Update service template cache keys when a template category is updated (

#1899)

* Update service template cache keys when a template category is updated

* Rever unneeded changes

app/notify_client/cache.py

@@ -32,6 +32,46 @@ def _make_key(key_format, client_method, args, kwargs):
     )
 
 
+def set_service_template(key_format):
+    def _set(client_method):
+        @wraps(client_method)
+        def new_client_method(client_instance, *args, **kwargs):
+            """
+            This decorator is functionaly the same as the `set` decorator. The only difference is that it checks if the
+            category of the service template is dirty and updates it if it is. When a category is updated via the admin
+            UI, the category is updated in the cache. However, the service template is not updated in the cache. This
+            decorator checks the category on the template against the cached category and updates the template if it is
+            dirty
+            """
+            redis_key = _make_key(key_format, client_method, args, kwargs)
+            cached_template = redis_client.get(redis_key)
+
+            if cached_template:
+                template_category = json.loads(cached_template.decode("utf-8")).get("template_category")
+                cached_category = redis_client.get(f"template_category-{template_category['id']}") if template_category else None
+
+                if cached_category:
+                    category = json.loads(cached_category.decode("utf-8"))
+
+                    if not category == template_category:
+                        redis_client.set(redis_key, json.dumps(cached_category), ex=TTL)
+
+                return json.loads(cached_template.decode("utf-8"))
+
+            api_response = client_method(client_instance, *args, **kwargs)
+
+            redis_client.set(
+                redis_key,
+                json.dumps(api_response),
+                ex=TTL,
+            )
+            return api_response
+
+        return new_client_method
+
+    return _set
+
+
 def set(key_format):
     def _set(client_method):
         @wraps(client_method)

app/notify_client/service_api_client.py

@@ -268,7 +268,7 @@ def update_service_template_postage(self, service_id, template_id, postage):
             _attach_current_user({"postage": postage}),
         )
 
-    @cache.set("template-{template_id}-version-{version}")
+    @cache.set_service_template("template-{template_id}-version-{version}")
     def get_service_template(self, service_id, template_id, version=None):
         """
         Retrieve a service template.