make the 'last_activity' field in /tickets show the actual last activity by making it a virtual field

core/tickets/api_v2.py

@@ -13,11 +13,12 @@ from core.settings import MAIL_DOMAIN
 from mail.models import Email
 from mail.protocol import send_smtp, make_reply, collect_references
 from notify_sessions.models import SystemEvent
-from tickets.models import IssueThread, Comment, STATE_CHOICES, StateChange
+from tickets.models import IssueThread, Comment, STATE_CHOICES
 
 
 class IssueSerializer(serializers.ModelSerializer):
     timeline = serializers.SerializerMethodField()
+    last_activity = serializers.SerializerMethodField()
 
     class Meta:
         model = IssueThread
@@ -36,6 +37,18 @@ class IssueSerializer(serializers.ModelSerializer):
                 raise serializers.ValidationError('invalid state')
         return attrs
 
+    @staticmethod
+    def get_last_activity(self):
+        try:
+            last_state_change = self.state_changes.order_by('-timestamp').first().timestamp \
+                if self.state_changes.count() > 0 else None
+            last_comment = self.comments.order_by('-timestamp').first().timestamp if self.comments.count() > 0 else None
+            last_mail = self.emails.order_by('-timestamp').first().timestamp if self.emails.count() > 0 else None
+            args = [x for x in [last_state_change, last_comment, last_mail] if x is not None]
+            return max(args)
+        except AttributeError:
+            return None
+
     @staticmethod
     def get_timeline(obj):
         timeline = []
@@ -65,6 +78,9 @@ class IssueSerializer(serializers.ModelSerializer):
             })
         return sorted(timeline, key=lambda x: x['timestamp'])
 
+    def get_queryset(self):
+        return IssueThread.objects.all().order_by('-last_activity')
+
 
 class IssueViewSet(viewsets.ModelViewSet):
     serializer_class = IssueSerializer