Implement Quotes Board

application/config.json.template

@@ -194,6 +194,11 @@
         "videoLinkPattern": "http(s)?://www\\.youtube.com.*",
         "pollIntervalInMinutes": 10
     },
+    "quoteBoardConfig": {
+        "minimumReactionsToTrigger": 5,
+        "channel": "quotes",
+        "reactionEmoji": "⭐"
+    },
     "memberCountCategoryPattern": "Info",
     "topHelpers": {
         "rolePattern": "Top Helper.*",

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

@@ -48,6 +48,7 @@ public final class Config {
     private final RSSFeedsConfig rssFeedsConfig;
     private final String selectRolesChannelPattern;
     private final String memberCountCategoryPattern;
+    private final QuoteBoardConfig quoteBoardConfig;
     private final TopHelpersConfig topHelpers;
 
     @SuppressWarnings("ConstructorWithTooManyParameters")
@@ -102,6 +103,8 @@ 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 = "quoteBoardConfig",
+                    required = true) QuoteBoardConfig quoteBoardConfig,
             @JsonProperty(value = "topHelpers", required = true) TopHelpersConfig topHelpers) {
         this.token = Objects.requireNonNull(token);
         this.githubApiKey = Objects.requireNonNull(githubApiKey);
@@ -137,6 +140,7 @@ 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.quoteBoardConfig = Objects.requireNonNull(quoteBoardConfig);
         this.topHelpers = Objects.requireNonNull(topHelpers);
     }
 
@@ -431,6 +435,18 @@ public String getSelectRolesChannelPattern() {
         return selectRolesChannelPattern;
     }
 
+    /**
+     * The configuration of the quote messages config.
+     *
+     * <p>
+     * >The configuration of the quote board feature. Quotes user selected messages.
+     *
+     * @return configuration of quote messages config
+     */
+    public QuoteBoardConfig getQuoteBoardConfig() {
+        return quoteBoardConfig;
+    }
+
     /**
      * Gets the pattern matching the category that is used to display the total member count.
      *

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

@@ -0,0 +1,43 @@
+package org.togetherjava.tjbot.config;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonRootName;
+import org.apache.logging.log4j.LogManager;
+
+import org.togetherjava.tjbot.features.basic.QuoteBoardForwarder;
+
+import java.util.Objects;
+
+/**
+ * Configuration for the quote board feature, see {@link QuoteBoardForwarder}.
+ */
+@JsonRootName("quoteBoardConfig")
+public record QuoteBoardConfig(
+        @JsonProperty(value = "minimumReactionsToTrigger", required = true) int minimumReactions,
+        @JsonProperty(required = true) String channel,
+        @JsonProperty(value = "reactionEmoji", required = true) String reactionEmoji) {
+
+    /**
+     * Creates a QuoteBoardConfig.
+     *
+     * @param minimumReactions the minimum amount of reactions
+     * @param channel the pattern for the board channel
+     * @param reactionEmoji the emoji with which users should react to
+     */
+    public QuoteBoardConfig {
+        if (minimumReactions <= 0) {
+            throw new IllegalArgumentException("minimumReactions must be greater than zero");
+        }
+        Objects.requireNonNull(channel);
+        if (channel.isBlank()) {
+            throw new IllegalArgumentException("channel must not be empty or blank");
+        }
+        Objects.requireNonNull(reactionEmoji);
+        if (reactionEmoji.isBlank()) {
+            throw new IllegalArgumentException("reactionEmoji must not be empty or blank");
+        }
+        LogManager.getLogger(QuoteBoardConfig.class)
+            .debug("Quote-Board configs loaded: minimumReactions={}, channel='{}', reactionEmoji='{}'",
+                    minimumReactions, channel, reactionEmoji);
+    }
+}

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

@@ -8,6 +8,7 @@
 import org.togetherjava.tjbot.db.Database;
 import org.togetherjava.tjbot.features.basic.MemberCountDisplayRoutine;
 import org.togetherjava.tjbot.features.basic.PingCommand;
+import org.togetherjava.tjbot.features.basic.QuoteBoardForwarder;
 import org.togetherjava.tjbot.features.basic.RoleSelectCommand;
 import org.togetherjava.tjbot.features.basic.SlashCommandEducator;
 import org.togetherjava.tjbot.features.basic.SuggestionsUpDownVoter;
@@ -160,6 +161,7 @@ public static Collection<Feature> createFeatures(JDA jda, Database database, Con
         features.add(new CodeMessageManualDetection(codeMessageHandler));
         features.add(new SlashCommandEducator());
         features.add(new PinnedNotificationRemover(config));
+        features.add(new QuoteBoardForwarder(config));
 
         // Event receivers
         features.add(new RejoinModerationRoleListener(actionsStore, config));

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

@@ -3,6 +3,7 @@
 import net.dv8tion.jda.api.events.message.MessageDeleteEvent;
 import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
 import net.dv8tion.jda.api.events.message.MessageUpdateEvent;
+import net.dv8tion.jda.api.events.message.react.MessageReactionAddEvent;
 
 import java.util.regex.Pattern;
 
@@ -56,4 +57,13 @@ public interface MessageReceiver extends Feature {
      *        message that was deleted
      */
     void onMessageDeleted(MessageDeleteEvent event);
+
+    /**
+     * Triggered by the core system whenever a new reaction was added to a message 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
+     *        reaction that was added
+     */
+    void onMessageReactionAdd(MessageReactionAddEvent event);
 }

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

@@ -3,6 +3,7 @@
 import net.dv8tion.jda.api.events.message.MessageDeleteEvent;
 import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
 import net.dv8tion.jda.api.events.message.MessageUpdateEvent;
+import net.dv8tion.jda.api.events.message.react.MessageReactionAddEvent;
 
 import java.util.regex.Pattern;
 
@@ -57,4 +58,10 @@ public void onMessageUpdated(MessageUpdateEvent event) {
     public void onMessageDeleted(MessageDeleteEvent event) {
         // Adapter does not react by default, subclasses may change this behavior
     }
+
+    @SuppressWarnings("NoopMethodInAbstractClass")
+    @Override
+    public void onMessageReactionAdd(MessageReactionAddEvent event) {
+        // Adapter does not react by default, subclasses may change this behavior
+    }
 }

application/src/main/java/org/togetherjava/tjbot/features/basic/QuoteBoardForwarder.java

@@ -0,0 +1,150 @@
+package org.togetherjava.tjbot.features.basic;
+
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.entities.MessageReaction;
+import net.dv8tion.jda.api.entities.channel.concrete.TextChannel;
+import net.dv8tion.jda.api.entities.emoji.Emoji;
+import net.dv8tion.jda.api.events.message.react.MessageReactionAddEvent;
+import net.dv8tion.jda.api.requests.RestAction;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.togetherjava.tjbot.config.Config;
+import org.togetherjava.tjbot.config.QuoteBoardConfig;
+import org.togetherjava.tjbot.features.MessageReceiverAdapter;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+
+/**
+ * Listens for reaction-add events and turns popular messages into "quotes".
+ * <p>
+ * When someone reacts to a message with the configured emoji, the listener counts how many users
+ * have used that same emoji. If the total meets or exceeds the minimum threshold and the bot has
+ * not processed the message before, it copies (forwards) the message to the first text channel
+ * whose name matches the configured quote-board pattern, then reacts to the original message itself
+ * to mark it as handled (and to not let people spam react a message and give a way to the bot to
+ * know that a message has been quoted before).
+ * <p>
+ * Key points: - Trigger emoji, minimum vote count and quote-board channel pattern are supplied via
+ * {@code QuoteBoardConfig}.
+ */
+public final class QuoteBoardForwarder extends MessageReceiverAdapter {
+
+    private static final Logger logger = LoggerFactory.getLogger(QuoteBoardForwarder.class);
+    private final Emoji triggerReaction;
+    private final Predicate<String> isQuoteBoardChannelName;
+    private final QuoteBoardConfig config;
+
+    /**
+     * Constructs a new instance of QuoteBoardForwarder.
+     *
+     * @param config the configuration containing settings specific to the cool messages board,
+     *        including the reaction emoji and the pattern to match board channel names
+     */
+    public QuoteBoardForwarder(Config config) {
+        this.config = config.getQuoteBoardConfig();
+        this.triggerReaction = Emoji.fromUnicode(this.config.reactionEmoji());
+
+        this.isQuoteBoardChannelName = Pattern.compile(this.config.channel()).asMatchPredicate();
+    }
+
+    @Override
+    public void onMessageReactionAdd(MessageReactionAddEvent event) {
+        logger.debug("Received MessageReactionAddEvent: messageId={}, channelId={}, userId={}",
+                event.getMessageId(), event.getChannel().getId(), event.getUserId());
+
+        final MessageReaction messageReaction = event.getReaction();
+
+        if (!messageReaction.getEmoji().equals(triggerReaction)) {
+            logger.debug("Reaction emoji '{}' does not match trigger emoji '{}'. Ignoring.",
+                    messageReaction.getEmoji(), triggerReaction);
+            return;
+        }
+
+        if (hasAlreadyForwardedMessage(event.getJDA(), messageReaction)) {
+            logger.debug("Message has already been forwarded by the bot. Skipping.");
+            return;
+        }
+
+        long reactionCount = messageReaction.retrieveUsers().stream().count();
+        if (reactionCount < config.minimumReactions()) {
+            logger.debug("Reaction count {} is less than minimum required {}. Skipping.",
+                    reactionCount, config.minimumReactions());
+            return;
+        }
+
+        final long guildId = event.getGuild().getIdLong();
+
+        Optional<TextChannel> boardChannel = findQuoteBoardChannel(event.getJDA(), guildId);
+
+        if (boardChannel.isEmpty()) {
+            logger.warn(
+                    "Could not find board channel with pattern '{}' in server with ID '{}'. Skipping reaction handling...",
+                    this.config.channel(), guildId);
+            return;
+        }
+
+        logger.debug("Forwarding message to quote board channel: {}", boardChannel.get().getName());
+
+        event.retrieveMessage()
+            .queue(message -> markAsProcessed(message)
+                .flatMap(v -> message.forwardTo(boardChannel.orElseThrow()))
+                .queue(_ -> logger.debug("Message forwarded to quote board channel: {}",
+                        boardChannel.get().getName())),
+
+                    e -> logger.warn(
+                            "Unknown error while attempting to retrieve and forward message for quote-board, message is ignored.",
+                            e));
+
+    }
+
+    private RestAction<Void> markAsProcessed(Message message) {
+        return message.addReaction(triggerReaction);
+    }
+
+    /**
+     * Gets the board text channel where the quotes go to, wrapped in an optional.
+     *
+     * @param jda the JDA
+     * @param guildId the guild ID
+     * @return the board text channel
+     */
+    private Optional<TextChannel> findQuoteBoardChannel(JDA jda, long guildId) {
+        var guild = jda.getGuildById(guildId);
+
+        if (guild == null) {
+            throw new IllegalStateException(
+                    String.format("Guild with ID '%d' not found.", guildId));
+        }
+
+        List<TextChannel> matchingChannels = guild.getTextChannelCache()
+            .stream()
+            .filter(channel -> isQuoteBoardChannelName.test(channel.getName()))
+            .toList();
+
+        if (matchingChannels.size() > 1) {
+            logger.warn(
+                    "Multiple quote board channels found matching pattern '{}' in guild with ID '{}'. Selecting the first one anyway.",
+                    this.config.channel(), guildId);
+        }
+
+        return matchingChannels.stream().findFirst();
+    }
+
+    /**
+     * Checks a {@link MessageReaction} to see if the bot has reacted to it.
+     */
+    private boolean hasAlreadyForwardedMessage(JDA jda, MessageReaction messageReaction) {
+        if (!triggerReaction.equals(messageReaction.getEmoji())) {
+            return false;
+        }
+
+        return messageReaction.retrieveUsers()
+            .parallelStream()
+            .anyMatch(user -> jda.getSelfUser().getIdLong() == user.getIdLong());
+    }
+}

application/src/main/java/org/togetherjava/tjbot/features/system/BotCore.java

@@ -13,6 +13,7 @@
 import net.dv8tion.jda.api.events.message.MessageDeleteEvent;
 import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
 import net.dv8tion.jda.api.events.message.MessageUpdateEvent;
+import net.dv8tion.jda.api.events.message.react.MessageReactionAddEvent;
 import net.dv8tion.jda.api.hooks.ListenerAdapter;
 import net.dv8tion.jda.api.interactions.callbacks.IReplyCallback;
 import net.dv8tion.jda.api.interactions.components.ComponentInteraction;
@@ -238,6 +239,14 @@ public void onMessageDelete(final MessageDeleteEvent event) {
         }
     }
 
+    @Override
+    public void onMessageReactionAdd(final MessageReactionAddEvent event) {
+        if (event.isFromGuild()) {
+            getMessageReceiversSubscribedTo(event.getChannel())
+                .forEach(messageReceiver -> messageReceiver.onMessageReactionAdd(event));
+        }
+    }
+
     private Stream<MessageReceiver> getMessageReceiversSubscribedTo(Channel channel) {
         String channelName = channel.getName();
         return channelNameToMessageReceiver.entrySet()