From 1ba742d99e3c33766ece5a64ef2776f73d1fc8a6 Mon Sep 17 00:00:00 2001
From: Matias Bordese <mbordese@gmail.com>
Date: Tue, 16 Aug 2022 18:13:31 -0300
Subject: [PATCH] Fix for final event calculation when splitting events

---
 .../apps/schedules/models/on_call_schedule.py | 21 ++++--
 .../schedules/tests/test_on_call_schedule.py  | 67 +++++++++++++++++++
 2 files changed, 81 insertions(+), 7 deletions(-)

diff --git a/engine/apps/schedules/models/on_call_schedule.py b/engine/apps/schedules/models/on_call_schedule.py
index 98d605f3..d05cc0f4 100644
--- a/engine/apps/schedules/models/on_call_schedule.py
+++ b/engine/apps/schedules/models/on_call_schedule.py
@@ -276,14 +276,18 @@ class OnCallSchedule(PolymorphicModel):
         if not events:
             return []
 
-        # sort schedule events by (type desc, priority desc, start timestamp asc)
-        events.sort(
-            key=lambda e: (
-                -e["calendar_type"] if e["calendar_type"] else 0,  # overrides: 1, shifts: 0, gaps: None
-                -e["priority_level"] if e["priority_level"] else 0,
-                e["start"],
+        def apply_sorting(eventlist):
+            """Sort events keeping the events priority criteria."""
+            eventlist.sort(
+                key=lambda e: (
+                    -e["calendar_type"] if e["calendar_type"] else 0,  # overrides: 1, shifts: 0, gaps: None
+                    -e["priority_level"] if e["priority_level"] else 0,
+                    e["start"],
+                )
             )
-        )
+
+        # sort schedule events by (type desc, priority desc, start timestamp asc)
+        apply_sorting(events)
 
         def _merge_intervals(evs):
             """Keep track of scheduled intervals."""
@@ -345,6 +349,9 @@ class OnCallSchedule(PolymorphicModel):
                     # event ends after current interval, update event start timestamp to match the interval end
                     # and process the updated event as any other event
                     ev["start"] = intervals[current_interval_idx][1]
+                    # reorder pending events after updating current event start date
+                    # (ie. insert the event where it should be to keep the order criteria)
+                    apply_sorting(pending)
                 else:
                     # done, go to next event
                     current_event_idx += 1
diff --git a/engine/apps/schedules/tests/test_on_call_schedule.py b/engine/apps/schedules/tests/test_on_call_schedule.py
index a6e875ba..9fae6517 100644
--- a/engine/apps/schedules/tests/test_on_call_schedule.py
+++ b/engine/apps/schedules/tests/test_on_call_schedule.py
@@ -322,6 +322,73 @@ def test_final_schedule_events(make_organization, make_user_for_organization, ma
     assert returned_events == expected_events
 
 
+@pytest.mark.django_db
+def test_final_schedule_splitting_events(
+    make_organization, make_user_for_organization, make_on_call_shift, make_schedule
+):
+    organization = make_organization()
+    schedule = make_schedule(
+        organization,
+        schedule_class=OnCallScheduleWeb,
+        name="test_web_schedule",
+    )
+
+    now = timezone.now().replace(hour=0, minute=0, second=0, microsecond=0)
+    start_date = now - timezone.timedelta(days=7)
+
+    user_a, user_b, user_c = (make_user_for_organization(organization, username=i) for i in "ABC")
+
+    shifts = (
+        # user, priority, start time (h), duration (hs)
+        (user_a, 1, 10, 10),  # r1-1: 10-20 / A
+        (user_b, 1, 12, 4),  # r1-2: 12-16 / B
+        (user_c, 2, 15, 3),  # r2-1: 15-18 / C
+    )
+    for user, priority, start_h, duration in shifts:
+        data = {
+            "start": start_date + timezone.timedelta(hours=start_h),
+            "rotation_start": start_date + timezone.timedelta(hours=start_h),
+            "duration": timezone.timedelta(hours=duration),
+            "priority_level": priority,
+            "frequency": CustomOnCallShift.FREQUENCY_DAILY,
+            "schedule": schedule,
+        }
+        on_call_shift = make_on_call_shift(
+            organization=organization, shift_type=CustomOnCallShift.TYPE_ROLLING_USERS_EVENT, **data
+        )
+        on_call_shift.add_rolling_users([[user]])
+
+    returned_events = schedule.final_events("UTC", start_date, days=1)
+
+    expected = (
+        # start (h), duration (H), user, priority
+        (10, 5, "A", 1),  # 10-15 A
+        (12, 3, "B", 1),  # 12-15 B
+        (15, 3, "C", 2),  # 15-18 C
+        (18, 2, "A", 1),  # 18-20 A
+    )
+    expected_events = [
+        {
+            "end": start_date + timezone.timedelta(hours=start + duration),
+            "priority_level": priority,
+            "start": start_date + timezone.timedelta(hours=start),
+            "user": user,
+        }
+        for start, duration, user, priority in expected
+    ]
+    returned_events = [
+        {
+            "end": e["end"],
+            "priority_level": e["priority_level"],
+            "start": e["start"],
+            "user": e["users"][0]["display_name"] if e["users"] else None,
+        }
+        for e in returned_events
+        if not e["is_gap"]
+    ]
+    assert returned_events == expected_events
+
+
 @pytest.mark.django_db
 def test_preview_shift(make_organization, make_user_for_organization, make_schedule, make_on_call_shift):
     organization = make_organization()