Interfaces/Job: Add check for currencyId format in ZUGFeRD documents

Interfaces/ZUGFeRDInterface.vb

@@ -1,4 +1,6 @@
-Imports System.IO
+Imports System.Collections.Generic
+Imports System.IO
+Imports System.Reflection.Emit
 Imports System.Xml
 Imports System.Xml.Serialization
 Imports System.Xml.XPath
@@ -54,6 +56,13 @@ Public Class ZUGFeRDInterface
         Public Property XPathObject As XPathDocument
         Public Property SchemaObject As Object
         Public Property Specification As String
+        Public Property ValidationErrors As New List(Of ZugferdValidationError)
+    End Class
+
+    Public Class ZugferdValidationError
+        Public ElementName As String
+        Public ElementValue As String
+        Public ErrorMessage As String
     End Class
 
     ''' <summary>
@@ -125,9 +134,10 @@ Public Class ZUGFeRDInterface
     ''' <exception cref="ZUGFeRDExecption"></exception>
     Public Function ExtractZUGFeRDFileWithGDPicture(Path As String) As ZugferdResult
         Dim oResult = ValidateZUGFeRDFileWithGDPicture(Path)
+        oResult = ValidateZUGFeRDDocument(oResult)
 
         'If IsNothing(oResult.SchemaObject) Then
-        '    Throw New ZUGFeRDExecption(ErrorType.NoZugferd, "Datei ist keine ZUGFeRD Datei.")
+        Throw New ZUGFeRDExecption(ErrorType.NoZugferd, "Datei ist keine ZUGFeRD Datei.")
         'End If
 
         Return SerializeZUGFeRDDocument(oResult)
@@ -140,6 +150,7 @@ Public Class ZUGFeRDInterface
     ''' <exception cref="ZUGFeRDExecption"></exception>
     Public Function ExtractZUGFeRDFileWithGDPicture(Stream As Stream) As ZugferdResult
         Dim oResult = ValidateZUGFeRDFileWithGDPicture(Stream)
+        oResult = ValidateZUGFeRDDocument(oResult)
 
         'If IsNothing(oResult.SchemaObject) Then
         '    Throw New ZUGFeRDExecption(ErrorType.NoZugferd, "Datei ist keine ZUGFeRD Datei.")
@@ -256,6 +267,72 @@ Public Class ZUGFeRDInterface
         Public Specification As String
     End Class
 
+    Public Function ValidateZUGFeRDDocument(pResult As ZugferdResult) As ZugferdResult
+        Dim oNavigator As XPathNavigator = pResult.XPathObject.CreateNavigator()
+        Dim oNamespaceManager As New XmlNamespaceManager(oNavigator.NameTable)
+
+        oNamespaceManager.AddNamespace("ram", "urn:un:unece:uncefact:data:standard:ReusableAggregateBusinessInformationEntity:12")
+        oNamespaceManager.AddNamespace("rsm", "urn:ferd:CrossIndustryDocument:invoice:1p0")
+
+        ' CurrencyCode Nodes
+        Try
+            Dim oCurrencyCodeIterator As XPathNodeIterator = oNavigator.
+           Select("//ram:InvoiceCurrencyCode | //ram:TaxCurrencyCode | //ram:TaxCurrencyCode | //ram:SourceCurrencyCode", oNamespaceManager)
+
+            While oCurrencyCodeIterator.MoveNext()
+                Dim oNode As XPathNavigator = oCurrencyCodeIterator.Current
+                Dim oValid = ValidateCurrencyCode(oNode.Value)
+                If oValid = False Then
+                    pResult.ValidationErrors.Add(New ZugferdValidationError() With {
+                        .ElementName = oNode.Name,
+                        .ElementValue = oNode.Value,
+                        .ErrorMessage = "Invalid CurrencyCode. Only 3-Character codes are allowed."
+                    })
+                End If
+            End While
+        Catch ex As Exception
+            _logger.Error(ex)
+        End Try
+
+        ' currencyID
+        Try
+            Dim oCurrencyIDIterator As XPathNodeIterator = oNavigator.Select("//*[@currencyID]")
+
+            While oCurrencyIDIterator.MoveNext()
+                Dim oNode As XPathNavigator = oCurrencyIDIterator.Current
+                Dim oCurrencyID As String = oNode.GetAttribute("currencyID", "")
+
+                ' CurrencyID is optional per spec
+                If String.IsNullOrWhiteSpace(oCurrencyID) Then
+                    Continue While
+                End If
+
+                Dim oValid = ValidateCurrencyCode(oCurrencyID)
+                If oValid = False Then
+                    pResult.ValidationErrors.Add(New ZugferdValidationError() With {
+                        .ElementName = oNode.Name,
+                        .ElementValue = oCurrencyID,
+                        .ErrorMessage = "Invalid currencyID. Only 3-Character codes or empty values are allowed."
+                    })
+                End If
+            End While
+        Catch ex As Exception
+            _logger.Error(ex)
+        End Try
+
+        Return pResult
+    End Function
+
+    Private Function ValidateCurrencyCode(pValue As String) As Boolean
+        Dim oValueRegex As New Text.RegularExpressions.Regex("[A-Z]{3}")
+
+        If oValueRegex.IsMatch(pValue) = False Then
+            Return False
+        End If
+
+        Return True
+    End Function
+
     Public Function SerializeZUGFeRDDocument(pResult As ZugferdResult) As ZugferdResult
         Try
             Dim oNavigator As XPathNavigator = pResult.XPathObject.CreateNavigator()