[IMP] sale_coupon: allow discount on multiple specific products

Before this commit, a discount could only target the whole order, the cheapeast
product or a specific product.

With this commit, it becomes possible to select multiple specific products.
This will ease some realistic ecommerce flows.

For instance, one might create a promotion targetting all his bikes by simply
adding all bikes products into the specific products field. This is easily done
with the many2many widget on the form view.

task-33737

closes odoo/odoo#35500

Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>


Co-authored-by: Pratima Gupta <pgu@odoo.com>
Co-authored-by: Romain Derie <rde@odoo.com>

7 files changed, 131 insertions, 24 deletions

diff --git a/addons/sale_coupon/data/sale_coupon_email_data.xml b/addons/sale_coupon/data/sale_coupon_email_data.xml
index afe32281dce..9d385b9272c 100644
--- a/addons/sale_coupon/data/sale_coupon_email_data.xml
+++ b/addons/sale_coupon/data/sale_coupon_email_data.xml
@@ -26,10 +26,18 @@
             <span style="font-size: 50px; color: #875A7B; font-weight: bold;">
                 ${object.program_id.discount_percentage} %
             </span>
-            % if object.program_id.discount_apply_on == 'specific_product':
-            <br /><strong style="font-size: 24px;">
-                ${'on %s' % object.program_id.discount_specific_product_id.name}
-            </strong>
+            % if object.program_id.discount_apply_on == 'specific_products'
+                <br />
+                % if len(object.program_id.discount_specific_product_ids) != 1
+                % set display_specific_products = True
+                <strong style="font-size: 24px;">
+                    on some products*
+                </strong>
+                % else
+                <strong style="font-size: 24px;">
+                    ${'on %s' % object.program_id.discount_specific_product_ids.name}
+                </strong>
+                % endif
             % elif object.program_id.discount_apply_on == 'cheapest_product':
             <br /><strong style="font-size: 24px;">
                 off on the cheapest product
@@ -73,6 +81,11 @@
             Valid for purchase above ${object.program_id.company_id.currency_id.symbol}${'%0.2f' % object.program_id.rule_minimum_amount |float}
         </span><br />
         % endif
+        % if display_specific_products
+        <span>
+            *Valid for following products: ${', '.join(object.program_id.discount_specific_product_ids.mapped('name'))}
+        </span><br />
+        % endif
         <br/>
         Thank you,
         <br/>
diff --git a/addons/sale_coupon/models/sale_coupon_program.py b/addons/sale_coupon/models/sale_coupon_program.py
index 8ce426ee98c..bbdb4807070 100644
--- a/addons/sale_coupon/models/sale_coupon_program.py
+++ b/addons/sale_coupon/models/sale_coupon_program.py
@@ -110,7 +110,7 @@ class SaleCouponProgram(models.Model):
         res = super(SaleCouponProgram, self).write(vals)
         reward_fields = [
             'reward_type', 'reward_product_id', 'discount_type', 'discount_percentage',
-            'discount_apply_on', 'discount_specific_product_id', 'discount_fixed_amount'
+            'discount_apply_on', 'discount_specific_product_ids', 'discount_fixed_amount'
         ]
         if any(field in reward_fields for field in vals):
             self.mapped('discount_line_product_id').write({'name': self[0].reward_id.display_name})
@@ -259,8 +259,8 @@ class SaleCouponProgram(models.Model):
             if program.reward_type == 'product' and \
                not order.order_line.filtered(lambda line: line.product_id == program.reward_product_id):
                 continue
-            elif program.reward_type == 'discount' and program.discount_apply_on == 'specific_product' and \
-               not order.order_line.filtered(lambda line: line.product_id == program.discount_specific_product_id):
+            elif program.reward_type == 'discount' and program.discount_apply_on == 'specific_products' and \
+               not order.order_line.filtered(lambda line: line.product_id in program.discount_specific_product_ids):
                 continue
             programs |= program
         return programs
diff --git a/addons/sale_coupon/models/sale_coupon_reward.py b/addons/sale_coupon/models/sale_coupon_reward.py
index e7af055055d..57450c1d17d 100644
--- a/addons/sale_coupon/models/sale_coupon_reward.py
+++ b/addons/sale_coupon/models/sale_coupon_reward.py
@@ -33,12 +33,12 @@ class SaleCouponReward(models.Model):
     discount_apply_on = fields.Selection([
         ('on_order', 'On Order'),
         ('cheapest_product', 'On Cheapest Product'),
-        ('specific_product', 'On Specific Product')], default="on_order",
+        ('specific_products', 'On Specific Products')], default="on_order",
         help="On Order - Discount on whole order\n" +
         "Cheapest product - Discount on cheapest product of the order\n" +
-        "Specific product - Discount on selected specific product")
-    discount_specific_product_id = fields.Many2one('product.product', string="Product",
-        help="Product that will be discounted if the discount is applied on a specific product")
+        "Specific products - Discount on selected specific products")
+    discount_specific_product_ids = fields.Many2many('product.product', string="Products",
+        help="Products that will be discounted if the discount is applied on specific products")
     discount_max_amount = fields.Float(default=0,
         help="Maximum amount of discount that can be provided")
     discount_fixed_amount = fields.Float(string="Fixed Amount", help='The discount in fixed amount')
@@ -65,8 +65,11 @@ class SaleCouponReward(models.Model):
                     reward_percentage = str(reward.discount_percentage)
                     if reward.discount_apply_on == 'on_order':
                         reward_string = _("%s%% discount on total amount" % (reward_percentage))
-                    elif reward.discount_apply_on == 'specific_product':
-                        reward_string = _("%s%% discount on %s" % (reward_percentage, reward.discount_specific_product_id.name))
+                    elif reward.discount_apply_on == 'specific_products':
+                        if len(reward.discount_specific_product_ids) > 1:
+                            reward_string = _("%s%% discount on products" % (reward_percentage))
+                        else:
+                            reward_string = _("%s%% discount on %s" % (reward_percentage, reward.discount_specific_product_ids.name))
                     elif reward.discount_apply_on == 'cheapest_product':
                         reward_string = _("%s%% discount on cheapest product" % (reward_percentage))
                 elif reward.discount_type == 'fixed_amount':
diff --git a/addons/sale_coupon/models/sale_order.py b/addons/sale_coupon/models/sale_order.py
index 01183d35cbe..8a7a8913795 100644
--- a/addons/sale_coupon/models/sale_order.py
+++ b/addons/sale_coupon/models/sale_order.py
@@ -155,11 +155,11 @@ class SaleOrder(models.Model):
                         'is_reward_line': True,
                         'tax_id': [(4, tax.id, False) for tax in taxes],
                     }
-        elif program.discount_apply_on in ['specific_product', 'on_order']:
-            if program.discount_apply_on == 'specific_product':
+        elif program.discount_apply_on in ['specific_products', 'on_order']:
+            if program.discount_apply_on == 'specific_products':
                 # We should not exclude reward line that offer this product since we need to offer only the discount on the real paid product (regular product - free product)
-                free_product_lines = self.env['sale.coupon.program'].search([('reward_type', '=', 'product'), ('reward_product_id', '=', program.discount_specific_product_id.id)]).mapped('discount_line_product_id')
-                lines = lines.filtered(lambda x: x.product_id == program.discount_specific_product_id or x.product_id in free_product_lines)
+                free_product_lines = self.env['sale.coupon.program'].search([('reward_type', '=', 'product'), ('reward_product_id', 'in', program.discount_specific_product_ids.ids)]).mapped('discount_line_product_id')
+                lines = lines.filtered(lambda x: x.product_id in (program.discount_specific_product_ids | free_product_lines))
 
             for line in lines:
                 discount_line_amount = self._get_reward_values_discount_percentage_per_line(program, line)
diff --git a/addons/sale_coupon/report/sale_coupon_report_templates.xml b/addons/sale_coupon/report/sale_coupon_report_templates.xml
index 10f6fe32591..1bdd96ad56d 100644
--- a/addons/sale_coupon/report/sale_coupon_report_templates.xml
+++ b/addons/sale_coupon/report/sale_coupon_report_templates.xml
@@ -19,8 +19,14 @@
                                     <h1 t-if="o.program_id.discount_type == 'percentage'" class="text-success">
                                         <strong><span t-field="o.program_id.discount_percentage"/>%</strong>
                                     </h1>
-                                    <t t-if="o.program_id.discount_apply_on == 'specific_product'">
-                                        <t t-set="text" t-value="'OFF ON %s' % (o.program_id.discount_specific_product_id.name.upper())"/>
+                                    <t t-if="o.program_id.discount_apply_on == 'specific_products'">
+                                        <t t-if="len(o.program_id.discount_specific_product_ids) > 1">
+                                            <t t-set="text" t-value="'OFF ON SOME PRODUCTS*'"/>
+                                            <t t-set="display_specific_products" t-value="True"/>
+                                        </t>
+                                        <t t-else="">
+                                            <t t-set="text" t-value="'OFF ON %s' % o.program_id.discount_specific_product_ids.name.upper()"/>
+                                        </t>
                                     </t>
                                     <t t-if="o.program_id.discount_apply_on == 'cheapest_product'">
                                         <t t-set="text" t-value="'%s' % ('OFF ON THE CHEAPEST PRODUCT')"/>
@@ -49,6 +55,11 @@
                                     Valid for purchase above
                                     <strong t-esc="o.program_id.rule_minimum_amount" t-options="{'widget': 'monetary', 'display_currency': o.program_id.currency_id}"/>
                                 </h4>
+                                <p t-if="display_specific_products">
+                                    <small>
+                                        *Valid for following products: <t t-esc="', '.join(o.program_id.discount_specific_product_ids.mapped('name')).upper()"/>
+                                    </small>
+                                </p>
                                 <br/>
                                 <img alt="Barcode" t-att-src="'/report/barcode/Code128/%s' % o.code"/>
                                 <br/>
diff --git a/addons/sale_coupon/tests/test_program_numbers.py b/addons/sale_coupon/tests/test_program_numbers.py
index 9edc5d06989..31dc651118b 100644
--- a/addons/sale_coupon/tests/test_program_numbers.py
+++ b/addons/sale_coupon/tests/test_program_numbers.py
@@ -142,8 +142,8 @@ class TestSaleCouponProgramNumbers(TestSaleCouponCommon):
             'discount_type': 'percentage',
             'discount_percentage': 20.0,
             'rule_minimum_amount': 320.00,
-            'discount_apply_on': 'specific_product',
-            'discount_specific_product_id': self.largeCabinet.id,
+            'discount_apply_on': 'specific_products',
+            'discount_specific_product_ids': [(6, 0, [self.largeCabinet.id])],
         })
         order = self.empty_order
         self.largeCabinet.taxes_id = percent_tax
@@ -377,8 +377,8 @@ class TestSaleCouponProgramNumbers(TestSaleCouponCommon):
             'program_type': 'promotion_program',
             'discount_type': 'percentage',
             'discount_percentage': 20.0,
-            'discount_apply_on': 'specific_product',
-            'discount_specific_product_id': self.largeCabinet.id,
+            'discount_apply_on': 'specific_products',
+            'discount_specific_product_ids': [(6, 0, [self.largeCabinet.id])],
         })
         order.recompute_coupon_lines()
         # Note: we have 7 regular Large Cabinets and 3 free Large Cabinets. We should then discount only 4 really paid Large Cabinets
@@ -537,3 +537,83 @@ class TestSaleCouponProgramNumbers(TestSaleCouponCommon):
         generated_coupon = order.generated_coupon_ids
         self.assertEqual(len(generated_coupon), 1, "We should still have only 1 coupon as we now benefit again from the program but no need to create a new one (see next assert)")
         self.assertEqual(generated_coupon.state, 'reserved', "The coupon should be set back to reserved as we had already an expired one, no need to create a new one")
+
+    def test_program_discount_on_multiple_specific_products(self):
+        """ Ensure a discount on multiple specific products is correctly computed.
+            - Simple: Discount must be applied on all the products set on the promotion
+            - Advanced: This discount must be split by different taxes
+        """
+        order = self.empty_order
+        p_specific_products = self.env['sale.coupon.program'].create({
+            'name': '20% reduction on Conference Chair and Drawer Black in cart',
+            'promo_code_usage': 'no_code_needed',
+            'reward_type': 'discount',
+            'program_type': 'promotion_program',
+            'discount_type': 'percentage',
+            'discount_percentage': 25.0,
+            'discount_apply_on': 'specific_products',
+            'discount_specific_product_ids': [(6, 0, [self.conferenceChair.id, self.drawerBlack.id])],
+        })
+
+        self.env['sale.order.line'].create({
+            'product_id': self.conferenceChair.id,
+            'name': 'Conference Chair',
+            'product_uom_qty': 4.0,
+            'order_id': order.id,
+        })
+        sol2 = self.env['sale.order.line'].create({
+            'product_id': self.drawerBlack.id,
+            'name': 'Drawer Black',
+            'product_uom_qty': 2.0,
+            'order_id': order.id,
+        })
+
+        order.recompute_coupon_lines()
+        self.assertEqual(len(order.order_line.ids), 3, "Conference Chair + Drawer Black + 20% discount line")
+        # Name                 | Qty | price_unit |  Tax     |  HTVA   |   TVAC  |  TVA  |
+        # --------------------------------------------------------------------------------
+        # Conference Chair     |  4  |     16.50  |       /  |   66.00 |   66.00 |   0.00
+        # Drawer Black         |  2  |     25.00  |       /  |   50.00 |   50.00 |   0.00
+        # 25% discount         |  1  |    -29.00  |       /  |  -29.00 |  -29.00 |   0.00
+        # --------------------------------------------------------------------------------
+        # TOTAL                                              |   87.00 |   87.00 |   0.00
+        self.assertEqual(order.amount_total, 87.00, "Total should be 87.00, see above comment")
+
+        # remove Drawer Black case from promotion
+        p_specific_products.discount_specific_product_ids = [(6, 0, [self.conferenceChair.id])]
+        order.recompute_coupon_lines()
+        self.assertEqual(len(order.order_line.ids), 3, "Should still be Conference Chair + Drawer Black + 20% discount line")
+        # Name                 | Qty | price_unit |  Tax     |  HTVA   |   TVAC  |  TVA  |
+        # --------------------------------------------------------------------------------
+        # Conference Chair     |  4  |     16.50  |       /  |   66.00 |   66.00 |   0.00
+        # Drawer Black         |  2  |     25.00  |       /  |   50.00 |   50.00 |   0.00
+        # 25% discount         |  1  |    -16.50  |       /  |  -16.50 |  -16.50 |   0.00
+        # --------------------------------------------------------------------------------
+        # TOTAL                                              |   99.50 |   99.50 |   0.00
+        self.assertEqual(order.amount_total, 99.50, "The 12.50 discount from the drawer black should be gone")
+
+        # =========================================================================
+        # PART 2: Same flow but with different taxes on products to ensure discount is split per VAT
+        # Add back Drawer Black in promotion
+        p_specific_products.discount_specific_product_ids = [(6, 0, [self.conferenceChair.id, self.drawerBlack.id])]
+
+        percent_tax = self.env['account.tax'].create({
+            'name': "30% Tax",
+            'amount_type': 'percent',
+            'amount': 30,
+            'price_include': True,
+        })
+        sol2.tax_id = percent_tax
+
+        order.recompute_coupon_lines()
+        self.assertEqual(len(order.order_line.ids), 4, "Conference Chair + Drawer Black + 20% on no TVA product (Conference Chair) + 20% on 15% tva product (Drawer Black)")
+        # Name                 | Qty | price_unit |  Tax     |  HTVA   |   TVAC  |  TVA  |
+        # --------------------------------------------------------------------------------
+        # Conference Chair     |  4  |     16.50  |       /  |   66.00 |   66.00 |   0.00
+        # Drawer Black         |  2  |     25.00  | 30% incl |   38.46 |   50.00 |  11.54
+        # 25% discount         |  1  |    -16.50  |       /  |  -16.50 |  -16.50 |   0.00
+        # 25% discount         |  1  |    -12.50  | 30% incl |   -9.62 |  -12.50 |  -2.88
+        # --------------------------------------------------------------------------------
+        # TOTAL                                              |   78.34 |   87.00 |   8.66
+        self.assertEqual(order.amount_total, 87.00, "Total untaxed should be as per above comment")
+        self.assertEqual(order.amount_untaxed, 78.34, "Total with taxes should be as per above comment")
diff --git a/addons/sale_coupon/views/sale_coupon_program_views.xml b/addons/sale_coupon/views/sale_coupon_program_views.xml
index ffd15643321..f6c72b23e4d 100644
--- a/addons/sale_coupon/views/sale_coupon_program_views.xml
+++ b/addons/sale_coupon/views/sale_coupon_program_views.xml
@@ -60,7 +60,7 @@
                             </div>
                             <field name="discount_apply_on" attrs="{'invisible':
                             ['|', ('reward_type', 'in', ('product', 'free_shipping')), ('discount_type', '!=', 'percentage')]}" widget="radio"/>
-                            <field name="discount_specific_product_id" attrs="{'invisible': ['|', '|', ('discount_apply_on', '!=', 'specific_product'),('discount_type', '!=', 'percentage'), ('reward_type', 'in', ('product', 'free_shipping'))], 'required': [('reward_type', '=', 'discount'),('discount_apply_on', '=', 'specific_product'),('discount_type', '=', 'percentage')]}" placeholder="Select product"/>
+                            <field name="discount_specific_product_ids" widget='many2many_tags' attrs="{'invisible': ['|', '|', ('discount_apply_on', '!=', 'specific_products'),('discount_type', '!=', 'percentage'), ('reward_type', 'in', ('product', 'free_shipping'))], 'required': [('reward_type', '=', 'discount'),('discount_apply_on', '=', 'specific_products'),('discount_type', '=', 'percentage')]}" placeholder="Select products"/>
                             <label for="discount_max_amount" string="Max Discount Amount" attrs="{'invisible': ['|', ('reward_type', 'in', ('product', 'free_shipping')), ('discount_type', '!=', 'percentage')]}"/>
                             <div attrs="{'invisible': ['|', ('reward_type', 'in', ('product', 'free_shipping')), ('discount_type', '!=', 'percentage')]}">
                                 <field name="discount_max_amount" class="oe_inline" widget='monetary' options="{'currency_field': 'currency_id'}"/>