fix: Implement correct ratelimit handles for 429's (#2110)

* init

* fix errors

src/Discord.Net.Rest/Net/Queue/RequestQueueBucket.cs

@@ -88,7 +88,7 @@ namespace Discord.Net.Queue
 #if DEBUG_LIMITS
                                     Debug.WriteLine($"[{id}] (!) 429");
 #endif
-                                    UpdateRateLimit(id, request, info, true);
+                                    UpdateRateLimit(id, request, info, true, body:response.Stream);
                                 }
                                 await _queue.RaiseRateLimitTriggered(Id, info, $"{request.Method} {request.Endpoint}").ConfigureAwait(false);
                                 continue; //Retry
@@ -316,7 +316,7 @@ namespace Discord.Net.Queue
             }
         }
 
-        private void UpdateRateLimit(int id, IRequest request, RateLimitInfo info, bool is429, bool redirected = false)
+        private void UpdateRateLimit(int id, IRequest request, RateLimitInfo info, bool is429, bool redirected = false, Stream body = null)
         {
             if (WindowCount == 0)
                 return;
@@ -373,7 +373,17 @@ namespace Discord.Net.Queue
                     Debug.WriteLine($"[{id}] X-RateLimit-Remaining: " + info.Remaining.Value);
                     _semaphore = info.Remaining.Value;
                 }*/
-                if (info.RetryAfter.HasValue)
+                if (is429)
+                {
+                    // use the payload reset after value
+                    var payload = info.ReadRatelimitPayload(body);
+
+                    resetTick = DateTimeOffset.UtcNow.Add(TimeSpan.FromSeconds(payload.RetryAfter));
+#if DEBUG_LIMITS
+                    Debug.WriteLine($"[{id}] Reset-After: {info.ResetAfter.Value} ({info.ResetAfter?.TotalMilliseconds} ms)");
+#endif
+                }
+                else if (info.RetryAfter.HasValue)
                 {
                     //RetryAfter is more accurate than Reset, where available
                     resetTick = DateTimeOffset.UtcNow.AddSeconds(info.RetryAfter.Value);

src/Discord.Net.Rest/Net/RateLimitInfo.cs

@@ -61,22 +61,18 @@ namespace Discord.Net
                 DateTimeOffset.TryParse(temp, CultureInfo.InvariantCulture, DateTimeStyles.None, out var date) ? DateTimeOffset.UtcNow - date : (TimeSpan?)null;
         }
 
-        internal void ReadRatelimitPayload(Stream response)
+        internal Ratelimit ReadRatelimitPayload(Stream response)
         {
-            try
+            if (response != null && response.Length != 0)
             {
-                if (response != null && response.Length != 0)
+                using (TextReader text = new StreamReader(response))
+                using (JsonReader reader = new JsonTextReader(text))
                 {
-                    using (TextReader text = new StreamReader(response))
-                    using (JsonReader reader = new JsonTextReader(text))
-                    {
-                        var ratelimit = Discord.Rest.DiscordRestClient.Serializer.Deserialize<Ratelimit>(reader);
-
-                        ResetAfter = TimeSpan.FromSeconds(ratelimit.RetryAfter);
-                    }
+                    return Discord.Rest.DiscordRestClient.Serializer.Deserialize<Ratelimit>(reader);
                 }
             }
-            catch { }
+
+            return null;
         }
     }
 }