From 3be35f6b0aae281d1173516f59f9116bc22567c6 Mon Sep 17 00:00:00 2001
From: Semprini <atkinpa@gmail.com>
Date: Mon, 25 May 2026 19:13:10 +1200
Subject: [PATCH] Refactor _compute_metrics to improve longest job duration
 calculation and handle None values in due dates

---
 app/views/views.py | 46 ++++++++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/app/views/views.py b/app/views/views.py
index 0088686..461c7bb 100644
--- a/app/views/views.py
+++ b/app/views/views.py
@@ -178,15 +178,14 @@ def _compute_metrics(
     avg_duration_today = (sum(durations_today) / len(durations_today)) if durations_today else None
 
     longest_today = None
+    longest_today_seconds = 0.0
     if today_jobs:
-        finished_today = [
-            j for j in today_jobs if j.start_datetime and j.finish_datetime
-        ]
-        if finished_today:
-            longest_today = max(
-                finished_today,
-                key=lambda j: (j.finish_datetime - j.start_datetime).total_seconds(),
-            )
+        for j in today_jobs:
+            if j.start_datetime and j.finish_datetime:
+                secs = (j.finish_datetime - j.start_datetime).total_seconds()
+                if longest_today is None or secs > longest_today_seconds:
+                    longest_today = j
+                    longest_today_seconds = secs
 
     # On-time = job started within 15 min of due_datetime (when both known)
     on_time = late = 0
@@ -222,8 +221,8 @@ def _compute_metrics(
     # --- Upcoming today ---
     upcoming_today = sorted(
         (j for j in today_jobs
-         if j.start_datetime is None and j.due_datetime and j.due_datetime >= now),
-        key=lambda j: j.due_datetime,
+         if j.start_datetime is None and j.due_datetime is not None and j.due_datetime >= now),
+        key=lambda j: j.due_datetime or datetime.max,
     )[:5]
 
     return {
@@ -248,8 +247,7 @@ def _compute_metrics(
             "avg_duration_today": _fmt_duration(avg_duration_today) if avg_duration_today is not None else None,
             "longest_today_name": longest_today.name if longest_today else None,
             "longest_today_duration": (
-                _fmt_duration((longest_today.finish_datetime - longest_today.start_datetime).total_seconds())
-                if longest_today else None
+                _fmt_duration(longest_today_seconds) if longest_today else None
             ),
             "on_time_rate_today": on_time_rate_today,
             "on_time": on_time,
@@ -269,8 +267,11 @@ def _compute_metrics(
                 "name": j.name,
                 "as_at": j.as_at_date.isoformat(),
                 "reason": j.status_reason or "—",
-                "when": (j.finish_datetime or j.start_datetime).isoformat(timespec="minutes")
-                if (j.finish_datetime or j.start_datetime) else "",
+                "when": (
+                    _when.isoformat(timespec="minutes")
+                    if (_when := j.finish_datetime or j.start_datetime) is not None
+                    else ""
+                ),
             }
             for j in recent_failures
         ],
@@ -278,7 +279,7 @@ def _compute_metrics(
             {
                 "id": j.id,
                 "name": j.name,
-                "due": j.due_datetime.strftime("%H:%M"),
+                "due": j.due_datetime.strftime("%H:%M") if j.due_datetime else "",
             }
             for j in upcoming_today
         ],
@@ -449,11 +450,16 @@ async def job_detail_view(request: Request, job_id: int):
             lateness_str = f"{_fmt_duration(delta)} late"
 
     # Aggregate stats across history
-    finished_related = [j for j in related if j.start_datetime and j.finish_datetime]
-    avg_dur = (
-        sum((j.finish_datetime - j.start_datetime).total_seconds() for j in finished_related)
-        / len(finished_related)
-    ) if finished_related else None
+    finished_related = [
+        j for j in related
+        if j.start_datetime is not None and j.finish_datetime is not None
+    ]
+    finished_durations = [
+        (j.finish_datetime - j.start_datetime).total_seconds()
+        for j in finished_related
+        if j.start_datetime is not None and j.finish_datetime is not None
+    ]
+    avg_dur = (sum(finished_durations) / len(finished_durations)) if finished_durations else None
     success_count = sum(1 for j in related if j.status == "completed")
     fail_count = sum(1 for j in related if j.status == "failed")
     finished_count = success_count + fail_count