[FIX] l10n_it_reverse_charge: Find only one mapped tax

l10n_it_reverse_charge/models/account_invoice.py

@@ -2,6 +2,7 @@
 # Copyright 2017 Alex Comba - Agile Business Group
 # Copyright 2017 Lorenzo Battistini - Agile Business Group
 # Copyright 2017 Marco Calcagni - Dinamiche Aziendali srl
+# Copyright 2022 Simone Rubino - TAKOBI
 
 from odoo import api, fields, models
 from odoo.exceptions import Warning as UserError
@@ -348,17 +349,14 @@ def generate_self_invoice(self):
                     raise UserError(_(
                         "Invoice %s, line\n%s\nis RC but has not tax"
                     ) % ((self.reference or self.partner_id.display_name), line.name))
-                tax_ids = list()
-                for tax_mapping in rc_type.tax_ids:
-                    for line_tax_id in line_tax_ids:
-                        if tax_mapping.purchase_tax_id == line_tax_id:
-                            tax_ids.append(tax_mapping.sale_tax_id.id)
-                if not tax_ids:
-                    raise UserError(_("Tax code used is not a RC tax.\nCan't "
-                                      "find tax mapping"))
-                if line_tax_ids:
+                mapped_taxes = rc_type.map_tax(
+                    line_tax_ids,
+                    'purchase_tax_id',
+                    'sale_tax_id',
+                )
+                if line_tax_ids and mapped_taxes:
                     rc_invoice_line['invoice_line_tax_ids'] = [
-                        (6, False, tax_ids)]
+                        (6, False, mapped_taxes.ids)]
                 rc_invoice_line[
                     'account_id'] = rc_type.transitory_account_id.id
                 rc_invoice_lines.append([0, False, rc_invoice_line])
@@ -408,17 +406,15 @@ def generate_supplier_self_invoice(self):
         supplier_invoice.journal_id = rc_type.supplier_journal_id.id
         for inv_line in supplier_invoice.invoice_line_ids:
             line_tax_ids = inv_line.invoice_line_tax_ids
-            tax_ids = list()
-            for tax_mapping in rc_type.tax_ids:
-                for line_tax_id in line_tax_ids:
-                    if tax_mapping.original_purchase_tax_id == line_tax_id:
-                        tax_ids.append(tax_mapping.purchase_tax_id.id)
-            if not tax_ids:
-                raise UserError(_("Tax code used is not a RC tax.\nCan't "
-                                  "find tax mapping"))
-            if line_tax_ids:
+            mapped_taxes = rc_type.map_tax(
+                line_tax_ids,
+                'original_purchase_tax_id',
+                'purchase_tax_id',
+            )
+            if line_tax_ids and mapped_taxes:
                 inv_line.invoice_line_tax_ids = [
-                    (6, False, tax_ids)]
+                    (6, False, mapped_taxes.ids),
+                ]
 
             inv_line.account_id = rc_type.transitory_account_id.id
         self.rc_self_purchase_invoice_id = supplier_invoice.id

l10n_it_reverse_charge/models/account_rc_type.py

@@ -5,7 +5,7 @@
 # Copyright 2022 Simone Rubino - TAKOBI
 
 from odoo import _, api, fields, models
-from odoo.exceptions import ValidationError
+from odoo.exceptions import UserError, ValidationError
 
 
 class AccountRCTypeTax(models.Model):
@@ -124,3 +124,35 @@ def _constrain_with_supplier_self_invoice(self):
         if with_supplier_types:
             with_supplier_types.mapped('tax_ids') \
                 ._constrain_supplier_self_invoice_mapping()
+
+    def map_tax(self, taxes, key_tax_field, value_tax_field):
+        """
+        Map each tax in `taxes`, based on the mapping defined by `self.tax_ids`.
+
+        Raise an exception if a mapping is not found for some of `taxes`.
+
+        :param key_tax_field: Field of the mapping lines
+            to be used as key for searching the tax
+        :param value_tax_field: Field of the mapping lines
+            to be used as value for mapping the tax
+        :param taxes: Taxes to be mapped
+        """
+        self.ensure_one()
+        mapped_taxes = self.env['account.tax'].browse()
+        for tax in taxes:
+            for tax_mapping in self.tax_ids:
+                if tax_mapping[key_tax_field] == tax:
+                    mapped_taxes |= tax_mapping[value_tax_field]
+                    break
+            else:
+                # Tax not found in mapping
+                raise UserError(
+                    _("Can't find tax mapping for {tax_name} "
+                      "in Reverse Charge Type {rc_type_name}, "
+                      "please check the configuration.")
+                    .format(
+                        tax_name=tax.display_name,
+                        rc_type_name=self.display_name,
+                    )
+                )
+        return mapped_taxes

l10n_it_reverse_charge/tests/test_account_rc_type.py

@@ -1,7 +1,7 @@
 #  Copyright 2022 Simone Rubino - TAKOBI
 #  License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
 
-from odoo.exceptions import ValidationError
+from odoo.exceptions import UserError, ValidationError
 from odoo.fields import first
 
 from .rc_common import ReverseChargeCommon
@@ -26,3 +26,48 @@ def test_with_supplier_self_invoice(self):
 
         self.assertIn("Original Purchase Tax is required", exc_message)
         self.assertIn(rc_type.display_name, exc_message)
+
+    def test_tax_map_find(self):
+        """
+        Check that Reverse Charge Types can map
+        Original Purchase Tax to Purchase Tax.
+        """
+        rc_type = self.rc_type_eeu
+        rc_type_mapping = first(rc_type.tax_ids)
+        key_tax = rc_type_mapping.original_purchase_tax_id
+
+        mapped_tax = rc_type.map_tax(
+            key_tax,
+            'original_purchase_tax_id',
+            'purchase_tax_id',
+        )
+
+        value_tax = rc_type_mapping.purchase_tax_id
+        self.assertEqual(value_tax, mapped_tax)
+
+    def test_tax_map_not_found(self):
+        """
+        Check that Reverse Charge Types
+        raise an Error when can't map a tax.
+        """
+        rc_type = self.rc_type_eeu
+        key_taxes = rc_type.tax_ids.mapped('original_purchase_tax_id')
+        other_tax = self.env['account.tax'].search(
+            [
+                ('id', 'not in', key_taxes.ids),
+            ],
+            limit=1,
+        )
+        self.assertTrue(other_tax)
+
+        with self.assertRaises(UserError) as ue:
+            rc_type.map_tax(
+                other_tax,
+                'original_purchase_tax_id',
+                'purchase_tax_id',
+            )
+        exc_message = ue.exception.args[0]
+
+        self.assertIn("Can't find tax mapping", exc_message)
+        self.assertIn(rc_type.display_name, exc_message)
+        self.assertIn(other_tax.display_name, exc_message)