feat(DynamicVoiceChat): implement main logic

application/config.json.template

@@ -199,5 +199,10 @@
         "rolePattern": "Top Helper.*",
         "assignmentChannelPattern": "community-commands",
         "announcementChannelPattern": "hall-of-fame"
-    }
+    },
+    "dynamicVoiceChannelPatterns": [
+        "Gaming",
+        "Support/Studying Room",
+        "Chit Chat"
+    ]
 }

application/src/main/java/org/togetherjava/tjbot/config/Config.java

@@ -49,6 +49,7 @@ public final class Config {
     private final String selectRolesChannelPattern;
     private final String memberCountCategoryPattern;
     private final TopHelpersConfig topHelpers;
+    private final List<String> dynamicVoiceChannelPatterns;
 
     @SuppressWarnings("ConstructorWithTooManyParameters")
     @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
@@ -102,7 +103,9 @@ private Config(@JsonProperty(value = "token", required = true) String token,
             @JsonProperty(value = "rssConfig", required = true) RSSFeedsConfig rssFeedsConfig,
             @JsonProperty(value = "selectRolesChannelPattern",
                     required = true) String selectRolesChannelPattern,
-            @JsonProperty(value = "topHelpers", required = true) TopHelpersConfig topHelpers) {
+            @JsonProperty(value = "topHelpers", required = true) TopHelpersConfig topHelpers,
+            @JsonProperty(value = "dynamicVoiceChannelPatterns",
+                    required = true) List<String> dynamicVoiceChannelPatterns) {
         this.token = Objects.requireNonNull(token);
         this.githubApiKey = Objects.requireNonNull(githubApiKey);
         this.databasePath = Objects.requireNonNull(databasePath);
@@ -138,6 +141,7 @@ private Config(@JsonProperty(value = "token", required = true) String token,
         this.rssFeedsConfig = Objects.requireNonNull(rssFeedsConfig);
         this.selectRolesChannelPattern = Objects.requireNonNull(selectRolesChannelPattern);
         this.topHelpers = Objects.requireNonNull(topHelpers);
+        this.dynamicVoiceChannelPatterns = Objects.requireNonNull(dynamicVoiceChannelPatterns);
     }
 
     /**
@@ -457,4 +461,13 @@ public RSSFeedsConfig getRSSFeedsConfig() {
     public TopHelpersConfig getTopHelpers() {
         return topHelpers;
     }
+
+    /**
+     * Gets the list of voice channel patterns that are treated dynamically.
+     *
+     * @return the list of dynamic voice channel patterns
+     */
+    public List<String> getDynamicVoiceChannelPatterns() {
+        return dynamicVoiceChannelPatterns;
+    }
 }

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

@@ -77,6 +77,7 @@
 import org.togetherjava.tjbot.features.tophelper.TopHelpersMessageListener;
 import org.togetherjava.tjbot.features.tophelper.TopHelpersPurgeMessagesRoutine;
 import org.togetherjava.tjbot.features.tophelper.TopHelpersService;
+import org.togetherjava.tjbot.features.voicechat.DynamicVoiceChat;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -161,6 +162,9 @@ public static Collection<Feature> createFeatures(JDA jda, Database database, Con
         features.add(new SlashCommandEducator());
         features.add(new PinnedNotificationRemover(config));
 
+        // Voice receivers
+        features.add(new DynamicVoiceChat(config));
+
         // Event receivers
         features.add(new RejoinModerationRoleListener(actionsStore, config));
         features.add(new GuildLeaveCloseThreadListener(config));

application/src/main/java/org/togetherjava/tjbot/features/voicechat/DynamicVoiceChat.java

@@ -0,0 +1,114 @@
+package org.togetherjava.tjbot.features.voicechat;
+
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.entities.Guild;
+import net.dv8tion.jda.api.entities.Member;
+import net.dv8tion.jda.api.entities.MessageEmbed;
+import net.dv8tion.jda.api.entities.channel.concrete.VoiceChannel;
+import net.dv8tion.jda.api.entities.channel.middleman.AudioChannel;
+import net.dv8tion.jda.api.entities.channel.unions.AudioChannelUnion;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceUpdateEvent;
+import org.jetbrains.annotations.NotNull;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.togetherjava.tjbot.config.Config;
+import org.togetherjava.tjbot.features.VoiceReceiverAdapter;
+
+import java.util.List;
+import java.util.regex.Pattern;
+
+/**
+ * Handles dynamic voice channel creation and deletion based on user activity.
+ * <p>
+ * When a member joins a configured root channel, a temporary copy is created and the member is
+ * moved into it. Once the channel becomes empty, it is deleted.
+ */
+public final class DynamicVoiceChat extends VoiceReceiverAdapter {
+    private static final Logger logger = LoggerFactory.getLogger(DynamicVoiceChat.class);
+    private final List<Pattern> dynamicVoiceChannelPatterns;
+
+    public DynamicVoiceChat(Config config) {
+        this.dynamicVoiceChannelPatterns =
+                config.getDynamicVoiceChannelPatterns().stream().map(Pattern::compile).toList();
+    }
+
+    @Override
+    public void onVoiceUpdate(@NotNull GuildVoiceUpdateEvent event) {
+        AudioChannelUnion channelJoined = event.getChannelJoined();
+        AudioChannelUnion channelLeft = event.getChannelLeft();
+
+        if (channelJoined != null && eventHappenOnDynamicRootChannel(channelJoined)) {
+            logger.debug("Event happened on joined channel {}", channelJoined);
+            createDynamicVoiceChannel(event, channelJoined.asVoiceChannel());
+        }
+
+        if (channelLeft != null && !eventHappenOnDynamicRootChannel(channelLeft)) {
+            logger.debug("Event happened on left channel {}", channelLeft);
+            deleteDynamicVoiceChannel(channelLeft);
+        }
+    }
+
+    private boolean eventHappenOnDynamicRootChannel(AudioChannelUnion channel) {
+        return dynamicVoiceChannelPatterns.stream()
+            .anyMatch(pattern -> pattern.matcher(channel.getName()).matches());
+    }
+
+    private void createDynamicVoiceChannel(@NotNull GuildVoiceUpdateEvent event,
+            VoiceChannel channel) {
+        Guild guild = event.getGuild();
+        Member member = event.getMember();
+        String newChannelName = "%s's %s".formatted(member.getEffectiveName(), channel.getName());
+
+        channel.createCopy()
+            .setName(newChannelName)
+            .setPosition(channel.getPositionRaw())
+            .onSuccess(newChannel -> {
+                moveMember(guild, member, newChannel);
+                sendWarningEmbed(newChannel);
+            })
+            .queue(newChannel -> logger.trace("Successfully created {} voice channel.",
+                    newChannel.getName()),
+                    error -> logger.error("Failed to create dynamic voice channel", error));
+    }
+
+    private void moveMember(Guild guild, Member member, AudioChannel channel) {
+        guild.moveVoiceMember(member, channel)
+            .queue(_ -> logger.trace(
+                    "Successfully moved {} to newly created dynamic voice channel {}",
+                    member.getEffectiveName(), channel.getName()),
+                    error -> logger.error(
+                            "Failed to move user into dynamically created voice channel {}, {}",
+                            member.getNickname(), channel.getName(), error));
+    }
+
+    private void deleteDynamicVoiceChannel(AudioChannelUnion channel) {
+        int memberCount = channel.getMembers().size();
+
+        if (memberCount > 0) {
+            logger.debug("Voice channel {} not empty ({} members), so not removing.",
+                    channel.getName(), memberCount);
+            return;
+        }
+
+        channel.delete()
+            .queue(_ -> logger.trace("Deleted dynamically created voice channel: {} ",
+                    channel.getName()),
+                    error -> logger.error("Failed to delete dynamically created voice channel: {} ",
+                            channel.getName(), error));
+    }
+
+    private void sendWarningEmbed(VoiceChannel channel) {
+        MessageEmbed messageEmbed = new EmbedBuilder()
+            .addField("👋 Heads up!",
+                    """
+                            This is a **temporary** voice chat channel. Messages sent here will be *cleared* once \
+                            the channel is deleted when everyone leaves. If you need to keep something important, \
+                            make sure to save it elsewhere. 💬
+                            """,
+                    false)
+            .build();
+
+        channel.sendMessageEmbeds(messageEmbed).queue();
+    }
+}