[IMP] mrp_multi_level: safety stock

When a product has a safety stock in an area, and the current stock is
below safety, but there are moves in the future, mrp_multi_level does
not compute an immediate action to get back to the safety stock.

This PR changes this behavior: when the mrp_moves are considered, before
processing the first move in the future, we insert a resupply action to
rebuild the safety stock.

We also add some refactoring in the process:

* add extension point on the wizard to compute the quantity to reorder
(so we can choose in a separate module whether to rebuild safety stock
or not)
* add extension point on the wizard to get the date at which the safety
stock must be rebuilt (defaults to today)
* make the code of the wizard symetric between the groupes and non
grouped configuration

mrp_multi_level/tests/common.py

@@ -15,6 +15,7 @@ class TestMrpMultiLevelCommon(TransactionCase):
         cls.po_obj = cls.env["purchase.order"]
         cls.product_obj = cls.env["product.product"]
         cls.loc_obj = cls.env["stock.location"]
+        cls.quant_obj = cls.env["stock.quant"]
         cls.mrp_area_obj = cls.env["mrp.area"]
         cls.product_mrp_area_obj = cls.env["product.mrp.area"]
         cls.partner_obj = cls.env["res.partner"]

mrp_multi_level/tests/test_mrp_multi_level.py

@@ -1,7 +1,7 @@
 # Copyright 2018-19 ForgeFlow S.L. (https://www.forgeflow.com)
 # License LGPL-3.0 or later (https://www.gnu.org/licenses/lgpl.html).
 
-from datetime import date, datetime
+from datetime import date, datetime, timedelta
 
 from odoo import fields
 
@@ -445,3 +445,82 @@ class TestMrpMultiLevel(TestMrpMultiLevelCommon):
         ]
         product_mrp_area._compute_supply_method()
         self.assertEqual(product_mrp_area.supply_method, "buy")
+
+    def test_18_priorize_safety_stock(self):
+        now = datetime.now()
+        product = self.prod_test  # has Buy route
+        product.seller_ids[0].delay = 2  # set a purchase lead time
+        self.quant_obj._update_available_quantity(product, self.cases_loc, 5)
+        self.product_mrp_area_obj.create(
+            {
+                "product_id": product.id,
+                "mrp_area_id": self.cases_area.id,
+                "mrp_minimum_stock": 15,
+                "mrp_applicable": True,  # needed?
+            }
+        )
+        self._create_picking_out(
+            product, 6.0, now + timedelta(days=3), location=self.cases_loc
+        )
+        self._create_picking_in(
+            product, 10.0, now + timedelta(days=7), location=self.cases_loc
+        )
+        self._create_picking_out(
+            product, 12.0, now + timedelta(days=14), location=self.cases_loc
+        )
+        self.mrp_multi_level_wiz.create(
+            {"mrp_area_ids": [(6, 0, self.cases_area.ids)]}
+        ).run_mrp_multi_level()
+        inventory = self.mrp_inventory_obj.search(
+            [
+                ("mrp_area_id", "=", self.cases_area.id),
+                ("product_id", "=", product.id),
+            ]
+        )
+        expected = [
+            {
+                "date": now.date(),
+                "demand_qty": 0.0,
+                "final_on_hand_qty": 5.0,
+                "initial_on_hand_qty": 5.0,
+                "running_availability": 15.0,
+                "supply_qty": 0.0,
+                "to_procure": 10.0,
+            },
+            {
+                "date": now.date() + timedelta(days=3),
+                "demand_qty": 6.0,
+                "final_on_hand_qty": -1.0,
+                "initial_on_hand_qty": 5.0,
+                "running_availability": 15.0,
+                "supply_qty": 0.0,
+                "to_procure": 6.0,
+            },
+            {
+                "date": now.date() + timedelta(days=7),
+                "demand_qty": 0.0,
+                "final_on_hand_qty": 9.0,
+                "initial_on_hand_qty": -1.0,
+                "running_availability": 25.0,
+                "supply_qty": 10.0,
+                "to_procure": 0.0,
+            },
+            {
+                "date": now.date() + timedelta(days=14),
+                "demand_qty": 12.0,
+                "final_on_hand_qty": -3.0,
+                "initial_on_hand_qty": 9.0,
+                "running_availability": 15.0,
+                "supply_qty": 0.0,
+                "to_procure": 2.0,
+            },
+        ]
+        self.assertEqual(len(expected), len(inventory))
+        for test_vals, inv in zip(expected, inventory):
+            for key in test_vals:
+                self.assertEqual(
+                    test_vals[key],
+                    inv[key],
+                    f"unexpected value for {key}: {inv[key]} "
+                    f"(expected {test_vals[key]} on {inv.date}",
+                )