Dynamically create and delete voice channels based on activity

application/config.json.template

@@ -115,5 +115,10 @@
         "fallbackChannelPattern": "java-news-and-changes",
         "pollIntervalInMinutes": 10
     },
-    "memberCountCategoryPattern": "Info"
+    "memberCountCategoryPattern": "Info",
+    "dynamicVoiceChannelPatterns": [
+        "Gaming",
+        "Support/Studying Room",
+        "Chit Chat"
+    ]
 }

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

@@ -46,6 +46,7 @@ public final class Config {
     private final RSSFeedsConfig rssFeedsConfig;
     private final String selectRolesChannelPattern;
     private final String memberCountCategoryPattern;
+    private final List<String> dynamicVoiceChannelPatterns;
 
     @SuppressWarnings("ConstructorWithTooManyParameters")
     @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
@@ -94,7 +95,9 @@ private Config(@JsonProperty(value = "token", required = true) String token,
                     required = true) FeatureBlacklistConfig featureBlacklistConfig,
             @JsonProperty(value = "rssConfig", required = true) RSSFeedsConfig rssFeedsConfig,
             @JsonProperty(value = "selectRolesChannelPattern",
-                    required = true) String selectRolesChannelPattern) {
+                    required = true) String selectRolesChannelPattern,
+            @JsonProperty(value = "dynamicVoiceChannelPatterns",
+                    required = true) List<String> dynamicVoiceChannelPatterns) {
         this.token = Objects.requireNonNull(token);
         this.githubApiKey = Objects.requireNonNull(githubApiKey);
         this.databasePath = Objects.requireNonNull(databasePath);
@@ -127,6 +130,7 @@ private Config(@JsonProperty(value = "token", required = true) String token,
         this.featureBlacklistConfig = Objects.requireNonNull(featureBlacklistConfig);
         this.rssFeedsConfig = Objects.requireNonNull(rssFeedsConfig);
         this.selectRolesChannelPattern = Objects.requireNonNull(selectRolesChannelPattern);
+        this.dynamicVoiceChannelPatterns = Objects.requireNonNull(dynamicVoiceChannelPatterns);
     }
 
     /**
@@ -418,4 +422,14 @@ public String getMemberCountCategoryPattern() {
     public RSSFeedsConfig getRSSFeedsConfig() {
         return rssFeedsConfig;
     }
+
+    /**
+     * Gets the list of voice channel patterns that are treated dynamically.
+     *
+     * @return the list of dynamic voice channel patterns
+     */
+    public List<String> getDynamicVoiceChannelPatterns() {
+        return this.dynamicVoiceChannelPatterns;
+    }
+
 }

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

@@ -20,6 +20,7 @@
 import org.togetherjava.tjbot.features.code.CodeMessageAutoDetection;
 import org.togetherjava.tjbot.features.code.CodeMessageHandler;
 import org.togetherjava.tjbot.features.code.CodeMessageManualDetection;
+import org.togetherjava.tjbot.features.dynamicvc.DynamicVoiceListener;
 import org.togetherjava.tjbot.features.filesharing.FileSharingMessageListener;
 import org.togetherjava.tjbot.features.github.GitHubCommand;
 import org.togetherjava.tjbot.features.github.GitHubReference;
@@ -151,6 +152,9 @@ public static Collection<Feature> createFeatures(JDA jda, Database database, Con
         features.add(new SlashCommandEducator());
         features.add(new PinnedNotificationRemover(config));
 
+        // Voice receivers
+        features.add(new DynamicVoiceListener(config));
+
         // Event receivers
         features.add(new RejoinModerationRoleListener(actionsStore, config));
         features.add(new GuildLeaveCloseThreadListener(config));

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

@@ -0,0 +1,69 @@
+package org.togetherjava.tjbot.features;
+
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceDeafenEvent;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceMuteEvent;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceStreamEvent;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceUpdateEvent;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceVideoEvent;
+
+import java.util.regex.Pattern;
+
+/**
+ * Receives incoming Discord guild events from voice channels matching a given pattern.
+ * <p>
+ * All voice receivers have to implement this interface. For convenience, there is a
+ * {@link VoiceReceiverAdapter} 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 event was sent or an
+ * existing event was updated in any channel matching the {@link #getChannelNamePattern()} the bot
+ * is added to.
+ */
+public interface VoiceReceiver extends Feature {
+    /**
+     * Retrieves the pattern matching the names of channels of which this receiver is interested in
+     * receiving events 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
+     */
+    Pattern getChannelNamePattern();
+
+    /**
+     * Triggered by the core system whenever a member joined, left or moved voice channels.
+     *
+     * @param event the event that triggered this
+     */
+    void onVoiceUpdate(GuildVoiceUpdateEvent event);
+
+    /**
+     * Triggered by the core system whenever a member toggled their camera in a voice channel.
+     *
+     * @param event the event that triggered this
+     */
+    void onVideoToggle(GuildVoiceVideoEvent event);
+
+    /**
+     * Triggered by the core system whenever a member started or stopped a stream.
+     *
+     * @param event the event that triggered this
+     */
+    void onStreamToggle(GuildVoiceStreamEvent event);
+
+    /**
+     * Triggered by the core system whenever a member toggled their mute status.
+     *
+     * @param event the event that triggered this
+     */
+    void onMuteToggle(GuildVoiceMuteEvent event);
+
+    /**
+     * Triggered by the core system whenever a member toggled their deafened status.
+     *
+     * @param event the event that triggered this
+     */
+    void onDeafenToggle(GuildVoiceDeafenEvent event);
+}

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

@@ -0,0 +1,52 @@
+package org.togetherjava.tjbot.features;
+
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceDeafenEvent;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceMuteEvent;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceStreamEvent;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceUpdateEvent;
+import net.dv8tion.jda.api.events.guild.voice.GuildVoiceVideoEvent;
+
+import java.util.regex.Pattern;
+
+public class VoiceReceiverAdapter implements VoiceReceiver {
+
+    private final Pattern channelNamePattern;
+
+    protected VoiceReceiverAdapter() {
+        this(Pattern.compile(".*"));
+    }
+
+    protected VoiceReceiverAdapter(Pattern channelNamePattern) {
+        this.channelNamePattern = channelNamePattern;
+    }
+
+    @Override
+    public Pattern getChannelNamePattern() {
+        return channelNamePattern;
+    }
+
+    @Override
+    public void onVoiceUpdate(GuildVoiceUpdateEvent event) {
+        // Adapter does not react by default, subclasses may change this behavior
+    }
+
+    @Override
+    public void onVideoToggle(GuildVoiceVideoEvent event) {
+        // Adapter does not react by default, subclasses may change this behavior
+    }
+
+    @Override
+    public void onStreamToggle(GuildVoiceStreamEvent event) {
+        // Adapter does not react by default, subclasses may change this behavior
+    }
+
+    @Override
+    public void onMuteToggle(GuildVoiceMuteEvent event) {
+        // Adapter does not react by default, subclasses may change this behavior
+    }
+
+    @Override
+    public void onDeafenToggle(GuildVoiceDeafenEvent event) {
+        // Adapter does not react by default, subclasses may change this behavior
+    }
+}