sale_delivery_date: Only deliver on open days

sale_delivery_date/models/sale_order_line.py

@@ -13,6 +13,18 @@
 
 _logger = logging.getLogger(__name__)
 
+# When postponing a delivery date based on calendar leaves, it could happen
+# that we have to look far in the future for a valid day.
+# I.E. when customer's time window is wednesday, and all wednesdays are leaves
+# on the warehouse calendar.
+# In such case, it would create an infinite loop, because no matter how
+# far we look in the future, we will never find an open time window for this customer.
+# In order to avoid this, we use LOOP_THRESHOLD as a hard limit about how
+# far in the future we are willing to look for a valid delivery date.
+# If no valid delivery_date date has been found within this date range,
+# then the next day (with less restrictive constraints) will be used.
+LOOP_THRESHOLD = 20
+
 
 class SaleOrderLine(models.Model):
     """This override adds delays to the date_deadline and the date_planned.
@@ -259,11 +271,32 @@ def _delivery_date_from_expedition_date(
             )
         else:
             earliest_delivery_date_naive = expedition_date
-        # /TODO extract
-        expected_delivery_date = self._apply_customer_window(
-            earliest_delivery_date_naive, partner
+        return self._get_next_open_customer_window(partner, calendar, from_date=earliest_delivery_date_naive)
+
+    def _get_next_open_customer_window(self, partner, calendar, from_date=None):
+        if from_date is None:
+            from_date = datetime.today()
+        # Try to find an opened customer window within LOOP_THRESHOLD
+        for days in range(LOOP_THRESHOLD):
+            window_date = self._apply_customer_window(
+                from_date + timedelta(days=days), partner
+            )
+            open_date = self._postpone_to_working_day(
+                datetime.combine(window_date, time.min),
+                calendar=calendar,
+            )
+            if window_date.date() == open_date.date():
+                # We found an opened delivery window
+                return window_date
+        # Fallback to the next customer window
+
+        # TODO should we log something?
+        window_date = self._apply_customer_window(from_date, partner)
+        _logger.warning(
+            f"Unable to find a valid delivery date for line {self.name}. "
+            f"Falling back to {str(window_date.date())}."
         )
-        return expected_delivery_date
+        return window_date
 
     @api.model
     def _expedition_date_from_delivery_date(

sale_delivery_date/tests/test_integration.py

@@ -259,3 +259,59 @@ def test_friday_order_with_monday_leave(self):
         picking = order.picking_ids
         self.assertEqual(str(picking.scheduled_date), "2023-08-22 08:00:00")
         self.assertEqual(str(picking.expected_delivery_date.date()), "2023-08-23")
+
+    @freeze_time("2023-10-09 08:00:00")
+    def test_delivery_window_on_public_holiday(self):
+        order = self.order_warehouse_cutoff
+        weekday_numbers = tuple(range(5))
+        time_ranges = [(8.0, 12.0), (13.0, 17.5)]
+        self._set_calendar_attendances(self.calendar, weekday_numbers, time_ranges)
+        # Set customer to receive goods on Wednesday, from 12 to 17
+        weekday_numbers = (2,)  # Wednesday
+        time_window_ranges = [(12.00, 17.00), ]
+        self._set_partner_time_window(
+            self.customer_warehouse_cutoff, weekday_numbers, time_window_ranges
+        )
+        # add a public holiday the 11th of October
+        days = ["2023-10-11", ]
+        self._add_calendar_leaves(self.calendar, days)
+        order.action_confirm()
+        picking = order.picking_ids
+        self.assertEqual(str(picking.scheduled_date.date()), "2023-10-17")
+        self.assertEqual(str(picking.date_deadline.date()), "2023-10-18")
+
+    @freeze_time("2023-10-09 08:00:00")
+    def test_no_open_delivery_window_within_twenty_days(self):
+        order = self.order_warehouse_cutoff
+        weekday_numbers = tuple(range(5))
+        time_ranges = [(8.0, 12.0), (13.0, 17.5)]
+        self._set_calendar_attendances(self.calendar, weekday_numbers, time_ranges)
+        # Set customer to receive goods on Wednesday, from 12 to 17
+        weekday_numbers = (2,)  # Wednesday
+        time_window_ranges = [(12.00, 17.00), ]
+        self._set_partner_time_window(
+            self.customer_warehouse_cutoff, weekday_numbers, time_window_ranges
+        )
+        # add a public holiday all fridays
+        days = [
+            "2023-10-11",
+            "2023-10-18",
+            "2023-10-25",
+            "2023-11-01",
+        ]
+        self._add_calendar_leaves(self.calendar, days)
+        logger_name = "odoo.addons.sale_delivery_date.models.sale_order_line"
+        with self.assertLogs(logger_name, level="WARNING") as watcher:
+            line = order.order_line
+            order.action_confirm()
+            expected_message = (
+                f"WARNING:{logger_name}:"
+                f"Unable to find a valid delivery date for line {line.name}. "
+                f"Falling back to 2023-10-11."
+            )
+            self.assertEqual(watcher.output[0], expected_message)
+        picking = order.picking_ids
+        # since we weren't able to find an open friday within 20 days,
+        # we fell back on the first one, being the 11th of october
+        self.assertEqual(str(picking.scheduled_date.date()), "2023-10-10")
+        self.assertEqual(str(picking.date_deadline.date()), "2023-10-11")