Add better messaging for %statistics/%summary errors (#460)

* Add better messaging for %statistics/%summary errors

* update changelog

* Add messaging for StatisticsNotAvailableException

---------

Co-authored-by: Michael Chin <chnmch@amazon.com>

Author: michaelnchin

ChangeLog.md

@@ -3,6 +3,7 @@
 Starting with v1.31.6, this file will contain a record of major features and updates made in each release of graph-notebook.
 
 ## Upcoming
+- Added more helpful error messaging for `%statistics`/`%summary` ([Link to PR](https://github.com/aws/graph-notebook/pull/460))
 - Added Neptune Notebook CloudFormation template ([Link to PR](https://github.com/aws/graph-notebook/pull/442))
 
 ## Release 3.7.2 (March 9, 2023)

src/graph_notebook/magics/graph_magic.py

@@ -241,6 +241,24 @@ def get_load_ids(neptune_client):
     return ids, res
 
 
+def process_statistics_400(is_summary: bool, response):
+    bad_request_res = json.loads(response.text)
+    res_code = bad_request_res['code']
+    if res_code == 'StatisticsNotAvailableException':
+        print("No statistics found. Please ensure that auto-generation of DFE statistics is enabled by running "
+              "'%statistics' and checking if 'autoCompute' if set to True. Alternately, you can manually "
+              "trigger statistics generation by running: '%statistics --mode refresh'.")
+    elif res_code == "BadRequestException":
+        print("Unable to query the statistics endpoint. Please check that your Neptune instance is of size r5.large or "
+              "greater in order to have DFE statistics enabled.")
+        if is_summary and "Statistics is disabled" not in bad_request_res["detailedMessage"]:
+            print("\nPlease also note that the Graph Summary API is only available in Neptune engine version 1.2.1.0 "
+                  "and later.")
+    else:
+        print("Query encountered 400 error, please see below.")
+    print(f"\nFull response: {bad_request_res}")
+
+
 # TODO: refactor large magic commands into their own modules like what we do with %neptune_ml
 # noinspection PyTypeChecker
 @magics_class
@@ -424,6 +442,12 @@ def statistics(self, line, local_ns: dict = None):
             return
 
         statistics_res = self.client.statistics(args.language, args.summary, mode)
+        if statistics_res.status_code == 400:
+            if args.summary:
+                process_statistics_400(True, statistics_res)
+            else:
+                process_statistics_400(False, statistics_res)
+            return
         statistics_res.raise_for_status()
         statistics_res_json = statistics_res.json()
         if not args.silent:
@@ -452,6 +476,9 @@ def summary(self, line, local_ns: dict = None):
             mode = "basic"
 
         summary_res = self.client.statistics(args.language, True, mode)
+        if summary_res.status_code == 400:
+            process_statistics_400(True, summary_res)
+            return
         summary_res.raise_for_status()
         summary_res_json = summary_res.json()
         if not args.silent: