refactor: Conditionally sleep between Chat API requests

For a slight performance improvement only sleep between Chat API requests on a 429 response,
as opposed to between every request.

src/google.rs

@@ -1,6 +1,8 @@
+use std::time;
 use anyhow::{Context, Result};
 use serde::{Deserialize, Serialize};
 use url::Url;
+use log::info;
 
 #[derive(Serialize, Deserialize, Debug)]
 pub struct GoogleChatMessage {
@@ -40,14 +42,25 @@ impl GoogleChatMessage {
             .body(serde_json::to_string(&self)?)
             .header("User-Agent", "GU-PR-Bot")
             .send()
-            .await?
-            .text()
+            .await?;
+
+        if response.status().eq(&reqwest::StatusCode::TOO_MANY_REQUESTS) {
+            /*
+            Sleep for 1.5 seconds to avoid rate limiting, at 60 requests per minute.
+            See https://developers.google.com/workspace/chat/limits
+            */
+            info!("Received {} response. Sleeping for 1.5 seconds before retrying", response.status());
+            tokio::time::sleep(time::Duration::from_millis(1500)).await;
+            Box::pin(self.send(webhook_url, thread_key)).await?;
+        }
+
+        let response_text = response.text()
             .await
             .context(format!("Failed to get response from: {}", &webhook_url))?;
 
-        serde_json::from_str(&response).context(format!(
+        serde_json::from_str(&response_text).context(format!(
             "Failed to parse JSON when querying {}: {}",
-            &webhook_url, response
+            &webhook_url, response_text
         ))
     }
 }

src/main.rs

@@ -4,7 +4,7 @@ mod google;
 use anyhow::{Context, Error};
 use chrono::{DateTime, Datelike, Utc};
 use log::{info, Level};
-use std::{env, time};
+use std::env;
 
 use github::GithubPullRequest;
 use google::GoogleChatMessage;
@@ -193,12 +193,6 @@ async fn main() -> Result<(), Error> {
             .await?;
 
         for pull_request in pull_requests_to_review {
-            /*
-            Sleep for 1 second to avoid rate limiting, at 60 requests per minute.
-            See https://developers.google.com/workspace/chat/limits
-             */
-            tokio::time::sleep(time::Duration::from_secs(1)).await;
-
             info!("Sending message for PR {} #{}", pull_request.head.repo.name, pull_request.number);
             GoogleChatMessage::from(make_message(pull_request, show_pr_age))
                 .send(&webhook_url, &thread_key)