Chunk events by day

Scanning the page is difficult at the moment because it’s hard to tell
how far apart in time events are, and thereby determine which events
might be related.

Grouping the events by day quickly lets users narrow their focus to
a meaningful subset of the events.

app/main/views/history.py

@@ -1,5 +1,8 @@
+from collections import defaultdict
+
 from flask import render_template
 
+from app import current_service, format_date_numeric
 from app.main import main
 from app.utils import user_has_permissions
 
@@ -7,4 +10,17 @@ from app.utils import user_has_permissions
 @main.route("/services/<service_id>/history")
 @user_has_permissions('manage_service')
 def history(service_id):
-    return render_template('views/temp-history.html')
+    return render_template(
+        'views/temp-history.html',
+        days=_chunk_events_by_day(current_service.history)
+    )
+
+
+def _chunk_events_by_day(events):
+
+    days = defaultdict(list)
+
+    for event in reversed(events):
+        days[format_date_numeric(event.time)].append(event)
+
+    return sorted(days.items(), reverse=True)