From 10b437009d18c2c828ce266138babab80fae6c83 Mon Sep 17 00:00:00 2001
From: Omar Bahareth <omar@omar.engineer>
Date: Wed, 29 Nov 2023 15:07:46 +0300
Subject: [PATCH] Support Billing References for Credit & Debit Notes

---
 lib/zatca/ubl/invoice.rb | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/lib/zatca/ubl/invoice.rb b/lib/zatca/ubl/invoice.rb
index f84d342..49f61b7 100644
--- a/lib/zatca/ubl/invoice.rb
+++ b/lib/zatca/ubl/invoice.rb
@@ -24,6 +24,7 @@ class ZATCA::UBL::Invoice < ZATCA::UBL::BaseComponent
   option :uuid, type: Dry::Types["coercible.string"]
   option :note, type: Dry::Types["coercible.string"].optional, optional: true, default: proc {}
   option :instruction_note, type: Dry::Types["coercible.string"].optional, optional: true, default: proc {}
+  option :billing_reference, type: Dry::Types["coercible.string"].optional, optional: true, default: proc {}
   option :note_language_id, type: Dry::Types["coercible.string"].optional, optional: true, default: proc {}
   option :issue_date, type: Dry::Types["coercible.string"]
   option :issue_time, type: Dry::Types["coercible.string"]
@@ -110,6 +111,9 @@ def elements
       ZATCA::UBL::BaseComponent.new(name: "cbc:DocumentCurrencyCode", value: currency_code),
       ZATCA::UBL::BaseComponent.new(name: "cbc:TaxCurrencyCode", value: currency_code),
 
+      # Billing reference for debit and credit notes
+      billing_reference_element,
+
       # Line Count Numeric (Standard Invoice only)
       line_count_numeric_element,
 
@@ -407,6 +411,16 @@ def instruction_note_element
     ZATCA::UBL::BaseComponent.new(name: "cbc:InstructionNote", value: instruction_note)
   end
 
+  def billing_reference_element
+    return nil if billing_reference.blank?
+
+    ZATCA::UBL::BaseComponent.new(name: "cac:BillingReference", elements: [
+      ZATCA::UBL::BaseComponent.new(name: "cac:InvoiceDocumentReference", elements: [
+        ZATCA::UBL::BaseComponent.new(name: "cbc:ID", value: billing_reference)
+      ])
+    ])
+  end
+
   def add_sequential_ids
     add_sequential_ids_to_allowance_charges
     add_sequential_ids_to_invoice_lines