Sets up an echo command

Tools/BiblioTech/BiblioTech.csproj

@@ -7,4 +7,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Discord.Net" Version="3.12.0" />
+  </ItemGroup>
+
 </Project>

Tools/BiblioTech/CommandHandler.cs

@@ -0,0 +1,62 @@
+using Discord.Commands;
+using Discord.WebSocket;
+using System.Reflection;
+
+namespace BiblioTech
+{
+    public class CommandHandler
+    {
+        private readonly DiscordSocketClient client;
+        private readonly CommandService commands;
+
+        // Retrieve client and CommandService instance via ctor
+        public CommandHandler(DiscordSocketClient client, CommandService commands)
+        {
+            this.commands = commands;
+            this.client = client;
+        }
+
+        public async Task InstallCommandsAsync()
+        {
+            // Hook the MessageReceived event into our command handler
+            client.MessageReceived += HandleCommandAsync;
+
+            // Here we discover all of the command modules in the entry 
+            // assembly and load them. Starting from Discord.NET 2.0, a
+            // service provider is required to be passed into the
+            // module registration method to inject the 
+            // required dependencies.
+            //
+            // If you do not use Dependency Injection, pass null.
+            // See Dependency Injection guide for more information.
+            await commands.AddModulesAsync(assembly: Assembly.GetEntryAssembly(),
+                                            services: null);
+        }
+
+        private async Task HandleCommandAsync(SocketMessage messageParam)
+        {
+            // Don't process the command if it was a system message
+            var message = messageParam as SocketUserMessage;
+            if (message == null) return;
+
+            // Create a number to track where the prefix ends and the command begins
+            int argPos = 0;
+
+            // Determine if the message is a command based on the prefix and make sure no bots trigger commands
+            if (!(message.HasCharPrefix('!', ref argPos) ||
+                message.HasMentionPrefix(client.CurrentUser, ref argPos)) ||
+                message.Author.IsBot)
+                return;
+
+            // Create a WebSocket-based command context based on the message
+            var context = new SocketCommandContext(client, message);
+
+            // Execute the command with the command context we just
+            // created, along with the service provider for precondition checks.
+            await commands.ExecuteAsync(
+                context: context,
+                argPos: argPos,
+                services: null);
+        }
+    }
+}

Tools/BiblioTech/HelloWorldModule.cs

@@ -0,0 +1,14 @@
+using Discord.Commands;
+
+namespace BiblioTech
+{
+    public class HelloWorldModule : ModuleBase<SocketCommandContext>
+    {
+        [Command("say")]
+        [Summary("Echoes a message.")]
+        public Task SayAsync([Remainder][Summary("The text to echo")] string echo)
+        {
+            return ReplyAsync("I say: " + echo);
+        }
+    }
+}

Tools/BiblioTech/Program.cs

@@ -1,8 +1,29 @@
-public class Program
+using Discord;
-{
+using Discord.WebSocket;
-    public static void Main(string[] args)
-    {
-        Console.WriteLine("Starting Codex Discord bot BiblioTech...");
 
+public class Program
+{
+    public static Task Main(string[] args) => new Program().MainAsync();
+
+    private DiscordSocketClient client;
+
+    public async Task MainAsync()
+    {
+        client = new DiscordSocketClient();
+
+        client.Log += Log;
+
+        //  You can assign your bot token to a string, and pass that in to connect.
+        //  This is, however, insecure, particularly if you plan to have your code hosted in a public repository.
+        var token = "token";
+
+        await client.LoginAsync(TokenType.Bot, token);
+        await client.StartAsync();
+        await Task.Delay(-1);
+    }
+    private Task Log(LogMessage msg)
+    {
+        Console.WriteLine(msg.ToString());
+        return Task.CompletedTask;
     }
 }