Moved the notifications code to go to admin to get the the template

preview document rather than go to template preview.

This will remove the logic from admin and place it in api so it is
easier to expand on later when there are precompiled PDFs

app/main/views/notifications.py

@@ -1,4 +1,7 @@
 # -*- coding: utf-8 -*-
+import base64
+import json
+from collections import ItemsView
 from datetime import datetime
 
 from flask import (
@@ -88,6 +91,8 @@ def view_notification(service_id, notification_id):
 @user_has_permissions('view_activity', admin_override=True)
 def view_letter_notification_as_preview(service_id, notification_id, filetype):
 
+    print("\n\nview_letter_notification_as_preview\n\n")
+
     if filetype not in ('pdf', 'png'):
         abort(404)
 
@@ -107,8 +112,15 @@ def view_letter_notification_as_preview(service_id, notification_id, filetype):
 
     template.values = notification['personalisation']
 
-    return TemplatePreview.from_utils_template(template, filetype, page=request.args.get('page'))
+    preview = notification_api_client.get_notification_letter_preview(
+        service_id,
+        template.id,
+        notification_id,
+        filetype,
+        page=request.args.get('page')
+    )
 
+    return base64.b64decode(preview['content']), preview['status'], ItemsView(dict(preview['headers']))
 
 @main.route("/services/<service_id>/notification/<notification_id>.json")
 @user_has_permissions('view_activity', admin_override=True)

app/notify_client/notification_api_client.py

@@ -78,3 +78,15 @@ class NotificationApiClient(NotifyAdminAPIClient):
             if notification['notification_type'] == 'letter' and notification['status'] in ('created', 'sending'):
                 notification['status'] = 'accepted'
         return notifications
+
+    def get_notification_letter_preview(self, service_id, template_id, notification_id, file_type, page=None):
+
+        get_url = '/service/{}/template/{}/pdf-preview/{}/{}{}'.format(
+            service_id,
+            template_id,
+            notification_id,
+            file_type,
+            '?page={}'.format(page) if page else ''
+        )
+
+        return self.get(url=get_url)