update

ts/formats/cii/facturx/facturx.decoder.ts

@@ -0,0 +1,220 @@
+import { CIIBaseDecoder } from '../cii.decoder.js';
+import type { TInvoice, TCreditNote, TDebitNote } from '../../../interfaces/common.js';
+import { FACTURX_PROFILE_IDS } from './facturx.types.js';
+import { business, finance, general } from '@tsclass/tsclass';
+
+/**
+ * Decoder for Factur-X invoice format
+ */
+export class FacturXDecoder extends CIIBaseDecoder {
+  /**
+   * Decodes a Factur-X credit note
+   * @returns Promise resolving to a TCreditNote object
+   */
+  protected async decodeCreditNote(): Promise<TCreditNote> {
+    // Get common invoice data
+    const commonData = await this.extractCommonData();
+
+    // Create a credit note with the common data
+    return {
+      ...commonData,
+      invoiceType: 'creditnote'
+    } as TCreditNote;
+  }
+
+  /**
+   * Decodes a Factur-X debit note (invoice)
+   * @returns Promise resolving to a TDebitNote object
+   */
+  protected async decodeDebitNote(): Promise<TDebitNote> {
+    // Get common invoice data
+    const commonData = await this.extractCommonData();
+
+    // Create a debit note with the common data
+    return {
+      ...commonData,
+      invoiceType: 'debitnote'
+    } as TDebitNote;
+  }
+
+  /**
+   * Extracts common invoice data from Factur-X XML
+   * @returns Common invoice data
+   */
+  private async extractCommonData(): Promise<Partial<TInvoice>> {
+    // Extract invoice ID
+    const invoiceId = this.getText('//rsm:ExchangedDocument/ram:ID');
+
+    // Extract issue date
+    const issueDateStr = this.getText('//ram:IssueDateTime/udt:DateTimeString');
+    const issueDate = issueDateStr ? new Date(issueDateStr).getTime() : Date.now();
+
+    // Extract seller information
+    const seller = this.extractParty('//ram:SellerTradeParty');
+
+    // Extract buyer information
+    const buyer = this.extractParty('//ram:BuyerTradeParty');
+
+    // Extract items
+    const items = this.extractItems();
+
+    // Extract due date
+    const dueDateStr = this.getText('//ram:SpecifiedTradePaymentTerms/ram:DueDateDateTime/udt:DateTimeString');
+    const dueDate = dueDateStr ? new Date(dueDateStr).getTime() : Date.now();
+    const dueInDays = Math.round((dueDate - issueDate) / (1000 * 60 * 60 * 24));
+
+    // Extract currency
+    const currencyCode = this.getText('//ram:InvoiceCurrencyCode') || 'EUR';
+
+    // Extract total amount
+    const totalAmount = this.getNumber('//ram:GrandTotalAmount');
+
+    // Extract notes
+    const notes = this.extractNotes();
+
+    // Check for reverse charge
+    const reverseCharge = this.exists('//ram:SpecifiedTradeAllowanceCharge/ram:ReasonCode[text()="62"]');
+
+    // Create the common invoice data
+    return {
+      type: 'invoice',
+      id: invoiceId,
+      date: issueDate,
+      status: 'invoice',
+      versionInfo: {
+        type: 'final',
+        version: '1.0.0'
+      },
+      language: 'en',
+      incidenceId: invoiceId,
+      from: seller,
+      to: buyer,
+      subject: `Invoice ${invoiceId}`,
+      items: items,
+      dueInDays: dueInDays,
+      reverseCharge: reverseCharge,
+      currency: currencyCode as finance.TCurrency,
+      notes: notes,
+      deliveryDate: issueDate,
+      objectActions: [],
+      invoiceType: 'debitnote' // Default to debit note, will be overridden in decode methods
+    };
+  }
+
+  /**
+   * Extracts party information from Factur-X XML
+   * @param partyXPath XPath to the party node
+   * @returns Party information as TContact
+   */
+  private extractParty(partyXPath: string): business.TContact {
+    // Extract name
+    const name = this.getText(`${partyXPath}/ram:Name`);
+
+    // Extract address
+    const address: business.IAddress = {
+      streetName: this.getText(`${partyXPath}/ram:PostalTradeAddress/ram:LineOne`) || '',
+      houseNumber: this.getText(`${partyXPath}/ram:PostalTradeAddress/ram:LineTwo`) || '0',
+      postalCode: this.getText(`${partyXPath}/ram:PostalTradeAddress/ram:PostcodeCode`) || '',
+      city: this.getText(`${partyXPath}/ram:PostalTradeAddress/ram:CityName`) || '',
+      country: this.getText(`${partyXPath}/ram:PostalTradeAddress/ram:CountryID`) || '',
+      countryCode: this.getText(`${partyXPath}/ram:PostalTradeAddress/ram:CountryID`) || ''
+    };
+
+    // Extract VAT ID
+    const vatId = this.getText(`${partyXPath}/ram:SpecifiedTaxRegistration/ram:ID[@schemeID="VA"]`) || '';
+
+    // Extract registration ID
+    const registrationId = this.getText(`${partyXPath}/ram:SpecifiedTaxRegistration/ram:ID[@schemeID="FC"]`) || '';
+
+    // Create contact object
+    return {
+      type: 'company',
+      name: name,
+      description: '',
+      address: address,
+      status: 'active',
+      foundedDate: this.createDefaultDate(),
+      registrationDetails: {
+        vatId: vatId,
+        registrationId: registrationId,
+        registrationName: ''
+      }
+    } as business.TContact;
+  }
+
+  /**
+   * Extracts invoice items from Factur-X XML
+   * @returns Array of invoice items
+   */
+  private extractItems(): finance.TInvoiceItem[] {
+    const items: finance.TInvoiceItem[] = [];
+
+    // Get all item nodes
+    const itemNodes = this.select('//ram:IncludedSupplyChainTradeLineItem', this.doc);
+
+    // Process each item
+    if (Array.isArray(itemNodes)) {
+      for (let i = 0; i < itemNodes.length; i++) {
+        const itemNode = itemNodes[i];
+
+        // Extract item data
+        const name = this.getText('ram:SpecifiedTradeProduct/ram:Name', itemNode);
+        const articleNumber = this.getText('ram:SpecifiedTradeProduct/ram:SellerAssignedID', itemNode);
+        const unitQuantity = this.getNumber('ram:SpecifiedLineTradeDelivery/ram:BilledQuantity', itemNode);
+        const unitType = this.getText('ram:SpecifiedLineTradeDelivery/ram:BilledQuantity/@unitCode', itemNode) || 'EA';
+        const unitNetPrice = this.getNumber('ram:SpecifiedLineTradeAgreement/ram:NetPriceProductTradePrice/ram:ChargeAmount', itemNode);
+        const vatPercentage = this.getNumber('ram:SpecifiedLineTradeSettlement/ram:ApplicableTradeTax/ram:RateApplicablePercent', itemNode);
+
+        // Create item object
+        items.push({
+          position: i + 1,
+          name: name,
+          articleNumber: articleNumber,
+          unitType: unitType,
+          unitQuantity: unitQuantity,
+          unitNetPrice: unitNetPrice,
+          vatPercentage: vatPercentage
+        });
+      }
+    }
+
+    return items;
+  }
+
+  /**
+   * Extracts notes from Factur-X XML
+   * @returns Array of notes
+   */
+  private extractNotes(): string[] {
+    const notes: string[] = [];
+
+    // Get all note nodes
+    const noteNodes = this.select('//ram:IncludedNote', this.doc);
+
+    // Process each note
+    if (Array.isArray(noteNodes)) {
+      for (let i = 0; i < noteNodes.length; i++) {
+        const noteNode = noteNodes[i];
+        const noteText = this.getText('ram:Content', noteNode);
+
+        if (noteText) {
+          notes.push(noteText);
+        }
+      }
+    }
+
+    return notes;
+  }
+
+  /**
+   * Creates a default date object
+   * @returns Default date object
+   */
+  private createDefaultDate(): general.IDate {
+    return {
+      year: 2000,
+      month: 1,
+      day: 1
+    };
+  }
+}

ts/formats/cii/facturx/facturx.encoder.ts

@@ -0,0 +1,465 @@
+import { CIIBaseEncoder } from '../cii.encoder.js';
+import type { TInvoice, TCreditNote, TDebitNote } from '../../../interfaces/common.js';
+import { FACTURX_PROFILE_IDS } from './facturx.types.js';
+import { DOMParser, XMLSerializer } from 'xmldom';
+
+/**
+ * Encoder for Factur-X invoice format
+ */
+export class FacturXEncoder extends CIIBaseEncoder {
+  /**
+   * Encodes a TCreditNote object into Factur-X XML
+   * @param creditNote TCreditNote object to encode
+   * @returns Factur-X XML string
+   */
+  protected async encodeCreditNote(creditNote: TCreditNote): Promise<string> {
+    // Create base XML
+    const xmlDoc = this.createBaseXml();
+
+    // Set document type code to credit note (381)
+    this.setDocumentTypeCode(xmlDoc, '381');
+
+    // Add common invoice data
+    this.addCommonInvoiceData(xmlDoc, creditNote);
+
+    // Serialize to string
+    return new XMLSerializer().serializeToString(xmlDoc);
+  }
+
+  /**
+   * Encodes a TDebitNote object into Factur-X XML
+   * @param debitNote TDebitNote object to encode
+   * @returns Factur-X XML string
+   */
+  protected async encodeDebitNote(debitNote: TDebitNote): Promise<string> {
+    // Create base XML
+    const xmlDoc = this.createBaseXml();
+
+    // Set document type code to invoice (380)
+    this.setDocumentTypeCode(xmlDoc, '380');
+
+    // Add common invoice data
+    this.addCommonInvoiceData(xmlDoc, debitNote);
+
+    // Serialize to string
+    return new XMLSerializer().serializeToString(xmlDoc);
+  }
+
+  /**
+   * Creates a base Factur-X XML document
+   * @returns XML document with basic structure
+   */
+  private createBaseXml(): Document {
+    // Create XML document from template
+    const xmlString = this.createXmlRoot();
+    const doc = new DOMParser().parseFromString(xmlString, 'application/xml');
+
+    // Add Factur-X profile
+    this.addProfile(doc);
+
+    return doc;
+  }
+
+  /**
+   * Adds Factur-X profile information to the XML document
+   * @param doc XML document
+   */
+  private addProfile(doc: Document): void {
+    // Get root element
+    const root = doc.documentElement;
+
+    // Create context element if it doesn't exist
+    let contextElement = root.getElementsByTagName('rsm:ExchangedDocumentContext')[0];
+    if (!contextElement) {
+      contextElement = doc.createElement('rsm:ExchangedDocumentContext');
+      root.appendChild(contextElement);
+    }
+
+    // Create guideline parameter element
+    const guidelineElement = doc.createElement('ram:GuidelineSpecifiedDocumentContextParameter');
+    contextElement.appendChild(guidelineElement);
+
+    // Add ID element with profile
+    const idElement = doc.createElement('ram:ID');
+
+    // Set profile based on the selected profile
+    let profileId = FACTURX_PROFILE_IDS.EN16931;
+    if (this.profile === 'BASIC') {
+      profileId = FACTURX_PROFILE_IDS.BASIC;
+    } else if (this.profile === 'MINIMUM') {
+      profileId = FACTURX_PROFILE_IDS.MINIMUM;
+    }
+
+    idElement.textContent = profileId;
+    guidelineElement.appendChild(idElement);
+  }
+
+  /**
+   * Sets the document type code in the XML document
+   * @param doc XML document
+   * @param typeCode Document type code (380 for invoice, 381 for credit note)
+   */
+  private setDocumentTypeCode(doc: Document, typeCode: string): void {
+    // Get root element
+    const root = doc.documentElement;
+
+    // Create document element if it doesn't exist
+    let documentElement = root.getElementsByTagName('rsm:ExchangedDocument')[0];
+    if (!documentElement) {
+      documentElement = doc.createElement('rsm:ExchangedDocument');
+      root.appendChild(documentElement);
+    }
+
+    // Add type code element
+    const typeCodeElement = doc.createElement('ram:TypeCode');
+    typeCodeElement.textContent = typeCode;
+    documentElement.appendChild(typeCodeElement);
+  }
+
+  /**
+   * Adds common invoice data to the XML document
+   * @param doc XML document
+   * @param invoice Invoice data
+   */
+  private addCommonInvoiceData(doc: Document, invoice: TInvoice): void {
+    // Get root element
+    const root = doc.documentElement;
+
+    // Get document element or create it
+    let documentElement = root.getElementsByTagName('rsm:ExchangedDocument')[0];
+    if (!documentElement) {
+      documentElement = doc.createElement('rsm:ExchangedDocument');
+      root.appendChild(documentElement);
+    }
+
+    // Add ID element
+    const idElement = doc.createElement('ram:ID');
+    idElement.textContent = invoice.id;
+    documentElement.appendChild(idElement);
+
+    // Add issue date element
+    const issueDateElement = doc.createElement('ram:IssueDateTime');
+    const dateStringElement = doc.createElement('udt:DateTimeString');
+    dateStringElement.setAttribute('format', '102'); // YYYYMMDD format
+    dateStringElement.textContent = this.formatDateYYYYMMDD(invoice.date);
+    issueDateElement.appendChild(dateStringElement);
+    documentElement.appendChild(issueDateElement);
+
+    // Create transaction element if it doesn't exist
+    let transactionElement = root.getElementsByTagName('rsm:SupplyChainTradeTransaction')[0];
+    if (!transactionElement) {
+      transactionElement = doc.createElement('rsm:SupplyChainTradeTransaction');
+      root.appendChild(transactionElement);
+    }
+
+    // Add agreement section with seller and buyer
+    this.addAgreementSection(doc, transactionElement, invoice);
+
+    // Add delivery section
+    this.addDeliverySection(doc, transactionElement, invoice);
+
+    // Add settlement section with payment terms and totals
+    this.addSettlementSection(doc, transactionElement, invoice);
+
+    // Add line items
+    this.addLineItems(doc, transactionElement, invoice);
+  }
+
+  /**
+   * Adds agreement section with seller and buyer information
+   * @param doc XML document
+   * @param transactionElement Transaction element
+   * @param invoice Invoice data
+   */
+  private addAgreementSection(doc: Document, transactionElement: Element, invoice: TInvoice): void {
+    // Create agreement element
+    const agreementElement = doc.createElement('ram:ApplicableHeaderTradeAgreement');
+    transactionElement.appendChild(agreementElement);
+
+    // Add seller
+    const sellerElement = doc.createElement('ram:SellerTradeParty');
+    this.addPartyInfo(doc, sellerElement, invoice.from);
+    agreementElement.appendChild(sellerElement);
+
+    // Add buyer
+    const buyerElement = doc.createElement('ram:BuyerTradeParty');
+    this.addPartyInfo(doc, buyerElement, invoice.to);
+    agreementElement.appendChild(buyerElement);
+  }
+
+  /**
+   * Adds party information to an element
+   * @param doc XML document
+   * @param partyElement Party element
+   * @param party Party data
+   */
+  private addPartyInfo(doc: Document, partyElement: Element, party: any): void {
+    // Add name
+    const nameElement = doc.createElement('ram:Name');
+    nameElement.textContent = party.name;
+    partyElement.appendChild(nameElement);
+
+    // Add postal address
+    const addressElement = doc.createElement('ram:PostalTradeAddress');
+
+    // Add address line 1 (street)
+    const line1Element = doc.createElement('ram:LineOne');
+    line1Element.textContent = party.address.streetName;
+    addressElement.appendChild(line1Element);
+
+    // Add address line 2 (house number)
+    const line2Element = doc.createElement('ram:LineTwo');
+    line2Element.textContent = party.address.houseNumber;
+    addressElement.appendChild(line2Element);
+
+    // Add postal code
+    const postalCodeElement = doc.createElement('ram:PostcodeCode');
+    postalCodeElement.textContent = party.address.postalCode;
+    addressElement.appendChild(postalCodeElement);
+
+    // Add city
+    const cityElement = doc.createElement('ram:CityName');
+    cityElement.textContent = party.address.city;
+    addressElement.appendChild(cityElement);
+
+    // Add country
+    const countryElement = doc.createElement('ram:CountryID');
+    countryElement.textContent = party.address.countryCode || party.address.country;
+    addressElement.appendChild(countryElement);
+
+    partyElement.appendChild(addressElement);
+
+    // Add VAT ID if available
+    if (party.registrationDetails && party.registrationDetails.vatId) {
+      const taxRegistrationElement = doc.createElement('ram:SpecifiedTaxRegistration');
+      const taxIdElement = doc.createElement('ram:ID');
+      taxIdElement.setAttribute('schemeID', 'VA');
+      taxIdElement.textContent = party.registrationDetails.vatId;
+      taxRegistrationElement.appendChild(taxIdElement);
+      partyElement.appendChild(taxRegistrationElement);
+    }
+
+    // Add registration ID if available
+    if (party.registrationDetails && party.registrationDetails.registrationId) {
+      const regRegistrationElement = doc.createElement('ram:SpecifiedTaxRegistration');
+      const regIdElement = doc.createElement('ram:ID');
+      regIdElement.setAttribute('schemeID', 'FC');
+      regIdElement.textContent = party.registrationDetails.registrationId;
+      regRegistrationElement.appendChild(regIdElement);
+      partyElement.appendChild(regRegistrationElement);
+    }
+  }
+
+  /**
+   * Adds delivery section with delivery information
+   * @param doc XML document
+   * @param transactionElement Transaction element
+   * @param invoice Invoice data
+   */
+  private addDeliverySection(doc: Document, transactionElement: Element, invoice: TInvoice): void {
+    // Create delivery element
+    const deliveryElement = doc.createElement('ram:ApplicableHeaderTradeDelivery');
+    transactionElement.appendChild(deliveryElement);
+
+    // Add delivery date if available
+    if (invoice.deliveryDate) {
+      const deliveryDateElement = doc.createElement('ram:ActualDeliverySupplyChainEvent');
+      const occurrenceDateElement = doc.createElement('ram:OccurrenceDateTime');
+      const dateStringElement = doc.createElement('udt:DateTimeString');
+      dateStringElement.setAttribute('format', '102'); // YYYYMMDD format
+      dateStringElement.textContent = this.formatDateYYYYMMDD(invoice.deliveryDate);
+      occurrenceDateElement.appendChild(dateStringElement);
+      deliveryDateElement.appendChild(occurrenceDateElement);
+      deliveryElement.appendChild(deliveryDateElement);
+    }
+  }
+
+  /**
+   * Adds settlement section with payment terms and totals
+   * @param doc XML document
+   * @param transactionElement Transaction element
+   * @param invoice Invoice data
+   */
+  private addSettlementSection(doc: Document, transactionElement: Element, invoice: TInvoice): void {
+    // Create settlement element
+    const settlementElement = doc.createElement('ram:ApplicableHeaderTradeSettlement');
+    transactionElement.appendChild(settlementElement);
+
+    // Add currency
+    const currencyElement = doc.createElement('ram:InvoiceCurrencyCode');
+    currencyElement.textContent = invoice.currency;
+    settlementElement.appendChild(currencyElement);
+
+    // Add payment terms
+    const paymentTermsElement = doc.createElement('ram:SpecifiedTradePaymentTerms');
+
+    // Add due date
+    const dueDateElement = doc.createElement('ram:DueDateDateTime');
+    const dateStringElement = doc.createElement('udt:DateTimeString');
+    dateStringElement.setAttribute('format', '102'); // YYYYMMDD format
+
+    // Calculate due date
+    const dueDate = new Date(invoice.date);
+    dueDate.setDate(dueDate.getDate() + invoice.dueInDays);
+
+    dateStringElement.textContent = this.formatDateYYYYMMDD(dueDate.getTime());
+    dueDateElement.appendChild(dateStringElement);
+    paymentTermsElement.appendChild(dueDateElement);
+
+    settlementElement.appendChild(paymentTermsElement);
+
+    // Add totals
+    const monetarySummationElement = doc.createElement('ram:SpecifiedTradeSettlementHeaderMonetarySummation');
+
+    // Calculate totals
+    let totalNetAmount = 0;
+    let totalTaxAmount = 0;
+
+    // Calculate from items
+    if (invoice.items) {
+      for (const item of invoice.items) {
+        const itemNetAmount = item.unitNetPrice * item.unitQuantity;
+        const itemTaxAmount = itemNetAmount * (item.vatPercentage / 100);
+
+        totalNetAmount += itemNetAmount;
+        totalTaxAmount += itemTaxAmount;
+      }
+    }
+
+    const totalGrossAmount = totalNetAmount + totalTaxAmount;
+
+    // Add line total amount
+    const lineTotalElement = doc.createElement('ram:LineTotalAmount');
+    lineTotalElement.textContent = totalNetAmount.toFixed(2);
+    monetarySummationElement.appendChild(lineTotalElement);
+
+    // Add tax total amount
+    const taxTotalElement = doc.createElement('ram:TaxTotalAmount');
+    taxTotalElement.textContent = totalTaxAmount.toFixed(2);
+    taxTotalElement.setAttribute('currencyID', invoice.currency);
+    monetarySummationElement.appendChild(taxTotalElement);
+
+    // Add grand total amount
+    const grandTotalElement = doc.createElement('ram:GrandTotalAmount');
+    grandTotalElement.textContent = totalGrossAmount.toFixed(2);
+    monetarySummationElement.appendChild(grandTotalElement);
+
+    // Add due payable amount
+    const duePayableElement = doc.createElement('ram:DuePayableAmount');
+    duePayableElement.textContent = totalGrossAmount.toFixed(2);
+    monetarySummationElement.appendChild(duePayableElement);
+
+    settlementElement.appendChild(monetarySummationElement);
+  }
+
+  /**
+   * Adds line items to the XML document
+   * @param doc XML document
+   * @param transactionElement Transaction element
+   * @param invoice Invoice data
+   */
+  private addLineItems(doc: Document, transactionElement: Element, invoice: TInvoice): void {
+    // Add each line item
+    if (invoice.items) {
+      for (const item of invoice.items) {
+        // Create line item element
+        const lineItemElement = doc.createElement('ram:IncludedSupplyChainTradeLineItem');
+
+        // Add line ID
+        const lineIdElement = doc.createElement('ram:AssociatedDocumentLineDocument');
+        const lineIdValueElement = doc.createElement('ram:LineID');
+        lineIdValueElement.textContent = item.position.toString();
+        lineIdElement.appendChild(lineIdValueElement);
+        lineItemElement.appendChild(lineIdElement);
+
+        // Add product information
+        const productElement = doc.createElement('ram:SpecifiedTradeProduct');
+
+        // Add name
+        const nameElement = doc.createElement('ram:Name');
+        nameElement.textContent = item.name;
+        productElement.appendChild(nameElement);
+
+        // Add article number if available
+        if (item.articleNumber) {
+          const articleNumberElement = doc.createElement('ram:SellerAssignedID');
+          articleNumberElement.textContent = item.articleNumber;
+          productElement.appendChild(articleNumberElement);
+        }
+
+        lineItemElement.appendChild(productElement);
+
+        // Add agreement information (price)
+        const agreementElement = doc.createElement('ram:SpecifiedLineTradeAgreement');
+        const priceElement = doc.createElement('ram:NetPriceProductTradePrice');
+        const chargeAmountElement = doc.createElement('ram:ChargeAmount');
+        chargeAmountElement.textContent = item.unitNetPrice.toFixed(2);
+        priceElement.appendChild(chargeAmountElement);
+        agreementElement.appendChild(priceElement);
+        lineItemElement.appendChild(agreementElement);
+
+        // Add delivery information (quantity)
+        const deliveryElement = doc.createElement('ram:SpecifiedLineTradeDelivery');
+        const quantityElement = doc.createElement('ram:BilledQuantity');
+        quantityElement.textContent = item.unitQuantity.toString();
+        quantityElement.setAttribute('unitCode', item.unitType);
+        deliveryElement.appendChild(quantityElement);
+        lineItemElement.appendChild(deliveryElement);
+
+        // Add settlement information (tax)
+        const settlementElement = doc.createElement('ram:SpecifiedLineTradeSettlement');
+
+        // Add tax information
+        const taxElement = doc.createElement('ram:ApplicableTradeTax');
+
+        // Add tax type code
+        const taxTypeCodeElement = doc.createElement('ram:TypeCode');
+        taxTypeCodeElement.textContent = 'VAT';
+        taxElement.appendChild(taxTypeCodeElement);
+
+        // Add tax category code
+        const taxCategoryCodeElement = doc.createElement('ram:CategoryCode');
+        taxCategoryCodeElement.textContent = 'S';
+        taxElement.appendChild(taxCategoryCodeElement);
+
+        // Add tax rate
+        const taxRateElement = doc.createElement('ram:RateApplicablePercent');
+        taxRateElement.textContent = item.vatPercentage.toString();
+        taxElement.appendChild(taxRateElement);
+
+        settlementElement.appendChild(taxElement);
+
+        // Add monetary summation
+        const monetarySummationElement = doc.createElement('ram:SpecifiedLineTradeSettlementMonetarySummation');
+
+        // Calculate item total
+        const itemNetAmount = item.unitNetPrice * item.unitQuantity;
+
+        // Add line total amount
+        const lineTotalElement = doc.createElement('ram:LineTotalAmount');
+        lineTotalElement.textContent = itemNetAmount.toFixed(2);
+        monetarySummationElement.appendChild(lineTotalElement);
+
+        settlementElement.appendChild(monetarySummationElement);
+
+        lineItemElement.appendChild(settlementElement);
+
+        // Add line item to transaction
+        transactionElement.appendChild(lineItemElement);
+      }
+    }
+  }
+
+  /**
+   * Formats a date as YYYYMMDD
+   * @param timestamp Timestamp to format
+   * @returns Formatted date string
+   */
+  private formatDateYYYYMMDD(timestamp: number): string {
+    const date = new Date(timestamp);
+    const year = date.getFullYear();
+    const month = (date.getMonth() + 1).toString().padStart(2, '0');
+    const day = date.getDate().toString().padStart(2, '0');
+    return `${year}${month}${day}`;
+  }
+}

ts/formats/cii/facturx/facturx.types.ts

@@ -0,0 +1,18 @@
+import { CIIProfile, CII_PROFILE_IDS } from '../cii.types.js';
+
+/**
+ * Factur-X specific constants and types
+ */
+
+// Factur-X profile IDs
+export const FACTURX_PROFILE_IDS = {
+  MINIMUM: CII_PROFILE_IDS.FACTURX_MINIMUM,
+  BASIC: CII_PROFILE_IDS.FACTURX_BASIC,
+  EN16931: CII_PROFILE_IDS.FACTURX_EN16931
+};
+
+// Factur-X PDF attachment filename
+export const FACTURX_ATTACHMENT_FILENAME = 'factur-x.xml';
+
+// Factur-X PDF attachment description
+export const FACTURX_ATTACHMENT_DESCRIPTION = 'Factur-X XML Invoice';

ts/formats/cii/facturx/facturx.validator.ts

@@ -0,0 +1,180 @@
+import { CIIBaseValidator } from '../cii.validator.js';
+import { ValidationLevel } from '../../../interfaces/common.js';
+import type { ValidationResult } from '../../../interfaces/common.js';
+
+/**
+ * Validator for Factur-X invoice format
+ * Implements validation rules according to EN16931 and Factur-X specification
+ */
+export class FacturXValidator extends CIIBaseValidator {
+  /**
+   * Validates structure of the Factur-X XML document
+   * @returns True if structure validation passed
+   */
+  protected validateStructure(): boolean {
+    if (!this.doc) return false;
+
+    let valid = true;
+
+    // Check for required main sections
+    const sections = [
+      'rsm:ExchangedDocumentContext',
+      'rsm:ExchangedDocument',
+      'rsm:SupplyChainTradeTransaction'
+    ];
+
+    for (const section of sections) {
+      if (!this.exists(section)) {
+        this.addError('FX-STRUCT-1', `Required section ${section} is missing`, '/rsm:CrossIndustryInvoice');
+        valid = false;
+      }
+    }
+
+    // Check for SupplyChainTradeTransaction sections
+    if (this.exists('rsm:SupplyChainTradeTransaction')) {
+      const tradeSubsections = [
+        'ram:ApplicableHeaderTradeAgreement',
+        'ram:ApplicableHeaderTradeDelivery',
+        'ram:ApplicableHeaderTradeSettlement'
+      ];
+
+      for (const subsection of tradeSubsections) {
+        if (!this.exists(`rsm:SupplyChainTradeTransaction/${subsection}`)) {
+          this.addError('FX-STRUCT-2', `Required subsection ${subsection} is missing`,
+            '/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction');
+          valid = false;
+        }
+      }
+    }
+
+    return valid;
+  }
+
+  /**
+   * Validates business rules
+   * @returns True if business rule validation passed
+   */
+  protected validateBusinessRules(): boolean {
+    if (!this.doc) return false;
+
+    let valid = true;
+
+    // BR-16: Amount due for payment (BT-115) = Invoice total amount with VAT (BT-112) - Paid amount (BT-113)
+    valid = this.validateAmounts() && valid;
+
+    // BR-CO-3: Value added tax point date (BT-7) and Value added tax point date code (BT-8) are mutually exclusive
+    valid = this.validateMutuallyExclusiveFields() && valid;
+
+    // BR-S-1: An Invoice that contains a line (BG-25) where the Invoiced item VAT category code (BT-151) is "Standard rated"
+    // shall contain the Seller VAT Identifier (BT-31), the Seller tax registration identifier (BT-32)
+    // and/or the Seller tax representative VAT identifier (BT-63).
+    valid = this.validateSellerVatIdentifier() && valid;
+
+    return valid;
+  }
+
+  /**
+   * Validates amount calculations in the invoice
+   * @returns True if amount validation passed
+   */
+  private validateAmounts(): boolean {
+    if (!this.doc) return false;
+
+    try {
+      // Extract amounts
+      const totalAmount = this.getNumber(
+        '//ram:ApplicableHeaderTradeSettlement/ram:SpecifiedTradeSettlementHeaderMonetarySummation/ram:GrandTotalAmount'
+      );
+
+      const paidAmount = this.getNumber(
+        '//ram:ApplicableHeaderTradeSettlement/ram:SpecifiedTradeSettlementHeaderMonetarySummation/ram:TotalPrepaidAmount'
+      ) || 0;
+
+      const dueAmount = this.getNumber(
+        '//ram:ApplicableHeaderTradeSettlement/ram:SpecifiedTradeSettlementHeaderMonetarySummation/ram:DuePayableAmount'
+      );
+
+      // Calculate expected due amount
+      const expectedDueAmount = totalAmount - paidAmount;
+
+      // Compare with a small tolerance for rounding errors
+      if (Math.abs(dueAmount - expectedDueAmount) > 0.01) {
+        this.addError(
+          'BR-16',
+          `Amount due for payment (${dueAmount}) must equal Invoice total amount with VAT (${totalAmount}) - Paid amount (${paidAmount})`,
+          '//ram:ApplicableHeaderTradeSettlement/ram:SpecifiedTradeSettlementHeaderMonetarySummation'
+        );
+        return false;
+      }
+
+      return true;
+    } catch (error) {
+      this.addError('FX-AMOUNT', `Error validating amounts: ${error}`, '/');
+      return false;
+    }
+  }
+
+  /**
+   * Validates mutually exclusive fields
+   * @returns True if validation passed
+   */
+  private validateMutuallyExclusiveFields(): boolean {
+    if (!this.doc) return false;
+
+    try {
+      // Check for VAT point date and code (BR-CO-3)
+      const vatPointDate = this.exists('//ram:ApplicableHeaderTradeSettlement/ram:ApplicableTradeTax/ram:TaxPointDate');
+      const vatPointDateCode = this.exists('//ram:ApplicableHeaderTradeSettlement/ram:ApplicableTradeTax/ram:DueDateTypeCode');
+
+      if (vatPointDate && vatPointDateCode) {
+        this.addError(
+          'BR-CO-3',
+          'Value added tax point date and Value added tax point date code are mutually exclusive',
+          '//ram:ApplicableHeaderTradeSettlement/ram:ApplicableTradeTax'
+        );
+        return false;
+      }
+
+      return true;
+    } catch (error) {
+      this.addError('FX-MUTUAL', `Error validating mutually exclusive fields: ${error}`, '/');
+      return false;
+    }
+  }
+
+  /**
+   * Validates seller VAT identifier requirements
+   * @returns True if validation passed
+   */
+  private validateSellerVatIdentifier(): boolean {
+    if (!this.doc) return false;
+
+    try {
+      // Check if there are any standard rated line items
+      const standardRatedItems = this.exists(
+        '//ram:SpecifiedLineTradeSettlement/ram:ApplicableTradeTax/ram:CategoryCode[text()="S"]'
+      );
+
+      if (standardRatedItems) {
+        // Check for seller VAT identifier
+        const sellerVatId = this.exists('//ram:ApplicableHeaderTradeAgreement/ram:SellerTradeParty/ram:SpecifiedTaxRegistration/ram:ID[@schemeID="VA"]');
+        const sellerTaxId = this.exists('//ram:ApplicableHeaderTradeAgreement/ram:SellerTradeParty/ram:SpecifiedTaxRegistration/ram:ID[@schemeID="FC"]');
+        const sellerTaxRepId = this.exists('//ram:ApplicableHeaderTradeAgreement/ram:SellerTaxRepresentativeTradeParty/ram:SpecifiedTaxRegistration/ram:ID[@schemeID="VA"]');
+
+        if (!sellerVatId && !sellerTaxId && !sellerTaxRepId) {
+          this.addError(
+            'BR-S-1',
+            'An Invoice with standard rated items must contain the Seller VAT Identifier, Tax registration identifier or Tax representative VAT identifier',
+            '//ram:ApplicableHeaderTradeAgreement/ram:SellerTradeParty'
+          );
+          return false;
+        }
+      }
+
+      return true;
+    } catch (error) {
+      this.addError('FX-VAT', `Error validating seller VAT identifier: ${error}`, '/');
+      return false;
+    }
+  }
+}