fix open ended permit end time calculation.

ParkingPermit end_time was wrong after renewal in some cases when
incrementing end time by a month.

refs: PV-852

.github/workflows/ci.yml

@@ -45,6 +45,7 @@ jobs:
 
       - name: Install required Ubuntu packages
         run: |
+          sudod apt-get update
           sudo apt-get install gdal-bin
 
       - name: Install PyPI dependencies

parking_permits/models/parking_permit.py

@@ -822,7 +822,9 @@ def renew_open_ended_permit(self):
         if self.contract_type != ContractType.OPEN_ENDED:
             raise ValueError("This permit is not open-ended so cannot be renewed")
         self.end_time = increment_end_time(
-            self.end_time or self.current_period_end_time(), months=1
+            self.start_time,
+            self.end_time or self.current_period_end_time(),
+            months=1
         )
         self.save()
 

parking_permits/tests/models/test_parking_permit.py

@@ -1119,6 +1119,92 @@ def test_extend_permit(self):
         self.assertEqual(permit.month_count, 4)
         self.assertEqual(permit.end_time.date(), date(2024, 7, 3))
 
+    def test_renew_parking_permit_multiple_renews_middle_of_month(self):
+        permit = ParkingPermitFactory(
+            status=ParkingPermitStatus.VALID,
+            contract_type=ContractType.OPEN_ENDED,
+            start_time=timezone.make_aware(datetime(2024, 1, 10, 21, 0), pytz.UTC),
+            end_time=timezone.make_aware(datetime(2024, 2, 9, 20, 59, 59, 999999), pytz.UTC),
+            month_count=1,
+        )
+
+        with freeze_time("2024-1-15"):
+            permit.renew_open_ended_permit()
+            permit.refresh_from_db()
+
+        self.assertEqual(
+            permit.end_time.isoformat(),
+            "2024-03-09T21:59:59.999999+00:00",
+        )
+
+        self.assertEqual(
+            timezone.localtime(permit.end_time).isoformat(),
+            "2024-03-09T23:59:59.999999+02:00",
+        )
+
+        with freeze_time("2024-2-15"):
+            permit.renew_open_ended_permit()
+            permit.refresh_from_db()
+
+        self.assertEqual(
+            permit.end_time.isoformat(),
+            "2024-04-09T21:59:59.999999+00:00",
+        )
+
+        self.assertEqual(
+            timezone.localtime(permit.end_time).isoformat(),
+            "2024-04-09T23:59:59.999999+02:00",
+        )
+
+    def test_renew_parking_permit_multiple_renews_end_of_month(self):
+        permit = ParkingPermitFactory(
+            status=ParkingPermitStatus.VALID,
+            contract_type=ContractType.OPEN_ENDED,
+            start_time=timezone.make_aware(datetime(2024, 1, 1, 21, 0), pytz.UTC),
+            end_time=timezone.make_aware(datetime(2024, 1, 31, 20, 59, 59, 999999), pytz.UTC),
+            month_count=1,
+        )
+
+        with freeze_time("2024-1-24"):
+            permit.renew_open_ended_permit()
+            permit.refresh_from_db()
+
+        self.assertEqual(
+            permit.end_time.isoformat(),
+            "2024-02-29T21:59:59.999999+00:00",
+        )
+
+        self.assertEqual(
+            timezone.localtime(permit.end_time).isoformat(),
+            "2024-02-29T23:59:59.999999+02:00",
+        )
+
+        with freeze_time("2024-2-24"):
+            permit.renew_open_ended_permit()
+            permit.refresh_from_db()
+        self.assertEqual(
+            permit.end_time.isoformat(),
+            "2024-03-31T20:59:59.999999+00:00",
+        )
+
+        self.assertEqual(
+            timezone.localtime(permit.end_time).isoformat(),
+            "2024-03-31T23:59:59.999999+03:00",
+        )
+        with freeze_time("2024-3-24"):
+            permit.renew_open_ended_permit()
+            permit.refresh_from_db()
+
+        self.assertEqual(
+            permit.end_time.isoformat(),
+            "2024-04-30T20:59:59.999999+00:00",
+        )
+
+        self.assertEqual(
+            timezone.localtime(permit.end_time).isoformat(),
+            "2024-04-30T23:59:59.999999+03:00",
+        )
+
     @freeze_time("2024-1-28")
     def test_renew_parking_permit(self):
         permit = ParkingPermitFactory(

parking_permits/tests/test_utils.py

@@ -16,10 +16,32 @@
     diff_months_floor,
     find_next_date,
     flatten_dict,
+    get_last_day_of_month,
     get_model_diff,
 )
 
 
+def test_get_last_day_of_month():
+    assert get_last_day_of_month(datetime(2024, 1, 2, 12, 12, 00)) == 31
+    assert get_last_day_of_month(datetime(2023, 2, 2, 12, 12, 00)) == 28
+    assert get_last_day_of_month(datetime(2024, 3, 2, 12, 12, 00)) == 31
+    assert get_last_day_of_month(datetime(2024, 4, 2, 12, 12, 00)) == 30
+    assert get_last_day_of_month(datetime(2024, 5, 2, 12, 12, 00)) == 31
+    assert get_last_day_of_month(datetime(2024, 6, 2, 12, 12, 00)) == 30
+    assert get_last_day_of_month(datetime(2024, 7, 2, 12, 12, 00)) == 31
+    assert get_last_day_of_month(datetime(2024, 8, 2, 12, 12, 00)) == 31
+    assert get_last_day_of_month(datetime(2024, 9, 2, 12, 12, 00)) == 30
+    assert get_last_day_of_month(datetime(2024, 10, 2, 12, 12, 00)) == 31
+    assert get_last_day_of_month(datetime(2024, 11, 2, 12, 12, 00)) == 30
+    assert get_last_day_of_month(datetime(2024, 12, 2, 12, 12, 00)) == 31
+
+    # leap year
+    assert get_last_day_of_month(datetime(2024, 2, 2, 12, 12, 00)) == 29
+
+    for i in range(1, 31):
+        assert get_last_day_of_month(datetime(2024, 5, i, 12, 12, 00)) == 31
+
+
 @pytest.mark.parametrize(
     "gross_price,vat,net_price,vat_price",
     [

parking_permits/utils.py

@@ -3,7 +3,7 @@
 import zoneinfo
 from collections import OrderedDict
 from collections.abc import Callable
-from datetime import datetime
+from datetime import datetime, timedelta
 from decimal import ROUND_UP, Decimal
 from itertools import chain
 from typing import Any, Iterable, Iterator, Optional, Union
@@ -129,15 +129,30 @@ def get_end_time(start_time, diff_months):
     return normalize_end_time(end_time)
 
 
-def increment_end_time(end_time, months=1):
+def get_last_day_of_month(date: datetime):
+    next_month = date.replace(day=28) + timedelta(days=4)
+    return (next_month - timedelta(days=next_month.day)).day
+
+
+def increment_end_time(start_time, end_time, months=1):
     """Increment the end time based on the current value (rather than start time).
+    start_time is used to calculate the original end day, which is used when setting
+    permit end_time's day after the month has been incremented.
 
     Example: 1st Jan 23:59 -> 1st Feb 23:59.
     Should account for DST changes.
     """
+    original_end_day = (start_time.date() + relativedelta(days=30)).day
 
     end_time = end_time.astimezone(tz.get_default_timezone())
+
     end_time += relativedelta(months=months)
+    try:
+        # try to set end day to be same as originally
+        end_time = end_time.replace(day=original_end_day)
+    except ValueError:
+        # end day not in month -> set to last day of the month
+        end_time = end_time.replace(day=get_last_day_of_month(end_time))
     return normalize_end_time(end_time)