feat(progression): reward unique boss kills

src/main/java/games/dmg/triggerspawn/ProgressionReminder.java

@@ -0,0 +1,31 @@
+package games.dmg.triggerspawn;
+
+import java.time.Duration;
+import java.util.Arrays;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+import org.bukkit.ChatColor;
+
+final class ProgressionReminder {
+    private ProgressionReminder() {
+    }
+
+    static Optional<String> create(Set<BossType> defeated, PluginSettings settings) {
+        if (defeated.size() >= BossType.values().length) {
+            return Optional.empty();
+        }
+        String remaining = Arrays.stream(BossType.values())
+                .filter(boss -> !defeated.contains(boss))
+                .map(BossType::displayName)
+                .collect(Collectors.joining(", "));
+        Duration nextTier = switch (defeated.size()) {
+            case 0 -> settings.oneKillCooldown();
+            case 1 -> settings.twoKillCooldown();
+            default -> settings.threeKillCooldown();
+        };
+        return Optional.of(ChatColor.GOLD + "Progression reminder: " + ChatColor.YELLOW
+                + "defeat " + remaining + " to permanently reduce your boss cooldown; "
+                + "the next tier is " + DurationFormatter.format(nextTier) + ".");
+    }
+}

src/main/java/games/dmg/triggerspawn/SpawnCommand.java

@@ -27,6 +27,7 @@ final class SpawnCommand implements CommandExecutor, Listener {
     private final Plugin plugin;
     private final SpawnStateManager stateManager;
     private final AccessService access;
+    private final PluginSettings settings;
     private final SpawnAreaService spawnAreas;
     private final SafeSpawnFinder safeSpawnFinder;
     private final Clock clock;
@@ -36,12 +37,14 @@ final class SpawnCommand implements CommandExecutor, Listener {
             Plugin plugin,
             SpawnStateManager stateManager,
             AccessService access,
+            PluginSettings settings,
             SpawnAreaService spawnAreas,
             SafeSpawnFinder safeSpawnFinder,
             Clock clock) {
         this.plugin = plugin;
         this.stateManager = stateManager;
         this.access = access;
+        this.settings = settings;
         this.spawnAreas = spawnAreas;
         this.safeSpawnFinder = safeSpawnFinder;
         this.clock = clock;
@@ -140,10 +143,8 @@ final class SpawnCommand implements CommandExecutor, Listener {
                     recordSuccessfulUse(player);
                     player.sendTitle(ChatColor.GREEN + "Welcome to spawn", "", 5, 30, 10);
                     PlayerState completed = stateManager.player(player.getUniqueId(), player.getName());
-                    if (completed.defeatedBosses().size() < BossType.values().length) {
-                        player.sendMessage(ChatColor.GOLD
-                                + "Defeat each remaining boss to permanently reduce your /spawn cooldown.");
-                    }
+                    ProgressionReminder.create(completed.defeatedBosses(), settings)
+                            .ifPresent(player::sendMessage);
                 } else {
                     player.sendMessage(ChatColor.RED
                             + "The spawn teleport failed. Your cooldown was not used.");

src/main/java/games/dmg/triggerspawn/TriggerSpawnPlugin.java

@@ -37,6 +37,7 @@ public final class TriggerSpawnPlugin extends JavaPlugin {
                     this,
                     stateManager,
                     access,
+                    settings,
                     new SpawnAreaService(stateManager),
                     new SafeSpawnFinder(),
                     Clock.systemUTC());

src/test/java/games/dmg/triggerspawn/ProgressionReminderTest.java

@@ -0,0 +1,27 @@
+package games.dmg.triggerspawn;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.Optional;
+import java.util.Set;
+import org.bukkit.configuration.MemoryConfiguration;
+import org.junit.jupiter.api.Test;
+
+final class ProgressionReminderTest {
+    @Test
+    void identifiesRemainingBossesAndNextPermanentTier() {
+        PluginSettings settings = PluginSettings.from(new MemoryConfiguration());
+
+        String reminder = ProgressionReminder.create(Set.of(BossType.WARDEN), settings).orElseThrow();
+
+        assertTrue(reminder.contains("Dragon"));
+        assertTrue(reminder.contains("Wither"));
+        assertTrue(reminder.contains("4h"));
+    }
+
+    @Test
+    void completedProgressionNeedsNoReminder() {
+        PluginSettings settings = PluginSettings.from(new MemoryConfiguration());
+        assertTrue(ProgressionReminder.create(Set.of(BossType.values()), settings).isEmpty());
+    }
+}

src/test/java/games/dmg/triggerspawn/ProgressionServiceTest.java

@@ -44,6 +44,18 @@ final class ProgressionServiceTest {
         assertEquals(Duration.ofHours(4), second.applicableCooldown());
         assertEquals(2, second.defeatedBosses().size());
         assertTrue(manager.snapshot().players().get(playerId).lastSpawnUse().isEmpty());
+
+        Instant laterUse = Instant.parse("2026-08-08T12:00:00Z");
+        PlayerState current = manager.snapshot().players().get(playerId);
+        manager.putPlayer(new PlayerState(
+                current.playerId(),
+                current.latestName(),
+                current.defeatedBosses(),
+                current.grantedCooldown(),
+                false,
+                Optional.of(laterUse)));
+        progression.creditKill(identity, BossType.WARDEN);
+        assertEquals(laterUse, manager.snapshot().players().get(playerId).lastSpawnUse().orElseThrow());
     }
 
     @Test

src/test/java/games/dmg/triggerspawn/SpawnCommandTest.java

@@ -43,6 +43,7 @@ final class SpawnCommandTest {
                 mock(Plugin.class),
                 manager,
                 access,
+                settings,
                 new SpawnAreaService(manager),
                 new SafeSpawnFinder(),
                 Clock.fixed(Instant.parse("2026-08-08T11:00:00Z"), ZoneOffset.UTC));