[FIX] website_sale: harmonize tax computation

Standard `sale` tax flows rely on `_get_tax_included_price_unit`,
whereas part of `website_sale` flows do, while another part relies
on `_fix_tax_included_price_company`, which doesn't handle some
advanced cases (fiscal position mapping of price_included taxes).

This commit drops the use of `_fix_tax_included_price_company` in
website_sale, to only use the newest API of `_get_tax_included_price_unit`,
supposed to handle more cases.

Also makes all taxes computation go through a single entry point,
`_apply_taxes_to_price`, already used for `combination_info` logic (/shop/product),
but not in `_get_sales_prices` (/shop page).

opw-3700803

original commit : 662ea281515156a781ab68079d0123ea45ebf40f

closes odoo/odoo#160198

Signed-off-by: Laurent Smet (las) <las@odoo.com>
Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>

addons/website_sale/models/product_product.py

@@ -103,24 +103,13 @@ class Product(models.Model):
 
     def _get_contextual_price_tax_selection(self):
         self.ensure_one()
-        price = self._get_contextual_price()
+        website = self.env['website'].get_current_website()
+        fiscal_position_sudo = website.sudo().fiscal_position_id
         product_taxes = self.sudo().taxes_id.filtered(lambda x: x.company_id in self.env.company.parent_ids)
-        if product_taxes:
-            website = self.env['website'].get_current_website()
-            fiscal_position = website.sudo().fiscal_position_id
-
-            price = self._get_tax_included_unit_price(
-                website.company_id,
-                website.currency_id,
-                fields.Date.context_today(self),
-                'sale',
-                fiscal_position=fiscal_position,
-                product_price_unit=price,
-                product_currency=website.currency_id,
-            )
-            line_tax_type = website.show_line_subtotals_tax_selection
-            tax_display = "total_included" if line_tax_type == "tax_included" else "total_excluded"
-
-            taxes = fiscal_position.map_tax(product_taxes)
-            price = taxes.compute_all(price, product=self, partner=self.env['res.partner'])[tax_display]
-        return price
+        return self.env['product.template']._apply_taxes_to_price(
+            self._get_contextual_price(),
+            website.currency_id,
+            product_taxes,
+            fiscal_position_sudo.map_tax(product_taxes),
+            self,
+        )

addons/website_sale/models/product_template.py

@@ -254,7 +254,6 @@ class ProductTemplate(models.Model):
             return {}
 
         pricelist and pricelist.ensure_one()
-        partner_sudo = self.env.user.partner_id
         pricelist = pricelist or self.env['product.pricelist']
         currency = pricelist.currency_id or self.env.company.currency_id
         date = fields.Date.context_today(self)
@@ -264,11 +263,6 @@ class ProductTemplate(models.Model):
         show_strike_price = self.env.user.has_group('website_sale.group_product_price_comparison')
 
         base_sales_prices = self._price_compute('list_price', currency=currency)
-        website = self.env['website'].get_current_website()
-        if website.show_line_subtotals_tax_selection == 'tax_excluded':
-            tax_display = 'total_excluded'
-        else:
-            tax_display = 'total_included'
 
         res = {}
         for template in self:
@@ -286,10 +280,10 @@ class ProductTemplate(models.Model):
                 if not price_list_contains_template:
                     price_reduce = base_sales_prices[template.id]
 
-                if template.currency_id != pricelist.currency_id:
+                if template.currency_id != currency:
                     base_price = template.currency_id._convert(
                         base_price,
-                        pricelist.currency_id,
+                        currency,
                         self.env.company,
                         date,
                         round=False
@@ -299,13 +293,13 @@ class ProductTemplate(models.Model):
                 base_price = base_sales_prices[template.id]
 
                 # Compare_list_price are never tax included
-                base_price = self.env['account.tax']._fix_tax_included_price_company(
-                    base_price, product_taxes, taxes, self.env.company)
-                base_price = taxes.compute_all(base_price, pricelist.currency_id, 1, template, partner_sudo)[tax_display]
+                base_price = self._apply_taxes_to_price(
+                    base_price, currency, product_taxes, taxes, self,
+                )
 
-            price_reduce = self.env['account.tax']._fix_tax_included_price_company(
-                price_reduce, product_taxes, taxes, self.env.company)
-            price_reduce = taxes.compute_all(price_reduce, pricelist.currency_id, 1, template, partner_sudo)[tax_display]
+            price_reduce = self._apply_taxes_to_price(
+                price_reduce, currency, product_taxes, taxes, self,
+            )
 
             template_price_vals = {
                 'price_reduce': price_reduce,
@@ -560,11 +554,12 @@ class ProductTemplate(models.Model):
     def _apply_taxes_to_price(
         self, price, currency, product_taxes, taxes, product_or_template,
     ):
-        # Ideally, we should use _get_tax_included_unit_price
-        #   but it doesn't allow to request tax-excluded amount.
         website = self.env['website'].get_current_website()
-        price = self.env['account.tax']._fix_tax_included_price_company(
-            price, product_taxes, taxes, self.env.company,
+        price = self.env['product.product']._get_tax_included_unit_price_from_price(
+            price,
+            currency,
+            product_taxes,
+            product_taxes_after_fp=taxes,
         )
         show_tax = website.show_line_subtotals_tax_selection
         tax_display = 'total_excluded' if show_tax == 'tax_excluded' else 'total_included'

addons/website_sale/tests/test_website_sale_product_attribute_value_config.py

@@ -170,6 +170,13 @@ class TestWebsiteSaleProductAttributeValueConfig(TestSaleProductAttributeValueCo
         self.assertEqual(round(combination_info['list_price'], 2), 434.78, "434.78$ + 0% tax (mapped from fp 15% -> 0%)")
         self.assertEqual(combination_info['price_extra'], 173.91, "173.91$ + 0% tax (mapped from fp 15% -> 0%)")
 
+        # Try same flow with tax included for apply tax
+        tax0.write({'name': "Test tax 5", 'amount': 5, 'price_include': True})
+        combination_info = product._get_combination_info()
+        self.assertEqual(round(combination_info['price'], 2), 456.52, "434.78$ + 5% tax (mapped from fp 15% -> 5% for BE)")
+        self.assertEqual(round(combination_info['list_price'], 2), 456.52, "434.78$ + 5% tax (mapped from fp 15% -> 5% for BE)")
+        self.assertEqual(combination_info['price_extra'], 182.61, "173.91$ + 5% tax (mapped from fp 15% -> 5% for BE)")
+
 
 @tagged('post_install', '-at_install', 'product_pricelist')
 class TestWebsiteSaleProductPricelist(TestSaleProductAttributeValueCommon):