How ProcureFlow Reduced Invoice Processing Costs by 78% and Saved $4.2M with B2B Invoice Currency Conversion API

// B2B Invoice Currency Conversion Processing System
async function processMultiCurrencyInvoice(invoiceData, supplierProfile) {
  try {
    // Step 1: Validate invoice currency and format
    const invoiceCurrency = invoiceData.currency || supplierProfile.preferredCurrency;
    const baseCurrency = 'USD'; // Our company's base currency

    if (!isValidCurrency(invoiceCurrency)) {
      throw new Error(`Invalid currency code: ${invoiceCurrency}`);
    }

    // Step 2: Get real-time exchange rate with audit trail
    const rateResponse = await fetch(
      `https://api.currency-exchange.app/v1-convert-currency?from=${invoiceCurrency}&to=${baseCurrency}&amount=${invoiceData.totalAmount}`,
      {
        method: 'GET',
        headers: {
          'accept': 'application/json',
          'x-api-key': process.env.CURRENCY_API_KEY,
          'x-request-id': generateRequestId(),
          'x-client-version': 'procureflow-v2.1.0'
        }
      }
    );

    const rateData = await rateResponse.json();

    // Step 3: Create rate lock for payment processing
    const rateLock = await createExchangeRateLock({
      invoiceId: invoiceData.invoiceNumber,
      supplierId: supplierProfile.id,
      fromCurrency: invoiceCurrency,
      toCurrency: baseCurrency,
      rate: rateData.exchangeRate,
      originalAmount: invoiceData.totalAmount,
      convertedAmount: rateData.convertedAmount,
      rateTimestamp: rateData.rateTime,
      validUntil: new Date(Date.now() + 30 * 24 * 60 * 60 * 1000), // 30 days
      auditTrail: {
        processedBy: 'automated-system',
        processedAt: new Date().toISOString(),
        sourceSystem: 'procureflow-ap-v2',
        complianceChecked: true
      }
    });

    // Step 4: Process invoice with currency details
    const processedInvoice = {
      invoiceId: invoiceData.invoiceNumber,
      supplier: {
        id: supplierProfile.id,
        name: supplierProfile.companyName,
        taxId: supplierProfile.taxId,
        registeredCountry: supplierProfile.country,
        preferredCurrency: invoiceCurrency
      },
      originalInvoice: {
        currency: invoiceCurrency,
        totalAmount: invoiceData.totalAmount,
        issueDate: invoiceData.issueDate,
        dueDate: invoiceData.dueDate,
        lineItems: invoiceData.lineItems.map(item => ({
          description: item.description,
          quantity: item.quantity,
          unitPrice: {
            amount: item.unitPrice,
            currency: invoiceCurrency
          },
          total: {
            amount: item.quantity * item.unitPrice,
            currency: invoiceCurrency
          }
        }))
      },
      currencyConversion: {
        exchangeRate: rateData.exchangeRate,
        rateTimestamp: rateData.rateTime,
        rateSource: 'currency-exchange.app',
        convertedAmount: rateData.convertedAmount,
        baseCurrency: baseCurrency,
        rateLockId: rateLock.id,
        rateLockExpiry: rateLock.validUntil
      },
      taxAndCompliance: {
        supplierTaxRegion: supplierProfile.taxRegion,
        applicableTaxes: calculateInternationalTaxes(invoiceData, supplierProfile, rateData.exchangeRate),
        vatCompliance: supplierProfile.country in euCountries,
        taxWithholding: calculateTaxWithholding(supplierProfile.country, invoiceData.totalAmount),
        complianceChecks: {
          currencyFormatValid: true,
          taxIdValid: await validateTaxId(supplierProfile.taxId, supplierProfile.country),
          sanctionsChecked: await checkSanctionsList(supplierProfile),
          paymentRestrictions: getPaymentRestrictions(supplierProfile.country)
        }
      },
      paymentProcessing: {
        scheduledPaymentDate: calculateOptimalPaymentDate(invoiceData.dueDate, supplierProfile.country),
        paymentMethod: supplierProfile.preferredPaymentMethod,
        paymentCurrency: baseCurrency,
        conversionFees: calculateConversionFees(rateData.convertedAmount, invoiceCurrency, baseCurrency),
        estimatedDeliveryTime: estimatePaymentDelivery(supplierProfile.country, supplierProfile.preferredPaymentMethod)
      },
      auditTrail: {
        processedAt: new Date().toISOString(),
        processedBy: 'automated-currency-converter-v2.1.0',
        originalInvoiceHash: generateDocumentHash(invoiceData),
        conversionAuditId: rateLock.id,
        complianceSignedOff: true
      }
    };

    // Step 5: Update supplier portal and notifications
    await updateSupplierPortal(supplierProfile.id, {
      invoiceProcessed: processedInvoice,
      paymentScheduled: processedInvoice.paymentProcessing,
      conversionDetails: {
        originalAmount: formatCurrency(invoiceData.totalAmount, invoiceCurrency),
        convertedAmount: formatCurrency(rateData.convertedAmount, baseCurrency),
        exchangeRate: rateData.exchangeRate,
        conversionDate: rateData.rateTime
      }
    });

    // Step 6: Send notifications to relevant stakeholders
    await sendStakeholderNotifications({
      supplier: {
        email: supplierProfile.billingEmail,
        template: 'invoice_processed_multi_currency',
        data: processedInvoice
      },
      internal: {
        procurementManager: supplierProfile.procurementManager,
        apTeam: 'ap-team@procureflow.com',
        template: 'invoice_currency_conversion_complete',
        data: processedInvoice
      }
    });

    return processedInvoice;

  } catch (error) {
    console.error('Invoice processing error:', error);

    // Escalate to manual processing for critical errors
    await escalateForManualReview({
      invoiceId: invoiceData.invoiceNumber,
      error: error.message,
      severity: 'high',
      escalationTeam: 'ap-escalations@procureflow.com'
    });

    throw new Error(`Failed to process invoice ${invoiceData.invoiceNumber}: ${error.message}`);
  }
}

// Bulk currency conversion for high-volume processing
async function processBulkCurrencyConversions(invoices) {
  const batchSize = 50;
  const results = [];

  for (let i = 0; i < invoices.length; i += batchSize) {
    const batch = invoices.slice(i, i + batchSize);

    // Process batch concurrently with rate limiting
    const batchPromises = batch.map(invoice =>
      processWithRetry(() => processMultiCurrencyInvoice(invoice.data, invoice.supplier), 3)
    );

    const batchResults = await Promise.allSettled(batchPromises);
    results.push(...batchResults);

    // Rate limiting to avoid API quota issues
    await new Promise(resolve => setTimeout(resolve, 100));
  }

  return {
    totalProcessed: results.length,
    successful: results.filter(r => r.status === 'fulfilled').length,
    failed: results.filter(r => r.status === 'rejected').length,
    details: results.map((result, index) => ({
      invoiceId: invoices[index].data.invoiceNumber,
      status: result.status,
      result: result.status === 'fulfilled' ? result.value : result.reason.message
    }))
  };
}

// Supplier currency preference management
async function updateSupplierCurrencyPreferences(supplierId, preferences) {
  const supplier = await getSupplierProfile(supplierId);

  const updatedPreferences = {
    preferredInvoiceCurrency: preferences.invoiceCurrency,
    acceptedPaymentCurrencies: preferences.paymentCurrencies,
    currencyConversionTiming: preferences.conversionTiming, // 'invoice-date' or 'payment-date'
    rateLockPreference: preferences.rateLockDays || 30,
    notificationPreferences: {
      conversionNotifications: preferences.conversionNotifications,
      rateChangeAlerts: preferences.rateChangeAlerts,
      paymentReminders: preferences.paymentReminders
    }
  };

  // Validate currency preferences
  for (const currency of [preferences.invoiceCurrency, ...preferences.paymentCurrencies]) {
    if (!isValidCurrency(currency)) {
      throw new Error(`Invalid currency: ${currency}`);
    }
  }

  await updateSupplierProfile(supplierId, {
    currencyPreferences: updatedPreferences,
    updatedAt: new Date().toISOString(),
    updatedBy: 'supplier-portal-v2.1.0'
  });

  return updatedPreferences;
}

// Automated Payment Processing with Currency Optimization
async function optimizePaymentProcessing(invoice, supplierProfile) {
  const paymentOptimization = {
    scheduling: await calculateOptimalPaymentSchedule(invoice, supplierProfile),
    currencyRouting: await determineBestCurrencyRoute(invoice, supplierProfile),
    costOptimization: await minimizePaymentCosts(invoice, supplierProfile),
    compliance: await ensurePaymentCompliance(invoice, supplierProfile)
  };

  return paymentOptimization;
}

// Dynamic payment scheduling based on supplier location and banking hours
async function calculateOptimalPaymentSchedule(invoice, supplier) {
  const supplierTimezone = getTimezone(supplier.country);
  const bankingHours = getBankingHours(supplier.country);
  const processingDelays = getPaymentProcessingTimes(supplier.preferredPaymentMethod, supplier.country);

  // Calculate optimal payment date to maximize supplier satisfaction and minimize costs
  const optimalDate = calculateOptimalPaymentDate(
    invoice.dueDate,
    bankingHours,
    processingDelays,
    supplier.paymentTerms
  );

  return {
    scheduledPaymentDate: optimalDate,
    supplierTimezone: supplierTimezone,
    expectedDeliveryDate: addBusinessDays(optimalDate, processingDelays.delivery),
    processingTimeDays: processingDelays.total,
    costOptimization: {
      earlyPaymentDiscount: calculateEarlyPaymentDiscount(invoice, optimalDate),
      processingFees: calculateProcessingFees(invoice.convertedAmount, supplier.preferredPaymentMethod),
      currencyConversionCosts: calculateConversionCosts(invoice.currencyConversion)
    }
  };
}

// Intelligent currency routing to minimize conversion costs
async function determineBestCurrencyRoute(invoice, supplier) {
  const possibleRoutes = [
    {
      fromCurrency: 'USD',
      toCurrency: supplier.preferredCurrency,
      method: 'direct-conversion',
      estimatedCost: calculateConversionCost(invoice.convertedAmount, 'USD', supplier.preferredCurrency)
    },
    {
      fromCurrency: 'USD',
      toCurrency: 'EUR',
      toCurrencyFinal: supplier.preferredCurrency,
      method: 'via-euro',
      estimatedCost: calculateViaCurrencyCost(invoice.convertedAmount, 'USD', 'EUR', supplier.preferredCurrency)
    },
    {
      fromCurrency: 'USD',
      toCurrency: supplier.localCurrency,
      method: 'local-currency',
      estimatedCost: calculateLocalCurrencyCost(invoice.convertedAmount, supplier.country)
    }
  ];

  // Select the most cost-effective route
  const optimalRoute = possibleRoutes.reduce((best, current) =>
    current.estimatedCost < best.estimatedCost ? current : best
  );

  return optimalRoute;
}

// Real-time payment cost optimization
async function minimizePaymentCosts(invoice, supplier) {
  const costAnalysis = {
    currencyConversion: await analyzeConversionCosts(invoice, supplier),
    paymentMethod: await analyzePaymentMethodCosts(invoice, supplier),
    timing: await analyzeTimingCosts(invoice, supplier),
    bulkDiscounts: await checkBulkPaymentDiscounts(supplier)
  };

  // Apply cost optimization strategies
  const optimizations = [];

  if (costAnalysis.currencyConversion.savings > 100) {
    optimizations.push({
      type: 'currency-conversion',
      description: 'Optimal currency routing',
      savings: costAnalysis.currencyConversion.savings,
      implementation: costAnalysis.currencyConversion.recommendation
    });
  }

  if (costAnalysis.timing.earlyPaymentDiscount > 50) {
    optimizations.push({
      type: 'early-payment',
      description: 'Early payment discount capture',
      savings: costAnalysis.timing.earlyPaymentDiscount,
      implementation: 'Schedule payment ' + costAnalysis.timing.optimalDaysEarly + ' days early'
    });
  }

  return {
    totalSavings: optimizations.reduce((sum, opt) => sum + opt.savings, 0),
    optimizations: optimizations,
    recommendedActions: optimizations.map(opt => opt.implementation)
  };
}