Connections were not closed successfully.")
-            End Try
-        End Try
-    End Function
-
-    Private Function ProcessFile(pMessageId As String, oFile As FileInfo, oConnections As DatabaseConnections, pArgs As WorkerArgs) As ProcessFileResult
-        ' 09.12.2021: oDocument is now an Object, because have different classes corresponding to the 
-        '   different versions of ZUGFeRD and the type is unknown at compile-time.
-        ' 17.11.2022: oDocument is now a Tuple of (String, Object), to be able to return the filename
-        '   of the extracted xml file.
-        ' 21.12.2022: oDocument is now an object of type ZugferdResult to be able to save
-        '   the new meta data, ie. the type of schema (zugferd version)
         Dim oDocument As ZUGFeRDInterface.ZugferdResult
-
+        Dim oResult As New ProcessFileResult()
-        Dim oMissingProperties = New List(Of String)
+        Dim oMissingProperties As New List(Of String)
-        Dim oEmailAttachmentFiles = New List(Of FileInfo)
-        Dim oEmbeddedAttachmentFiles = New List(Of PDFEmbeds.EmbeddedFile)
-        Dim oZugferdFiles As Integer = 0
-
-        ' Start a global group counter for each file
-        Dim oGlobalGroupCounter = 0
-        ' Clear missing properties for the new file
-        oMissingProperties = New List(Of String)
 
         ' Only pdf files are allowed from here on
         If Not oFile.Name.ToUpper.EndsWith(".PDF") Then
             _logger.Debug("Skipping non-pdf file {0}", oFile.Name)
-            oEmailAttachmentFiles.Add(oFile)
+            oResult.EmailAttachmentFiles.Add(oFile)
 
             ' Checking filesize for attachment files
             If _filesystem.TestFileSizeIsLessThanMaxFileSize(oFile.FullName, pArgs.MaxAttachmentSizeInMegaBytes) = False Then
@@ -928,8 +432,7 @@ Public Class ImportZUGFeRDFiles
                 Throw New FileSizeLimitReachedException(oFile.Name, pArgs.MaxAttachmentSizeInMegaBytes)
             End If
 
-            'TODO: how to handle?
+            Return oResult
-            'Continue For
         End If
 
         _logger.Info("Start processing file {0}", oFile.Name)
@@ -950,10 +453,9 @@ Public Class ImportZUGFeRDFiles
             Select Case ex.ErrorType
                 Case ZUGFeRDInterface.ErrorType.NoZugferd
                     _logger.Info("File [{0}] is not a valid ZUGFeRD document. Skipping.", oFile.Name)
-                    oEmailAttachmentFiles.Add(oFile)
 
-                    'TODO: How to handle?
+                    oResult.EmailAttachmentFiles.Add(oFile)
-                    'Continue For
+                    Return oResult
 
                 Case ZUGFeRDInterface.ErrorType.UnsupportedFormat
                     _logger.Info("File [{0}/{1}] is an unsupported ZUFeRD document format!", oFile.Name, ex.XmlFile)
@@ -970,12 +472,12 @@ Public Class ImportZUGFeRDFiles
         End Try
 
         ' Check if there are more than one ZUGFeRD files
-        If oZugferdFiles = 1 Then
+        If pZugferdFiles = 1 Then
             Throw New TooMuchFerdsException()
         End If
 
         ' Since extraction went well, increase the amount of ZUGFeRD files
-        oZugferdFiles += 1
+        pZugferdFiles += 1
 
         ' Extract all attachments with the extensions specified in `AllowedExtensions`.
         ' If you need to extract and use embedded xml files, you need to filter out the zugferd-invoice.xml yourself.
@@ -984,11 +486,11 @@ Public Class ImportZUGFeRDFiles
         If oAttachments Is Nothing Then
             _logger.Warn("Attachments for file [{0}] could not be extracted", oFile.FullName)
         Else
-            oEmbeddedAttachmentFiles.AddRange(oAttachments)
+            oResult.EmbeddedAttachmentFiles.AddRange(oAttachments)
         End If
 
         ' Check the Checksum and rejection status
-        Dim oMD5CheckSum = GenerateAndCheck_MD5Sum(oFile, pMessageId, pArgs.IgnoreRejectionStatus)
+        Dim oMD5Checksum = _hash.GenerateAndCheck_MD5Sum(oFile, pMessageId, pArgs.IgnoreRejectionStatus)
 
         ' Check the document against the configured property map and return:
         ' - a List of valid properties 
@@ -1002,7 +504,7 @@ Public Class ImportZUGFeRDFiles
         If oCheckResult.MissingProperties.Count > 0 Then
             _logger.Warn("[{0}] missing properties found. Exiting.", oCheckResult.MissingProperties.Count)
             oMissingProperties = oCheckResult.MissingProperties
-            Throw New MissingValueException(oFile)
+            Throw New MissingValueException(oFile, oCheckResult.MissingProperties)
         Else
             _logger.Debug("No missing properties found. Continuing.")
 
@@ -1027,12 +529,15 @@ Public Class ImportZUGFeRDFiles
             InsertPropertyValue(pMessageId, oConnections, oProperty)
         Next
 
-        Return New ProcessFileResult With {
+        _logger.Debug("File processed.")
-            .ZugferdFileCount = oZugferdFiles
-        }
-    End Function
-#End Region
 
+        oResult.ZugferdFileFound = True
+        oResult.MD5Checksum = oMD5Checksum
+        oResult.ZugferdFileCount = pZugferdFiles
+
+        Return oResult
+
+    End Function
 
     Private Sub DeleteExistingPropertyValues(pMessageId As String, pConnections As DatabaseConnections)
         Dim oDelSQL = $"DELETE FROM TBEDMI_ITEM_VALUE where REFERENCE_GUID = '{pMessageId}'"
@@ -1057,182 +562,15 @@ Public Class ImportZUGFeRDFiles
 
         Dim oCommand = $"INSERT INTO {pProperty.TableName} (REFERENCE_GUID, ITEM_DESCRIPTION, ITEM_VALUE, GROUP_COUNTER, SPEC_NAME, IS_REQUIRED) VALUES 
                                             ('{pMessageId}', '{pProperty.Description}', '{pProperty.Value.Replace("'", "''")}', {oGroupCounterValue},'{pProperty.TableColumn}','{pProperty.IsRequired}')"
-        _logger.Debug("Mapping Property [{0}]  with value [{1}], Will be inserted into table [{2}]", pProperty.TableColumn, pProperty.Value.Replace("'", "''"), pProperty.TableName)
+        _logger.Debug("Mapping Property [{0}] with value [{1}], Will be inserted into table [{2}]", pProperty.TableColumn, pProperty.Value.Replace("'", "''"), pProperty.TableName)
-        ' Insert into SQL Server
 
+        ' Insert into SQL Server
         Dim oResult = _mssql.ExecuteNonQueryWithConnectionObject(oCommand, pConnections.SQLServerConnection, MSSQLServer.TransactionMode.ExternalTransaction, pConnections.SQLServerTransaction)
         If oResult = False Then
             _logger.Warn($"SQL Command [{oCommand}] was not successful. Check the log.")
         End If
     End Sub
 
-    Private Function CreateMD5(pFilename As String) As String
-        Try
-            Dim oMD5 As New MD5CryptoServiceProvider
-            Dim oHash As Byte()
-            Dim oHashString As String
-            Dim oResult As String = ""
-
-            Using oFileStream As New FileStream(pFilename, FileMode.Open, FileAccess.Read, FileShare.Read, 8192)
-                oHash = oMD5.ComputeHash(oFileStream)
-                oHashString = BitConverter.ToString(oHash)
-            End Using
-
-            oResult = oHashString.Replace("-", "")
-            Return oResult
-        Catch ex As Exception
-            _logger.Error(ex)
-            Return ""
-        End Try
-    End Function
-
-
-
-    ''' <summary>
-    ''' Generates the MD5 Checksum of a file and checks it against the histroy table TBEDM_ZUGFERD_HISTORY_IN
-    ''' </summary>
-    ''' <param name="pFilePath">The path of the file to be checked</param>
-    ''' <param name="pIgnoreRejectionStatus">Should the check take into account the rejection status of the file?</param>
-    ''' <returns>The MD5 Checksum of the file, or an empty string, if the Checksum could not be created</returns>
-    ''' <exception cref="MD5HashException">Throws, when the file should be rejected, ie. if it already exists in the table</exception>
-    Private Function GenerateAndCheck_MD5Sum(pFile As FileInfo, pMessageId As String, pIgnoreRejectionStatus As Boolean) As String
-        Dim oMD5CheckSum = CreateMD5(pFile.FullName)
-
-        ' Exit if MD5 could not be created
-        If oMD5CheckSum = String.Empty Then
-            _logger.Warn("MD5 Checksum is nothing for file [{0}]!", pFile.FullName)
-            Return oMD5CheckSum
-        End If
-
-        ' Check if Checksum exists in History Table
-        'Dim oCheckCommand = $"SELECT * FROM TBEDM_ZUGFERD_HISTORY_IN WHERE GUID = (SELECT MAX(GUID) FROM TBEDM_ZUGFERD_HISTORY_IN WHERE UPPER(MD5HASH) = UPPER('{oMD5CheckSum}'))"
-        'Dim oTable As DataTable = _firebird.GetDatatable(oCheckCommand, Firebird.TransactionMode.NoTransaction)
-
-        ' Check if Checksum exists in History Table
-        ' TODO: WHAT THE FUCK IS THIS
-        Dim oCheckCommand = $"SELECT * FROM TBEMLP_HISTORY WHERE GUID = (SELECT MAX(GUID) FROM TBEMLP_HISTORY WHERE UPPER(MD5HASH) = UPPER('{oMD5CheckSum}'))"
-        Dim oTable As DataTable = _mssql.GetDatatable(oCheckCommand, MSSQLServer.TransactionMode.NoTransaction)
-
-        ' If History entries could not be fetched, just return the MD5 Checksum
-        If IsNothing(oTable) Then
-            _logger.Warn("Be careful: oExistsDT is nothing for file [{0}]!", pFile.FullName)
-            Return oMD5CheckSum
-        End If
-
-        ' If Checksum does not exist in History entries, just return the MD5 Checksum
-        If oTable.Rows.Count = 0 Then
-            _logger.Debug("File [{0}] was not found in History!", pFile.FullName)
-            Return oMD5CheckSum
-        End If
-
-        ' ====================================================
-        ' Checksum exists in History entries, reject!
-        ' ====================================================
-
-        Dim oRejected As Boolean
-        Dim oHistoryId As Integer
-
-        ' Try to read Rejected Status and History Id
-        Try
-            Dim oRow As DataRow = oTable.Rows.Item(0)
-            oRejected = oRow.ItemEx("CUST_REJECTED", False)
-            oHistoryId = oRow.Item("GUID")
-
-        Catch ex As Exception
-            _logger.Warn("Error while converting REJECTED: " & ex.Message)
-            oRejected = False
-
-        End Try
-
-        _logger.Info("File with MessageId [{0}] has already been processed.", pMessageId)
-
-        ' If the file was already rejected, it is allowed to be processed again, 
-        ' even if the Checksum exists in the history entries (default case)
-        ' Which means, if it was not rejected before, it will be rejected in any case!
-        '
-        ' This logic can be overwritten by the IgnoreRejectionStatus parameter.
-        ' If it is set to true, the file will be rejected if the file exists in the history entries,
-        ' regardless of the rejected parameter.
-
-        If oRejected = True And pIgnoreRejectionStatus = True Then
-            _logger.Info("ZuGFeRDFile already has been processed, but Rejection Status will be ignored!")
-        ElseIf oRejected = False Then
-            _logger.Info("ZuGFeRDFile already has been processed. Will be rejected.")
-            Throw New MD5HashException($"There is already an identical invoice! - HistoryID [{oHistoryId}] - Case 1", pFile.Name)
-        Else
-            _logger.Info("ZuGFeRDFile already has been processed. Will be rejected.")
-            Throw New MD5HashException($"There is already an identical invoice! - HistoryID [{oHistoryId}] - Case 2", pFile.Name)
-        End If
-
-        Return oMD5CheckSum
-    End Function
-
-    Private Function MoveAndRenameEmailToRejected(pArgs As WorkerArgs, pMessageId As String) As EmailData
-        _logger.Info("Moving Mail with MessageId [{0}] to Rejected folder", pMessageId)
-        _logger.Debug("Fetching Email Data")
-
-        Dim oEmailData = _email.GetEmailDataForMessageId(pMessageId)
-        _logger.Debug("Email Data fetched!")
-
-        Dim oSource = _email.GetOriginalEmailPath(pArgs.OriginalEmailDirectory, pMessageId)
-        _logger.Debug("Original email path: [{0}]", oSource)
-
-        Dim oDateSubDirectoryName As String = Now.ToString("yyyy-MM-dd")
-        Dim oDestination As String
-
-        Dim oRejectedDirectory As String = Path.Combine(pArgs.RejectedEmailDirectory, oDateSubDirectoryName)
-
-        ' Create the destination directory if it does not exist
-        _logger.Debug("Creating destination directory [{0}]", oRejectedDirectory)
-        If Not Directory.Exists(oRejectedDirectory) Then
-            Try
-                Directory.CreateDirectory(oRejectedDirectory)
-            Catch ex As Exception
-                _logger.Error(ex)
-            End Try
-        End If
-
-        If oSource = String.Empty Then
-            _logger.Warn("Original Email for [{0}] could not be found. Exiting.", pMessageId)
-            Return New EmailData()
-        End If
-
-        ' If oEmailData is Nothing, TBEDM_EMAIL_PROFILER_HISTORY for MessageId was not found. 
-        ' This only should happen when testing and db-tables are deleted frequently
-        If oEmailData Is Nothing Then
-            oDestination = _email.GetEmailPathWithSubjectAsName(oRejectedDirectory, pMessageId)
-        Else
-            oDestination = _email.GetEmailPathWithSubjectAsName(oRejectedDirectory, StringEx.ConvertTextToSlug(oEmailData.Subject))
-        End If
-
-        _logger.Debug("Destination for eml file is {0}", oDestination)
-
-        Dim oFinalFileName = _filesystem.GetVersionedFilename(oDestination)
-
-        _logger.Debug("Versioned filename for eml file is {0}", oFinalFileName)
-
-        If oEmailData Is Nothing Then
-            _logger.Warn("Could not get Email Data from firebird-database. File {0} will not be moved!", oSource)
-            Return New EmailData()
-        End If
-
-        '---------------------------
-
-        Try
-            _logger.Info("Moving email from {0} to {1}", oSource, oFinalFileName)
-            File.Move(oSource, oFinalFileName)
-            oEmailData.Attachment = oFinalFileName
-        Catch ex As Exception
-            _logger.Warn("File {0} could not be moved! Original Filename will be used!", oSource)
-            _logger.Error(ex)
-            oEmailData.Attachment = oSource
-        End Try
-
-        _logger.Info("Email [{0}] moved to rejected folder!", pMessageId)
-
-        Return oEmailData
-    End Function
-
     Private Sub AddRejectedState(pMessageID As String, pTitle As String, pTitle1 As String, pComment As String, pTransaction As SqlTransaction)
         Try
             'PRCUST_ADD_HISTORY_STATE: @MessageID VARCHAR(250), @TITLE1 VARCHAR(250), @TITLE2 VARCHAR(250)