Added beginning of stateless help channel management.

Author: andrewlalis

src/main/java/com/javadiscord/javabot/Bot.java

@@ -2,6 +2,8 @@
 
 import com.javadiscord.javabot.data.H2DataSource;
 import com.javadiscord.javabot.events.*;
+import com.javadiscord.javabot.help.HelpChannelListener;
+import com.javadiscord.javabot.help.HelpChannelUpdater;
 import com.javadiscord.javabot.properties.config.BotConfig;
 import net.dv8tion.jda.api.JDA;
 import net.dv8tion.jda.api.JDABuilder;
@@ -16,6 +18,7 @@
 import java.util.TimeZone;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 
 /**
  * The main class where the bot is initialized.
@@ -74,6 +77,7 @@ public static void main(String[] args) throws Exception {
                 .addEventListeners(slashCommands)
                 .build();
         addEventListeners(jda);
+        asyncPool.scheduleAtFixedRate(new HelpChannelUpdater(jda), 1, 1, TimeUnit.SECONDS);
     }
 
     /**
@@ -92,7 +96,8 @@ private static void addEventListeners(JDA jda) {
                 new AutoMod(),
                 new SubmissionListener(),
                 new StarboardListener(),
-                new InteractionListener()
+                new InteractionListener(),
+                new HelpChannelListener()
         );
     }
 }

src/main/java/com/javadiscord/javabot/help/HelpChannelListener.java

@@ -0,0 +1,29 @@
+package com.javadiscord.javabot.help;
+
+import com.javadiscord.javabot.Bot;
+import net.dv8tion.jda.api.entities.Category;
+import net.dv8tion.jda.api.entities.TextChannel;
+import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
+import net.dv8tion.jda.api.hooks.ListenerAdapter;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * This listener is responsible for handling messages that are sent in one or
+ * more designated help channels.
+ */
+public class HelpChannelListener extends ListenerAdapter {
+	@Override
+	public void onGuildMessageReceived(@NotNull GuildMessageReceivedEvent event) {
+		if (event.getAuthor().isBot() || event.getAuthor().isSystem()) return;
+
+		var config = Bot.config.get(event.getGuild()).getHelp();
+		TextChannel channel = event.getChannel();
+		Category category = channel.getParent();
+		if (category == null) return;
+		if (channel.getName().startsWith(config.getOpenChannelPrefix())) {
+			String rawChannelName = channel.getName().substring(config.getOpenChannelPrefix().length());
+			channel.getManager().setName(config.getReservedChannelPrefix() + rawChannelName).queue();
+			channel.getManager().setPosition(category.getTextChannels().size()).queue();
+		}
+	}
+}

src/main/java/com/javadiscord/javabot/help/HelpChannelManager.java

@@ -0,0 +1,38 @@
+package com.javadiscord.javabot.help;
+
+import com.javadiscord.javabot.properties.config.guild.HelpConfig;
+import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.entities.TextChannel;
+
+import java.util.List;
+
+public class HelpChannelManager {
+	/**
+	 * Opens a text channel so that it is ready for a new question.
+	 * @param channel The channel to open.
+	 * @param config The configuration properties.
+	 */
+	public void open(TextChannel channel, HelpConfig config) {
+		String rawName = channel.getName().substring(config.getReservedChannelPrefix().length());
+		channel.getManager().setName(config.getOpenChannelPrefix() + rawName).queue();
+		channel.getManager().setPosition(0).queue();
+		removeAllMessages(channel);
+	}
+
+	/**
+	 * Utility method to remove all messages from a channel.
+	 * @param channel The channel to remove messages from.
+	 */
+	private void removeAllMessages(TextChannel channel) {
+		List<Message> messages;
+		do {
+			messages = channel.getHistory().retrievePast(50).complete();
+			if (messages.isEmpty()) break;
+			if (messages.size() == 1) {
+				channel.deleteMessageById(messages.get(0).getIdLong()).complete();
+			} else {
+				channel.deleteMessages(messages).complete();
+			}
+		} while (!messages.isEmpty());
+	}
+}

src/main/java/com/javadiscord/javabot/help/HelpChannelUpdater.java

@@ -0,0 +1,49 @@
+package com.javadiscord.javabot.help;
+
+import com.javadiscord.javabot.Bot;
+import com.javadiscord.javabot.properties.config.guild.HelpConfig;
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.entities.TextChannel;
+import net.dv8tion.jda.api.entities.User;
+
+import java.time.OffsetDateTime;
+
+public class HelpChannelUpdater implements Runnable {
+	private final JDA jda;
+	private final HelpChannelManager channelManager;
+
+	public HelpChannelUpdater(JDA jda) {
+		this.jda = jda;
+		this.channelManager = new HelpChannelManager();
+	}
+
+
+	@Override
+	public void run() {
+		for (var guild : this.jda.getGuilds()) {
+			var config = Bot.config.get(guild).getHelp();
+			var channels = guild.getTextChannels();
+			for (var channel : channels) {
+				if (channel.getName().startsWith(config.getReservedChannelPrefix())) {
+					this.checkReservedChannel(channel, config);
+				}
+			}
+		}
+	}
+
+	private void checkReservedChannel(TextChannel channel, HelpConfig config) {
+		channel.getHistoryFromBeginning(1).queue(history -> {
+			if (history.isEmpty()) {
+				// Revert to open channel.
+				this.channelManager.open(channel, config);
+			} else {
+				Message firstMsg = history.getRetrievedHistory().get(0);
+				var channelBecomesInactiveAt = firstMsg.getTimeCreated().plusSeconds(config.getInactivityTimeoutSeconds());
+				if (OffsetDateTime.now().isAfter(channelBecomesInactiveAt)) {
+					User user = firstMsg.getAuthor();
+				}
+			}
+		});
+	}
+}

src/main/java/com/javadiscord/javabot/properties/config/GuildConfig.java

@@ -27,6 +27,7 @@ public class GuildConfig {
 	private transient Path file;
 
 	private SlashCommandConfig slashCommand;
+	private HelpConfig help;
 	private ModerationConfig moderation;
 	private QOTWConfig qotw;
 	private WelcomeConfig welcome;
@@ -38,6 +39,7 @@ public GuildConfig(Guild guild, Path file) {
 		this.file = file;
 		// Initialize all config items.
 		this.slashCommand = new SlashCommandConfig();
+		this.help = new HelpConfig();
 		this.moderation = new ModerationConfig();
 		this.qotw = new QOTWConfig();
 		this.welcome = new WelcomeConfig();
@@ -50,6 +52,7 @@ public GuildConfig(Guild guild, Path file) {
 	private void setGuild(Guild guild) {
 		this.guild = guild;
 		this.slashCommand.setGuildConfig(this);
+		this.help.setGuildConfig(this);
 		this.moderation.setGuildConfig(this);
 		this.qotw.setGuildConfig(this);
 		this.welcome.setGuildConfig(this);

src/main/java/com/javadiscord/javabot/properties/config/guild/HelpConfig.java

@@ -0,0 +1,38 @@
+package com.javadiscord.javabot.properties.config.guild;
+
+import com.javadiscord.javabot.properties.config.GuildConfigItem;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+
+@Data
+@EqualsAndHashCode(callSuper = true)
+public class HelpConfig extends GuildConfigItem {
+	/**
+	 * The string which is prefixed to any open help channel, where users are
+	 * free to ask a question.
+	 */
+	private String openChannelPrefix = "\uD83D\uDFE2";
+
+	/**
+	 * The string which is prefixed to any reserved help channel, where a user
+	 * has already asked a question and is in the process of getting an answer.
+	 */
+	private String reservedChannelPrefix = "⛔";
+
+	/**
+	 * The string which is prefixed to any inactive reserved help channel, where
+	 * a user has asked a question but the channel has been inactive for a set
+	 * amount of time.
+	 */
+	private String inactiveChannelPrefix = "\uD83D\uDFE0";
+
+	/**
+	 * The number of seconds of inactivity before a channel is considered inactive.
+	 */
+	private int inactivityTimeoutSeconds = 1_800;
+
+	/**
+	 * The number of seconds to wait between each help channel update check.
+	 */
+	private long updateIntervalSeconds = 60;
+}