Implement PlaceholderAPI support

module/placeholderapi-integration/build.gradle.kts

@@ -0,0 +1,7 @@
+repositories {
+    maven("https://repo.extendedclip.com/content/repositories/placeholderapi/")
+}
+
+dependencies {
+    compileOnly("me.clip:placeholderapi:2.11.6")
+}

module/placeholderapi-integration/src/main/java/org/battleplugins/arena/module/placeholderapi/BattleArenaExpansion.java

@@ -0,0 +1,123 @@
+package org.battleplugins.arena.module.placeholderapi;
+
+import me.clip.placeholderapi.expansion.PlaceholderExpansion;
+import org.battleplugins.arena.Arena;
+import org.battleplugins.arena.ArenaPlayer;
+import org.battleplugins.arena.BattleArena;
+import org.battleplugins.arena.competition.Competition;
+import org.battleplugins.arena.competition.phase.CompetitionPhaseType;
+import org.battleplugins.arena.resolver.Resolver;
+import org.battleplugins.arena.resolver.ResolverKey;
+import org.battleplugins.arena.resolver.ResolverKeys;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class BattleArenaExpansion extends PlaceholderExpansion {
+    private final BattleArena plugin;
+
+    public BattleArenaExpansion(BattleArena plugin) {
+        this.plugin = plugin;
+    }
+
+    @Override
+    public @NotNull String getIdentifier() {
+        return "ba";
+    }
+
+    @Override
+    public @NotNull String getAuthor() {
+        return "BattlePlugins";
+    }
+
+    @Override
+    public @NotNull String getVersion() {
+        return this.plugin.getPluginMeta().getVersion();
+    }
+
+    @Override
+    public @Nullable String onPlaceholderRequest(Player player, @NotNull String params) {
+        String[] split = params.split("_");
+
+        // No data for us to parse
+        if (split.length < 2) {
+            return null;
+        }
+
+        ArenaPlayer arenaPlayer = ArenaPlayer.getArenaPlayer(player);
+        if (arenaPlayer != null && params.startsWith("competition")) {
+            String placeholder = String.join("_", split).substring("competition_".length());
+
+            Resolver resolver = arenaPlayer.resolve();
+            ResolverKey<?> resolverKey = ResolverKeys.get(placeholder.replace("_", "-"));
+            if (resolverKey != null && resolver.has(resolverKey)) {
+                return resolver.resolveToString(resolverKey);
+            }
+        }
+
+        // If player is null or no other placeholder resolvers have made it to this point,
+        // handle more general placeholders
+
+        String arenaName = split[0];
+        Arena arena = this.plugin.getArena(arenaName);
+
+        // No arena, so not much we can do here
+        if (arena == null) {
+            return null;
+        }
+
+        // Remaining text in split array
+        String placeholder = String.join("_", split).substring(arenaName.length() + 1);
+        switch (placeholder) {
+            case "active_competitions": {
+                return String.valueOf(this.plugin.getCompetitions(arena).size());
+            }
+            case "online_players": {
+                int players = 0;
+                for (Competition<?> competition : this.plugin.getCompetitions(arena)) {
+                    players += competition.getAlivePlayerCount() + competition.getSpectatorCount();
+                }
+
+                return String.valueOf(players);
+            }
+            case "alive_players": {
+                int online = 0;
+                for (Competition<?> competition : this.plugin.getCompetitions(arena)) {
+                    online += competition.getAlivePlayerCount();
+                }
+
+                return String.valueOf(online);
+            }
+            case "spectators": {
+                int spectators = 0;
+                for (Competition<?> competition : this.plugin.getCompetitions(arena)) {
+                    spectators += competition.getSpectatorCount();
+                }
+
+                return String.valueOf(spectators);
+            }
+            case "waiting_competitions": {
+                int waitingCompetitions = 0;
+                for (Competition<?> competition : this.plugin.getCompetitions(arena)) {
+                    CompetitionPhaseType<?, ?> phase = competition.getPhase();
+                    if (CompetitionPhaseType.WAITING.equals(phase)) {
+                        waitingCompetitions++;
+                    }
+                }
+                return String.valueOf(waitingCompetitions);
+            }
+            case "ingame_competitions": {
+                int ingameCompetitions = 0;
+                for (Competition<?> competition : this.plugin.getCompetitions(arena)) {
+                    CompetitionPhaseType<?, ?> phase = competition.getPhase();
+                    if (CompetitionPhaseType.INGAME.equals(phase)) {
+                        ingameCompetitions++;
+                    }
+                }
+                return String.valueOf(ingameCompetitions);
+            }
+        }
+
+        return null;
+    }
+}

module/placeholderapi-integration/src/main/java/org/battleplugins/arena/module/placeholderapi/PlaceholderApiContainer.java

@@ -0,0 +1,16 @@
+package org.battleplugins.arena.module.placeholderapi;
+
+import org.battleplugins.arena.BattleArena;
+
+public class PlaceholderApiContainer {
+    private final BattleArenaExpansion expansion;
+
+    public PlaceholderApiContainer(BattleArena plugin) {
+        this.expansion = new BattleArenaExpansion(plugin);
+        this.expansion.register();
+    }
+
+    public void disable() {
+        this.expansion.unregister();
+    }
+}

module/placeholderapi-integration/src/main/java/org/battleplugins/arena/module/placeholderapi/PlaceholderApiIntegration.java

@@ -0,0 +1,39 @@
+package org.battleplugins.arena.module.placeholderapi;
+
+import org.battleplugins.arena.event.BattleArenaPostInitializeEvent;
+import org.battleplugins.arena.event.BattleArenaShutdownEvent;
+import org.battleplugins.arena.module.ArenaModule;
+import org.battleplugins.arena.module.ArenaModuleInitializer;
+import org.bukkit.Bukkit;
+import org.bukkit.event.EventHandler;
+
+/**
+ * A module that allows for hooking into the PlaceholderAPI plugin.
+ */
+@ArenaModule(id = PlaceholderApiIntegration.ID, name = "PlaceholderAPI", description = "Adds support for hooking into the PlaceholderAPI plugin.", authors = "BattlePlugins")
+public class PlaceholderApiIntegration implements ArenaModuleInitializer {
+    public static final String ID = "placeholderapi";
+
+    private PlaceholderApiContainer container;
+
+    @EventHandler
+    public void onPostInitialize(BattleArenaPostInitializeEvent event) {
+        // Check that we have Vault installed
+        if (!Bukkit.getServer().getPluginManager().isPluginEnabled("PlaceholderAPI")) {
+            event.getBattleArena().module(PlaceholderApiIntegration.ID).ifPresent(container ->
+                    container.disable("PlaceholderAPI is required for the PlaceholderAPI integration module to work!")
+            );
+
+            return;
+        }
+
+        this.container = new PlaceholderApiContainer(event.getBattleArena());
+    }
+
+    @EventHandler
+    public void onShutdown(BattleArenaShutdownEvent event) {
+        if (this.container != null) {
+            this.container.disable();
+        }
+    }
+}

plugin/src/main/java/org/battleplugins/arena/Arena.java

@@ -27,6 +27,7 @@
 import org.battleplugins.arena.resolver.Resolver;
 import org.battleplugins.arena.resolver.ResolverKeys;
 import org.battleplugins.arena.resolver.ResolverProvider;
+import org.battleplugins.arena.util.Describable;
 import org.bukkit.configuration.ConfigurationSection;
 import org.jetbrains.annotations.Nullable;
 
@@ -49,7 +50,7 @@
  * active game actions will occur (i.e. game timer, score, etc.)
  */
 @DocumentationSource("https://docs.battleplugins.org/books/user-guide/chapter/configuration")
-public class Arena implements ArenaLike, ArenaListener, Resolvable, ConfigHolder {
+public class Arena implements ArenaLike, ArenaListener, ConfigHolder, Resolvable, Describable {
 
     @Scoped
     private BattleArena plugin;
@@ -330,6 +331,11 @@ public final Arena getArena() {
         return this;
     }
 
+    @Override
+    public final String describe() {
+        return this.getName();
+    }
+
     @Override
     public Resolver resolve() {
         return Resolver.builder()

plugin/src/main/java/org/battleplugins/arena/ArenaLoader.java

@@ -35,7 +35,7 @@ public void load() {
 
             Bukkit.getPluginManager().registerEvents(arena, this.battleArena);
 
-            this.battleArena.arenas.put(arena.getName(), arena);
+            this.battleArena.arenas.put(arena.getName().toLowerCase(Locale.ROOT), arena);
 
             // Register command
             PluginCommand command = this.battleArena.getCommand(arena.getName().toLowerCase(Locale.ROOT));

plugin/src/main/java/org/battleplugins/arena/BattleArena.java

@@ -224,7 +224,7 @@ void postInitialize() {
 
         // Initialize events
         for (Map.Entry<String, List<EventOptions>> entry : this.config.getEvents().entrySet()) {
-            Arena arena = this.arenas.get(entry.getKey());
+            Arena arena = this.getArena(entry.getKey());
             if (arena == null) {
                 this.warn("Event {} does not have a valid arena!", entry.getKey());
                 continue;
@@ -283,7 +283,7 @@ public boolean isInArena(Player player) {
      * @return the arena from the given name
      */
     public Optional<Arena> arena(String name) {
-        return Optional.ofNullable(this.arenas.get(name));
+        return Optional.ofNullable(this.getArena(name));
     }
 
     /**
@@ -294,7 +294,7 @@ public Optional<Arena> arena(String name) {
      */
     @Nullable
     public Arena getArena(String name) {
-        return this.arenas.get(name);
+        return this.arenas.get(name.toLowerCase(Locale.ROOT));
     }
 
     /**
@@ -714,7 +714,7 @@ private void loadArenaMaps() {
                     }
                 });
             } catch (IOException e) {
-                throw new RuntimeException("Error loading maps for arena " + arenaName, e);
+                throw new RuntimeException("Error loading maps for arena " + arena.getName(), e);
             }
         }
     }

plugin/src/main/java/org/battleplugins/arena/competition/Competition.java

@@ -65,6 +65,20 @@ public interface Competition<T extends Competition<T>> extends CompetitionLike<T
      */
     void leave(Player player, ArenaLeaveEvent.Cause cause);
 
+    /**
+     * Gets the amount of players currently in the competition.
+     *
+     * @return the amount of players currently in the competition
+     */
+    int getAlivePlayerCount();
+
+    /**
+     * Gets the amount of spectators currently in the competition.
+     *
+     * @return the amount of spectators currently in the competition
+     */
+    int getSpectatorCount();
+
     /**
      * Gets the maximum amount of players that can join this competition.
      *

plugin/src/main/java/org/battleplugins/arena/competition/LiveCompetition.java

@@ -279,6 +279,16 @@ public final Set<ArenaPlayer> getPlayers() {
     public final Set<ArenaPlayer> getSpectators() {
         return Collections.unmodifiableSet(this.playersByRole.getOrDefault(PlayerRole.SPECTATING, Set.of()));
     }
+
+    @Override
+    public final int getAlivePlayerCount() {
+        return this.getPlayers().size();
+    }
+
+    @Override
+    public final int getSpectatorCount() {
+        return this.getSpectators().size();
+    }
 
     @Override
     public final int getMaxPlayers() {
@@ -385,11 +395,13 @@ private int calculateMaxPlayers() {
     @Override
     public Resolver resolve() {
         Resolver.Builder builder = this.arena.resolve().toBuilder()
+                .define(ResolverKeys.ALIVE_PLAYERS, ResolverProvider.simple(this.getAlivePlayerCount(), String::valueOf))
                 .define(ResolverKeys.COMPETITION, ResolverProvider.simple(this.getCompetition(), this.getMap()::getName))
-                .define(ResolverKeys.ONLINE_PLAYERS, ResolverProvider.simple(this.getPlayers().size(), String::valueOf))
+                .define(ResolverKeys.ONLINE_PLAYERS, ResolverProvider.simple(this.getAlivePlayerCount() + this.getSpectatorCount(), String::valueOf))
                 .define(ResolverKeys.MAP, ResolverProvider.simple(this.getMap(), CompetitionMap::getName))
                 .define(ResolverKeys.MAX_PLAYERS, ResolverProvider.simple(this.getMaxPlayers(), String::valueOf))
-                .define(ResolverKeys.PHASE, ResolverProvider.simple(this.getPhaseManager().getCurrentPhase(), p -> p.getType().getName()));
+                .define(ResolverKeys.PHASE, ResolverProvider.simple(this.getPhaseManager().getCurrentPhase(), p -> p.getType().getName()))
+                .define(ResolverKeys.SPECTATORS, ResolverProvider.simple(this.getSpectatorCount(), String::valueOf));
 
         this.getVictoryManager().resolve().mergeInto(builder);
         if (this.getPhaseManager().getCurrentPhase() instanceof LiveCompetitionPhase<?> phase) {

plugin/src/main/java/org/battleplugins/arena/competition/map/CompetitionMap.java

@@ -1,9 +1,11 @@
 package org.battleplugins.arena.competition.map;
 
+import org.battleplugins.arena.util.Describable;
+
 /**
  * A map for a competition.
  */
-public interface CompetitionMap {
+public interface CompetitionMap extends Describable {
 
     /**
      * Gets the name of the map.
@@ -18,4 +20,9 @@ public interface CompetitionMap {
      * @return the type of map
      */
     MapType getType();
+
+    @Override
+    default String describe() {
+        return this.getName();
+    }
 }

plugin/src/main/java/org/battleplugins/arena/competition/phase/CompetitionPhase.java

@@ -11,6 +11,7 @@
 import org.battleplugins.arena.event.ArenaListener;
 import org.battleplugins.arena.event.action.EventAction;
 import org.battleplugins.arena.options.ArenaOptionType;
+import org.battleplugins.arena.util.Describable;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
@@ -20,7 +21,7 @@
 /**
  * Represents the phase of a competition.
  */
-public abstract class CompetitionPhase<T extends Competition<T>> implements CompetitionLike<T>, ArenaListener {
+public abstract class CompetitionPhase<T extends Competition<T>> implements CompetitionLike<T>, ArenaListener, Describable {
     @Id
     private CompetitionPhaseType<T, CompetitionPhase<T>> type;
 
@@ -162,4 +163,9 @@ public final CompetitionPhase<T> getPreviousPhase() {
     protected final void setPreviousPhase(CompetitionPhase<T> previousPhase) {
         this.previousPhase = previousPhase;
     }
+
+    @Override
+    public final String describe() {
+        return this.type.describe();
+    }
 }

plugin/src/main/java/org/battleplugins/arena/competition/phase/CompetitionPhaseType.java

@@ -5,6 +5,7 @@
 import org.battleplugins.arena.competition.phase.phases.IngamePhase;
 import org.battleplugins.arena.competition.phase.phases.VictoryPhase;
 import org.battleplugins.arena.competition.phase.phases.WaitingPhase;
+import org.battleplugins.arena.util.Describable;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.HashMap;
@@ -18,7 +19,7 @@
  * @param <C> the type of competition
  * @param <T> the type of competition phase
  */
-public final class CompetitionPhaseType<C extends Competition<C>, T extends CompetitionPhase<C>> {
+public final class CompetitionPhaseType<C extends Competition<C>, T extends CompetitionPhase<C>> implements Describable {
     private static final Map<String, CompetitionPhaseType<?, ?>> PHASE_TYPES = new HashMap<>();
 
     public static final CompetitionPhaseType<?, WaitingPhase<?>> WAITING = new CompetitionPhaseType("waiting", WaitingPhase.class);
@@ -53,6 +54,11 @@ public static <C extends Competition<C>, T extends CompetitionPhase<C>> Competit
         return new CompetitionPhaseType<>(name, clazz);
     }
 
+    @Override
+    public String describe() {
+        return this.getName();
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;