Add Starboard support

application/config.json.template

@@ -103,6 +103,10 @@
         "special": [
         ]
     },
+    "starboard": {
+        "emojiNames" : ["⭐"],
+        "channelPattern": "starboard"
+    },
     "selectRolesChannelPattern": "select-your-roles",
     "rssConfig": {
         "feeds": [

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

@@ -42,11 +42,13 @@ public final class Config {
     private final String openaiApiKey;
     private final String sourceCodeBaseUrl;
     private final JShellConfig jshell;
+    private final StarboardConfig starboard;
     private final FeatureBlacklistConfig featureBlacklistConfig;
     private final RSSFeedsConfig rssFeedsConfig;
     private final String selectRolesChannelPattern;
     private final String memberCountCategoryPattern;
 
+
     @SuppressWarnings("ConstructorWithTooManyParameters")
     @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
     private Config(@JsonProperty(value = "token", required = true) String token,
@@ -94,7 +96,8 @@ 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 = "starboard", required = true) StarboardConfig starboard) {
         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.starboard = Objects.requireNonNull(starboard);
     }
 
     /**
@@ -391,6 +395,17 @@ public FeatureBlacklistConfig getFeatureBlacklistConfig() {
         return featureBlacklistConfig;
     }
 
+    /**
+     * Gets the config for the Starboard. The starboard displays certain messages in a special
+     * emojis{@link StarboardConfig#emojiNames()} channel {@link StarboardConfig#channelPattern()}
+     * if a user reacts with one of the recognized
+     *
+     * @return the config of the Starboard
+     */
+    public StarboardConfig getStarboard() {
+        return starboard;
+    }
+
     /**
      * Gets the REGEX pattern used to identify the channel in which users can select their helper
      * roles.

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

@@ -0,0 +1,53 @@
+package org.togetherjava.tjbot.config;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonRootName;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.regex.Pattern;
+
+/**
+ * Starboard Config
+ *
+ * @param emojiNames the List of emojis which are recognized by the starboard
+ * @param channelPattern the pattern of the channel with the starboard
+ */
+@JsonRootName("starboard")
+public record StarboardConfig(List<String> emojiNames, Pattern channelPattern) {
+    /**
+     * Creates a Starboard config.
+     *
+     * @param emojiNames the List of emojis which are recognized by the starboard
+     * @param channelPattern the pattern of the channel with the starboard
+     */
+    @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
+    public StarboardConfig {
+        Objects.requireNonNull(emojiNames);
+        Objects.requireNonNull(channelPattern);
+    }
+
+    /**
+     * Gets the list of emotes that are recognized by the starboard feature. A message that is
+     * reacted on with an emote in this list will be reposted in a special channel
+     * {@link #channelPattern()}.
+     * <p>
+     * Empty to deactivate the feature.
+     *
+     * @return The List of emojis recognized by the starboard
+     */
+    @Override
+    public List<String> emojiNames() {
+        return emojiNames;
+    }
+
+    /**
+     * Gets the pattern of the channel with the starboard. Deactivate by using a non-existent
+     * channel name.
+     *
+     * @return the pattern of the channel with the starboard
+     */
+    public Pattern channelPattern() {
+        return channelPattern;
+    }
+}

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

@@ -10,6 +10,7 @@
 import org.togetherjava.tjbot.features.basic.PingCommand;
 import org.togetherjava.tjbot.features.basic.RoleSelectCommand;
 import org.togetherjava.tjbot.features.basic.SlashCommandEducator;
+import org.togetherjava.tjbot.features.basic.Starboard;
 import org.togetherjava.tjbot.features.basic.SuggestionsUpDownVoter;
 import org.togetherjava.tjbot.features.bookmarks.BookmarksCommand;
 import org.togetherjava.tjbot.features.bookmarks.BookmarksSystem;
@@ -131,6 +132,7 @@ public static Collection<Feature> createFeatures(JDA jda, Database database, Con
         features.add(new GuildLeaveCloseThreadListener(config));
         features.add(new LeftoverBookmarksListener(bookmarksSystem));
         features.add(new HelpThreadCreatedListener(helpSystemHelper));
+        features.add(new Starboard(config, database));
 
         // Message context commands
         features.add(new TransferQuestionCommand(config));

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

@@ -0,0 +1,111 @@
+package org.togetherjava.tjbot.features.basic;
+
+import com.github.benmanes.caffeine.cache.Cache;
+import com.github.benmanes.caffeine.cache.Caffeine;
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.Permission;
+import net.dv8tion.jda.api.entities.*;
+import net.dv8tion.jda.api.entities.channel.concrete.TextChannel;
+import net.dv8tion.jda.api.entities.channel.middleman.GuildChannel;
+import net.dv8tion.jda.api.events.message.react.MessageReactionAddEvent;
+import net.dv8tion.jda.api.events.message.react.MessageReactionRemoveEvent;
+import net.dv8tion.jda.api.hooks.ListenerAdapter;
+import org.jetbrains.annotations.NotNull;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.togetherjava.tjbot.config.Config;
+import org.togetherjava.tjbot.config.StarboardConfig;
+import org.togetherjava.tjbot.db.Database;
+import org.togetherjava.tjbot.features.EventReceiver;
+
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+
+import static org.togetherjava.tjbot.db.generated.tables.StarboardMessages.STARBOARD_MESSAGES;
+
+public class Starboard extends ListenerAdapter implements EventReceiver {
+
+    private static final Logger logger = LoggerFactory.getLogger(Starboard.class);
+    private final StarboardConfig config;
+    private final Database database;
+
+    private final Cache<Long, Object> messageCache;
+
+    public Starboard(Config config, Database database) {
+        this.config = config.getStarboard();
+        this.database = database;
+        this.messageCache = Caffeine.newBuilder()
+            .maximumSize(100)
+            .expireAfterAccess(24, TimeUnit.HOURS) // TODO make these constants
+            .build();
+    }
+
+    @Override
+    public void onMessageReactionAdd(@NotNull MessageReactionAddEvent event) {
+        String emojiName = event.getEmoji().getName();
+        Guild guild = event.getGuild();
+        long messageId = event.getMessageIdLong();
+        if (shouldIgnoreMessage(emojiName, guild, event.getGuildChannel(), messageId, true)) {
+            return;
+        }
+        Optional<TextChannel> starboardChannel = getStarboardChannel(guild);
+        if (starboardChannel.isEmpty()) {
+            logger.warn("There is no channel for the starboard in the guild with the name {}",
+                    config.channelPattern());
+            return;
+        }
+        database.write(context -> context.newRecord(STARBOARD_MESSAGES).setMessageId(messageId));
+        messageCache.put(messageId, new Object());
+        event.retrieveMessage()
+            .flatMap(
+                    message -> starboardChannel.orElseThrow().sendMessageEmbeds(formEmbed(message)))
+            .queue();
+    }
+
+    @Override
+    public void onMessageReactionRemove(@NotNull MessageReactionRemoveEvent event) {
+        String emojiName = event.getEmoji().getName();
+        Guild guild = event.getGuild();
+        long messageId = event.getMessageIdLong();
+        if (shouldIgnoreMessage(emojiName, guild, event.getGuildChannel(), messageId, false)) {
+            return;
+        }
+        event.retrieveMessage()
+            .map(m -> m.getReactions()
+                .stream()
+                .map(reaction -> reaction.getEmoji().getName())
+                .noneMatch(config.emojiNames()::contains))
+            .onSuccess(noGoodReactions -> {
+                if (noGoodReactions) {
+                    database.write(context -> context.data().remove(messageId));
+                    messageCache.invalidate(messageId);
+                }
+            })
+            .queue();
+    }
+
+    private boolean shouldIgnoreMessage(String emojiName, Guild guild, GuildChannel channel,
+            long messageId, boolean addingMessage) {
+        return !config.emojiNames().contains(emojiName)
+                || !guild.getPublicRole().hasPermission(channel, Permission.VIEW_CHANNEL)
+                || (addingMessage == (messageCache.getIfPresent(messageId) != null || database
+                    .read(context -> context.fetchExists(context.selectFrom(STARBOARD_MESSAGES)
+                        .where(STARBOARD_MESSAGES.MESSAGE_ID.eq(messageId))))));
+    }
+
+    private Optional<TextChannel> getStarboardChannel(Guild guild) {
+        return guild.getTextChannels()
+            .stream()
+            .filter(channel -> config.channelPattern().matcher(channel.getName()).find())
+            .findFirst();
+    }
+
+    private static MessageEmbed formEmbed(Message message) {
+        User author = message.getAuthor();
+        return new EmbedBuilder().setAuthor(author.getName(), null, author.getAvatarUrl())
+            .setDescription(message.getContentDisplay())
+            .appendDescription("%n [Link](%s)".formatted(message.getJumpUrl()))
+            .build();
+    }
+}

application/src/main/resources/db/V15__Add_Starboard.sql

@@ -0,0 +1,4 @@
+CREATE TABLE starboard_messages
+(
+    message_id BIGINT NOT NULL PRIMARY KEY
+)