[Telegram] Wait then retry if rate limited

src/notify/platform/telegram/request.rs

@@ -33,22 +33,35 @@ impl<'a> Request<'a> {
         method: &str,
         body: &json::Value,
     ) -> anyhow::Result<Response<T>> {
-        Self::send_request_with_files(self, method, body, None as Option<[FileUrl; 0]>).await
+        self.send_request_inner(method, body, None as Option<[&FileUrl; 0]>, true)
+            .await
     }
 
     async fn send_request_with_files<T: DeserializeOwned>(
+        &self,
+        method: &str,
+        body: &json::Value,
+        file_urls: Option<impl IntoIterator<Item = FileUrl<'_>>>,
+    ) -> anyhow::Result<Response<T>> {
+        let file_urls = file_urls.map(|f| f.into_iter().collect::<Vec<_>>());
+        self.send_request_inner(method, body, file_urls.as_ref().map(|f| f.iter()), true)
+            .await
+    }
+
+    async fn send_request_inner<'b, T: DeserializeOwned>(
         &self,
         method: &str,
         body: &json::Value,
         // If `file_urls` specified, the media fields in body should be replaced with
         // "attach://{index}"
-        file_urls: Option<impl IntoIterator<Item = FileUrl<'_>>>,
+        file_urls: Option<impl IntoIterator<Item = &'b FileUrl<'b>> + Clone>,
+        retry: bool,
     ) -> anyhow::Result<Response<T>> {
         let url = format!("https://api.telegram.org/bot{}/{}", self.token, method);
 
         let mut client = helper::reqwest_client()?.post(url);
 
-        if let Some(file_urls) = file_urls {
+        if let Some(file_urls) = file_urls.clone() {
             let form = form_append_json(Form::new(), body.as_object().unwrap());
             let form = futures::stream::iter(file_urls)
                 .enumerate()
@@ -103,6 +116,27 @@ impl<'a> Request<'a> {
         let resp: Response<T> = json::from_str(&text).map_err(|err| {
             anyhow!("failed to deserialize response: {err}, status: {status}, text: '{text}', request '{body}'")
         })?;
+
+        if retry {
+            if !resp.ok && resp.description.is_some() {
+                if let Some(after) = resp
+                    .description
+                    .as_deref()
+                    .unwrap()
+                    .strip_prefix("Too Many Requests: retry after ")
+                {
+                    warn!("Telegram rate limited, retry after '{}' + 1 seconds", after);
+
+                    let after = after
+                        .parse::<u64>()
+                        .map_err(|err| anyhow!("failed to parse rate limit duration: {err}"))?;
+                    tokio::time::sleep(tokio::time::Duration::from_secs(after + 1)).await;
+
+                    return Box::pin(self.send_request_inner(method, body, file_urls, false)).await;
+                }
+            }
+        }
+
         Ok(resp)
     }