Add Message and Event receivers

application/src/main/java/org/togetherjava/tjbot/Application.java

@@ -5,8 +5,8 @@
 import net.dv8tion.jda.api.requests.GatewayIntent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.togetherjava.tjbot.commands.Commands;
-import org.togetherjava.tjbot.commands.system.CommandSystem;
+import org.togetherjava.tjbot.commands.Features;
+import org.togetherjava.tjbot.commands.system.BotCore;
 import org.togetherjava.tjbot.config.Config;
 import org.togetherjava.tjbot.db.Database;
 
@@ -22,7 +22,7 @@
  * New commands can be created by implementing
  * {@link net.dv8tion.jda.api.events.interaction.SlashCommandEvent} or extending
  * {@link org.togetherjava.tjbot.commands.SlashCommandAdapter}. They can then be registered in
- * {@link Commands}.
+ * {@link Features}.
  */
 public enum Application {
     ;
@@ -79,7 +79,7 @@ public static void runBot(String token, Path databasePath) {
             JDA jda = JDABuilder.createDefault(token)
                 .enableIntents(GatewayIntent.GUILD_MEMBERS)
                 .build();
-            jda.addEventListener(new CommandSystem(jda, database));
+            jda.addEventListener(new BotCore(jda, database));
             jda.awaitReady();
             logger.info("Bot is ready");
 

application/src/main/java/org/togetherjava/tjbot/commands/EventReceiver.java

@@ -0,0 +1,22 @@
+package org.togetherjava.tjbot.commands;
+
+import net.dv8tion.jda.api.hooks.EventListener;
+
+/**
+ * Receives all incoming Discord events, unfiltered. A list of all available event types can be
+ * found in {@link net.dv8tion.jda.api.hooks.ListenerAdapter}.
+ *
+ * If possible, prefer one of the more concrete features instead, such as {@link SlashCommand} or
+ * {@link MessageReceiver}. Take care to not accidentally implement both, this and one of the other
+ * {@link Feature}s, as this might result in events being received multiple times.
+ * <p>
+ * All event receivers have to implement this interface. A new receiver can then be registered by
+ * adding it to {@link Features}.
+ * <p>
+ * <p>
+ * After registration, the system will notify a receiver for any incoming Discord event.
+ */
+@FunctionalInterface
+public interface EventReceiver extends EventListener, Feature {
+    // Basically a renaming of JDAs EventListener, plus our Feature marker interface
+}

application/src/main/java/org/togetherjava/tjbot/commands/Feature.java

@@ -0,0 +1,11 @@
+package org.togetherjava.tjbot.commands;
+
+/**
+ * Interface for features supported by the bots core system.
+ * <p>
+ * New features are added in {@link org.togetherjava.tjbot.commands.Features} and from there picked
+ * up by {@link org.togetherjava.tjbot.commands.system.BotCore}.
+ */
+public interface Feature {
+    // Marker interface
+}

application/src/main/java/org/togetherjava/tjbot/commands/Features.java

@@ -0,0 +1,84 @@
+package org.togetherjava.tjbot.commands;
+
+import net.dv8tion.jda.api.JDA;
+import org.jetbrains.annotations.NotNull;
+import org.togetherjava.tjbot.commands.basic.PingCommand;
+import org.togetherjava.tjbot.commands.basic.VcActivityCommand;
+import org.togetherjava.tjbot.commands.free.FreeCommand;
+import org.togetherjava.tjbot.commands.mathcommands.TeXCommand;
+import org.togetherjava.tjbot.commands.moderation.*;
+import org.togetherjava.tjbot.commands.moderation.temp.TemporaryModerationRoutine;
+import org.togetherjava.tjbot.commands.system.BotCore;
+import org.togetherjava.tjbot.commands.tags.TagCommand;
+import org.togetherjava.tjbot.commands.tags.TagManageCommand;
+import org.togetherjava.tjbot.commands.tags.TagSystem;
+import org.togetherjava.tjbot.commands.tags.TagsCommand;
+import org.togetherjava.tjbot.db.Database;
+import org.togetherjava.tjbot.routines.ModAuditLogRoutine;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+/**
+ * Utility class that offers all features that should be registered by the system, such as commands.
+ * New features have to be added here, where {@link BotCore} will then pick it up from and register
+ * it with the system.
+ * <p>
+ * To add a new slash command, extend the commands returned by
+ * {@link #createFeatures(JDA, Database)}.
+ */
+public enum Features {
+    ;
+
+    /**
+     * Creates all features that should be registered with this application.
+     * <p>
+     * Calling this method multiple times will result in multiple features being created, which
+     * generally should be avoided.
+     *
+     * @param jda the JDA instance commands will be registered at
+     * @param database the database of the application, which features can use to persist data
+     * @return a collection of all features
+     */
+    public static @NotNull Collection<Feature> createFeatures(@NotNull JDA jda,
+            @NotNull Database database) {
+        TagSystem tagSystem = new TagSystem(database);
+        ModerationActionsStore actionsStore = new ModerationActionsStore(database);
+
+        // NOTE The system can add special system relevant commands also by itself,
+        // hence this list may not necessarily represent the full list of all commands actually
+        // available.
+        Collection<Feature> features = new ArrayList<>();
+
+        // Routines
+        // TODO This should be moved into some proper command system instead (see GH issue #235
+        // which adds support for routines)
+        new ModAuditLogRoutine(jda, database).start();
+        new TemporaryModerationRoutine(jda, actionsStore).start();
+
+        // Message receivers
+
+        // Event receivers
+        features.add(new RejoinMuteListener(actionsStore));
+
+        // Slash commands
+        features.add(new PingCommand());
+        features.add(new TeXCommand());
+        features.add(new TagCommand(tagSystem));
+        features.add(new TagManageCommand(tagSystem));
+        features.add(new TagsCommand(tagSystem));
+        features.add(new VcActivityCommand());
+        features.add(new WarnCommand(actionsStore));
+        features.add(new KickCommand(actionsStore));
+        features.add(new BanCommand(actionsStore));
+        features.add(new UnbanCommand(actionsStore));
+        features.add(new AuditCommand(actionsStore));
+        features.add(new MuteCommand(actionsStore));
+        features.add(new UnmuteCommand(actionsStore));
+
+        // Mixtures
+        features.add(new FreeCommand());
+
+        return features;
+    }
+}

application/src/main/java/org/togetherjava/tjbot/commands/MessageReceiver.java

@@ -0,0 +1,51 @@
+package org.togetherjava.tjbot.commands;
+
+import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
+import net.dv8tion.jda.api.events.message.guild.GuildMessageUpdateEvent;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.regex.Pattern;
+
+/**
+ * Receives incoming Discord guild messages from channels matching a given pattern.
+ * <p>
+ * All message receivers have to implement this interface. For convenience, there is a
+ * {@link MessageReceiverAdapter} available that implemented most methods already. A new receiver
+ * can then be registered by adding it to {@link Features}.
+ * <p>
+ * <p>
+ * After registration, the system will notify a receiver whenever a new message was sent or an
+ * existing message was updated in any channel matching the {@link #getChannelNamePattern()} the bot
+ * is added to.
+ */
+public interface MessageReceiver extends Feature {
+    /**
+     * Retrieves the pattern matching the names of channels of which this receiver is interested in
+     * receiving sent messages from. Called by the core system once during the startup in order to
+     * register the receiver accordingly.
+     * <p>
+     * Changes on the pattern returned by this method afterwards will not be picked up.
+     *
+     * @return the pattern matching the names of relevant channels
+     */
+    @NotNull
+    Pattern getChannelNamePattern();
+
+    /**
+     * Triggered by the core system whenever a new message was sent and received in a text channel
+     * of a guild the bot has been added to.
+     *
+     * @param event the event that triggered this, containing information about the corresponding
+     *        message that was sent and received
+     */
+    void onMessageReceived(@NotNull GuildMessageReceivedEvent event);
+
+    /**
+     * Triggered by the core system whenever an existing message was edited in a text channel of a
+     * guild the bot has been added to.
+     *
+     * @param event the event that triggered this, containing information about the corresponding
+     *        message that was edited
+     */
+    void onMessageUpdated(@NotNull GuildMessageUpdateEvent event);
+}

application/src/main/java/org/togetherjava/tjbot/commands/MessageReceiverAdapter.java

@@ -0,0 +1,47 @@
+package org.togetherjava.tjbot.commands;
+
+import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
+import net.dv8tion.jda.api.events.message.guild.GuildMessageUpdateEvent;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.regex.Pattern;
+
+/**
+ * Adapter implementation of a {@link MessageReceiver}. A new receiver can then be registered by
+ * adding it to {@link Features}.
+ * <p>
+ * {@link #onMessageReceived(GuildMessageReceivedEvent)} and
+ * {@link #onMessageUpdated(GuildMessageUpdateEvent)} can be overridden if desired. The default
+ * implementation is empty, the adapter will not react to such events.
+ */
+public abstract class MessageReceiverAdapter implements MessageReceiver {
+
+    private final Pattern channelNamePattern;
+
+    /**
+     * Creates an instance of a message receiver with the given pattern.
+     *
+     * @param channelNamePattern the pattern matching names of channels interested in, only messages
+     *        from matching channels will be received
+     */
+    protected MessageReceiverAdapter(@NotNull Pattern channelNamePattern) {
+        this.channelNamePattern = channelNamePattern;
+    }
+
+    @Override
+    public final @NotNull Pattern getChannelNamePattern() {
+        return channelNamePattern;
+    }
+
+    @SuppressWarnings("NoopMethodInAbstractClass")
+    @Override
+    public void onMessageReceived(@NotNull GuildMessageReceivedEvent event) {
+        // Adapter does not react by default, subclasses may change this behavior
+    }
+
+    @SuppressWarnings("NoopMethodInAbstractClass")
+    @Override
+    public void onMessageUpdated(@NotNull GuildMessageUpdateEvent event) {
+        // Adapter does not react by default, subclasses may change this behavior
+    }
+}