wip: create dynamic voice channel system

application/config.json.template

@@ -115,5 +115,9 @@
         "fallbackChannelPattern": "java-news-and-changes",
         "pollIntervalInMinutes": 10
     },
-    "memberCountCategoryPattern": "Info"
+    "memberCountCategoryPattern": "Info",
+    "dynamicVoiceChannelPattern": [
+        "Gaming",
+        "Chit Chat"
+    ]
 }

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

@@ -148,7 +148,7 @@ public static Collection<Feature> createFeatures(JDA jda, Database database, Con
         features.add(new PinnedNotificationRemover(config));
 
         // Voice receivers
-        features.add(new DynamicVoiceListener());
+        features.add(new DynamicVoiceListener(config));
 
         // Event receivers
         features.add(new RejoinModerationRoleListener(actionsStore, config));

application/src/main/java/org/togetherjava/tjbot/features/dynamicvc/DynamicVoiceListener.java

@@ -1,14 +1,141 @@
 package org.togetherjava.tjbot.features.dynamicvc;
 
+import net.dv8tion.jda.api.entities.Guild;
+import net.dv8tion.jda.api.entities.channel.concrete.VoiceChannel;
+import net.dv8tion.jda.api.entities.channel.unions.AudioChannelUnion;
 import net.dv8tion.jda.api.events.guild.voice.GuildVoiceUpdateEvent;
+import org.apache.commons.lang3.tuple.Pair;
 import org.jetbrains.annotations.NotNull;
 
+import org.togetherjava.tjbot.config.Config;
 import org.togetherjava.tjbot.features.VoiceReceiverAdapter;
 
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Predicate;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
 public class DynamicVoiceListener extends VoiceReceiverAdapter {
 
+    private final Map<String, Predicate<String>> patterns = new HashMap<>();
+    private static final Pattern channelTopicPattern = Pattern.compile("(\\s+\\d+)$");
+
+    public DynamicVoiceListener(Config config) {
+        config.getDynamicVoiceChannelPatterns()
+            .forEach(pattern -> patterns.put(pattern, Pattern.compile(pattern).asMatchPredicate()));
+    }
+
     @Override
     public void onVoiceUpdate(@NotNull GuildVoiceUpdateEvent event) {
-        // TODO: Complete
+        AudioChannelUnion joinChannel = event.getChannelJoined();
+        AudioChannelUnion leftChannel = event.getChannelLeft();
+
+        if (joinChannel != null && leftChannel != null) {
+            if (!getChannelTopic(joinChannel.getName())
+                .equals(getChannelTopic(leftChannel.getName()))) {
+                handleTopicUpdate(event, joinChannel);
+                handleTopicUpdate(event, leftChannel);
+                return;
+            }
+        }
+
+        if (joinChannel != null) {
+            handleTopicUpdate(event, joinChannel);
+        } else if (leftChannel != null) {
+            handleTopicUpdate(event, leftChannel);
+        }
+    }
+
+    private void handleTopicUpdate(GuildVoiceUpdateEvent event, AudioChannelUnion channel) {
+        if (channel == null) {
+            return;
+        }
+
+        Guild guild = event.getGuild();
+        String channelTopic = getChannelTopic(channel.getName());
+
+        if (patterns.get(channelTopic) == null) {
+            return;
+        }
+
+        long emptyChannelsCount = getEmptyChannelsCountFromTopic(guild, channelTopic);
+
+        if (emptyChannelsCount == 0) {
+            createVoiceChannelFromTopic(channel, getChannelCountFromTopic(guild, channelTopic));
+        } else if (emptyChannelsCount != 1) {
+            removeDuplicateEmptyChannels(guild, channelTopic);
+        }
+    }
+
+    private static void createVoiceChannelFromTopic(AudioChannelUnion originalChannel,
+            long topicChannelsCount) {
+        String channelTopic = getChannelTopic(originalChannel.getName());
+
+        originalChannel.createCopy()
+            .setName(getNumberedChannelTopic(channelTopic, topicChannelsCount + 1))
+            .setPosition(originalChannel.getPositionRaw())
+            .queue();
+
+    }
+
+    private void removeDuplicateEmptyChannels(Guild guild, String channelTopic) {
+        List<VoiceChannel> channelsToRemove = getVoiceChannelsFromTopic(guild, channelTopic)
+            .filter(channel -> channel.getMembers().isEmpty())
+            .toList();
+
+        channelsToRemove.subList(1, channelsToRemove.size())
+            .forEach(channel -> channel.delete().queue(success -> {
+                List<VoiceChannel> channels =
+                        getVoiceChannelsFromTopic(guild, channelTopic).toList();
+
+                IntStream.range(0, channels.size())
+                    .asLongStream()
+                    .mapToObj(number -> Pair.of(number + 1, channels.get((int) number)))
+                    .filter(pair -> pair.getLeft() != 1)
+                    .forEach(pair -> {
+                        long number = pair.getLeft();
+                        VoiceChannel voiceChannel = pair.getRight();
+                        String voiceChannelNameTopic = getChannelTopic(voiceChannel.getName());
+
+                        voiceChannel.getManager()
+                            .setName(getNumberedChannelTopic(voiceChannelNameTopic, number))
+                            .queue();
+                    });
+            }));
+    }
+
+    private long getChannelCountFromTopic(Guild guild, String channelTopic) {
+        return getVoiceChannelsFromTopic(guild, channelTopic).count();
+    }
+
+    private Stream<VoiceChannel> getVoiceChannelsFromTopic(Guild guild, String channelTopic) {
+        return guild.getVoiceChannels()
+            .stream()
+            .filter(channel -> patterns.get(channelTopic).test(getChannelTopic(channel.getName())));
+    }
+
+    private long getEmptyChannelsCountFromTopic(Guild guild, String channelTopic) {
+        return getVoiceChannelsFromTopic(guild, channelTopic)
+            .map(channel -> channel.getMembers().size())
+            .filter(number -> number == 0)
+            .count();
+    }
+
+    private static String getChannelTopic(String channelName) {
+        Matcher matcher = channelTopicPattern.matcher(channelName);
+
+        if (matcher.find()) {
+            return matcher.replaceAll("");
+        }
+
+        return channelName;
+    }
+
+    private static String getNumberedChannelTopic(String channelTopic, long id) {
+        return String.format("%s %d", channelTopic, id);
     }
 }