Secret! (#8276)

Co-authored-by: moonheart08 <moonheart08@users.noreply.github.com>

Content.Shared/Random/Helpers/SharedRandomExtensions.cs

@@ -1,4 +1,5 @@
-using Content.Shared.Dataset;
+using System.Linq;
+using Content.Shared.Dataset;
 using Robust.Shared.Random;
 
 namespace Content.Shared.Random.Helpers
@@ -9,5 +10,28 @@ namespace Content.Shared.Random.Helpers
         {
             return random.Pick(prototype.Values);
         }
+
+        public static string Pick(this WeightedRandomPrototype prototype, IRobustRandom? random = null)
+        {
+            IoCManager.Resolve(ref random);
+            var picks = prototype.Weights;
+            var sum = picks.Values.Sum();
+            var accumulated = 0f;
+
+            var rand = random.NextFloat() * sum;
+
+            foreach (var (key, weight) in picks)
+            {
+                accumulated += weight;
+
+                if (accumulated >= rand)
+                {
+                    return key;
+                }
+            }
+
+            // Shouldn't happen
+            throw new InvalidOperationException($"Invalid weighted pick for {prototype.ID}!");
+        }
     }
 }