Add listener for #talk-to-james channel

Author: Bastian

src/main/java/org/javacord/bot/Constants.java

@@ -27,6 +27,11 @@ public final class Constants {
      */
     public static final long DAPI_JAVACORD_CHANNEL_ID = 381889796785831936L;
 
+    /**
+     * The ID of the #talk-to-james channel on the Javacord server.
+     */
+    public static final long TALK_TO_JAMES_CHANNEL_ID = 712366253603422209L;
+
     /**
      * The API URL where to obtain the latest release version for Javacord.
      */

src/main/java/org/javacord/bot/Main.java

@@ -17,6 +17,7 @@
 import org.javacord.bot.commands.SetupCommand;
 import org.javacord.bot.commands.WikiCommand;
 import org.javacord.bot.listeners.CommandCleanupListener;
+import org.javacord.bot.listeners.TalkToJamesListener;
 import org.javacord.bot.util.LatestVersionFinder;
 
 import java.io.BufferedReader;
@@ -80,6 +81,7 @@ public static void main(String[] args) throws IOException {
         handler.registerCommand(new HelpCommand(handler));
 
         api.addMessageDeleteListener(new CommandCleanupListener());
+        api.addMessageCreateListener(new TalkToJamesListener(handler));
     }
 
     private static void setupLogging() throws IOException {

src/main/java/org/javacord/bot/listeners/TalkToJamesListener.java

@@ -0,0 +1,49 @@
+package org.javacord.bot.listeners;
+
+import de.btobastian.sdcf4j.CommandHandler;
+import org.javacord.api.entity.message.embed.EmbedBuilder;
+import org.javacord.api.event.message.MessageCreateEvent;
+import org.javacord.api.listener.message.MessageCreateListener;
+import org.javacord.api.util.logging.ExceptionLogger;
+import org.javacord.bot.Constants;
+
+import java.util.Arrays;
+
+public class TalkToJamesListener implements MessageCreateListener {
+
+    private final CommandHandler commandHandler;
+
+    /**
+     * Initializes the listener.
+     *
+     * @param commandHandler The command handler used to extract commands.
+     */
+    public TalkToJamesListener(CommandHandler commandHandler) {
+        this.commandHandler = commandHandler;
+    }
+
+    @Override
+    public void onMessageCreate(MessageCreateEvent event) {
+        if (event.getChannel().getId() != Constants.TALK_TO_JAMES_CHANNEL_ID) {
+            return;
+        }
+        if (event.getMessageAuthor().isYourself()) {
+            return;
+        }
+
+        boolean messageIsCommand = commandHandler.getCommands().stream()
+                .flatMap(command -> Arrays.stream(command.getCommandAnnotation().aliases()))
+                .anyMatch(alias -> event.getMessageContent().startsWith(alias));
+
+        if (!messageIsCommand) {
+            EmbedBuilder embed = new EmbedBuilder()
+                    .setTitle("Information")
+                    .setDescription(
+                            "This channel is solely used to talk to me.\nYou can see all my commands with `!help`.")
+                    .setColor(Constants.JAVACORD_ORANGE);
+            CommandCleanupListener.insertResponseTracker(embed, event.getMessageId());
+            event.getChannel().sendMessage(embed).exceptionally(ExceptionLogger.get());
+        }
+    }
+
+}