refactor(#74): Enhance function robustness and configurability

supabase/migrations/20241112214000_add_token_cleanup_function.sql

@@ -6,16 +6,29 @@ grant all privileges on all tables in schema cron to postgres;
 
 -- Create a function to delete expired tokens
 CREATE OR REPLACE FUNCTION delete_expired_tokens()
-RETURNS void LANGUAGE plpgsql AS $$
+RETURNS integer LANGUAGE plpgsql AS $$
+DECLARE
+  deletion_count integer;
+  expiry_interval interval := '24 hours'::interval;
 BEGIN
   DELETE FROM account_deletion_requests
-  WHERE requested_at < NOW() - INTERVAL '24 hours';
+  WHERE requested_at < NOW() - expiry_interval
+  RETURNING COUNT(*) INTO deletion_count;
+  RAISE NOTICE 'Deleted % expired token(s)', deletion_count;
+  RETURN deletion_count;
 END;
 $$;
 
--- Schedule the function to run every hour
-SELECT cron.schedule(
-  'delete_expired_tokens',
-  '0 * * * *',
-  'CALL delete_expired_tokens()'
-);
+DO $$
+BEGIN
+  -- Schedule the function to run every hour
+  PERFORM cron.schedule(
+    'delete_expired_tokens',
+    '0 * * * *',
+    'SELECT delete_expired_tokens()'
+  );
+EXCEPTION WHEN OTHERS THEN
+  RAISE NOTICE 'Failed to schedule token cleanup: %', SQLERRM;
+  RAISE;
+END;
+$$;