Up- and down-voting on suggestions

application/config.json.template

@@ -16,5 +16,10 @@
                   ]
         }
    ],
-   "helpChannelPattern": "([a-zA-Z_]+_)?help(_\\d+)?"
+   "helpChannelPattern": "([a-zA-Z_]+_)?help(_\\d+)?",
+   "suggestions": {
+       "channelPattern": "tj_suggestions",
+       "upVoteEmoteName": "peepo_yes",
+       "downVoteEmoteName": "peepo_no"
+   }
 }

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

@@ -4,6 +4,7 @@
 import org.jetbrains.annotations.NotNull;
 import org.togetherjava.tjbot.commands.basic.PingCommand;
 import org.togetherjava.tjbot.commands.basic.RoleSelectCommand;
+import org.togetherjava.tjbot.commands.basic.SuggestionsUpDownVoter;
 import org.togetherjava.tjbot.commands.basic.VcActivityCommand;
 import org.togetherjava.tjbot.commands.free.FreeCommand;
 import org.togetherjava.tjbot.commands.mathcommands.TeXCommand;
@@ -63,6 +64,7 @@ public enum Features {
 
         // Message receivers
         features.add(new TopHelpersMessageListener(database, config));
+        features.add(new SuggestionsUpDownVoter(config));
 
         // Event receivers
         features.add(new RejoinMuteListener(actionsStore, config));

application/src/main/java/org/togetherjava/tjbot/commands/basic/SuggestionsUpDownVoter.java

@@ -0,0 +1,66 @@
+package org.togetherjava.tjbot.commands.basic;
+
+import net.dv8tion.jda.api.entities.Emote;
+import net.dv8tion.jda.api.entities.Guild;
+import net.dv8tion.jda.api.entities.Message;
+import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
+import org.jetbrains.annotations.NotNull;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.togetherjava.tjbot.commands.MessageReceiverAdapter;
+import org.togetherjava.tjbot.config.Config;
+import org.togetherjava.tjbot.config.SuggestionsConfig;
+
+import java.util.Optional;
+import java.util.regex.Pattern;
+
+/**
+ * Listener that receives all sent messages from suggestion channels and reacts with an up- and
+ * down-vote on them to indicate to users that they can vote on the suggestion.
+ */
+public final class SuggestionsUpDownVoter extends MessageReceiverAdapter {
+    private static final Logger logger = LoggerFactory.getLogger(SuggestionsUpDownVoter.class);
+    private static final String FALLBACK_UP_VOTE = "👍";
+    private static final String FALLBACK_DOWN_VOTE = "👎";
+
+    private final SuggestionsConfig config;
+
+    /**
+     * Creates a new listener to receive all message sent in suggestion channels.
+     *
+     * @param config the config to use for this
+     */
+    public SuggestionsUpDownVoter(@NotNull Config config) {
+        super(Pattern.compile(config.getSuggestions().getChannelPattern()));
+
+        this.config = config.getSuggestions();
+    }
+
+    @Override
+    public void onMessageReceived(@NotNull GuildMessageReceivedEvent event) {
+        if (event.getAuthor().isBot() || event.isWebhookMessage()) {
+            return;
+        }
+
+        Guild guild = event.getGuild();
+        Message message = event.getMessage();
+
+        reactWith(config.getUpVoteEmoteName(), FALLBACK_UP_VOTE, guild, message);
+        reactWith(config.getDownVoteEmoteName(), FALLBACK_DOWN_VOTE, guild, message);
+    }
+
+    private static void reactWith(@NotNull String emoteName, @NotNull String fallbackUnicodeEmote,
+            @NotNull Guild guild, @NotNull Message message) {
+        getEmoteByName(emoteName, guild).map(message::addReaction).orElseGet(() -> {
+            logger.warn(
+                    "Unable to vote on a suggestion with the configured emote ('{}'), using fallback instead.",
+                    emoteName);
+            return message.addReaction(fallbackUnicodeEmote);
+        }).queue();
+    }
+
+    private static @NotNull Optional<Emote> getEmoteByName(@NotNull String name,
+            @NotNull Guild guild) {
+        return guild.getEmotesByName(name, false).stream().findAny();
+    }
+}

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

@@ -15,7 +15,6 @@
  * Configuration of the application. Create instances using {@link #load(Path)}.
  */
 public final class Config {
-
     private final String token;
     private final String databasePath;
     private final String projectWebsite;
@@ -27,6 +26,7 @@ public final class Config {
     private final String tagManageRolePattern;
     private final List<FreeCommandConfig> freeCommand;
     private final String helpChannelPattern;
+    private final SuggestionsConfig suggestions;
 
     @SuppressWarnings("ConstructorWithTooManyParameters")
     @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
@@ -40,7 +40,8 @@ private Config(@JsonProperty("token") String token,
             @JsonProperty("softModerationRolePattern") String softModerationRolePattern,
             @JsonProperty("tagManageRolePattern") String tagManageRolePattern,
             @JsonProperty("freeCommand") List<FreeCommandConfig> freeCommand,
-            @JsonProperty("helpChannelPattern") String helpChannelPattern) {
+            @JsonProperty("helpChannelPattern") String helpChannelPattern,
+            @JsonProperty("suggestions") SuggestionsConfig suggestions) {
         this.token = token;
         this.databasePath = databasePath;
         this.projectWebsite = projectWebsite;
@@ -52,6 +53,7 @@ private Config(@JsonProperty("token") String token,
         this.tagManageRolePattern = tagManageRolePattern;
         this.freeCommand = Collections.unmodifiableList(freeCommand);
         this.helpChannelPattern = helpChannelPattern;
+        this.suggestions = suggestions;
     }
 
     /**
@@ -170,4 +172,13 @@ public String getTagManageRolePattern() {
     public String getHelpChannelPattern() {
         return helpChannelPattern;
     }
+
+    /**
+     * Gets the config for the suggestion system.
+     *
+     * @return the suggestion system config
+     */
+    public SuggestionsConfig getSuggestions() {
+        return suggestions;
+    }
 }

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

@@ -0,0 +1,53 @@
+package org.togetherjava.tjbot.config;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonRootName;
+
+/**
+ * Configuration for the suggestion system, see
+ * {@link org.togetherjava.tjbot.commands.basic.SuggestionsUpDownVoter}.
+ */
+@SuppressWarnings("ClassCanBeRecord")
+@JsonRootName("suggestions")
+public final class SuggestionsConfig {
+    private final String channelPattern;
+    private final String upVoteEmoteName;
+    private final String downVoteEmoteName;
+
+    @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
+    private SuggestionsConfig(@JsonProperty("channelPattern") String channelPattern,
+            @JsonProperty("upVoteEmoteName") String upVoteEmoteName,
+            @JsonProperty("downVoteEmoteName") String downVoteEmoteName) {
+        this.channelPattern = channelPattern;
+        this.upVoteEmoteName = upVoteEmoteName;
+        this.downVoteEmoteName = downVoteEmoteName;
+    }
+
+    /**
+     * Gets the REGEX pattern used to identify channels that are used for sending suggestions.
+     *
+     * @return the channel name pattern
+     */
+    public String getChannelPattern() {
+        return channelPattern;
+    }
+
+    /**
+     * Gets the name of the emote used to up-vote suggestions.
+     *
+     * @return the name of the up-vote emote
+     */
+    public String getUpVoteEmoteName() {
+        return upVoteEmoteName;
+    }
+
+    /**
+     * Gets the name of the emote used to down-vote suggestions.
+     *
+     * @return the name of the down-vote emote
+     */
+    public String getDownVoteEmoteName() {
+        return downVoteEmoteName;
+    }
+}