Add PlaceholderAPI (Bukkit) support

api/src/main/java/com/discordsrv/api/event/events/placeholder/PlaceholderLookupEvent.java

@@ -52,10 +52,11 @@ public class PlaceholderLookupEvent implements Event, Processable {
         return contexts;
     }
 
-    public Optional<Object> getContext(Class<?> type) {
+    @SuppressWarnings("unchecked")
+    public <T> Optional<T> getContext(Class<T> type) {
         for (Object o : contexts) {
             if (type.isAssignableFrom(o.getClass())) {
-                return Optional.of(o);
+                return Optional.of((T) o);
             }
         }
         return Optional.empty();

api/src/main/java/com/discordsrv/api/placeholder/PlaceholderService.java

@@ -25,6 +25,7 @@ package com.discordsrv.api.placeholder;
 
 import com.discordsrv.api.placeholder.mapper.PlaceholderResultMapper;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Set;
 import java.util.regex.Matcher;
@@ -52,6 +53,9 @@ public interface PlaceholderService {
     PlaceholderLookupResult lookupPlaceholder(@NotNull String placeholder, @NotNull Object... context);
 
     Object getResult(@NotNull Matcher matcher, @NotNull Set<Object> context);
+    @NotNull
     CharSequence getResultAsPlain(@NotNull Matcher matcher, @NotNull Set<Object> context);
+    @NotNull
+    CharSequence getResultAsPlain(@Nullable Object result);
 
 }

api/src/main/java/com/discordsrv/api/player/DiscordSRVPlayer.java

@@ -23,7 +23,6 @@
 
 package com.discordsrv.api.player;
 
-import com.discordsrv.api.placeholder.annotation.Placeholder;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.UUID;
@@ -37,7 +36,6 @@ public interface DiscordSRVPlayer {
      * The username of the player.
      * @return the player's username
      */
-    @Placeholder("player_name")
     @NotNull
     String username();
 
@@ -45,7 +43,6 @@ public interface DiscordSRVPlayer {
      * The {@link UUID} of the player.
      * @return the player's unique id
      */
-    @Placeholder("player_uuid")
     @NotNull
     UUID uniqueId();
 

bukkit/build.gradle

@@ -44,6 +44,7 @@ allprojects {
             }
             filter {
                 includeGroup 'net.milkbowl.vault'
+                includeGroup 'me.clip'
             }
         }
     }
@@ -79,6 +80,7 @@ dependencies {
 
     // Integrations
     compileOnly(libs.vaultapi)
+    compileOnly(libs.placeholderapi.bukkit)
 }
 
 processResources {

bukkit/src/main/java/com/discordsrv/bukkit/BukkitDiscordSRV.java

@@ -225,6 +225,7 @@ public class BukkitDiscordSRV extends ServerDiscordSRV<DiscordSRVBukkitBootstrap
 
         // Integrations
         registerIntegration("com.discordsrv.bukkit.integration.VaultIntegration");
+        registerIntegration("com.discordsrv.bukkit.integration.PlaceholderAPIIntegration");
 
         super.enable();
 

bukkit/src/main/java/com/discordsrv/bukkit/DiscordSRVBukkitBootstrap.java

@@ -37,6 +37,7 @@ public class DiscordSRVBukkitBootstrap extends BukkitBootstrap implements IBoots
     private final Logger logger;
     private final LifecycleManager lifecycleManager;
     private BukkitDiscordSRV discordSRV;
+    private final List<Runnable> mainThreadTasksForDisable = new ArrayList<>();
 
     public DiscordSRVBukkitBootstrap(JarInJarClassLoader classLoader, JavaPlugin plugin) throws IOException {
         // Don't change these parameters
@@ -73,6 +74,11 @@ public class DiscordSRVBukkitBootstrap extends BukkitBootstrap implements IBoots
     @Override
     public void onDisable() {
         lifecycleManager.disable(discordSRV);
+
+        // Run tasks on the main thread (scheduler cannot be used when disabling)
+        for (Runnable runnable : mainThreadTasksForDisable) {
+            runnable.run();
+        }
     }
 
     @Override
@@ -94,4 +100,8 @@ public class DiscordSRVBukkitBootstrap extends BukkitBootstrap implements IBoots
     public Path dataDirectory() {
         return getPlugin().getDataFolder().toPath();
     }
+
+    public List<Runnable> mainThreadTasksForDisable() {
+        return mainThreadTasksForDisable;
+    }
 }

bukkit/src/main/java/com/discordsrv/bukkit/integration/PlaceholderAPIIntegration.java

@@ -0,0 +1,155 @@
+/*
+ * This file is part of DiscordSRV, licensed under the GPLv3 License
+ * Copyright (c) 2016-2022 Austin "Scarsz" Shapiro, Henri "Vankka" Schubin and DiscordSRV contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.discordsrv.bukkit.integration;
+
+import com.discordsrv.api.event.bus.Subscribe;
+import com.discordsrv.api.event.events.placeholder.PlaceholderLookupEvent;
+import com.discordsrv.api.placeholder.PlaceholderLookupResult;
+import com.discordsrv.api.player.DiscordSRVPlayer;
+import com.discordsrv.api.profile.IProfile;
+import com.discordsrv.bukkit.BukkitDiscordSRV;
+import com.discordsrv.common.module.type.PluginIntegration;
+import com.discordsrv.common.player.IOfflinePlayer;
+import me.clip.placeholderapi.PlaceholderAPI;
+import me.clip.placeholderapi.expansion.PlaceholderExpansion;
+import org.bukkit.OfflinePlayer;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.*;
+
+public class PlaceholderAPIIntegration extends PluginIntegration<BukkitDiscordSRV> {
+
+    private static final String OPTIONAL_PREFIX = "placeholderapi_";
+    private Expansion expansion;
+
+    public PlaceholderAPIIntegration(BukkitDiscordSRV discordSRV) {
+        super(discordSRV);
+    }
+
+    @Override
+    public boolean isEnabled() {
+        try {
+            Class.forName("me.clip.placeholderapi.PlaceholderAPI");
+        } catch (ClassNotFoundException ignored) {
+            return false;
+        }
+
+        return super.isEnabled();
+    }
+
+    @Override
+    public void enable() {
+        expansion = new Expansion();
+        discordSRV.scheduler().runOnMainThread(() -> expansion.register());
+    }
+
+    @Override
+    public void disable() {
+        if (expansion != null) {
+            discordSRV.scheduler().runOnMainThread(() -> expansion.unregister());
+        }
+    }
+
+    @Subscribe
+    public void onPlaceholderLookup(PlaceholderLookupEvent event) {
+        String placeholder = event.getPlaceholder();
+        if (placeholder.startsWith(OPTIONAL_PREFIX)) {
+            placeholder = placeholder.substring(OPTIONAL_PREFIX.length());
+        }
+        placeholder = "%" + placeholder + "%";
+
+        Player player = event.getContext(DiscordSRVPlayer.class)
+                .map(p -> discordSRV.server().getPlayer(p.uniqueId()))
+                .orElse(null);
+        if (player != null) {
+            setResult(event, placeholder, PlaceholderAPI.setPlaceholders(player, placeholder));
+            return;
+        }
+
+        UUID uuid = event.getContext(IProfile.class)
+                .flatMap(IProfile::playerUUID)
+                .orElseGet(() -> event.getContext(IOfflinePlayer.class).map(IOfflinePlayer::uniqueId).orElse(null));
+
+        OfflinePlayer offlinePlayer = uuid != null ? discordSRV.server().getOfflinePlayer(uuid) : null;
+        setResult(event, placeholder, PlaceholderAPI.setPlaceholders(offlinePlayer, placeholder));
+    }
+
+    private void setResult(PlaceholderLookupEvent event, String placeholder, String result) {
+        if (result.equals(placeholder)) {
+            // Didn't resolve
+            return;
+        }
+
+        event.process(PlaceholderLookupResult.success(result));
+    }
+
+    public class Expansion extends PlaceholderExpansion {
+
+        @Override
+        public @NotNull String getIdentifier() {
+            return "discordsrv";
+        }
+
+        @Override
+        public @NotNull String getAuthor() {
+            return "DiscordSRV";
+        }
+
+        @Override
+        public @NotNull String getVersion() {
+            return discordSRV.version();
+        }
+
+        @Override
+        public @NotNull String getName() {
+            return "DiscordSRV";
+        }
+
+        @Override
+        public boolean persist() {
+            return true;
+        }
+
+        @Override
+        public @Nullable String onPlaceholderRequest(Player player, @NotNull String params) {
+            return onRequest(player, params);
+        }
+
+        @Override
+        public @Nullable String onRequest(OfflinePlayer player, @NotNull String params) {
+            Set<Object> context;
+            if (player != null) {
+                context = new HashSet<>(2);
+                discordSRV.profileManager().getProfile(player.getUniqueId()).ifPresent(context::add);
+                if (player instanceof Player) {
+                    context.add(discordSRV.playerProvider().player((Player) player));
+                } else {
+                    context.add(discordSRV.playerProvider().offlinePlayer(player));
+                }
+            } else {
+                context = Collections.emptySet();
+            }
+
+            String placeholder = "%" + params + "%";
+            return discordSRV.placeholderService().replacePlaceholders(placeholder, context);
+        }
+    }
+}

bukkit/src/main/java/com/discordsrv/bukkit/scheduler/BukkitScheduler.java

@@ -19,8 +19,13 @@
 package com.discordsrv.bukkit.scheduler;
 
 import com.discordsrv.bukkit.BukkitDiscordSRV;
-import com.discordsrv.common.server.scheduler.ServerScheduler;
+import com.discordsrv.bukkit.DiscordSRVBukkitBootstrap;
+import com.discordsrv.common.DiscordSRV;
 import com.discordsrv.common.scheduler.StandardScheduler;
+import com.discordsrv.common.server.scheduler.ServerScheduler;
+import org.bukkit.plugin.Plugin;
+
+import java.util.function.BiConsumer;
 
 public class BukkitScheduler extends StandardScheduler implements ServerScheduler {
 
@@ -31,18 +36,28 @@ public class BukkitScheduler extends StandardScheduler implements ServerSchedule
         this.discordSRV = discordSRV;
     }
 
+    private void checkDisable(Runnable task, BiConsumer<org.bukkit.scheduler.BukkitScheduler, Plugin> runNormal) {
+        // Can't run tasks when disabling, so we'll push those to the bootstrap to run after disable
+        if (!discordSRV.plugin().isEnabled() && discordSRV.status() == DiscordSRV.Status.SHUTTING_DOWN) {
+            ((DiscordSRVBukkitBootstrap) discordSRV.bootstrap()).mainThreadTasksForDisable().add(task);
+            return;
+        }
+
+        runNormal.accept(discordSRV.server().getScheduler(), discordSRV.plugin());
+    }
+
     @Override
     public void runOnMainThread(Runnable task) {
-        discordSRV.server().getScheduler().runTask(discordSRV.plugin(), task);
+        checkDisable(task, (scheduler, plugin) -> scheduler.runTask(plugin, task));
     }
 
     @Override
     public void runOnMainThreadLaterInTicks(Runnable task, int ticks) {
-        discordSRV.server().getScheduler().runTaskLater(discordSRV.plugin(), task, ticks);
+        checkDisable(task, (scheduler, plugin) -> scheduler.runTaskLater(plugin, task, ticks));
     }
 
     @Override
     public void runOnMainThreadAtFixedRateInTicks(Runnable task, int initialTicks, int rateTicks) {
-        discordSRV.server().getScheduler().runTaskTimer(discordSRV.plugin(), task, initialTicks, rateTicks);
+        checkDisable(task, (scheduler, plugin) -> scheduler.runTaskTimer(plugin, task, initialTicks, rateTicks));
     }
 }

common/src/main/java/com/discordsrv/common/placeholder/PlaceholderServiceImpl.java

@@ -175,12 +175,13 @@ public class PlaceholderServiceImpl implements PlaceholderService {
     }
 
     @Override
-    public CharSequence getResultAsPlain(@NotNull Matcher matcher, @NotNull Set<Object> context) {
+    public @NotNull CharSequence getResultAsPlain(@NotNull Matcher matcher, @NotNull Set<Object> context) {
         Object result = getResult(matcher, context);
         return getResultAsPlain(result);
     }
 
-    private CharSequence getResultAsPlain(Object result) {
+    @Override
+    public @NotNull CharSequence getResultAsPlain(@Nullable Object result) {
         if (result == null) {
             return "";
         } else if (result instanceof CharSequence) {
@@ -214,10 +215,6 @@ public class PlaceholderServiceImpl implements PlaceholderService {
         Object representation = getResultRepresentation(results, placeholder, matcher);
 
         CharSequence output = getResultAsPlain(representation);
-        if (output == null) {
-            output = String.valueOf(representation);
-        }
-
         return Pattern.compile(
                 matcher.group(1) + placeholder + matcher.group(3),
                 Pattern.LITERAL
@@ -274,15 +271,27 @@ public class PlaceholderServiceImpl implements PlaceholderService {
 
     private static class ClassProviderLoader implements CacheLoader<Class<?>, Set<PlaceholderProvider>> {
 
+        private Set<Class<?>> getAll(Class<?> clazz) {
+            Set<Class<?>> classes = new LinkedHashSet<>();
+            classes.add(clazz);
+
+            for (Class<?> anInterface : clazz.getInterfaces()) {
+                classes.addAll(getAll(anInterface));
+            }
+
+            Class<?> superClass = clazz.getSuperclass();
+            if (superClass != null) {
+                classes.addAll(getAll(superClass));
+            }
+
+            return classes;
+        }
+
         @Override
         public @Nullable Set<PlaceholderProvider> load(@NonNull Class<?> key) {
             Set<PlaceholderProvider> providers = new HashSet<>();
 
-            Class<?> currentClass = key;
-            do {
-                List<Class<?>> classes = new ArrayList<>(Arrays.asList(currentClass.getInterfaces()));
-                classes.add(currentClass);
-
+            Set<Class<?>> classes = getAll(key);
             for (Class<?> clazz : classes) {
                 for (Method method : clazz.getMethods()) {
                     Placeholder annotation = method.getAnnotation(Placeholder.class);
@@ -314,9 +323,6 @@ public class PlaceholderServiceImpl implements PlaceholderService {
                 }
             }
 
-                currentClass = currentClass.getSuperclass();
-            } while (currentClass != null);
-
             return providers;
         }
     }

common/src/main/java/com/discordsrv/common/player/IPlayer.java

@@ -45,6 +45,7 @@ public interface IPlayer extends DiscordSRVPlayer, IOfflinePlayer, ICommandSende
     }
 
     @NotNull
+    @Placeholder("player_name")
     String username();
 
     @Override

settings.gradle

@@ -94,6 +94,7 @@ dependencyResolutionManagement {
             // Integrations
             library('luckperms', 'net.luckperms', 'api').version('5.4')
             library('vaultapi', 'net.milkbowl.vault', 'VaultAPI').version('1.7')
+            library('placeholderapi-bukkit', 'me.clip', 'placeholderapi').version('2.11.1')
 
             // Logging
             library('slf4j-api', 'org.slf4j', 'slf4j-api').version('1.7.36')