feat(succession): transfer tyrant reign on death

src/main/java/games/dmg/spigottyrant/BukkitManagedRoleEffects.java

@@ -0,0 +1,28 @@
+package games.dmg.spigottyrant;
+
+public final class BukkitManagedRoleEffects implements ManagedRoleEffects {
+    private final TyrantStateManager stateManager;
+    private final TyrantPresentation presentation;
+
+    public BukkitManagedRoleEffects(
+        TyrantStateManager stateManager,
+        TyrantPresentation presentation
+    ) {
+        this.stateManager = stateManager;
+        this.presentation = presentation;
+    }
+
+    @Override
+    public void suppressAll() {
+        presentation.clear();
+    }
+
+    @Override
+    public void restoreAll() {
+        if (stateManager.game().lifecycle() == GameLifecycle.RUNNING) {
+            presentation.reconcile(stateManager.game().tyrantId());
+        } else {
+            presentation.clear();
+        }
+    }
+}

src/main/java/games/dmg/spigottyrant/BukkitTyrantPresentation.java

@@ -0,0 +1,55 @@
+package games.dmg.spigottyrant;
+
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.UUID;
+import org.bukkit.ChatColor;
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+import org.bukkit.scoreboard.Scoreboard;
+import org.bukkit.scoreboard.ScoreboardManager;
+import org.bukkit.scoreboard.Team;
+
+public final class BukkitTyrantPresentation implements TyrantPresentation {
+    private static final String TEAM_NAME = "tyrant-red";
+    private final Server server;
+    private final Team team;
+    private Optional<UUID> presentedTyrant = Optional.empty();
+
+    public BukkitTyrantPresentation(Server server) {
+        this.server = server;
+        ScoreboardManager manager = Objects.requireNonNull(
+            server.getScoreboardManager(), "Scoreboard manager is unavailable"
+        );
+        Scoreboard scoreboard = manager.getMainScoreboard();
+        Team existing = scoreboard.getTeam(TEAM_NAME);
+        team = existing == null ? scoreboard.registerNewTeam(TEAM_NAME) : existing;
+        team.setColor(ChatColor.RED);
+    }
+
+    @Override
+    public void reconcile(Optional<UUID> tyrantId) {
+        clear();
+        presentedTyrant = tyrantId;
+        tyrantId.map(server::getPlayer).ifPresent(player -> {
+            team.addEntry(player.getName());
+            player.setGlowing(true);
+            player.setPlayerListName(ChatColor.RED + player.getName());
+            player.setDisplayName(ChatColor.RED + player.getName());
+        });
+    }
+
+    @Override
+    public void clear() {
+        presentedTyrant.map(server::getPlayer).ifPresent(player -> {
+            player.setGlowing(false);
+            player.setPlayerListName(player.getName());
+            player.setDisplayName(player.getName());
+        });
+        for (String entry : new HashSet<>(team.getEntries())) {
+            team.removeEntry(entry);
+        }
+        presentedTyrant = Optional.empty();
+    }
+}

src/main/java/games/dmg/spigottyrant/PlayerJoinListener.java

@@ -8,10 +8,20 @@ import org.bukkit.event.player.PlayerJoinEvent;
 public final class PlayerJoinListener implements Listener {
     private final TyrantStateManager stateManager;
     private final Clock clock;
+    private final TyrantPresentation presentation;
 
     public PlayerJoinListener(TyrantStateManager stateManager, Clock clock) {
+        this(stateManager, clock, null);
+    }
+
+    public PlayerJoinListener(
+        TyrantStateManager stateManager,
+        Clock clock,
+        TyrantPresentation presentation
+    ) {
         this.stateManager = stateManager;
         this.clock = clock;
+        this.presentation = presentation;
     }
 
     @EventHandler
@@ -29,5 +39,11 @@ public final class PlayerJoinListener implements Listener {
         if (!reminder.isEmpty()) {
             event.getPlayer().sendMessage(reminder);
         }
+        if (presentation != null
+                && stateManager.game().lifecycle() == GameLifecycle.RUNNING
+                && stateManager.game().tyrantId()
+                    .filter(event.getPlayer().getUniqueId()::equals).isPresent()) {
+            presentation.reconcile(stateManager.game().tyrantId());
+        }
     }
 }

src/main/java/games/dmg/spigottyrant/SpigotTyrantPlugin.java

@@ -10,6 +10,7 @@ import org.bukkit.plugin.java.JavaPlugin;
 public final class SpigotTyrantPlugin extends JavaPlugin {
     private PluginSettings settings;
     private TyrantStateManager stateManager;
+    private TyrantPresentation tyrantPresentation;
 
     @Override
     public void onEnable() {
@@ -27,6 +28,11 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
             return;
         }
 
+        tyrantPresentation = new BukkitTyrantPresentation(getServer());
+        ManagedRoleEffects managedEffects = new BukkitManagedRoleEffects(
+            stateManager, tyrantPresentation
+        );
+        managedEffects.restoreAll();
         Objects.requireNonNull(getCommand("tyrant"), "Missing tyrant command metadata")
             .setExecutor(new TyrantCommand(stateManager, new TyrantProgressionService()));
         Objects.requireNonNull(getCommand("tyrantadmin"), "Missing tyrantadmin metadata")
@@ -34,7 +40,7 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
                 stateManager,
                 new GameLifecycleService(),
                 new BukkitOnlinePlayerDirectory(),
-                new NoopManagedRoleEffects(),
+                managedEffects,
                 Clock.systemUTC(),
                 new RoleCandidateSelector(),
                 settings.candidateActivityWindow(),
@@ -42,7 +48,22 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
                 java.util.random.RandomGenerator.getDefault()
             ));
         getServer().getPluginManager().registerEvents(
-            new PlayerJoinListener(stateManager, Clock.systemUTC()),
+            new PlayerJoinListener(stateManager, Clock.systemUTC(), tyrantPresentation),
+            this
+        );
+        getServer().getPluginManager().registerEvents(
+            new TyrantDeathListener(
+                stateManager,
+                new TyrantSuccessionService(
+                    new RoleCandidateSelector(),
+                    settings.candidateActivityWindow(),
+                    settings.pendingSelectionTimeout(),
+                    java.util.random.RandomGenerator.getDefault()
+                ),
+                tyrantPresentation,
+                getServer(),
+                Clock.systemUTC()
+            ),
             this
         );
         getServer().getScheduler().runTaskTimer(this, stateManager::saveIfDirty, 600L, 600L);
@@ -51,6 +72,9 @@ public final class SpigotTyrantPlugin extends JavaPlugin {
 
     @Override
     public void onDisable() {
+        if (tyrantPresentation != null) {
+            tyrantPresentation.clear();
+        }
         if (stateManager != null) {
             stateManager.saveIfDirty();
         }

src/main/java/games/dmg/spigottyrant/TyrantDeathListener.java

@@ -0,0 +1,65 @@
+package games.dmg.spigottyrant;
+
+import java.time.Clock;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import org.bukkit.ChatColor;
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.PlayerDeathEvent;
+
+public final class TyrantDeathListener implements Listener {
+    private final TyrantStateManager stateManager;
+    private final TyrantSuccessionService succession;
+    private final TyrantPresentation presentation;
+    private final Server server;
+    private final Clock clock;
+
+    public TyrantDeathListener(
+        TyrantStateManager stateManager,
+        TyrantSuccessionService succession,
+        TyrantPresentation presentation,
+        Server server,
+        Clock clock
+    ) {
+        this.stateManager = stateManager;
+        this.succession = succession;
+        this.presentation = presentation;
+        this.server = server;
+        this.clock = clock;
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void onDeath(PlayerDeathEvent event) {
+        UUID victimId = event.getEntity().getUniqueId();
+        GameState game = stateManager.game();
+        if (game.lifecycle() != GameLifecycle.RUNNING
+                || game.tyrantId().filter(victimId::equals).isEmpty()) {
+            return;
+        }
+        Optional<UUID> killerId = Optional.ofNullable(event.getEntity().getKiller())
+            .map(Player::getUniqueId);
+        Set<UUID> online = server.getOnlinePlayers().stream()
+            .map(Player::getUniqueId)
+            .collect(Collectors.toUnmodifiableSet());
+        LifecycleState succeeded = succession.succeed(
+            stateManager.snapshot(), killerId, online, clock.instant()
+        );
+        stateManager.replaceState(succeeded);
+        stateManager.saveIfDirty();
+        presentation.reconcile(succeeded.game().tyrantId());
+        String successor = succeeded.game().tyrantId()
+            .map(id -> {
+                Player player = server.getPlayer(id);
+                return player == null ? id.toString() : player.getName();
+            })
+            .orElse("pending selection");
+        String message = ChatColor.RED + successor + " is the new Tyrant!";
+        server.getOnlinePlayers().forEach(player -> player.sendMessage(message));
+    }
+}

src/main/java/games/dmg/spigottyrant/TyrantPresentation.java

@@ -0,0 +1,10 @@
+package games.dmg.spigottyrant;
+
+import java.util.Optional;
+import java.util.UUID;
+
+public interface TyrantPresentation {
+    void reconcile(Optional<UUID> tyrantId);
+
+    void clear();
+}

src/main/java/games/dmg/spigottyrant/TyrantSuccessionService.java

@@ -0,0 +1,109 @@
+package games.dmg.spigottyrant;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+import java.util.random.RandomGenerator;
+
+public final class TyrantSuccessionService {
+    private final RoleCandidateSelector candidates;
+    private final Duration activityWindow;
+    private final Duration pendingTimeout;
+    private final RandomGenerator random;
+
+    public TyrantSuccessionService(
+        RoleCandidateSelector candidates,
+        Duration activityWindow,
+        Duration pendingTimeout,
+        RandomGenerator random
+    ) {
+        this.candidates = candidates;
+        this.activityWindow = activityWindow;
+        this.pendingTimeout = pendingTimeout;
+        this.random = random;
+    }
+
+    public LifecycleState succeed(
+        PersistentState state,
+        Optional<UUID> killerId,
+        Set<UUID> onlinePlayerIds,
+        Instant now
+    ) {
+        if (state.game().lifecycle() != GameLifecycle.RUNNING
+                || state.game().tyrantId().isEmpty()) {
+            throw new IllegalStateException("a running Tyrant reign is required");
+        }
+        UUID formerTyrant = state.game().tyrantId().orElseThrow();
+        Optional<UUID> formerVigilante = state.game().vigilanteId();
+        Map<UUID, PlayerState> clearedPlayers = clearAssignments(state.players());
+        Optional<UUID> selectedTyrant = killerId.isPresent()
+            ? killerId
+            : candidates.select(
+                clearedPlayers,
+                Set.of(),
+                Optional.of(formerTyrant),
+                now,
+                activityWindow,
+                random
+            );
+        Optional<UUID> activeTyrant = selectedTyrant
+            .filter(playerId -> killerId.isPresent() || onlinePlayerIds.contains(playerId));
+        Optional<PendingSelection> pendingTyrant = selectedTyrant
+            .filter(playerId -> activeTyrant.isEmpty())
+            .map(playerId -> new PendingSelection(playerId, now.plus(pendingTimeout)));
+
+        Optional<UUID> selectedVigilante = activeTyrant.flatMap(tyrantId ->
+            candidates.select(
+                clearedPlayers,
+                Set.of(tyrantId),
+                formerVigilante,
+                now,
+                activityWindow,
+                random
+            )
+        );
+        Optional<UUID> activeVigilante = selectedVigilante
+            .filter(onlinePlayerIds::contains);
+        Optional<PendingSelection> pendingVigilante = selectedVigilante
+            .filter(playerId -> activeVigilante.isEmpty())
+            .map(playerId -> new PendingSelection(playerId, now.plus(pendingTimeout)));
+
+        GameState game = new GameState(
+            GameLifecycle.RUNNING,
+            activeTyrant,
+            activeVigilante,
+            pendingTyrant,
+            pendingVigilante,
+            Optional.empty(),
+            state.game().accumulatedPausedTime(),
+            0,
+            1,
+            Set.of()
+        );
+        return new LifecycleState(game, clearedPlayers);
+    }
+
+    private static Map<UUID, PlayerState> clearAssignments(
+        Map<UUID, PlayerState> players
+    ) {
+        Map<UUID, PlayerState> cleared = new HashMap<>();
+        for (PlayerState player : players.values()) {
+            cleared.put(player.playerId(), new PlayerState(
+                player.playerId(),
+                player.latestName(),
+                player.lastLogin(),
+                player.optedOutUntil(),
+                TyrantClass.NONE,
+                Optional.empty(),
+                Map.of(),
+                Set.of(),
+                player.capturedMobs()
+            ));
+        }
+        return Map.copyOf(cleared);
+    }
+}