Fixed that zfCharges or zfAllowances may is null (why making a collection nullable?)

README.md

@@ -68,7 +68,7 @@ private fun createInvoice() = Invoice(
     invoicingDate = LocalDate.now(),
     sender = Party("codinux GmbH & Co. KG", "Fun Street 1", "12345", "Glückstadt"),
     recipient = Party("Abzock GmbH", "Ausbeutstr.", "12345", "Abzockhausen"),
-    items = listOf(LineItem("Erbrachte Dienstleistungen", "HUR", BigDecimal(170), BigDecimal(1_000_000), BigDecimal(19))) // HUR = EN code for hour
+    items = listOf(InvoiceItem("Erbrachte Dienstleistungen", BigDecimal(170), "HUR", BigDecimal(105), BigDecimal(19))) // HUR = EN code for hour
 )
 ```
 

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/calculator/AmountsCalculator.kt

@@ -0,0 +1,44 @@
+package net.codinux.invoicing.calculator
+
+import net.codinux.invoicing.mapper.MustangMapper
+import net.codinux.invoicing.model.Invoice
+import net.codinux.invoicing.model.TotalAmounts
+import org.mustangproject.ZUGFeRD.IExportableTransaction
+import org.mustangproject.ZUGFeRD.TransactionCalculator
+import java.math.BigDecimal
+
+open class AmountsCalculator {
+
+    protected open val mapper by lazy { MustangMapper() } // lazy to avoid circular dependency creation with MustangMapper
+
+
+    open fun calculateTotalAmounts(invoice: Invoice) =
+        calculateTotalAmounts(mapper.mapToTransaction(invoice))
+
+    open fun calculateTotalAmounts(invoice: IExportableTransaction): TotalAmounts {
+        val calculator = MustangTransactionCalculator(invoice)
+
+        return TotalAmounts(
+            lineTotalAmount = calculator.lineTotalAmount,
+            chargeTotalAmount = calculator.chargeTotal,
+            allowanceTotalAmount = calculator.allowanceTotal,
+            taxBasisTotalAmount = calculator.taxBasisTotalAmount,
+            taxTotalAmount = calculator.taxTotalAmount,
+            grandTotalAmount = calculator.grandTotal,
+            totalPrepaidAmount = calculator.totalPrepaidAmount,
+            duePayableAmount = calculator.duePayableAmount
+        )
+    }
+
+
+    protected open class MustangTransactionCalculator(invoice: IExportableTransaction): TransactionCalculator(invoice) {
+        val lineTotalAmount: BigDecimal = this.total
+
+        val taxBasisTotalAmount: BigDecimal = this.taxBasis
+        val taxTotalAmount: BigDecimal by lazy { this.getGrandTotal().subtract(this.taxBasis) }
+
+        val totalPrepaidAmount: BigDecimal = this.totalPrepaid
+        val duePayableAmount: BigDecimal by lazy { this.getGrandTotal().subtract(this.totalPrepaid) }
+    }
+
+}

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/converter/EInvoiceConverter.kt

@@ -6,12 +6,12 @@ import org.mustangproject.CII.CIIToUBL
 import org.mustangproject.ZUGFeRD.ZUGFeRDVisualizer
 import java.io.File
 
-class EInvoiceConverter {
+open class EInvoiceConverter {
 
-    fun convertInvoiceToHtml(invoice: Invoice, outputFile: File, language: ZUGFeRDVisualizer.Language = ZUGFeRDVisualizer.Language.DE) =
+    open fun convertInvoiceToHtml(invoice: Invoice, outputFile: File, language: ZUGFeRDVisualizer.Language = ZUGFeRDVisualizer.Language.DE) =
         convertInvoiceToHtml(createXRechnungXml(invoice), outputFile, language)
 
-    fun convertInvoiceToHtml(invoiceXml: String, outputFile: File, language: ZUGFeRDVisualizer.Language = ZUGFeRDVisualizer.Language.DE): String {
+    open fun convertInvoiceToHtml(invoiceXml: String, outputFile: File, language: ZUGFeRDVisualizer.Language = ZUGFeRDVisualizer.Language.DE): String {
         val xmlFile = File.createTempFile("Zugferd", ".xml")
             .also { it.writeText(invoiceXml) }
 
@@ -32,12 +32,12 @@ class EInvoiceConverter {
     /**
      * Converts a CII (Cross Industry Invoice) invoice, e.g. a ZUGFeRD or Factur-X invoice, to UBL (Universal Business Language).
      */
-    fun convertCiiToUbl(invoice: Invoice) = convertCiiToUbl(createXRechnungXml(invoice))
+    open fun convertCiiToUbl(invoice: Invoice) = convertCiiToUbl(createXRechnungXml(invoice))
 
     /**
      * Converts a CII (Cross Industry Invoice) invoice, e.g. a ZUGFeRD or Factur-X invoice, to UBL (Universal Business Language).
      */
-    fun convertCiiToUbl(invoiceXml: String): String {
+    open fun convertCiiToUbl(invoiceXml: String): String {
         // TODO: extract a common method for this
         val xmlFile = File.createTempFile("Zugferd", ".xml")
             .also { it.writeText(invoiceXml) }
@@ -56,15 +56,15 @@ class EInvoiceConverter {
     /**
      * Converts a CII (Cross Industry Invoice) invoice, e.g. a ZUGFeRD or Factur-X invoice, to UBL (Universal Business Language).
      */
-    fun convertCiiToUbl(xmlFile: File, outputFile: File) {
+    open fun convertCiiToUbl(xmlFile: File, outputFile: File) {
         val cii2Ubl = CIIToUBL()
         cii2Ubl.convert(xmlFile, outputFile)
     }
 
 
-    private fun createXRechnungXml(invoice: Invoice): String = EInvoiceCreator().createXRechnungXml(invoice)
+    protected open fun createXRechnungXml(invoice: Invoice): String = EInvoiceCreator().createXRechnungXml(invoice)
 
-    private fun copyResource(resourceName: String, outputFile: File, outputFileExtension: String) {
+    protected open fun copyResource(resourceName: String, outputFile: File, outputFileExtension: String) {
         javaClass.classLoader.getResourceAsStream(resourceName).use {
             it?.copyTo(File(outputFile.parentFile, outputFile.nameWithoutExtension + outputFileExtension).outputStream())
         }

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/creation/EInvoiceCreator.kt

@@ -5,11 +5,11 @@ import net.codinux.invoicing.model.Invoice
 import org.mustangproject.ZUGFeRD.*
 import java.io.File
 
-class EInvoiceCreator(
-    private val mapper: MustangMapper = MustangMapper()
+open class EInvoiceCreator(
+    protected open val mapper: MustangMapper = MustangMapper()
 ) {
 
-    fun createXRechnungXml(invoice: Invoice): String {
+    open fun createXRechnungXml(invoice: Invoice): String {
         val provider = ZUGFeRD2PullProvider()
         provider.profile = Profiles.getByName("XRechnung")
 
@@ -20,9 +20,9 @@ class EInvoiceCreator(
     /**
      * Synonym for [createFacturXXml] (ZUGFeRD 2 is a synonym for Factur-X).
      */
-    fun createZugferdXml(invoice: Invoice) = createFacturXXml(invoice)
+    open fun createZugferdXml(invoice: Invoice) = createFacturXXml(invoice)
 
-    fun createFacturXXml(invoice: Invoice): String {
+    open fun createFacturXXml(invoice: Invoice): String {
         val exporter = ZUGFeRDExporterFromA3()
             .setProfile("EN16931") // required for XML?
 
@@ -32,9 +32,9 @@ class EInvoiceCreator(
     /**
      * Synonym for [createFacturXPdf] (ZUGFeRD 2 is a synonym for Factur-X).
      */
-    fun createZugferdPdf(invoice: Invoice, outputFile: File) = createFacturXPdf(invoice, outputFile)
+    open fun createZugferdPdf(invoice: Invoice, outputFile: File) = createFacturXPdf(invoice, outputFile)
 
-    fun createFacturXPdf(invoice: Invoice, outputFile: File) {
+    open fun createFacturXPdf(invoice: Invoice, outputFile: File) {
         val xml = createFacturXXml(invoice)
         val xmlFile = File.createTempFile(outputFile.nameWithoutExtension, ".xml")
             .also { it.writeText(xml) }
@@ -50,10 +50,10 @@ class EInvoiceCreator(
     }
 
 
-    fun attachInvoiceXmlToPdf(invoice: Invoice, pdfFile: File, outputFile: File) =
+    open fun attachInvoiceXmlToPdf(invoice: Invoice, pdfFile: File, outputFile: File) =
         attachInvoiceXmlToPdf(createFacturXXml(invoice), pdfFile, outputFile)
 
-    fun attachInvoiceXmlToPdf(invoiceXml: String, pdfFile: File, outputFile: File) {
+    open fun attachInvoiceXmlToPdf(invoiceXml: String, pdfFile: File, outputFile: File) {
         val exporter = ZUGFeRDExporterFromA3()
             .setZUGFeRDVersion(2)
             .setProfile("EN16931") // available values: MINIMUM, BASICWL, BASIC, CIUS, EN16931, EXTENDED, XRECHNUNG
@@ -68,7 +68,7 @@ class EInvoiceCreator(
     }
 
 
-    private fun createXml(provider: IXMLProvider, invoice: Invoice): String {
+    protected open fun createXml(provider: IXMLProvider, invoice: Invoice): String {
         val transaction = mapper.mapToTransaction(invoice)
 
         provider.generateXML(transaction)

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/filesystem/FilesystemInvoiceReader.kt

@@ -6,16 +6,16 @@ import net.codinux.log.logger
 import java.nio.file.Path
 import kotlin.io.path.*
 
-class FilesystemInvoiceReader(
-    private val eInvoiceReader: EInvoiceReader = EInvoiceReader()
+open class FilesystemInvoiceReader(
+    protected open val eInvoiceReader: EInvoiceReader = EInvoiceReader()
 ) {
 
     private val log by logger()
 
-    fun readAllInvoicesOfDirectory(directory: Path, recursive: Boolean = false) =
+    open fun readAllInvoicesOfDirectory(directory: Path, recursive: Boolean = false) =
         readInvoicesFromFiles(collectFiles(directory, recursive))
 
-    private fun collectFiles(directory: Path, recursive: Boolean): List<Path> = buildList {
+    protected open fun collectFiles(directory: Path, recursive: Boolean): List<Path> = buildList {
         directory.listDirectoryEntries().forEach { child ->
             if (child.isRegularFile()) {
                 add(child)
@@ -25,13 +25,13 @@ class FilesystemInvoiceReader(
         }
     }
 
-    fun readInvoicesFromFiles(vararg files: Path) =
+    open fun readInvoicesFromFiles(vararg files: Path) =
         readInvoicesFromFiles(files.toList())
 
-    fun readInvoicesFromFiles(files: List<Path>): List<InvoiceOnFilesystem> =
+    open fun readInvoicesFromFiles(files: List<Path>): List<InvoiceOnFilesystem> =
         files.mapNotNull { file -> readInvoiceFromFile(file)?.let { InvoiceOnFilesystem(file, it) } }
 
-    fun readInvoiceFromFile(file: Path): Invoice? = try {
+    open fun readInvoiceFromFile(file: Path): Invoice? = try {
         val extension = file.extension.lowercase()
 
         if (extension == "pdf") {

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/mail/MailReader.kt

@@ -19,22 +19,22 @@ import java.util.*
 import java.util.concurrent.Executors
 import kotlin.math.max
 
-class MailReader(
-    private val eInvoiceReader: EInvoiceReader = EInvoiceReader()
+open class MailReader(
+    protected open val eInvoiceReader: EInvoiceReader = EInvoiceReader()
 ) {
 
-    private data class MessagePart(
+    protected data class MessagePart(
         val mediaType: String,
         val part: Part
     )
 
 
-    private val mailDispatcher = Executors.newFixedThreadPool(max(24, Runtime.getRuntime().availableProcessors() * 4)).asCoroutineDispatcher()
+    protected open val mailDispatcher = Executors.newFixedThreadPool(max(24, Runtime.getRuntime().availableProcessors() * 4)).asCoroutineDispatcher()
 
-    private val log by logger()
+    protected val log by logger()
 
 
-    fun listenForNewReceivedEInvoices(account: MailAccount, downloadMessageBody: Boolean = false, emailFolderName: String = "INBOX", eInvoiceReceived: (MailWithInvoice) -> Unit) = runBlocking {
+    open fun listenForNewReceivedEInvoices(account: MailAccount, downloadMessageBody: Boolean = false, emailFolderName: String = "INBOX", eInvoiceReceived: (MailWithInvoice) -> Unit) = runBlocking {
         try {
             connect(account) { store ->
                 val folder = store.getFolder(emailFolderName)
@@ -61,7 +61,7 @@ class MailReader(
         log.info { "Stopped listening to new received eInvoices of '${account.username}'" }
     }
 
-    private suspend fun keepConnectionOpen(account: MailAccount, folder: Folder) {
+    protected open suspend fun keepConnectionOpen(account: MailAccount, folder: Folder) {
         log.info { "Listening to new mails of ${account.username}" }
 
         // Use IMAP IDLE to keep the connection alive
@@ -78,7 +78,7 @@ class MailReader(
     }
 
 
-    fun listAllMessagesWithEInvoice(account: MailAccount, downloadMessageBody: Boolean = false, emailFolderName: String = "INBOX"): List<MailWithInvoice> {
+    open fun listAllMessagesWithEInvoice(account: MailAccount, downloadMessageBody: Boolean = false, emailFolderName: String = "INBOX"): List<MailWithInvoice> {
         try {
             return connect(account) { store ->
                 val inbox = store.getFolder(emailFolderName)
@@ -95,7 +95,7 @@ class MailReader(
         return emptyList()
     }
 
-    private fun listAllMessagesWithEInvoiceInFolder(folder: Folder, downloadMessageBody: Boolean): List<MailWithInvoice> = runBlocking {
+    protected open fun listAllMessagesWithEInvoiceInFolder(folder: Folder, downloadMessageBody: Boolean): List<MailWithInvoice> = runBlocking {
         val messageCount = folder.messageCount
         if (messageCount <= 0) {
             return@runBlocking emptyList()
@@ -115,7 +115,7 @@ class MailReader(
             .filterNotNull()
     }
 
-    private fun findEInvoice(message: Message, downloadMessageBody: Boolean): MailWithInvoice? {
+    protected open fun findEInvoice(message: Message, downloadMessageBody: Boolean): MailWithInvoice? {
         try {
             val parts = getAllMessageParts(message)
 
@@ -139,7 +139,7 @@ class MailReader(
         return null
     }
 
-    private fun findEInvoice(messagePart: MessagePart): MailAttachmentWithEInvoice? {
+    protected open fun findEInvoice(messagePart: MessagePart): MailAttachmentWithEInvoice? {
         try {
             val part = messagePart.part
             val invoice = tryToReadEInvoice(part, messagePart.mediaType)
@@ -160,7 +160,7 @@ class MailReader(
         return null
     }
 
-    private fun tryToReadEInvoice(part: Part, mediaType: String?): Invoice? = try {
+    protected open fun tryToReadEInvoice(part: Part, mediaType: String?): Invoice? = try {
         val filename = part.fileName?.lowercase() ?: ""
 
         if (filename.endsWith(".pdf") || mediaType == "application/pdf" || mediaType == "application/octet-stream") {
@@ -176,7 +176,7 @@ class MailReader(
     }
 
 
-    private fun getAllMessageParts(part: Part): List<MessagePart> {
+    protected open fun getAllMessageParts(part: Part): List<MessagePart> {
         return if (part.isMimeType("multipart/*")) {
             val multipart = part.content as Multipart
             val parts = IntRange(0, multipart.count - 1).map { multipart.getBodyPart(it) }
@@ -202,7 +202,7 @@ class MailReader(
      *
      * -> This method removes parameters and return media type (first part) only
      */
-    private fun getMediaType(part: Part): String? = part.contentType?.lowercase()?.let { contentType ->
+    protected open fun getMediaType(part: Part): String? = part.contentType?.lowercase()?.let { contentType ->
         val indexOfSeparator = contentType.indexOf(';')
 
         if (indexOfSeparator > -1) {
@@ -212,11 +212,11 @@ class MailReader(
         }
     }
 
-    private fun getPlainTextBody(parts: Collection<MessagePart>) = getBodyWithMediaType(parts, "text/plain")
+    protected open fun getPlainTextBody(parts: Collection<MessagePart>) = getBodyWithMediaType(parts, "text/plain")
 
-    private fun getHtmlBody(parts: Collection<MessagePart>) = getBodyWithMediaType(parts, "text/html")
+    protected open fun getHtmlBody(parts: Collection<MessagePart>) = getBodyWithMediaType(parts, "text/html")
 
-    private fun getBodyWithMediaType(parts: Collection<MessagePart>, mediaType: String): String? = try {
+    protected open fun getBodyWithMediaType(parts: Collection<MessagePart>, mediaType: String): String? = try {
         val partsForMediaType = parts.filter { it.mediaType == mediaType }
 
         if (partsForMediaType.size == 1) {
@@ -239,11 +239,11 @@ class MailReader(
         null
     }
 
-    private fun map(date: Date): Instant =
+    protected open fun map(date: Date): Instant =
         date.toInstant()
 
 
-    private fun <T> connect(account: MailAccount, connected: (Store) -> T): T {
+    protected open fun <T> connect(account: MailAccount, connected: (Store) -> T): T {
         val properties = mapAccountToJavaMailProperties(account)
 
         val session = Session.getInstance(properties)
@@ -254,7 +254,7 @@ class MailReader(
         }
     }
 
-    private fun mapAccountToJavaMailProperties(account: MailAccount) = Properties().apply {
+    protected open fun mapAccountToJavaMailProperties(account: MailAccount) = Properties().apply {
         put("mail.store.protocol", "imap")
 
         put("mail.imap.host", account.serverAddress)

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/mapper/MustangMapper.kt

@@ -1,18 +1,24 @@
 package net.codinux.invoicing.mapper
 
-import net.codinux.invoicing.model.LineItem
+import net.codinux.invoicing.calculator.AmountsCalculator
+import net.codinux.invoicing.model.AmountAdjustments
+import net.codinux.invoicing.model.ChargeOrAllowance
+import net.codinux.invoicing.model.InvoiceItem
 import net.codinux.invoicing.model.Party
 import org.mustangproject.*
 import org.mustangproject.ZUGFeRD.IExportableTransaction
 import org.mustangproject.ZUGFeRD.IZUGFeRDExportableItem
+import java.math.BigDecimal
 import java.time.Instant
 import java.time.LocalDate
 import java.time.ZoneId
 import java.util.*
 
-class MustangMapper {
+open class MustangMapper(
+    protected open val calculator: AmountsCalculator = AmountsCalculator()
+) {
 
-    fun mapToTransaction(invoice: net.codinux.invoicing.model.Invoice): IExportableTransaction = Invoice().apply {
+    open fun mapToTransaction(invoice: net.codinux.invoicing.model.Invoice): IExportableTransaction = Invoice().apply {
         this.number = invoice.invoiceNumber
         this.issueDate = map(invoice.invoicingDate)
         this.sender = mapParty(invoice.sender)
@@ -24,9 +30,19 @@ class MustangMapper {
         this.paymentTermDescription = invoice.paymentDescription
 
         this.referenceNumber = invoice.buyerReference
+
+        invoice.amountAdjustments?.let { adjustments ->
+            this.totalPrepaidAmount = adjustments.prepaidAmounts
+            adjustments.charges.forEach { this.addCharge(mapCharge(it)) }
+            adjustments.allowances.forEach { this.addAllowance(mapAllowance(it)) }
+        }
+
+        if (invoice.totalAmounts == null) {
+            invoice.totalAmounts = calculator.calculateTotalAmounts(this)
+        }
     }
 
-    fun mapParty(party: Party): TradeParty = TradeParty(
+    open fun mapParty(party: Party): TradeParty = TradeParty(
         party.name, party.street, party.postalCode, party.city, party.countryIsoCode
     ).apply {
         this.setVATID(party.vatId)
@@ -45,15 +61,35 @@ class MustangMapper {
         }
     }
 
-    fun mapLineItem(item: LineItem): IZUGFeRDExportableItem = Item(
+    open fun mapLineItem(item: InvoiceItem): IZUGFeRDExportableItem = Item(
         // description has to be an empty string if not set
-        Product(item.name, item.description ?: "", item.unit, item.vatPercentage), item.price, item.quantity
+        Product(item.name, item.description ?: "", item.unit, item.vatRate), item.unitPrice, item.quantity
     ).apply {
 
     }
 
+    protected open fun mapCharge(charge: ChargeOrAllowance) = Charge(charge.actualAmount).apply {
+        this.percent = charge.calculationPercent
 
-    fun mapToInvoice(invoice: Invoice) = net.codinux.invoicing.model.Invoice(
+        this.reason = charge.reason
+        this.reasonCode = charge.reasonCode
+
+        this.taxPercent = charge.taxRateApplicablePercent
+        this.categoryCode = charge.taxCategoryCode
+    }
+
+    protected open fun mapAllowance(allowance: ChargeOrAllowance) = Allowance(allowance.actualAmount).apply {
+        this.percent = allowance.calculationPercent
+
+        this.reason = allowance.reason
+        this.reasonCode = allowance.reasonCode
+
+        this.taxPercent = allowance.taxRateApplicablePercent
+        this.categoryCode = allowance.taxCategoryCode
+    }
+
+
+    open fun mapToInvoice(invoice: Invoice) = net.codinux.invoicing.model.Invoice(
         invoiceNumber = invoice.number,
         invoicingDate = map(invoice.issueDate),
         sender = mapParty(invoice.sender),
@@ -63,35 +99,57 @@ class MustangMapper {
         dueDate = map(invoice.dueDate ?: invoice.paymentTerms?.dueDate),
         paymentDescription = invoice.paymentTermDescription ?: invoice.paymentTerms?.description,
 
-        buyerReference = invoice.referenceNumber
+        buyerReference = invoice.referenceNumber,
+
+        amountAdjustments = mapAmountAdjustments(invoice),
+
+        totalAmounts = calculator.calculateTotalAmounts(invoice)
     )
 
-    fun mapParty(party: TradeParty) = Party(
+    open fun mapParty(party: TradeParty) = Party(
         party.name, party.street, party.zip, party.location, party.country, party.vatID,
         party.email ?: party.contact?.eMail, party.contact?.phone, party.contact?.fax, party.contact?.name,
         party.bankDetails?.firstOrNull()?.let { net.codinux.invoicing.model.BankDetails(it.iban, it.bic, it.accountName) }
     )
 
-    fun mapLineItem(item: IZUGFeRDExportableItem) = LineItem(
-        item.product.name, item.product.unit, item.quantity, item.price, item.product.vatPercent, item.product.description.takeUnless { it.isBlank() }
+    open fun mapLineItem(item: IZUGFeRDExportableItem) = InvoiceItem(
+        item.product.name, item.quantity, item.product.unit, item.price, item.product.vatPercent, item.product.description.takeUnless { it.isBlank() }
     )
 
+    protected open fun mapAmountAdjustments(invoice: Invoice): AmountAdjustments? {
+        if ((invoice.totalPrepaidAmount == null || invoice.totalPrepaidAmount == BigDecimal.ZERO)
+            && invoice.zfCharges.isNullOrEmpty() && invoice.zfAllowances.isNullOrEmpty()) {
+            return null
+        }
+
+        return AmountAdjustments(
+            invoice.totalPrepaidAmount,
+            invoice.zfCharges.mapNotNull { mapChargeOrAllowance(it as? Charge) },
+            invoice.zfAllowances.mapNotNull { mapChargeOrAllowance(it as? Allowance ?: it as? Charge) }
+        )
+    }
+
+    private fun mapChargeOrAllowance(chargeOrAllowance: Charge?) = chargeOrAllowance?.let {
+        ChargeOrAllowance(it.totalAmount, null, null, it.percent, it.reason, it.reasonCode, it.taxPercent, it.categoryCode)
+    }
+
+
 
     @JvmName("mapNullable")
-    private fun map(date: LocalDate?) =
+    protected fun map(date: LocalDate?) =
         date?.let { map(it) }
 
-    private fun map(date: LocalDate): Date =
+    protected open fun map(date: LocalDate): Date =
         Date.from(mapToInstant(date))
 
-    private fun mapToInstant(date: LocalDate): Instant =
+    protected open fun mapToInstant(date: LocalDate): Instant =
         date.atStartOfDay(ZoneId.systemDefault()).toInstant()
 
     @JvmName("mapNullable")
-    private fun map(date: Date?) =
+    protected fun map(date: Date?) =
         date?.let { map(it) }
 
-    private fun map(date: Date): LocalDate =
+    protected open fun map(date: Date): LocalDate =
         date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate()
 
 }

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/model/AmountAdjustments.kt

@@ -0,0 +1,22 @@
+package net.codinux.invoicing.model
+
+import java.math.BigDecimal
+
+class AmountAdjustments(
+    /**
+     * Vorauszahlungen.
+     */
+    val prepaidAmounts: BigDecimal = BigDecimal.ZERO,
+
+    /**
+     * Zusätzliche Gebühren.
+     */
+    val charges: List<ChargeOrAllowance> = emptyList(),
+
+    /**
+     * Abzüge / Nachlässe.
+     */
+    val allowances: List<ChargeOrAllowance> = emptyList()
+) {
+    override fun toString() = "${prepaidAmounts.toPlainString()} prepaid, ${charges.size} charges, ${allowances.size} allowances"
+}

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/model/ChargeOrAllowance.kt

@@ -0,0 +1,44 @@
+package net.codinux.invoicing.model
+
+import java.math.BigDecimal
+
+class ChargeOrAllowance(
+    /**
+     * Gesamtbetrag der Gebühr oder des Nachlasses.
+     * Evtl. berechnet aus [basisAmount] und [calculationPercent].
+     */
+    val actualAmount: BigDecimal,
+
+    /**
+     * Der Ausgangsbetrag auf den die Gebühr oder der Nachlass angewendet wird.
+     */
+    val basisAmount: BigDecimal? = null,
+    /**
+     * Menge der Ware oder Dienstleistung auf die die Gebühr oder der Nachlass angewendet wird.
+     */
+    val basisQuantity: BigDecimal? = null,
+    /**
+     * Der auf [basisAmount] anwendbare Prozentsatz der Gebühr oder des Nachlasses.
+     */
+    val calculationPercent: BigDecimal? = null,
+
+    /**
+     * Menschenlesbare Beschreibung der Gebühr oder des Nachlasses.
+     */
+    val reason: String? = null,
+    /**
+     * Code für Begründung der Gebühr oder des Nachlasses aus [UNTDID 5189](https://unece.org/fileadmin/DAM/trade/untdid/d16b/tred/tred5189.htm).
+     */
+    val reasonCode: String? = null,
+
+    /**
+     * Anzuwendender Steuersatz (z. B. in Deutschland 7 % oder 19 %).
+     */
+    val taxRateApplicablePercent: BigDecimal? = null,
+    /**
+     * Steuer Kategorie Code
+     */
+    val taxCategoryCode: String? = null
+) {
+    override fun toString() = "${reason?.let { "$it: " } ?: ""}${actualAmount.toPlainString()}"
+}

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/model/Invoice.kt

@@ -7,7 +7,7 @@ class Invoice(
     val invoicingDate: LocalDate,
     val sender: Party,
     val recipient: Party,
-    val items: List<LineItem>,
+    val items: List<InvoiceItem>,
 
     val dueDate: LocalDate? = null,
     val paymentDescription: String? = null,
@@ -15,7 +15,17 @@ class Invoice(
     /**
      * Unique reference number of the buyer, e.g. the Leitweg-ID required by German authorities (Behörden)
      */
-    val buyerReference: String? = null
+    val buyerReference: String? = null,
+
+    val amountAdjustments: AmountAdjustments? = null,
+
+    /**
+     * The total amounts of the invoice.
+     *
+     * For outgoing invoices: You don't have to calculate them, we do this for you. This ensures that all total amounts
+     * are in accordance to other data of the invoice like the invoice item amounts and amount adjustments.
+     */
+    var totalAmounts: TotalAmounts? = null
 ) {
-    override fun toString() = "$invoicingDate $invoiceNumber to $recipient"
+    override fun toString() = "$invoicingDate $invoiceNumber to $recipient ${totalAmounts?.duePayableAmount?.let { " (${it.toPlainString()})" } ?: ""}"
 }

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/model/InvoiceItem.kt

@@ -2,13 +2,13 @@ package net.codinux.invoicing.model
 
 import java.math.BigDecimal
 
-class LineItem(
+class InvoiceItem(
     val name: String,
-    val unit: String,
     val quantity: BigDecimal,
-    val price: BigDecimal,
-    val vatPercentage: BigDecimal,
+    val unit: String,
+    val unitPrice: BigDecimal,
+    val vatRate: BigDecimal,
     val description: String? = null,
 ) {
-    override fun toString() = "$name, $quantity x $price, $vatPercentage %"
+    override fun toString() = "$name, $quantity x $unitPrice, $vatRate %"
 }

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/model/TotalAmounts.kt

@@ -0,0 +1,49 @@
+package net.codinux.invoicing.model
+
+import java.math.BigDecimal
+
+class TotalAmounts(
+    /**
+     * Gesamtbetrag einer einzelnen Rechnungsposition.
+     */
+    val lineTotalAmount: BigDecimal,
+
+    val chargeTotalAmount: BigDecimal = BigDecimal.ZERO,
+
+    /**
+     * Gesamtbetrag aller gewährten Rabatte, Abzüge oder Nachlässe.
+     */
+    val allowanceTotalAmount: BigDecimal = BigDecimal.ZERO,
+
+    /**
+     * Der Gesamtbetrag, der als Grundlage für die Steuerberechnung dient, nach Abzug von Rabatten (Allowance) und vor
+     * Hinzufügen der Steuerbeträge.
+     */
+    val taxBasisTotalAmount: BigDecimal,
+
+    /**
+     * Die Gesamtsumme der auf der Rechnung anfallenden Steuern. Dies umfasst in der Regel alle Steuerarten, die auf den
+     * Tax Basis Total Amount angewendet werden (z. B. Mehrwertsteuer oder Umsatzsteuer).
+     */
+    val taxTotalAmount: BigDecimal,
+
+    /**
+     * Der Gesamtbetrag der Rechnung nach Berücksichtigung aller Kosten, Abzüge und Steuern. Dies ist der Betrag, der
+     * vor eventuellen Vorauszahlungen oder Gutschriften fällig wäre.
+     */
+    val grandTotalAmount: BigDecimal,
+
+    /**
+     * Der Betrag, der bereits im Voraus bezahlt wurde. Dieser Betrag wird vom Grand Total Amount abgezogen, um den
+     * verbleibenden Zahlungsbetrag zu ermitteln.
+     */
+    val totalPrepaidAmount: BigDecimal,
+
+    /**
+     * Der noch zu zahlende Betrag, den der Kunde begleichen muss. Er ergibt sich aus dem Grand Total Amount abzüglich
+     * des Total Prepaid Amount und eventueller weiterer Gutschriften oder Anpassungen.
+     */
+    val duePayableAmount: BigDecimal
+) {
+    override fun toString() = "${duePayableAmount.toPlainString()} (net: ${taxBasisTotalAmount.toPlainString()}, tax: ${taxTotalAmount.toPlainString()})"
+}

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/reader/EInvoiceReader.kt

@@ -6,39 +6,46 @@ import org.mustangproject.ZUGFeRD.ZUGFeRDInvoiceImporter
 import java.io.File
 import java.io.InputStream
 
-class EInvoiceReader(
-    private val mapper: MustangMapper = MustangMapper()
+open class EInvoiceReader(
+    protected open val mapper: MustangMapper = MustangMapper()
 ) {
 
-    fun extractFromXml(xmlFile: File) = extractFromXml(xmlFile.inputStream())
+    companion object {
+        val KnownEInvoiceXmlAttachmentNames = listOf(
+            "factur-x.xml", "zugferd-invoice.xml", "xrechnung.xml" // also "ZUGFeRD-invoice.xml" is found but we make compare case insensitive anyway
+        )
+    }
 
-    fun extractFromXml(stream: InputStream) = extractFromXml(stream.reader().readText())
 
-    fun extractFromXml(xml: String): Invoice {
+    open fun extractFromXml(xmlFile: File) = extractFromXml(xmlFile.inputStream())
+
+    open fun extractFromXml(stream: InputStream) = extractFromXml(stream.reader().readText())
+
+    open fun extractFromXml(xml: String): Invoice {
         val importer = ZUGFeRDInvoiceImporter() // XRechnungImporter only reads properties but not to a Invoice object
         importer.fromXML(xml)
 
         return extractInvoice(importer)
     }
 
-    fun extractFromPdf(pdfFile: File) = extractFromPdf(pdfFile.inputStream())
+    open fun extractFromPdf(pdfFile: File) = extractFromPdf(pdfFile.inputStream())
 
-    fun extractFromPdf(stream: InputStream): Invoice {
+    open fun extractFromPdf(stream: InputStream): Invoice {
         val importer = ZUGFeRDInvoiceImporter(stream)
 
         return extractInvoice(importer)
     }
 
-    fun extractXmlFromPdf(pdfFile: File) = extractXmlFromPdf(pdfFile.inputStream())
+    open fun extractXmlFromPdf(pdfFile: File) = extractXmlFromPdf(pdfFile.inputStream())
 
-    fun extractXmlFromPdf(stream: InputStream): String {
+    open fun extractXmlFromPdf(stream: InputStream): String {
         val importer = ZUGFeRDInvoiceImporter(stream)
 
         return String(importer.rawXML, Charsets.UTF_8)
     }
 
 
-    private fun extractInvoice(importer: ZUGFeRDInvoiceImporter): Invoice {
+    protected open fun extractInvoice(importer: ZUGFeRDInvoiceImporter): Invoice {
         val invoice = importer.extractInvoice()
 
         // TODO: the values LineTotalAmount, ChargeTotalAmount, AllowanceTotalAmount, TaxBasisTotalAmount, TaxTotalAmount,

e-invoice-domain/src/main/kotlin/net/codinux/invoicing/validation/EInvoiceValidator.kt

@@ -1,27 +1,31 @@
 package net.codinux.invoicing.validation
 
+import net.codinux.log.logger
 import org.mustangproject.validator.ZUGFeRDValidator
 import java.io.File
 import java.lang.reflect.Field
 
-class EInvoiceValidator {
+open class EInvoiceValidator {
 
     companion object {
         private val SectionField = getPrivateField("section")
         private val CriterionField = getPrivateField("criterion")
         private val StacktraceField = getPrivateField("stacktrace")
 
+        private val log by logger()
+
         private fun getPrivateField(fieldName: String): Field? = try {
            org.mustangproject.validator.ValidationResultItem::class.java.getDeclaredField(fieldName).apply {
                trySetAccessible()
            }
         } catch (e: Throwable) {
+            log.error(e) { "Could not access private field '$fieldName' of Mustang ValidationResultItem" }
             null
         }
     }
 
 
-    fun validate(fileToValidate: File, disableNotices: Boolean = false): InvoiceValidationResult {
+    open fun validate(fileToValidate: File, disableNotices: Boolean = false): InvoiceValidationResult {
         val validator = object : ZUGFeRDValidator() {
             fun getContext() = this.context
         }
@@ -42,10 +46,10 @@ class EInvoiceValidator {
         return InvoiceValidationResult(validator.wasCompletelyValid(), isXmlValid, xmlValidationResults, report)
     }
 
-    private fun mapValidationResultItem(item: org.mustangproject.validator.ValidationResultItem) =
+    protected open fun mapValidationResultItem(item: org.mustangproject.validator.ValidationResultItem) =
         ValidationResultItem(mapSeverity(item), item.message, item.location, SectionField?.get(item) as? Int, CriterionField?.get(item) as? String, StacktraceField?.get(item) as? String)
 
-    private fun mapSeverity(item: org.mustangproject.validator.ValidationResultItem): ValidationResultSeverity {
+    protected open fun mapSeverity(item: org.mustangproject.validator.ValidationResultItem): ValidationResultSeverity {
         var name = item.severity.name
         name = name.first().uppercase() + name.substring(1)
 

e-invoice-domain/src/test/kotlin/net/codinux/invoicing/Demonstration.kt

@@ -4,7 +4,7 @@ import net.codinux.invoicing.creation.EInvoiceCreator
 import net.codinux.invoicing.mail.MailAccount
 import net.codinux.invoicing.mail.MailReader
 import net.codinux.invoicing.model.Invoice
-import net.codinux.invoicing.model.LineItem
+import net.codinux.invoicing.model.InvoiceItem
 import net.codinux.invoicing.model.Party
 import net.codinux.invoicing.reader.EInvoiceReader
 import net.codinux.invoicing.validation.EInvoiceValidator
@@ -83,6 +83,6 @@ class Demonstration {
         invoicingDate = LocalDate.now(),
         sender = Party("codinux GmbH & Co. KG", "Fun Street 1", "12345", "Glückstadt"),
         recipient = Party("Abzock GmbH", "Ausbeutstr.", "12345", "Abzockhausen"),
-        items = listOf(LineItem("Erbrachte Dienstleistungen", "HUR", BigDecimal(170), BigDecimal(1_000_000), BigDecimal(19))) // HUR = EN code for hour
+        items = listOf(InvoiceItem("Erbrachte Dienstleistungen", BigDecimal(170), "HUR", BigDecimal(1_000_000), BigDecimal(19))) // HUR = EN code for hour
     )
 }

e-invoice-domain/src/test/kotlin/net/codinux/invoicing/test/DataGenerator.kt

@@ -2,7 +2,7 @@ package net.codinux.invoicing.test
 
 import net.codinux.invoicing.model.BankDetails
 import net.codinux.invoicing.model.Invoice
-import net.codinux.invoicing.model.LineItem
+import net.codinux.invoicing.model.InvoiceItem
 import net.codinux.invoicing.model.Party
 import java.math.BigDecimal
 import java.time.LocalDate
@@ -35,10 +35,10 @@ object DataGenerator {
     val RecipientBankDetails: BankDetails? = null
 
     const val ItemName = "Erbrachte Dienstleistungen"
-    const val ItemUnit = "HUR" // EN code for 'hour'
     val ItemQuantity = BigDecimal(1)
-    val ItemPrice = BigDecimal(99)
-    val ItemVatPercentage = BigDecimal(19)
+    const val ItemUnit = "HUR" // EN code for 'hour'
+    val ItemUnitPrice = BigDecimal(99)
+    val ItemVatRate = BigDecimal(19)
     val ItemDescription: String? = null
 
 
@@ -49,7 +49,7 @@ object DataGenerator {
             bankDetails = SenderBankDetails),
         recipient: Party = createParty(RecipientName, RecipientStreet, RecipientPostalCode, RecipientCity, RecipientCountry, RecipientVatId, RecipientEmail, RecipientPhone,
             bankDetails = RecipientBankDetails),
-        items: List<LineItem> = listOf(createItem()),
+        items: List<InvoiceItem> = listOf(createItem()),
         dueDate: LocalDate? = DueDate,
         paymentDescription: String? = dueDate?.let { "Zahlbar ohne Abzug bis ${DateTimeFormatter.ofPattern("dd.MM.yyyy").format(dueDate)}" },
         buyerReference: String? = null
@@ -71,11 +71,11 @@ object DataGenerator {
 
     fun createItem(
         name: String = ItemName,
-        unit: String = ItemUnit,
         quantity: BigDecimal = ItemQuantity,
-        price: BigDecimal = ItemPrice,
-        vatPercentage: BigDecimal = ItemVatPercentage,
+        unit: String = ItemUnit,
+        unitPrice: BigDecimal = ItemUnitPrice,
+        vatRate: BigDecimal = ItemVatRate,
         description: String? = ItemDescription,
-    ) = LineItem(name, unit, quantity, price, vatPercentage, description)
+    ) = InvoiceItem(name, quantity, unit, unitPrice, vatRate, description)
 
 }

e-invoice-domain/src/test/kotlin/net/codinux/invoicing/test/InvoiceAsserter.kt

@@ -4,7 +4,7 @@ import assertk.assertThat
 import assertk.assertions.*
 import net.codinux.invoicing.model.BankDetails
 import net.codinux.invoicing.model.Invoice
-import net.codinux.invoicing.model.LineItem
+import net.codinux.invoicing.model.InvoiceItem
 import net.codinux.invoicing.model.Party
 import java.math.BigDecimal
 
@@ -25,7 +25,7 @@ object InvoiceAsserter {
         assertParty(asserter, receiverXPath, DataGenerator.RecipientName, DataGenerator.RecipientStreet, DataGenerator.RecipientPostalCode, DataGenerator.RecipientCity, DataGenerator.RecipientVatId, DataGenerator.RecipientEmail, DataGenerator.RecipientPhone)
 
         val lineItemXPath = "//rsm:SupplyChainTradeTransaction/ram:IncludedSupplyChainTradeLineItem"
-        assertLineItem(asserter, lineItemXPath, DataGenerator.ItemName, DataGenerator.ItemUnit, DataGenerator.ItemQuantity, DataGenerator.ItemPrice, DataGenerator.ItemVatPercentage, DataGenerator.ItemDescription)
+        assertLineItem(asserter, lineItemXPath, DataGenerator.ItemName, DataGenerator.ItemQuantity, DataGenerator.ItemUnit, DataGenerator.ItemUnitPrice, DataGenerator.ItemVatRate, DataGenerator.ItemDescription)
     }
 
     private fun assertParty(asserter: XPathAsserter, partyXPath: String, name: String, street: String, postalCode: String, city: String, vatId: String, email: String, phone: String) {
@@ -42,14 +42,15 @@ object InvoiceAsserter {
         asserter.xpathHasValue("$partyXPath/ram:DefinedTradeContact/ram:TelephoneUniversalCommunication/ram:CompleteNumber", phone)
     }
 
-    private fun assertLineItem(asserter: XPathAsserter, itemXPath: String, name: String, unit: String, quantity: BigDecimal, price: BigDecimal, vatPercentage: BigDecimal, description: String?) {
+    private fun assertLineItem(asserter: XPathAsserter, itemXPath: String, name: String, quantity: BigDecimal, unit: String, unitPrice: BigDecimal, vatRate: BigDecimal, description: String?) {
         asserter.xpathHasValue("$itemXPath/ram:SpecifiedTradeProduct/ram:Name", name)
 
         asserter.xpathHasValue("$itemXPath/ram:SpecifiedLineTradeDelivery/ram:BilledQuantity/@unitCode", unit)
         asserter.xpathHasValue("$itemXPath/ram:SpecifiedLineTradeDelivery/ram:BilledQuantity", quantity, 4)
 
-        asserter.xpathHasValue("$itemXPath/ram:SpecifiedLineTradeSettlement/ram:SpecifiedTradeSettlementLineMonetarySummation/ram:LineTotalAmount", price, 2)
-        asserter.xpathHasValue("$itemXPath/ram:SpecifiedLineTradeSettlement/ram:ApplicableTradeTax/ram:RateApplicablePercent", vatPercentage, 2)
+        asserter.xpathHasValue("$itemXPath/ram:SpecifiedLineTradeSettlement/ram:SpecifiedTradeSettlementLineMonetarySummation/ram:LineTotalAmount", unitPrice, 2)
+        asserter.xpathHasValue("$itemXPath/ram:SpecifiedLineTradeSettlement/ram:ApplicableTradeTax/ram:RateApplicablePercent",
+            vatRate, 2)
 
 //        asserter.xpathHasValue("$partyXPath/ram:URIUniversalCommunication/ram:URIID", description)
     }
@@ -66,7 +67,7 @@ object InvoiceAsserter {
         assertParty(invoice.recipient, DataGenerator.RecipientName, DataGenerator.RecipientStreet, DataGenerator.RecipientPostalCode, DataGenerator.RecipientCity, DataGenerator.RecipientCountry, DataGenerator.RecipientVatId, DataGenerator.RecipientEmail, DataGenerator.RecipientPhone, DataGenerator.RecipientBankDetails)
 
         assertThat(invoice.items).hasSize(1)
-        assertLineItem(invoice.items.first(), DataGenerator.ItemName, DataGenerator.ItemUnit, DataGenerator.ItemQuantity, DataGenerator.ItemPrice, DataGenerator.ItemVatPercentage, DataGenerator.ItemDescription)
+        assertLineItem(invoice.items.first(), DataGenerator.ItemName, DataGenerator.ItemQuantity, DataGenerator.ItemUnit, DataGenerator.ItemUnitPrice, DataGenerator.ItemVatRate, DataGenerator.ItemDescription)
     }
 
     private fun assertParty(party: Party, name: String, street: String, postalCode: String, city: String, country: String?, vatId: String, email: String, phone: String, bankDetails: BankDetails?) {
@@ -92,14 +93,14 @@ object InvoiceAsserter {
         }
     }
 
-    private fun assertLineItem(item: LineItem, name: String, unit: String, quantity: BigDecimal, price: BigDecimal, vatPercentage: BigDecimal, description: String?) {
+    private fun assertLineItem(item: InvoiceItem, name: String, quantity: BigDecimal, unit: String, unitPrice: BigDecimal, vatRate: BigDecimal, description: String?) {
         assertThat(item.name).isEqualTo(name)
 
         assertThat(item.unit).isEqualTo(unit)
         assertThat(item.quantity).isEqualTo(quantity.setScale(4))
 
-        assertThat(item.price).isEqualTo(price.setScale(4))
-        assertThat(item.vatPercentage).isEqualTo(vatPercentage.setScale(2))
+        assertThat(item.unitPrice).isEqualTo(unitPrice.setScale(4))
+        assertThat(item.vatRate).isEqualTo(vatRate.setScale(2))
 
 //        assertThat(item.description).isEqualTo(description)
     }