prevent saturation of the user retrieval API

src/BirdsiteLive.Twitter/Statistics/TwitterStatisticsHandler.cs

@@ -13,6 +13,8 @@ namespace BirdsiteLive.Statistics.Domain
         void CalledTweetApi();
         void CalledTimelineApi();
         ApiStatistics GetStatistics();
+
+        int GetCurrentUserCalls();
     }
 
     //Rate limits: https://developer.twitter.com/en/docs/twitter-api/v1/rate-limits
@@ -60,7 +62,12 @@ namespace BirdsiteLive.Statistics.Domain
             foreach (var old in oldSnapshots) _snapshots.TryRemove(old, out var data);
         }
 
-        public void CalledUserApi()  //GET users/show - 900/15mins
+        public int GetCurrentUserCalls()
+        {
+            return _userCalls;
+        }
+
+        public void CalledUserApi()  //GET users/show - 300/15mins
         {
             Interlocked.Increment(ref _userCalls);
         }

src/BirdsiteLive.Twitter/TwitterUserService.cs

@@ -32,6 +32,12 @@ namespace BirdsiteLive.Twitter
 
         public TwitterUser GetUser(string username)
         {
+            //Check if API is saturated 
+            var currentCalls = _statisticsHandler.GetCurrentUserCalls();
+            var maxCalls = _statisticsHandler.GetStatistics().UserCallsMax;
+            if (currentCalls > maxCalls) return null;
+
+            //Proceed to account retrieval
             _twitterAuthenticationInitializer.EnsureAuthenticationIsInitialized();
             ExceptionHandler.SwallowWebExceptions = false;
 
@@ -49,9 +55,6 @@ namespace BirdsiteLive.Twitter
             catch (Exception e)
             {
                 _logger.LogError(e, "Error retrieving user {Username}", username);
-
-                // TODO keep track of error, see where to remove user if too much errors
-
                 return null;
             }