🤖 Milestone 2: AI-Powered Data Extraction

// Example: What happens during extraction
const extractedData = {
  // EXTRACTED from shipping document
  vendor: "Maersk Shipping",
  totalAmount: 25000,
  weight: 2500, // Found in document: "2,500 kg"
  weightUnit: "kg", // Found in document
  origin: "Shanghai", // Found in document
  destination: "Rotterdam", // Found in document
  transportMode: "maritime", // Found in document
  
  // NOT in document - will be CALCULATED
  distance: null, // Calculate via routing API
  emissions: null, // Calculate via emissions API
  emissionFactor: null // Get from EPA/Ecoinvent
};

// Then call APIs with extracted data
const emissions = await calculateEmissions(extractedData);

// Document-type aware extraction prompts
const extractionPrompts = {

  shipping: `
    Extract ALL of the following fields:
    
    FINANCIAL: vendor, amount, currency, date
    
    OPERATIONAL (for carbon calculation):
    - weight and unit (REQUIRED)
    - origin city/port (REQUIRED)
    - destination city/port (REQUIRED)
    - transport_mode (sea/air/road/rail)
    - container_type (if mentioned)
    - vessel/flight/truck number
    - distance (if stated)
    
    Return NULL for fields not found.`,

  utility: `
    Extract ALL of the following fields:
    
    FINANCIAL: vendor, amount, currency, billing_period
    
    OPERATIONAL (for carbon calculation):
    - electricity_kwh (REQUIRED if electric bill)
    - gas_therms or gas_cubic_meters (if gas bill)
    - water_gallons or water_liters (if water bill)
    - peak_usage_kwh (if mentioned)
    - off_peak_usage_kwh (if mentioned)
    - renewable_percentage (if mentioned)
    - service_address (for grid factors)
    
    Return NULL for fields not found.`,

  manufacturing: `
    Extract ALL of the following fields:
    
    FINANCIAL: vendor, amount, currency, date
    
    OPERATIONAL (for carbon calculation):
    - product_units (quantity produced)
    - materials_list (array of materials)
    - material_quantities (with units)
    - process_type (machining/molding/etc)
    - machine_hours (if mentioned)
    - energy_consumed_kwh (if mentioned)
    - waste_type and waste_quantity
    - scrap_percentage (if mentioned)
    
    Return NULL for fields not found.`,

  default: `
    Extract standard financial fields:
    vendor, amount, currency, date, line_items, tax, payment_method
    
    Also check for ANY operational data:
    quantities, weights, distances, energy usage, materials`
};

// Use in n8n-nodes-langchain
const documentType = detectDocumentType(extractedText);
const prompt = extractionPrompts[documentType] || extractionPrompts.default;