From 94d3dd4b13595781475210a19b7b5ca89a787d8c Mon Sep 17 00:00:00 2001
From: Alex Root Junior <jroot.junior@gmail.com>
Date: Sun, 29 Jul 2018 03:17:44 +0300
Subject: [PATCH] You can now use the Retry-After response header to configure
 the delay after which the Bot API will retry the request after an
 unsuccessful response from a webhook.

---
 aiogram/dispatcher/webhook.py | 10 ++++++++--
 aiogram/utils/executor.py     | 11 ++++++++---
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/aiogram/dispatcher/webhook.py b/aiogram/dispatcher/webhook.py
index 970fd655..83c5fb74 100644
--- a/aiogram/dispatcher/webhook.py
+++ b/aiogram/dispatcher/webhook.py
@@ -128,8 +128,14 @@ class WebhookRequestHandler(web.View):
         response = self.get_response(results)
 
         if response:
-            return response.get_web_response()
-        return web.Response(text='ok')
+            web_response = response.get_web_response()
+        else:
+            web_response = web.Response(text='ok')
+
+        if self.request.app['RETRY_AFTER']:
+            web_response.headers['Retry-After'] = self.request.app['RETRY_AFTER']
+
+        return web_response
 
     async def get(self):
         self.validate_ip()
diff --git a/aiogram/utils/executor.py b/aiogram/utils/executor.py
index e114e534..e3d8aa1f 100644
--- a/aiogram/utils/executor.py
+++ b/aiogram/utils/executor.py
@@ -40,7 +40,7 @@ def start_polling(dispatcher, *, loop=None, skip_updates=False, reset_webhook=Tr
 
 
 def start_webhook(dispatcher, webhook_path, *, loop=None, skip_updates=None,
-                  on_startup=None, on_shutdown=None, check_ip=False, **kwargs):
+                  on_startup=None, on_shutdown=None, check_ip=False, retry_after=None, **kwargs):
     """
     Start bot in webhook mode
 
@@ -54,7 +54,8 @@ def start_webhook(dispatcher, webhook_path, *, loop=None, skip_updates=None,
     :param kwargs:
     :return:
     """
-    executor = Executor(dispatcher, skip_updates=skip_updates, check_ip=check_ip, loop=loop)
+    executor = Executor(dispatcher, skip_updates=skip_updates, check_ip=check_ip, retry_after=retry_after,
+                        loop=loop)
     _setup_callbacks(executor, on_startup, on_shutdown)
 
     executor.start_webhook(webhook_path, **kwargs)
@@ -84,12 +85,13 @@ class Executor:
     Main executor class
     """
 
-    def __init__(self, dispatcher, skip_updates=None, check_ip=False, loop=None):
+    def __init__(self, dispatcher, skip_updates=None, check_ip=False, retry_after=None, loop=None):
         if loop is None:
             loop = dispatcher.loop
         self.dispatcher = dispatcher
         self.skip_updates = skip_updates
         self.check_ip = check_ip
+        self.retry_after = retry_after
         self.loop = loop
 
         self._identity = secrets.token_urlsafe(16)
@@ -186,6 +188,9 @@ class Executor:
         if app is None:
             self._web_app = app = web.Application()
 
+        if self.retry_after:
+            app['RETRY_AFTER'] = self.retry_after
+
         if self._identity == app.get(self._identity):
             # App is already configured
             return