Use the Segment Adapter for retrieving page visits

This fixes the last occurence of directly accessing the session in the
codebase

src/wagtail_personalisation/adapters.py

@@ -144,6 +144,15 @@ def add_page_visit(self, page):
                 'count': 1,
             })
 
+    def get_visit_count(self, page=None):
+        """Return the number of visits on the current request or given page"""
+        path = page.path if page else self.request.path
+        visit_count = self.request.session.setdefault('visit_count', [])
+        for visit in visit_count:
+            if visit['path'] == path:
+                return visit['count']
+        return 0
+
     def update_visit_count(self):
         """Update the visit count for all segments in the request session."""
         segments = self.request.session['segments']

src/wagtail_personalisation/rules.py

@@ -226,23 +226,12 @@ def test_user(self, request):
         operator = self.operator
         segment_count = self.count
 
-        def get_visit_count(request):
-            """Search through the request sessions to get the page visit count
-            corresponding to the request.
+        # Local import for cyclic import
+        from wagtail_personalisation.adapters import get_segment_adapter
 
-            :param request: The http request
-            :type request: django.http.HttpRequest
-            :returns: A number indicating the amount of visits
-                      to the requested page
-            :rtype: int
-
-            """
-            for page in request.session['visit_count']:
-                if page['path'] == request.path:
-                    return page['count']
-
-        visit_count = get_visit_count(request)
+        adapter = get_segment_adapter(request)
 
+        visit_count = adapter.get_visit_count()
         if visit_count and operator == "more_than":
             if visit_count > segment_count:
                 return True