fix(timezone): fix timer clock-skew

apps/time_entries/api/serializers.py

@@ -1,4 +1,5 @@
 from rest_framework import serializers
+from django.utils import timezone
 
 from core.serializers.base import BaseModelSerializer
 from apps.time_entries.models import TimeEntry
@@ -31,6 +32,27 @@ class TimeEntrySerializer(BaseModelSerializer):
     tag_details = serializers.SerializerMethodField()
     start_time = serializers.DateTimeField(format="%Y-%m-%d %H:%M:%S")
     end_time = serializers.DateTimeField(format="%Y-%m-%d %H:%M:%S", allow_null=True)
+    start_time_ms = serializers.SerializerMethodField()
+    end_time_ms = serializers.SerializerMethodField()
+    server_now_ms = serializers.SerializerMethodField()
+
+    @staticmethod
+    def _epoch_ms(value):
+        if value is None:
+            return None
+        if timezone.is_naive(value):
+            value = timezone.make_aware(value, timezone.get_current_timezone())
+        return int(value.timestamp() * 1000)
+
+    def get_start_time_ms(self, obj):
+        return self._epoch_ms(obj.start_time)
+
+    def get_end_time_ms(self, obj):
+        return self._epoch_ms(obj.end_time)
+
+    def get_server_now_ms(self, obj):
+        server_now = self.context.get("server_now") or timezone.now()
+        return self._epoch_ms(server_now)
 
     def get_tags(self, obj):
         return [str(tag.id) for tag in Tag.all_objects.filter(time_entries=obj).order_by("-updated_at", "-created_at")]
@@ -76,7 +98,10 @@ class TimeEntrySerializer(BaseModelSerializer):
             "project_details",
             "description",
             "start_time",
+            "start_time_ms",
             "end_time",
+            "end_time_ms",
+            "server_now_ms",
             "duration",
             "tags",
             "tag_details",

apps/time_entries/api/views.py

@@ -38,6 +38,17 @@ class TimeEntryViewSet(ModelViewSet):
     filterset_class = TimeEntryFilter
     search_fields = ["description", "project__name", "project__client__name", "tags__name"]
 
+    @staticmethod
+    def _epoch_ms(value):
+        if timezone.is_naive(value):
+            value = timezone.make_aware(value, timezone.get_current_timezone())
+        return int(value.timestamp() * 1000)
+
+    def _serializer_context(self, *, server_now=None):
+        context = self.get_serializer_context()
+        context["server_now"] = server_now or timezone.now()
+        return context
+
     @staticmethod
     def _serialize_duration_ms(entry):
         if entry.duration is not None:
@@ -51,8 +62,12 @@ class TimeEntryViewSet(ModelViewSet):
         days_since_sunday = (local_dt.weekday() + 1) % 7
         return (local_dt - timedelta(days=days_since_sunday)).date()
 
-    def _build_grouped_entries(self, entries):
-        serialized_entries = TimeEntrySerializer(entries, many=True, context=self.get_serializer_context()).data
+    def _build_grouped_entries(self, entries, *, server_now):
+        serialized_entries = TimeEntrySerializer(
+            entries,
+            many=True,
+            context=self._serializer_context(server_now=server_now),
+        ).data
         serialized_by_id = {item["id"]: item for item in serialized_entries}
         weeks = []
         weeks_by_key = {}
@@ -114,6 +129,7 @@ class TimeEntryViewSet(ModelViewSet):
         queryset = self.filter_queryset(self.get_queryset())
         paginator = self.pagination_class()
         page = paginator.paginate_queryset(queryset, request, view=self)
+        server_now = timezone.now()
         current_items_count = len(page)
         has_more = (paginator.offset + current_items_count) < paginator.count
 
@@ -125,7 +141,19 @@ class TimeEntryViewSet(ModelViewSet):
                 "offset": paginator.offset,
                 "next_offset": paginator.offset + current_items_count if has_more else None,
                 "has_more": has_more,
-                "groups": self._build_grouped_entries(page),
+                "server_now_ms": self._epoch_ms(server_now),
+                "server_now": server_now.isoformat(),
+                "groups": self._build_grouped_entries(page, server_now=server_now),
+            }
+        )
+
+    @action(detail=False, methods=["get"], url_path="debug-time")
+    def debug_time(self, request):
+        server_now = timezone.now()
+        return Response(
+            {
+                "server_now_ms": self._epoch_ms(server_now),
+                "server_now": server_now.isoformat(),
             }
         )
 
@@ -148,7 +176,7 @@ class TimeEntryViewSet(ModelViewSet):
             **serializer.validated_data
         )
         
-        output_serializer = TimeEntrySerializer(entry, context=self.get_serializer_context())
+        output_serializer = TimeEntrySerializer(entry, context=self._serializer_context())
         return Response(output_serializer.data, status=status.HTTP_201_CREATED)
 
     def update(self, request, *args, **kwargs):
@@ -168,7 +196,7 @@ class TimeEntryViewSet(ModelViewSet):
             **serializer.validated_data
         )
         
-        output_serializer = TimeEntrySerializer(updated_entry, context=self.get_serializer_context())
+        output_serializer = TimeEntrySerializer(updated_entry, context=self._serializer_context())
         return Response(output_serializer.data, status=status.HTTP_200_OK)
 
     @action(detail=True, methods=["post"])
@@ -189,7 +217,7 @@ class TimeEntryViewSet(ModelViewSet):
         end_time = serializer.validated_data.get("end_time")
         stopped_entry = stop_time_entry(entry, end_time=end_time)
         
-        output_serializer = TimeEntrySerializer(stopped_entry, context=self.get_serializer_context())
+        output_serializer = TimeEntrySerializer(stopped_entry, context=self._serializer_context())
         return Response(output_serializer.data, status=status.HTTP_200_OK)
 
     def destroy(self, request, *args, **kwargs):