.

atlas/models.py

@@ -847,6 +847,50 @@ class Case(models.Model, AuthorMixin, QuestionMixin):
         help_text="Optional manually overridden study date for linked case series.",
     )
 
+    def get_series_info(self):
+        try:
+            has_next = hasattr(self, 'next_case') and self.next_case is not None
+        except Case.DoesNotExist:
+            has_next = False
+
+        if not self.previous_case_id and not has_next:
+            return {"in_series": False}
+
+        # Find the start of the chain (the first case)
+        first_case = self
+        visited = {self.pk}
+        while first_case.previous_case:
+            if first_case.previous_case.pk in visited:
+                break
+            first_case = first_case.previous_case
+            visited.add(first_case.pk)
+
+        # Traverse the chain from the first case to find positions and count
+        chain = []
+        current = first_case
+        visited_forward = set()
+        while current:
+            if current.pk in visited_forward:
+                break
+            chain.append(current)
+            visited_forward.add(current.pk)
+            try:
+                current = current.next_case if hasattr(current, 'next_case') else None
+            except Case.DoesNotExist:
+                current = None
+
+        total = len(chain)
+        try:
+            position = chain.index(self) + 1
+        except ValueError:
+            position = 1
+
+        return {
+            "in_series": True,
+            "position": position,
+            "total": total,
+        }
+
     def get_ordered_series_details(self):
         cached = getattr(self, "_ordered_series_details_cache", None)
         if cached is not None: