Notify players when score buckets change

src/main/java/com/majinnaibu/minecraft/plugins/scorekeeper/ScoreKeeperPlugin.java

@@ -174,19 +174,33 @@ public class ScoreKeeperPlugin extends JavaPlugin {
   }
 
   public void switchPlayerBucket(Player player, String bucketId) {
-    requireBucket(bucketId);
+    ScoreBucket bucket = requireBucket(bucketId);
     UUID playerId = player.getUniqueId();
+    String previousBucketId = getPlayerBucket(player);
     if (bucketId.equals(_defaultBucketId)) {
       _playerBuckets.remove(playerId);
     } else {
       _playerBuckets.put(playerId, bucketId);
     }
+    if (!previousBucketId.equals(bucketId)) {
+      sendBucketChangeMessage(player, bucket);
+    }
   }
 
   public void switchAllPlayers(String bucketId) {
     requireBucket(bucketId);
+    Map<UUID, String> previousBuckets = new LinkedHashMap<>();
+    for (Player player : getServer().getOnlinePlayers()) {
+      previousBuckets.put(player.getUniqueId(), getPlayerBucket(player));
+    }
     _defaultBucketId = bucketId;
     _playerBuckets.clear();
+    ScoreBucket bucket = requireBucket(bucketId);
+    for (Player player : getServer().getOnlinePlayers()) {
+      if (!bucketId.equals(previousBuckets.get(player.getUniqueId()))) {
+        sendBucketChangeMessage(player, bucket);
+      }
+    }
   }
 
   // endregion
@@ -204,6 +218,15 @@ public class ScoreKeeperPlugin extends JavaPlugin {
     return bucket;
   }
 
+  private void sendBucketChangeMessage(Player player, ScoreBucket bucket) {
+    int score = getScore(player, bucket.getId());
+    String unit = score == 1 ? bucket.getSingular() : bucket.getPlural();
+    sendMessage(
+        player,
+        Component.text(
+            "You are now tracking " + bucket.getId() + ". You have " + score + " " + unit + "."));
+  }
+
   private void loadScores() {
     File scoreFile = new File(getDataFolder(), "scores.yml");
     if (!scoreFile.isFile()) {

src/main/java/com/majinnaibu/minecraft/plugins/scorekeeper/commands/ScoreBucketCommand.java

@@ -103,8 +103,10 @@ public class ScoreBucketCommand implements CommandExecutor {
   private void switchPlayerBucket(CommandSender sender, Player target, String bucketId) {
     try {
       _plugin.switchPlayerBucket(target, bucketId);
-      _plugin.sendMessage(
-          sender, Component.text(target.getName() + " is now tracking " + bucketId + "."));
+      if (sender != target) {
+        _plugin.sendMessage(
+            sender, Component.text(target.getName() + " is now tracking " + bucketId + "."));
+      }
     } catch (IllegalArgumentException ex) {
       sendError(sender, ex.getMessage());
     }