fix: Handle empty message content for suggestion threads (#1265)

* fix: handle empty message content for thread titles

Ensures a fallback thread title is provided when the original message content is empty.
The thread title will now default to the message author's name in such cases,
preventing empty or uninformative thread titles.

Co-authored-by: billpapat <50835814+billpapat@users.noreply.github.com>
Co-authored-by: Chris Sdogkos <work@chris-sdogkos.com>
Mentored-by: Chris Sdogkos <work@chris-sdogkos.com>

* style: apply gradle task `spotlessApply`

CI/CD is failing without this commit.

Co-authored-by: billpapat <50835814+billpapat@users.noreply.github.com>
Co-authored-by: Chris Sdogkos <work@chris-sdogkos.com>
Mentored-by: Chris Sdogkos <work@chris-sdogkos.com>

* fix: thread titles #1265

1) Created channels without title will default to "username's suggestions"
2) Change String threadTitle to final
3) ThreadTitle logic implemented in a helper method

Co-authored-by: Ethan McCue <5004262+bowbahdoe@users.noreply.github.com>

* docs(ThreadTitle): add JavaDocs and rename param

Addresses code review by @christolis.

Co-authorized-by: Chris Sdogkos <work@chris-sdogkos.com>
Signed-off-by: Chris Sdogkos <work@chris-sdogkos.com>
Signed-off-by: billpapat <50835814+billpapat@users.noreply.github.com>

* Changes as per requested by Zabuzard

* Changes as per requested by Zabuzard

* Changes as per requested by Taz03

---------

Signed-off-by: Chris Sdogkos <work@chris-sdogkos.com>
Signed-off-by: billpapat <50835814+billpapat@users.noreply.github.com>
Co-authored-by: Chris Sdogkos <work@chris-sdogkos.com>
Co-authored-by: Ethan McCue <5004262+bowbahdoe@users.noreply.github.com>

Author: 3 people

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

@@ -23,9 +23,9 @@
  */
 public final class SuggestionsUpDownVoter extends MessageReceiverAdapter {
     private static final Logger logger = LoggerFactory.getLogger(SuggestionsUpDownVoter.class);
-    private static final int TITLE_MAX_LENGTH = 60;
     private static final Emoji FALLBACK_UP_VOTE = Emoji.fromUnicode("👍");
     private static final Emoji FALLBACK_DOWN_VOTE = Emoji.fromUnicode("👎");
+    private static final int THREAD_TITLE_MAX_LENGTH = 60;
 
     private final SuggestionsConfig config;
 
@@ -55,19 +55,33 @@ public void onMessageReceived(MessageReceivedEvent event) {
     }
 
     private static void createThread(Message message) {
-        String title = message.getContentRaw();
+        String threadTitle = generateThreadTitle(message);
+        message.createThreadChannel(threadTitle).queue();
+    }
 
-        if (title.length() >= TITLE_MAX_LENGTH) {
-            int lastWordEnd = title.lastIndexOf(' ', TITLE_MAX_LENGTH);
+    /**
+     * Generates a title for the given message. The maximum length of the title is
+     * {@value #THREAD_TITLE_MAX_LENGTH}.
+     *
+     * @param message The message for which to generate the title.
+     * @return The generated and truncated thread title.
+     */
+    private static String generateThreadTitle(Message message) {
+        String primaryTitle = message.getContentStripped();
+        String fallbackTitle = message.getAuthor().getEffectiveName() + "'s suggestion";
+        String title = primaryTitle.isEmpty() ? fallbackTitle : primaryTitle;
 
-            if (lastWordEnd == -1) {
-                lastWordEnd = TITLE_MAX_LENGTH;
-            }
+        if (title.length() <= THREAD_TITLE_MAX_LENGTH) {
+            return title;
+        }
+
+        int lastWordEnd = title.lastIndexOf(' ', THREAD_TITLE_MAX_LENGTH);
 
-            title = title.substring(0, lastWordEnd);
+        if (lastWordEnd == -1) {
+            return title.substring(0, THREAD_TITLE_MAX_LENGTH);
         }
 
-        message.createThreadChannel(title).queue();
+        return title.substring(0, lastWordEnd);
     }
 
     private static void reactWith(String emojiName, Emoji fallbackEmoji, Guild guild,