[FIX] l10n_sa_edi: add support for global discounts

        This commit does two things:

        1) Global Discounts: When creating an invoice with a negative line, such as a Tax Invoice with global discount, we process the line as a document level allowance as required by ZATCA, and remove it from the lines sent in the UBL. This allows us to provide support for global discounts, such as those applied by promotion programs

        2) Add support for down-payment document type in _l10n_sa_get_invoice_type method: 386

closes odoo/odoo#153379

Signed-off-by: Josse Colpaert <jco@odoo.com>

addons/l10n_sa_edi/models/account_edi_xml_ubl_21_zatca.py

@@ -161,7 +161,11 @@ class AccountEdiXmlUBL21Zatca(models.AbstractModel):
                 - 381: Credit Note
                 - 388: Invoice
         """
-        return 383 if invoice.debit_origin_id else 381 if invoice.move_type == 'out_refund' else 388
+        return (
+            383 if invoice.debit_origin_id else
+            381 if invoice.move_type == 'out_refund' else
+            386 if invoice._is_downpayment() else 388
+        )
 
     def _l10n_sa_get_billing_reference_vals(self, invoice):
         """ Get the billing reference vals required to render the BillingReference for credit/debit notes """
@@ -215,30 +219,34 @@ class AccountEdiXmlUBL21Zatca(models.AbstractModel):
         # We use base_amount_currency + tax_amount_currency instead of amount_total because we do not want to include
         # withholding tax amounts in our calculations
         total_amount = abs(vals['taxes_vals']['base_amount_currency'] + vals['taxes_vals']['tax_amount_currency'])
-
+        line_extension_amount = vals['vals']['legal_monetary_total_vals']['line_extension_amount']
         tax_inclusive_amount = total_amount
         tax_exclusive_amount = abs(vals['taxes_vals']['base_amount_currency'])
         prepaid_amount = 0
         payable_amount = total_amount
-
         # - When we calculate the tax values, we filter out taxes and invoice lines linked to downpayments.
         #   As such, when we calculate the TaxInclusiveAmount, it already accounts for the tax amount of the downpayment
         #   Same goes for the TaxExclusiveAmount, and we do not need to add the Tax amount of the downpayment
         # - The payable amount does not account for the tax amount of the downpayment, so we add it
         downpayment_vals = self._l10n_sa_get_prepaid_amount(invoice, vals)
-
+        allowance_charge_vals = vals['vals']['allowance_charge_vals']
+        allowance_total_amount = sum(a['amount'] for a in allowance_charge_vals if a['charge_indicator'] == 'false')
         if downpayment_vals:
-            # Makes no sense, but according to ZATCA, if there is a downpayment, the TotalInclusiveAmount
-            # should include the total amount of the invoice (including downpayment amount) PLUS the downpayment
-            # total amount, AGAIN.
-            prepaid_amount = tax_inclusive_amount + downpayment_vals['total_amount']
-            payable_amount = - downpayment_vals['total_amount']
-
+            # - BR-KSA-80: To calculate prepaid, we need to sum up the amounts of standard lines (neither a down-payments, nor a discount)
+            #   then we add the total amount of the down-payment.
+            # - BR-CO-16: To calculate payable amount, we substract the calculated prepaid amount from the total tax inclusive amount of the invoice
+            regular_line_vals = invoice._prepare_edi_tax_details(
+                filter_invl_to_apply=lambda line: (line.price_subtotal > 0 and not line._get_downpayment_lines())
+            )
+            prepaid_amount = abs(regular_line_vals['base_amount_currency'] + regular_line_vals['tax_amount_currency']) + downpayment_vals['total_amount']
+            payable_amount = tax_inclusive_amount - prepaid_amount
         return {
+            'line_extension_amount': line_extension_amount - allowance_total_amount,
             'tax_inclusive_amount': tax_inclusive_amount,
             'tax_exclusive_amount': tax_exclusive_amount,
             'prepaid_amount': prepaid_amount,
-            'payable_amount': payable_amount
+            'payable_amount': payable_amount,
+            'allowance_total_amount': allowance_total_amount
         }
 
     def _get_tax_category_list(self, invoice, taxes):
@@ -246,6 +254,31 @@ class AccountEdiXmlUBL21Zatca(models.AbstractModel):
         non_retention_taxes = taxes.filtered(lambda t: not t.l10n_sa_is_retention)
         return super()._get_tax_category_list(invoice, non_retention_taxes)
 
+    def _get_document_allowance_charge_vals_list(self, invoice):
+        """
+        Charge Reasons & Codes (As per ZATCA):
+        https://unece.org/fileadmin/DAM/trade/untdid/d16b/tred/tred5189.htm
+        As far as ZATCA is concerned, we calculate Allowance/Charge vals for global discounts as
+        a document level allowance, and we do not include any other charges or allowances
+        """
+        res = super()._get_document_allowance_charge_vals_list(invoice)
+        for line in invoice.invoice_line_ids.filtered(lambda l: l._is_global_discount_line()):
+            taxes = line.tax_ids.flatten_taxes_hierarchy().filtered(lambda t: t.amount_type != 'fixed')
+            res.append({
+                'charge_indicator': 'false',
+                'allowance_charge_reason_code': "95",
+                'allowance_charge_reason': "Discount",
+                'amount': abs(line.price_subtotal),
+                'currency_dp': 2,
+                'currency_name': invoice.currency_id.name,
+                'tax_category_vals': [{
+                    'id': tax['id'],
+                    'percent': tax['percent'],
+                    'tax_scheme_id': 'VAT',
+                } for tax in self._get_tax_category_list(line.move_id, taxes)],
+            })
+        return res
+
     def _export_invoice_vals(self, invoice):
         """ Override to include/update values specific to ZATCA's UBL 2.1 specs """
         vals = super()._export_invoice_vals(invoice)
@@ -274,9 +307,21 @@ class AccountEdiXmlUBL21Zatca(models.AbstractModel):
         })
 
         vals['vals']['legal_monetary_total_vals'].update(self._l10n_sa_get_monetary_vals(invoice, vals))
+        self._l10n_sa_postprocess_line_vals(vals)
 
         return vals
 
+    def _l10n_sa_postprocess_line_vals(self, vals):
+        """
+            Postprocess vals to remove negative line amounts, as those will be used to compute
+            document level allowances (global discounts)
+        """
+        final_line_vals = []
+        for line_vals in vals['vals']['invoice_line_vals']:
+            if line_vals['price_vals']['price_amount'] >= 0:
+                final_line_vals.append(line_vals)
+        vals['vals']['invoice_line_vals'] = final_line_vals
+
     def _l10n_sa_get_additional_tax_total_vals(self, invoice, vals):
         """
             For ZATCA, an additional TaxTotal element needs to be included in the UBL file
@@ -327,6 +372,7 @@ class AccountEdiXmlUBL21Zatca(models.AbstractModel):
                 'tax_category_id': tax_category_vals['id'],
                 'tax_category_percent': tax_category_vals['percent'],
                 '_tax_category_vals_': tax_category_vals,
+                'tax_amount_type': tax.amount_type
             }
 
         if not line.move_id._is_downpayment() and line._get_downpayment_lines():

addons/l10n_sa_edi/models/account_move.py

@@ -205,6 +205,14 @@ class AccountMoveLine(models.Model):
     def _apply_retention_tax_filter(self, tax_values):
         return not tax_values['tax_id'].l10n_sa_is_retention
 
+    def _is_global_discount_line(self):
+        """
+            Any line that has a negative amount and is not linked to a down-payment is considered as a
+            global discount line. These can be created either manually, or through a promotions program.
+        """
+        self.ensure_one()
+        return not self._get_downpayment_lines() and self.price_subtotal < 0
+
     @api.depends('price_subtotal', 'price_total')
     def _compute_tax_amount(self):
         super()._compute_tax_amount()

addons/l10n_sa_edi/tests/compliance/simplified/credit.xml

@@ -184,6 +184,7 @@
     <cbc:LineExtensionAmount currencyID="SAR">795.00</cbc:LineExtensionAmount>
     <cbc:TaxExclusiveAmount currencyID="SAR">795.00</cbc:TaxExclusiveAmount>
     <cbc:TaxInclusiveAmount currencyID="SAR">914.25</cbc:TaxInclusiveAmount>
+    <cbc:AllowanceTotalAmount currencyID="SAR">0.00</cbc:AllowanceTotalAmount>
     <cbc:PrepaidAmount currencyID="SAR">0.00</cbc:PrepaidAmount>
     <cbc:PayableAmount currencyID="SAR">914.25</cbc:PayableAmount>
   </cac:LegalMonetaryTotal>

addons/l10n_sa_edi/tests/compliance/simplified/debit.xml

@@ -185,6 +185,7 @@
     <cbc:LineExtensionAmount currencyID="SAR">530.00</cbc:LineExtensionAmount>
     <cbc:TaxExclusiveAmount currencyID="SAR">530.00</cbc:TaxExclusiveAmount>
     <cbc:TaxInclusiveAmount currencyID="SAR">609.50</cbc:TaxInclusiveAmount>
+    <cbc:AllowanceTotalAmount currencyID="SAR">0.00</cbc:AllowanceTotalAmount>
     <cbc:PrepaidAmount currencyID="SAR">0.00</cbc:PrepaidAmount>
     <cbc:PayableAmount currencyID="SAR">609.50</cbc:PayableAmount>
   </cac:LegalMonetaryTotal>

addons/l10n_sa_edi/tests/compliance/simplified/invoice.xml

@@ -176,6 +176,7 @@
     <cbc:LineExtensionAmount currencyID="SAR">795.00</cbc:LineExtensionAmount>
     <cbc:TaxExclusiveAmount currencyID="SAR">795.00</cbc:TaxExclusiveAmount>
     <cbc:TaxInclusiveAmount currencyID="SAR">914.25</cbc:TaxInclusiveAmount>
+    <cbc:AllowanceTotalAmount currencyID="SAR">0.00</cbc:AllowanceTotalAmount>
     <cbc:PrepaidAmount currencyID="SAR">0.00</cbc:PrepaidAmount>
     <cbc:PayableAmount currencyID="SAR">914.25</cbc:PayableAmount>
   </cac:LegalMonetaryTotal>

addons/l10n_sa_edi/tests/compliance/standard/credit.xml

@@ -178,6 +178,7 @@
         <cbc:LineExtensionAmount currencyID="SAR">320.00</cbc:LineExtensionAmount>
         <cbc:TaxExclusiveAmount currencyID="SAR">320.00</cbc:TaxExclusiveAmount>
         <cbc:TaxInclusiveAmount currencyID="SAR">368.00</cbc:TaxInclusiveAmount>
+        <cbc:AllowanceTotalAmount currencyID="SAR">0.00</cbc:AllowanceTotalAmount>
         <cbc:PrepaidAmount currencyID="SAR">0.00</cbc:PrepaidAmount>
         <cbc:PayableAmount currencyID="SAR">368.00</cbc:PayableAmount>
     </cac:LegalMonetaryTotal>

addons/l10n_sa_edi/tests/compliance/standard/debit.xml

@@ -179,6 +179,7 @@
         <cbc:LineExtensionAmount currencyID="SAR">15.80</cbc:LineExtensionAmount>
         <cbc:TaxExclusiveAmount currencyID="SAR">15.80</cbc:TaxExclusiveAmount>
         <cbc:TaxInclusiveAmount currencyID="SAR">18.17</cbc:TaxInclusiveAmount>
+        <cbc:AllowanceTotalAmount currencyID="SAR">0.00</cbc:AllowanceTotalAmount>
         <cbc:PrepaidAmount currencyID="SAR">0.00</cbc:PrepaidAmount>
         <cbc:PayableAmount currencyID="SAR">18.17</cbc:PayableAmount>
     </cac:LegalMonetaryTotal>

addons/l10n_sa_edi/tests/compliance/standard/invoice.xml

@@ -169,6 +169,7 @@
         <cbc:LineExtensionAmount currencyID="SAR">320.00</cbc:LineExtensionAmount>
         <cbc:TaxExclusiveAmount currencyID="SAR">320.00</cbc:TaxExclusiveAmount>
         <cbc:TaxInclusiveAmount currencyID="SAR">368.00</cbc:TaxInclusiveAmount>
+        <cbc:AllowanceTotalAmount currencyID="SAR">0.00</cbc:AllowanceTotalAmount>
         <cbc:PrepaidAmount currencyID="SAR">0.00</cbc:PrepaidAmount>
         <cbc:PayableAmount currencyID="SAR">368.00</cbc:PayableAmount>
     </cac:LegalMonetaryTotal>