Extract Invoice Data

Extract all relevant data from the following invoice into structured JSON format.

Invoice:
{{invoice_text}}

Return the data in this exact JSON structure:

{
  "invoice_number": "[Invoice/Reference number]",
  "invoice_type": "[invoice/credit_note/proforma/quote]",
  "invoice_date": "[YYYY-MM-DD]",
  "due_date": "[YYYY-MM-DD or null]",
  "vendor": {
    "name": "[Company name]",
    "address": "[Full address]",
    "tax_id": "[VAT/Tax ID or null]",
    "email": "[Email or null]",
    "phone": "[Phone or null]"
  },
  "bill_to": {
    "name": "[Customer/Company name]",
    "address": "[Full address or null]",
    "contact": "[Contact name or null]"
  },
  "line_items": [
    {
      "description": "[Item description]",
      "quantity": [number],
      "unit_price": [number],
      "amount": [number],
      "tax_rate": [percentage as number or null]
    }
  ],
  "subtotal": [number],
  "tax_amount": [number or null],
  "discount": [number or null],
  "total": [number],
  "currency": "[3-letter currency code, e.g., USD, EUR, GBP]",
  "payment_terms": "[e.g., Net 30, Due on receipt, or null]",
  "payment_methods": ["[Method 1]", "[Method 2]"],
  "bank_details": {
    "bank_name": "[Bank name or null]",
    "account_number": "[Last 4 digits only or null]",
    "routing_number": "[Routing/Sort code or null]"
  },
  "notes": "[Any additional notes or null]",
  "po_number": "[Purchase order reference or null]"
}

Rules:
- All monetary amounts should be numbers without currency symbols
- Dates must be in YYYY-MM-DD format
- Use null for missing fields, never omit them
- For bank details, only include last 4 digits of account numbers for security
- Ensure line_items amounts match quantity × unit_price
- Verify subtotal + tax - discount = total (flag discrepancies in notes)
- Identify if this is a credit note (negative amounts) or proforma/quote (not yet due)
- Return valid JSON only