chore: remove hard depend on bukkit scheduler to support folia

bukkit/src/main/java/com/github/juliarn/npclib/bukkit/BukkitPlatform.java

@@ -28,8 +28,10 @@
 import com.github.juliarn.npclib.api.Platform;
 import com.github.juliarn.npclib.api.log.PlatformLogger;
 import com.github.juliarn.npclib.bukkit.protocol.BukkitProtocolAdapter;
+import com.github.juliarn.npclib.bukkit.util.BukkitPlatformUtil;
 import com.github.juliarn.npclib.common.platform.CommonPlatform;
 import com.github.juliarn.npclib.common.platform.CommonPlatformBuilder;
+import com.github.juliarn.npclib.common.task.AsyncPlatformTaskManager;
 import org.bukkit.World;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
@@ -54,7 +56,11 @@ protected void prepareBuild() {
 
     // set the default task manager
     if (this.taskManager == null) {
-      this.taskManager = BukkitPlatformTaskManager.taskManager(this.extension);
+      if (BukkitPlatformUtil.runsOnFolia()) {
+        this.taskManager = AsyncPlatformTaskManager.taskManager(this.extension.getName());
+      } else {
+        this.taskManager = BukkitPlatformTaskManager.taskManager(this.extension);
+      }
     }
 
     // set the default version accessor

bukkit/src/main/java/com/github/juliarn/npclib/bukkit/util/BukkitPlatformUtil.java

@@ -28,15 +28,23 @@
 
 import com.github.juliarn.npclib.api.Npc;
 import com.github.juliarn.npclib.api.Position;
+import com.github.juliarn.npclib.common.util.ClassHelper;
 import org.bukkit.Location;
 import org.jetbrains.annotations.NotNull;
 
 public final class BukkitPlatformUtil {
 
+  private static final boolean FOLIA =
+    ClassHelper.classExists("io.papermc.paper.threadedregions.RegionizedServerInitEvent");
+
   private BukkitPlatformUtil() {
     throw new UnsupportedOperationException();
   }
 
+  public static boolean runsOnFolia() {
+    return FOLIA;
+  }
+
   public static double distance(@NotNull Npc<?, ?, ?, ?> npc, @NotNull Location location) {
     Position pos = npc.position();
     return square(location.getX() - pos.x()) + square(location.getY() - pos.y()) + square(location.getZ() - pos.z());

common/src/main/java/com/github/juliarn/npclib/common/task/AsyncPlatformTaskManager.java

@@ -0,0 +1,75 @@
+/*
+ * This file is part of npc-lib, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2022-2023 Julian M., Pasqual K. and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.github.juliarn.npclib.common.task;
+
+import com.github.juliarn.npclib.api.PlatformTaskManager;
+import java.util.Objects;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import org.jetbrains.annotations.NotNull;
+
+public final class AsyncPlatformTaskManager implements PlatformTaskManager {
+
+  private static final long ONE_TICK_MS = 1000 / 20;
+
+  private final ExecutorService runOnceExecutorService;
+  private final ScheduledExecutorService scheduledExecutorService;
+
+  private AsyncPlatformTaskManager(@NotNull String extensionId) {
+    ThreadFactory runOnceThreadFactory = AsyncTaskThreadFactory.create(extensionId + " NPC-Lib Task #%d");
+    this.runOnceExecutorService = Executors.newCachedThreadPool(runOnceThreadFactory);
+
+    ThreadFactory scheduledThreadFactory = AsyncTaskThreadFactory.create(extensionId + " NPC-Lib Scheduled Task #%d");
+    this.scheduledExecutorService = Executors.newScheduledThreadPool(0, scheduledThreadFactory);
+  }
+
+  public static @NotNull PlatformTaskManager taskManager(@NotNull String extensionIdentifier) {
+    Objects.requireNonNull(extensionIdentifier, "extensionIdentifier");
+    return new AsyncPlatformTaskManager(extensionIdentifier);
+  }
+
+  @Override
+  public void scheduleSync(@NotNull Runnable task) {
+    this.runOnceExecutorService.execute(task);
+  }
+
+  @Override
+  public void scheduleDelayedSync(@NotNull Runnable task, int delayTicks) {
+    this.scheduledExecutorService.schedule(task, delayTicks * ONE_TICK_MS, TimeUnit.MILLISECONDS);
+  }
+
+  @Override
+  public void scheduleAsync(@NotNull Runnable task) {
+    this.runOnceExecutorService.execute(task);
+  }
+
+  @Override
+  public void scheduleDelayedAsync(@NotNull Runnable task, int delayTicks) {
+    this.scheduledExecutorService.schedule(task, delayTicks * ONE_TICK_MS, TimeUnit.MILLISECONDS);
+  }
+}

common/src/main/java/com/github/juliarn/npclib/common/task/AsyncTaskThreadFactory.java

@@ -0,0 +1,60 @@
+/*
+ * This file is part of npc-lib, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2022-2023 Julian M., Pasqual K. and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.github.juliarn.npclib.common.task;
+
+import java.util.Objects;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicLong;
+import org.jetbrains.annotations.NotNull;
+
+final class AsyncTaskThreadFactory implements ThreadFactory {
+
+  private final String threadNameFormat;
+  private final ThreadGroup parentThreadGroup;
+
+  private final AtomicLong createdThreadCount = new AtomicLong(0);
+
+  private AsyncTaskThreadFactory(@NotNull String threadNameFormat) {
+    this.threadNameFormat = threadNameFormat;
+    this.parentThreadGroup = Thread.currentThread().getThreadGroup();
+  }
+
+  public static @NotNull ThreadFactory create(@NotNull String threadNameFormat) {
+    Objects.requireNonNull(threadNameFormat, "threadNameFormat");
+    return new AsyncTaskThreadFactory(threadNameFormat);
+  }
+
+  @Override
+  public @NotNull Thread newThread(@NotNull Runnable runnable) {
+    // construct the name thread
+    String threadName = String.format(this.threadNameFormat, this.createdThreadCount.incrementAndGet());
+    Thread thread = new Thread(this.parentThreadGroup, runnable, threadName, 0);
+
+    // set up the thread configuration
+    thread.setDaemon(true);
+    thread.setPriority(Thread.NORM_PRIORITY);
+    return thread;
+  }
+}

common/src/main/java/com/github/juliarn/npclib/common/util/ClassHelper.java

@@ -0,0 +1,44 @@
+/*
+ * This file is part of npc-lib, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2022-2023 Julian M., Pasqual K. and contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.github.juliarn.npclib.common.util;
+
+import org.jetbrains.annotations.NotNull;
+
+public final class ClassHelper {
+
+  private ClassHelper() {
+    throw new UnsupportedOperationException();
+  }
+
+  public static boolean classExists(@NotNull String className) {
+    try {
+      ClassLoader classLoader = ClassHelper.class.getClassLoader();
+      Class.forName(className, false, classLoader);
+      return true;
+    } catch (ClassNotFoundException exception) {
+      return false;
+    }
+  }
+}