Improve performance (#162)

DiscordChatExporter.Core.Models/Mentionables.cs

@@ -0,0 +1,30 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace DiscordChatExporter.Core.Models
+{
+    public class Mentionables
+    {
+        public IReadOnlyList<User> Users { get; }
+
+        public IReadOnlyList<Channel> Channels { get; }
+
+        public IReadOnlyList<Role> Roles { get; }
+
+        public Mentionables(IReadOnlyList<User> users, IReadOnlyList<Channel> channels, IReadOnlyList<Role> roles)
+        {
+            Users = users;
+            Channels = channels;
+            Roles = roles;
+        }
+
+        public User GetUser(string id) =>
+            Users.FirstOrDefault(u => u.Id == id) ?? User.CreateUnknownUser(id);
+
+        public Channel GetChannel(string id) =>
+            Channels.FirstOrDefault(c => c.Id == id) ?? Channel.CreateDeletedChannel(id);
+
+        public Role GetRole(string id) =>
+            Roles.FirstOrDefault(r => r.Id == id) ?? Role.CreateDeletedRole(id);
+    }
+}