refactor(KSA VAT): QR Code as per ZATKA specification

erpnext/regional/saudi_arabia/utils.py

@@ -1,7 +1,10 @@
 import io
 import os
+from base64 import b64encode
 
 import frappe
+from frappe import _
+from frappe.utils.data import add_to_date, get_time, getdate
 from pyqrcode import create as qr_create
 
 from erpnext import get_region
@@ -28,24 +31,74 @@ def create_qr_code(doc, method):
 
 	for field in meta.get_image_fields():
 		if field.fieldname == 'qr_code':
-			from urllib.parse import urlencode
+			''' TLV conversion for
+			1. Seller's Name
+			2. VAT Number
+			3. Time Stamp
+			4. Invoice Amount
+			5. VAT Amount
+			'''
+			tlv_array = []
+			# Sellers Name
+
+			seller_name = frappe.db.get_value(
+				'Company',
+				doc.company,
+				'company_name_in_arabic')
+
+			if not seller_name:
+				frappe.throw(_('Arabic name missing for {} in the company document'.format(doc.company)))
+
+			tag = bytes([1]).hex()
+			length = bytes([len(seller_name.encode('utf-8'))]).hex()
+			value = seller_name.encode('utf-8').hex()
+			tlv_array.append(''.join([tag, length, value]))
+
+			# VAT Number
+			tax_id = frappe.db.get_value('Company', doc.company, 'tax_id')
+			if not tax_id:
+				frappe.throw(_('Tax ID missing for {} in the company document'.format(doc.company)))
+
+			tag = bytes([2]).hex()
+			length = bytes([len(tax_id)]).hex()
+			value = tax_id.encode('utf-8').hex()
+			tlv_array.append(''.join([tag, length, value]))
+
+			# Time Stamp
+			posting_date = getdate(doc.posting_date)
+			time = get_time(doc.posting_time)
+			seconds = time.hour * 60 * 60 + time.minute * 60 + time.second
+			time_stamp = add_to_date(posting_date, seconds=seconds)
+			time_stamp = time_stamp.strftime('%Y-%m-%dT%H:%M:%SZ')
+
+			tag = bytes([3]).hex()
+			length = bytes([len(time_stamp)]).hex()
+			value = time_stamp.encode('utf-8').hex()
+			tlv_array.append(''.join([tag, length, value]))
+
+			# Invoice Amount
+			invoice_amount = str(doc.total)
+			tag = bytes([4]).hex()
+			length = bytes([len(invoice_amount)]).hex()
+			value = invoice_amount.encode('utf-8').hex()
+			tlv_array.append(''.join([tag, length, value]))
+
+			# VAT Amount
+			vat_amount = str(doc.total_taxes_and_charges)
+
+			tag = bytes([5]).hex()
+			length = bytes([len(vat_amount)]).hex()
+			value = vat_amount.encode('utf-8').hex()
+			tlv_array.append(''.join([tag, length, value]))
+
+			# Joining bytes into one
+			tlv_buff = ''.join(tlv_array)
+
+			# base64 conversion for QR Code
+			base64_string = b64encode(bytes.fromhex(tlv_buff)).decode()
 
-			# Creating public url to print format
-			default_print_format = frappe.db.get_value('Property Setter', dict(property='default_print_format', doc_type=doc.doctype), "value")
-
-			# System Language
-			language = frappe.get_system_settings('language')
-
-			params = urlencode({
-				'format': default_print_format or 'Standard',
-				'_lang': language,
-				'key': doc.get_signature()
-			})
-
-			# creating qr code for the url
-			url = f"{ frappe.utils.get_url() }/{ doc.doctype }/{ doc.name }?{ params }"
 			qr_image = io.BytesIO()
-			url = qr_create(url, error='L')
+			url = qr_create(base64_string, error='L')
 			url.png(qr_image, scale=2, quiet_zone=1)
 
 			# making file