feat(invoice): add e-invoice support with XRechnung/ZUGFeRD and advanced export features

ts/skr.invoice.booking.ts

@@ -0,0 +1,738 @@
+import * as plugins from './plugins.js';
+import { JournalEntry } from './skr.classes.journalentry.js';
+import { SKRInvoiceMapper } from './skr.invoice.mapper.js';
+import type { TSKRType, IJournalEntry, IJournalEntryLine } from './skr.types.js';
+import type {
+  IInvoice,
+  IInvoiceLine,
+  IBookingRules,
+  IBookingInfo,
+  TTaxScenario,
+  IPaymentInfo
+} from './skr.invoice.entity.js';
+
+/**
+ * Options for booking an invoice
+ */
+export interface IBookingOptions {
+  autoBook?: boolean;
+  confidenceThreshold?: number;
+  bookingDate?: Date;
+  bookingReference?: string;
+  skipValidation?: boolean;
+}
+
+/**
+ * Result of booking an invoice
+ */
+export interface IBookingResult {
+  success: boolean;
+  journalEntry?: JournalEntry;
+  bookingInfo?: IBookingInfo;
+  confidence: number;
+  warnings?: string[];
+  errors?: string[];
+}
+
+/**
+ * Automatic booking engine for invoices
+ * Creates journal entries from invoice data based on SKR mapping rules
+ */
+export class InvoiceBookingEngine {
+  private logger: plugins.smartlog.ConsoleLog;
+  private skrType: TSKRType;
+  private mapper: SKRInvoiceMapper;
+  
+  constructor(skrType: TSKRType) {
+    this.skrType = skrType;
+    this.mapper = new SKRInvoiceMapper(skrType);
+    this.logger = new plugins.smartlog.ConsoleLog();
+  }
+  
+  /**
+   * Book an invoice to the ledger
+   */
+  public async bookInvoice(
+    invoice: IInvoice,
+    bookingRules?: Partial<IBookingRules>,
+    options?: IBookingOptions
+  ): Promise<IBookingResult> {
+    try {
+      // Get complete booking rules
+      const rules = this.mapper.mapInvoiceToSKR(invoice, bookingRules);
+      
+      // Calculate confidence
+      const confidence = this.mapper.calculateConfidence(invoice, rules);
+      
+      // Check if auto-booking is allowed
+      if (options?.autoBook && confidence < (options.confidenceThreshold || 80)) {
+        return {
+          success: false,
+          confidence,
+          warnings: [`Confidence score ${confidence}% is below threshold ${options.confidenceThreshold || 80}%`]
+        };
+      }
+      
+      // Validate invoice before booking
+      if (!options?.skipValidation) {
+        const validationErrors = this.validateInvoice(invoice);
+        if (validationErrors.length > 0) {
+          return {
+            success: false,
+            confidence,
+            errors: validationErrors
+          };
+        }
+      }
+      
+      // Build journal entry
+      const journalEntry = await this.buildJournalEntry(invoice, rules, options);
+      
+      // Create booking info
+      const bookingInfo: IBookingInfo = {
+        journalEntryId: journalEntry.id,
+        transactionIds: journalEntry.transactionIds || [],
+        bookedAt: new Date(),
+        bookedBy: 'system',
+        bookingRules: {
+          vendorAccount: rules.vendorControlAccount,
+          customerAccount: rules.customerControlAccount,
+          expenseAccounts: this.getUsedExpenseAccounts(invoice, rules),
+          revenueAccounts: this.getUsedRevenueAccounts(invoice, rules),
+          vatAccounts: this.getUsedVATAccounts(invoice, rules)
+        },
+        confidence,
+        autoBooked: options?.autoBook || false
+      };
+      
+      // Post the journal entry
+      // TODO: When MongoDB transactions are available, wrap this in a transaction
+      // Example: await db.withTransaction(async (session) => { ... })
+      try {
+        await journalEntry.validate();
+        await journalEntry.post();
+        
+        // Mark invoice as posted if we have a reference to it
+        if (invoice.status !== 'posted') {
+          invoice.status = 'posted';
+        }
+      } catch (postError) {
+        this.logger.log('error', `Failed to post journal entry: ${postError}`);
+        throw postError; // Re-throw to trigger rollback when transactions are available
+      }
+      
+      return {
+        success: true,
+        journalEntry,
+        bookingInfo,
+        confidence,
+        warnings: this.generateWarnings(invoice, rules)
+      };
+    } catch (error) {
+      this.logger.log('error', `Failed to book invoice: ${error}`);
+      return {
+        success: false,
+        confidence: 0,
+        errors: [`Booking failed: ${error.message}`]
+      };
+    }
+  }
+  
+  /**
+   * Build journal entry from invoice
+   */
+  private async buildJournalEntry(
+    invoice: IInvoice,
+    rules: IBookingRules,
+    options?: IBookingOptions
+  ): Promise<JournalEntry> {
+    const lines: IJournalEntryLine[] = [];
+    const isInbound = invoice.direction === 'inbound';
+    const isCredit = invoice.invoiceTypeCode === '381'; // Credit note
+    
+    // Determine if we need to reverse the normal booking direction
+    const reverseDirection = isCredit;
+    
+    if (isInbound) {
+      // Inbound invoice (AP)
+      lines.push(...this.buildAPEntry(invoice, rules, reverseDirection));
+    } else {
+      // Outbound invoice (AR)
+      lines.push(...this.buildAREntry(invoice, rules, reverseDirection));
+    }
+    
+    // Create journal entry
+    const journalData: IJournalEntry = {
+      date: options?.bookingDate || invoice.issueDate,
+      description: this.buildDescription(invoice),
+      reference: options?.bookingReference || invoice.invoiceNumber,
+      lines,
+      skrType: this.skrType
+    };
+    
+    const journalEntry = new JournalEntry(journalData);
+    return journalEntry;
+  }
+  
+  /**
+   * Build AP (Accounts Payable) journal entry lines
+   */
+  private buildAPEntry(
+    invoice: IInvoice,
+    rules: IBookingRules,
+    reverseDirection: boolean
+  ): IJournalEntryLine[] {
+    const lines: IJournalEntryLine[] = [];
+    
+    // Group lines by account
+    const accountGroups = this.groupLinesByAccount(invoice, rules);
+    
+    // Create expense/asset entries
+    for (const [accountNumber, group] of Object.entries(accountGroups)) {
+      const amount = group.reduce((sum, line) => sum + line.netAmount, 0);
+      
+      if (reverseDirection) {
+        // Credit note: credit expense account
+        lines.push({
+          accountNumber,
+          credit: Math.abs(amount),
+          description: this.getAccountDescription(accountNumber, group)
+        });
+      } else {
+        // Regular invoice: debit expense account
+        lines.push({
+          accountNumber,
+          debit: Math.abs(amount),
+          description: this.getAccountDescription(accountNumber, group)
+        });
+      }
+    }
+    
+    // Create VAT entries
+    const vatLines = this.buildVATLines(invoice, rules, 'input', reverseDirection);
+    lines.push(...vatLines);
+    
+    // Create vendor control account entry
+    const controlAccount = this.mapper.getControlAccount(invoice, rules);
+    const totalAmount = Math.abs(invoice.payableAmount);
+    
+    if (reverseDirection) {
+      // Credit note: debit vendor account
+      lines.push({
+        accountNumber: controlAccount,
+        debit: totalAmount,
+        description: `${invoice.supplier.name} - Credit Note ${invoice.invoiceNumber}`
+      });
+    } else {
+      // Regular invoice: credit vendor account
+      lines.push({
+        accountNumber: controlAccount,
+        credit: totalAmount,
+        description: `${invoice.supplier.name} - Invoice ${invoice.invoiceNumber}`
+      });
+    }
+    
+    return lines;
+  }
+  
+  /**
+   * Build AR (Accounts Receivable) journal entry lines
+   */
+  private buildAREntry(
+    invoice: IInvoice,
+    rules: IBookingRules,
+    reverseDirection: boolean
+  ): IJournalEntryLine[] {
+    const lines: IJournalEntryLine[] = [];
+    
+    // Group lines by account
+    const accountGroups = this.groupLinesByAccount(invoice, rules);
+    
+    // Create revenue entries
+    for (const [accountNumber, group] of Object.entries(accountGroups)) {
+      const amount = group.reduce((sum, line) => sum + line.netAmount, 0);
+      
+      if (reverseDirection) {
+        // Credit note: debit revenue account
+        lines.push({
+          accountNumber,
+          debit: Math.abs(amount),
+          description: this.getAccountDescription(accountNumber, group)
+        });
+      } else {
+        // Regular invoice: credit revenue account
+        lines.push({
+          accountNumber,
+          credit: Math.abs(amount),
+          description: this.getAccountDescription(accountNumber, group)
+        });
+      }
+    }
+    
+    // Create VAT entries
+    const vatLines = this.buildVATLines(invoice, rules, 'output', reverseDirection);
+    lines.push(...vatLines);
+    
+    // Create customer control account entry
+    const controlAccount = this.mapper.getControlAccount(invoice, rules);
+    const totalAmount = Math.abs(invoice.payableAmount);
+    
+    if (reverseDirection) {
+      // Credit note: credit customer account
+      lines.push({
+        accountNumber: controlAccount,
+        credit: totalAmount,
+        description: `${invoice.customer.name} - Credit Note ${invoice.invoiceNumber}`
+      });
+    } else {
+      // Regular invoice: debit customer account
+      lines.push({
+        accountNumber: controlAccount,
+        debit: totalAmount,
+        description: `${invoice.customer.name} - Invoice ${invoice.invoiceNumber}`
+      });
+    }
+    
+    return lines;
+  }
+  
+  /**
+   * Build VAT lines
+   */
+  private buildVATLines(
+    invoice: IInvoice,
+    rules: IBookingRules,
+    direction: 'input' | 'output',
+    reverseDirection: boolean
+  ): IJournalEntryLine[] {
+    const lines: IJournalEntryLine[] = [];
+    const taxScenario = invoice.taxScenario || 'domestic_taxed';
+    
+    // Handle reverse charge specially
+    if (taxScenario === 'reverse_charge') {
+      return this.buildReverseChargeVATLines(invoice, rules);
+    }
+    
+    // Standard VAT booking
+    for (const vatBreak of invoice.vatBreakdown) {
+      if (vatBreak.taxAmount === 0) continue;
+      
+      const vatAccount = this.mapper.getVATAccount(
+        vatBreak.vatCategory,
+        direction,
+        taxScenario
+      );
+      
+      const amount = Math.abs(vatBreak.taxAmount);
+      const description = `VAT ${vatBreak.vatCategory.rate}%`;
+      
+      if (direction === 'input') {
+        // Input VAT (Vorsteuer)
+        if (reverseDirection) {
+          lines.push({ accountNumber: vatAccount, credit: amount, description });
+        } else {
+          lines.push({ accountNumber: vatAccount, debit: amount, description });
+        }
+      } else {
+        // Output VAT (Umsatzsteuer)
+        if (reverseDirection) {
+          lines.push({ accountNumber: vatAccount, debit: amount, description });
+        } else {
+          lines.push({ accountNumber: vatAccount, credit: amount, description });
+        }
+      }
+    }
+    
+    return lines;
+  }
+  
+  /**
+   * Calculate VAT amount from taxable amount and rate
+   */
+  private calculateVAT(taxableAmount: number, rate: number): number {
+    return Math.round(taxableAmount * rate / 100 * 100) / 100; // Round to 2 decimals
+  }
+  
+  /**
+   * Calculate effective VAT rate for the invoice (weighted average)
+   */
+  private calculateEffectiveVATRate(invoice: IInvoice): number {
+    const totalTaxable = invoice.vatBreakdown.reduce((sum, vb) => sum + vb.taxableAmount, 0);
+    if (totalTaxable === 0) {
+      return 19; // Default to standard German VAT rate
+    }
+    
+    // Calculate weighted average VAT rate
+    const weightedRate = invoice.vatBreakdown.reduce((sum, vb) => {
+      return sum + (vb.vatCategory.rate * vb.taxableAmount);
+    }, 0);
+    
+    return Math.round(weightedRate / totalTaxable * 100) / 100;
+  }
+  
+  /**
+   * Build reverse charge VAT lines (§13b UStG)
+   */
+  private buildReverseChargeVATLines(
+    invoice: IInvoice,
+    rules: IBookingRules
+  ): IJournalEntryLine[] {
+    const lines: IJournalEntryLine[] = [];
+    
+    // For reverse charge, we book both input and output VAT
+    for (const vatBreak of invoice.vatBreakdown) {
+      // For reverse charge, calculate VAT if not provided
+      const amount = vatBreak.taxAmount > 0 
+        ? Math.abs(vatBreak.taxAmount)
+        : this.calculateVAT(Math.abs(vatBreak.taxableAmount), vatBreak.vatCategory.rate);
+      
+      // Input VAT (deductible)
+      const inputVATAccount = this.mapper.getVATAccount(
+        vatBreak.vatCategory,
+        'input',
+        'reverse_charge'
+      );
+      
+      // Output VAT (payable)
+      const outputVATAccount = this.mapper.getVATAccount(
+        vatBreak.vatCategory,
+        'output',
+        'reverse_charge'
+      );
+      
+      lines.push(
+        {
+          accountNumber: inputVATAccount,
+          debit: amount,
+          description: `Reverse charge input VAT ${vatBreak.vatCategory.rate}%`
+        },
+        {
+          accountNumber: outputVATAccount,
+          credit: amount,
+          description: `Reverse charge output VAT ${vatBreak.vatCategory.rate}%`
+        }
+      );
+    }
+    
+    return lines;
+  }
+  
+  /**
+   * Group invoice lines by account
+   */
+  private groupLinesByAccount(
+    invoice: IInvoice,
+    rules: IBookingRules
+  ): Record<string, IInvoiceLine[]> {
+    const groups: Record<string, IInvoiceLine[]> = {};
+    
+    for (const line of invoice.lines) {
+      const account = this.mapper.mapInvoiceLineToAccount(line, invoice, rules);
+      
+      if (!groups[account]) {
+        groups[account] = [];
+      }
+      groups[account].push(line);
+    }
+    
+    return groups;
+  }
+  
+  /**
+   * Book payment for an invoice
+   */
+  public async bookPayment(
+    invoice: IInvoice,
+    payment: IPaymentInfo,
+    rules: IBookingRules
+  ): Promise<IBookingResult> {
+    try {
+      const lines: IJournalEntryLine[] = [];
+      const isInbound = invoice.direction === 'inbound';
+      const controlAccount = this.mapper.getControlAccount(invoice, rules);
+      
+      // Check for skonto
+      const skontoAmount = payment.skontoTaken || 0;
+      const paymentAmount = payment.amount;
+      const fullAmount = paymentAmount + skontoAmount;
+      
+      if (isInbound) {
+        // Payment for vendor invoice
+        lines.push(
+          {
+            accountNumber: controlAccount,
+            debit: fullAmount,
+            description: `Payment to ${invoice.supplier.name}`
+          },
+          {
+            accountNumber: '1000', // Bank account (would be configurable)
+            credit: paymentAmount,
+            description: `Bank payment ${payment.endToEndId || payment.paymentId}`
+          }
+        );
+        
+        // Book skonto if taken
+        if (skontoAmount > 0) {
+          const skontoAccounts = this.mapper.getSkontoAccounts(invoice);
+          lines.push({
+            accountNumber: skontoAccounts.skontoAccount,
+            credit: skontoAmount,
+            description: `Skonto received`
+          });
+          
+          // VAT correction for skonto
+          if (rules.skontoMethod === 'gross') {
+            const effectiveRate = this.calculateEffectiveVATRate(invoice);
+            const vatCorrection = Math.round(skontoAmount * effectiveRate / (100 + effectiveRate) * 100) / 100;
+            lines.push(
+              {
+                accountNumber: skontoAccounts.vatCorrectionAccount,
+                credit: vatCorrection,
+                description: `Skonto VAT correction`
+              }
+            );
+          }
+        }
+      } else {
+        // Payment from customer
+        lines.push(
+          {
+            accountNumber: '1000', // Bank account
+            debit: paymentAmount,
+            description: `Payment from ${invoice.customer.name}`
+          },
+          {
+            accountNumber: controlAccount,
+            credit: fullAmount,
+            description: `Customer payment ${payment.endToEndId || payment.paymentId}`
+          }
+        );
+        
+        // Book skonto if granted
+        if (skontoAmount > 0) {
+          const skontoAccounts = this.mapper.getSkontoAccounts(invoice);
+          lines.push({
+            accountNumber: skontoAccounts.skontoAccount,
+            debit: skontoAmount,
+            description: `Skonto granted`
+          });
+          
+          // VAT correction for skonto
+          if (rules.skontoMethod === 'gross') {
+            const effectiveRate = this.calculateEffectiveVATRate(invoice);
+            const vatCorrection = Math.round(skontoAmount * effectiveRate / (100 + effectiveRate) * 100) / 100;
+            lines.push(
+              {
+                accountNumber: skontoAccounts.vatCorrectionAccount,
+                debit: vatCorrection,
+                description: `Skonto VAT correction`
+              }
+            );
+          }
+        }
+      }
+      
+      // Create journal entry for payment
+      const journalData: IJournalEntry = {
+        date: payment.paymentDate,
+        description: `Payment for invoice ${invoice.invoiceNumber}`,
+        reference: payment.endToEndId || payment.remittanceInfo || payment.paymentId,
+        lines,
+        skrType: this.skrType
+      };
+      
+      const journalEntry = new JournalEntry(journalData);
+      await journalEntry.validate();
+      await journalEntry.post();
+      
+      return {
+        success: true,
+        journalEntry,
+        confidence: 100
+      };
+    } catch (error) {
+      this.logger.log('error', `Failed to book payment: ${error}`);
+      return {
+        success: false,
+        confidence: 0,
+        errors: [`Payment booking failed: ${error.message}`]
+      };
+    }
+  }
+  
+  /**
+   * Validate invoice before booking
+   */
+  private validateInvoice(invoice: IInvoice): string[] {
+    const errors: string[] = [];
+    
+    // Check required fields
+    if (!invoice.invoiceNumber) {
+      errors.push('Invoice number is required');
+    }
+    
+    if (!invoice.issueDate) {
+      errors.push('Issue date is required');
+    }
+    
+    if (!invoice.supplier || !invoice.supplier.name) {
+      errors.push('Supplier information is required');
+    }
+    
+    if (!invoice.customer || !invoice.customer.name) {
+      errors.push('Customer information is required');
+    }
+    
+    if (invoice.lines.length === 0) {
+      errors.push('Invoice must have at least one line item');
+    }
+    
+    // Validate amounts
+    const calculatedNet = invoice.lines.reduce((sum, line) => sum + line.netAmount, 0);
+    const tolerance = 0.01;
+    
+    if (Math.abs(calculatedNet - invoice.lineNetAmount) > tolerance) {
+      errors.push(`Line net amount mismatch: calculated ${calculatedNet}, stated ${invoice.lineNetAmount}`);
+    }
+    
+    // Validate VAT
+    const calculatedVAT = invoice.vatBreakdown.reduce((sum, vb) => sum + vb.taxAmount, 0);
+    if (Math.abs(calculatedVAT - invoice.totalVATAmount) > tolerance) {
+      errors.push(`VAT amount mismatch: calculated ${calculatedVAT}, stated ${invoice.totalVATAmount}`);
+    }
+    
+    // Validate total
+    const calculatedTotal = invoice.taxExclusiveAmount + invoice.totalVATAmount;
+    if (Math.abs(calculatedTotal - invoice.taxInclusiveAmount) > tolerance) {
+      errors.push(`Total amount mismatch: calculated ${calculatedTotal}, stated ${invoice.taxInclusiveAmount}`);
+    }
+    
+    return errors;
+  }
+  
+  /**
+   * Generate warnings for the booking
+   */
+  private generateWarnings(invoice: IInvoice, rules: IBookingRules): string[] {
+    const warnings: string[] = [];
+    
+    // Warn about default account usage
+    const hasDefaultAccounts = invoice.lines.some(line => 
+      !line.accountNumber && !line.productCode
+    );
+    if (hasDefaultAccounts) {
+      warnings.push('Some lines are using default expense/revenue accounts');
+    }
+    
+    // Warn about mixed VAT rates
+    if (invoice.vatBreakdown.length > 1) {
+      warnings.push('Invoice contains mixed VAT rates');
+    }
+    
+    // Warn about reverse charge
+    if (invoice.taxScenario === 'reverse_charge') {
+      warnings.push('Reverse charge procedure applied - verify VAT treatment');
+    }
+    
+    // Warn about credit notes
+    if (invoice.invoiceTypeCode === '381') {
+      warnings.push('This is a credit note - amounts will be reversed');
+    }
+    
+    // Warn about foreign currency
+    if (invoice.currencyCode !== 'EUR') {
+      warnings.push(`Invoice is in foreign currency: ${invoice.currencyCode}`);
+    }
+    
+    return warnings;
+  }
+  
+  /**
+   * Build description for journal entry
+   */
+  private buildDescription(invoice: IInvoice): string {
+    const type = invoice.invoiceTypeCode === '381' ? 'Credit Note' : 'Invoice';
+    const party = invoice.direction === 'inbound' 
+      ? invoice.supplier.name 
+      : invoice.customer.name;
+    
+    return `${type} ${invoice.invoiceNumber} - ${party}`;
+  }
+  
+  /**
+   * Get account description for a group of lines
+   */
+  private getAccountDescription(accountNumber: string, lines: IInvoiceLine[]): string {
+    if (lines.length === 1) {
+      return lines[0].description;
+    }
+    
+    return `${this.mapper.getAccountDescription(accountNumber)} (${lines.length} items)`;
+  }
+  
+  /**
+   * Get used expense accounts
+   */
+  private getUsedExpenseAccounts(invoice: IInvoice, rules: IBookingRules): string[] {
+    if (invoice.direction !== 'inbound') return [];
+    
+    const accounts = new Set<string>();
+    for (const line of invoice.lines) {
+      const account = this.mapper.mapInvoiceLineToAccount(line, invoice, rules);
+      accounts.add(account);
+    }
+    return Array.from(accounts);
+  }
+  
+  /**
+   * Get used revenue accounts
+   */
+  private getUsedRevenueAccounts(invoice: IInvoice, rules: IBookingRules): string[] {
+    if (invoice.direction !== 'outbound') return [];
+    
+    const accounts = new Set<string>();
+    for (const line of invoice.lines) {
+      const account = this.mapper.mapInvoiceLineToAccount(line, invoice, rules);
+      accounts.add(account);
+    }
+    return Array.from(accounts);
+  }
+  
+  /**
+   * Get used VAT accounts
+   */
+  private getUsedVATAccounts(invoice: IInvoice, rules: IBookingRules): string[] {
+    const accounts = new Set<string>();
+    const direction = invoice.direction === 'inbound' ? 'input' : 'output';
+    const taxScenario = invoice.taxScenario || 'domestic_taxed';
+    
+    for (const vatBreak of invoice.vatBreakdown) {
+      const account = this.mapper.getVATAccount(
+        vatBreak.vatCategory,
+        direction,
+        taxScenario
+      );
+      accounts.add(account);
+    }
+    
+    // Add reverse charge accounts if applicable
+    if (taxScenario === 'reverse_charge') {
+      for (const vatBreak of invoice.vatBreakdown) {
+        const inputAccount = this.mapper.getVATAccount(
+          vatBreak.vatCategory,
+          'input',
+          'reverse_charge'
+        );
+        const outputAccount = this.mapper.getVATAccount(
+          vatBreak.vatCategory,
+          'output',
+          'reverse_charge'
+        );
+        accounts.add(inputAccount);
+        accounts.add(outputAccount);
+      }
+    }
+    
+    return Array.from(accounts);
+  }
+}