Refactor all the things!

src/Discord.Net/Collections/Users.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Discord.Collections
+{
+	public sealed class Users : AsyncCollection<User>
+	{
+		internal Users(DiscordClient client)
+			: base(client) { }
+
+		internal User GetOrAdd(string id) => GetOrAdd(id, () => new User(_client, id));
+		internal new User TryRemove(string id) => base.TryRemove(id);
+
+		protected override void OnCreated(User item) { }
+		protected override void OnRemoved(User item) { }
+
+		public User this[string id] => Get(id);
+		public User this[string name, string discriminator]
+		{
+			get
+			{
+				if (name == null) throw new ArgumentNullException(nameof(name));
+				if (discriminator == null) throw new ArgumentNullException(nameof(discriminator));
+
+				if (name.StartsWith("@"))
+					name = name.Substring(1);
+
+				return this.Where(x =>
+						string.Equals(x.Name, name, StringComparison.OrdinalIgnoreCase) &&
+						x.Discriminator == discriminator
+					)
+					.FirstOrDefault();
+			}
+		}
+
+		public IEnumerable<User> Find(string name)
+		{
+			if (name == null) throw new ArgumentNullException(nameof(name));
+
+			if (name.StartsWith("@"))
+			{
+				string name2 = name.Substring(1);
+				return this.Where(x =>
+					string.Equals(x.Name, name, StringComparison.OrdinalIgnoreCase) || string.Equals(x.Name, name2, StringComparison.OrdinalIgnoreCase));
+			}
+			else
+			{
+				return this.Where(x =>
+					string.Equals(x.Name, name, StringComparison.OrdinalIgnoreCase));
+			}
+		}
+	}
+}