[FIX] rma_purchase: write-off differences in price between rma line and vendor refund

rma_purchase/models/__init__.py

@@ -5,3 +5,4 @@ from . import purchase_order_line
 from . import rma_operation
 from . import procurement
 from . import account_move
+from . import account_move_line

rma_purchase/models/account_move.py

@@ -1,7 +1,8 @@
 # Copyright 2017-22 ForgeFlow S.L.
 # License LGPL-3.0 or later (https://www.gnu.org/licenses/lgpl.html)
 
-from odoo import models
+from odoo import fields, models
+from odoo.tools.float_utils import float_compare
 
 
 class AccountMove(models.Model):
@@ -40,3 +41,173 @@ class AccountMove(models.Model):
                         )
                         amls.reconcile()
         return res
+
+    def _stock_account_prepare_anglo_saxon_in_lines_vals(self):
+        lines_vals_list_rma = []
+        rma_refunds = self.env["account.move"]
+        price_unit_prec = self.env["decimal.precision"].precision_get("Product Price")
+        for move in self:
+            if (
+                move.move_type != "in_refund"
+                or not move.company_id.anglo_saxon_accounting
+            ):
+                continue
+            move = move.with_company(move.company_id)
+            for line in move.invoice_line_ids.filtered(lambda l: l.rma_line_id):
+                # Filter out lines being not eligible for price difference.
+                # Moreover, this function is used for standard cost method only.
+                if (
+                    line.product_id.type != "product"
+                    or line.product_id.valuation != "real_time"
+                ):
+                    continue
+
+                # Retrieve accounts needed to generate the price difference.
+                debit_expense_account = line._get_price_diff_account()
+                if not debit_expense_account:
+                    continue
+                # Retrieve stock valuation moves.
+                valuation_stock_moves = (
+                    self.env["stock.move"].search(
+                        [
+                            ("rma_line_id", "=", line.rma_line_id.id),
+                            ("state", "=", "done"),
+                            ("product_qty", "!=", 0.0),
+                        ]
+                    )
+                    if line.rma_line_id
+                    else self.env["stock.move"]
+                )
+
+                if line.product_id.cost_method != "standard" and line.rma_line_id:
+                    if move.move_type == "in_refund":
+                        valuation_stock_moves = valuation_stock_moves.filtered(
+                            lambda stock_move: stock_move._is_out()
+                        )
+                    else:
+                        valuation_stock_moves = valuation_stock_moves.filtered(
+                            lambda stock_move: stock_move._is_in()
+                        )
+
+                    if not valuation_stock_moves:
+                        continue
+
+                    (
+                        valuation_price_unit_total,
+                        valuation_total_qty,
+                    ) = valuation_stock_moves._get_valuation_price_and_qty(
+                        line, move.currency_id
+                    )
+                    valuation_price_unit = (
+                        valuation_price_unit_total / valuation_total_qty
+                    )
+                    valuation_price_unit = line.product_id.uom_id._compute_price(
+                        valuation_price_unit, line.product_uom_id
+                    )
+                else:
+                    # Valuation_price unit is always expressed in invoice currency,
+                    # so that it can always be computed with the good rate
+                    price_unit = line.product_id.uom_id._compute_price(
+                        line.product_id.standard_price, line.product_uom_id
+                    )
+                    price_unit = (
+                        -price_unit
+                        if line.move_id.move_type == "in_refund"
+                        else price_unit
+                    )
+                    valuation_date = (
+                        valuation_stock_moves
+                        and max(valuation_stock_moves.mapped("date"))
+                        or move.date
+                    )
+                    valuation_price_unit = line.company_currency_id._convert(
+                        price_unit,
+                        move.currency_id,
+                        move.company_id,
+                        valuation_date,
+                        round=False,
+                    )
+
+                price_unit = line._get_gross_unit_price()
+
+                price_unit_val_dif = abs(price_unit) - valuation_price_unit
+                relevant_qty = line.quantity
+                price_subtotal = relevant_qty * price_unit_val_dif
+                # We consider there is a price difference if the subtotal is not zero. In case a
+                # discount has been applied, we can't round the price unit anymore, and hence we
+                # can't compare them.
+                if (
+                    not move.currency_id.is_zero(price_subtotal)
+                    and float_compare(
+                        line["price_unit"],
+                        line.price_unit,
+                        precision_digits=price_unit_prec,
+                    )
+                    == 0
+                ):
+                    # Add price difference account line.
+                    vals = {
+                        "name": line.name[:64],
+                        "move_id": move.id,
+                        "partner_id": line.partner_id.id
+                        or move.commercial_partner_id.id,
+                        "currency_id": line.currency_id.id,
+                        "product_id": line.product_id.id,
+                        "product_uom_id": line.product_uom_id.id,
+                        "quantity": relevant_qty,
+                        "price_unit": price_unit_val_dif,
+                        "price_subtotal": relevant_qty * price_unit_val_dif,
+                        "amount_currency": relevant_qty
+                        * price_unit_val_dif
+                        * line.move_id.direction_sign,
+                        "balance": line.currency_id._convert(
+                            relevant_qty
+                            * price_unit_val_dif
+                            * line.move_id.direction_sign,
+                            line.company_currency_id,
+                            line.company_id,
+                            fields.Date.today(),
+                        ),
+                        "account_id": debit_expense_account.id,
+                        "analytic_distribution": line.analytic_distribution,
+                        "display_type": "cogs",
+                        "rma_line_id": line.rma_line_id.id,
+                    }
+
+                    lines_vals_list_rma.append(vals)
+
+                    # Correct the amount of the current line.
+                    vals = {
+                        "name": line.name[:64],
+                        "move_id": move.id,
+                        "partner_id": line.partner_id.id
+                        or move.commercial_partner_id.id,
+                        "currency_id": line.currency_id.id,
+                        "product_id": line.product_id.id,
+                        "product_uom_id": line.product_uom_id.id,
+                        "quantity": relevant_qty,
+                        "price_unit": -price_unit_val_dif,
+                        "price_subtotal": relevant_qty * -price_unit_val_dif,
+                        "amount_currency": relevant_qty
+                        * -price_unit_val_dif
+                        * line.move_id.direction_sign,
+                        "balance": line.currency_id._convert(
+                            relevant_qty
+                            * -price_unit_val_dif
+                            * line.move_id.direction_sign,
+                            line.company_currency_id,
+                            line.company_id,
+                            fields.Date.today(),
+                        ),
+                        "account_id": line.account_id.id,
+                        "analytic_distribution": line.analytic_distribution,
+                        "display_type": "cogs",
+                        "rma_line_id": line.rma_line_id.id,
+                    }
+                    lines_vals_list_rma.append(vals)
+                    rma_refunds |= move
+        lines_vals_list = super(
+            AccountMove, self - rma_refunds
+        )._stock_account_prepare_anglo_saxon_in_lines_vals()
+        lines_vals_list += lines_vals_list_rma
+        return lines_vals_list

rma_purchase/models/account_move_line.py

@@ -0,0 +1,20 @@
+from odoo import models
+
+
+class AccountMoveLine(models.Model):
+    _inherit = "account.move.line"
+
+    def _get_price_diff_account(self):
+        # force the price difference account to be taken from the price
+        # different properties as they was in the previous Odoo versions
+        self.ensure_one()
+        if self.product_id.cost_method != "standard":
+            debit_pdiff_account = (
+                self.product_id.property_account_creditor_price_difference
+                or self.product_id.categ_id.property_account_creditor_price_difference_categ
+            )
+            debit_pdiff_account = self.move_id.fiscal_position_id.map_account(
+                debit_pdiff_account
+            )
+            return debit_pdiff_account
+        return super()._get_price_diff_account()

rma_purchase/tests/test_rma_stock_account_purchase.py

@@ -17,7 +17,7 @@ class TestRmaStockAccountPurchase(TestRmaStockAccount):
         cls.rma_operation_supplier_refund = cls.env.ref(
             "rma_account.rma_operation_supplier_refund"
         )
-        acc_type = cls._create_account_type("expense", "other")
+        acc_type = "expense"
         cls.account_price_diff = cls._create_account(
             acc_type, "Refund Price Difference Expense", "rpde", cls.company, False
         )