Prepare support Folia

pom.xml

@@ -30,11 +30,15 @@
                 <enabled>false</enabled>
             </snapshots>
         </repository>
+        <repository>
+            <id>papermc</id>
+            <url>https://repo.papermc.io/repository/maven-public/</url>
+        </repository>
     </repositories>
     <dependencies>
         <dependency>
-            <groupId>org.spigotmc</groupId>
-            <artifactId>spigot-api</artifactId>
+            <groupId>io.papermc.paper</groupId>
+            <artifactId>paper-api</artifactId>
             <version>${bukkit.version}</version>
             <scope>provided</scope>
         </dependency>
@@ -74,6 +78,12 @@
             <version>4.3.4</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <url>http://www.citizensnpcs.co</url>
     <ciManagement>

src/main/java/net/citizensnpcs/api/CitizensAPI.java

@@ -2,6 +2,8 @@
 
 import java.io.File;
 
+import net.citizensnpcs.api.util.SpigotUtil;
+import net.citizensnpcs.api.util.schedulers.SchedulerAdapter;
 import org.bukkit.Bukkit;
 import org.bukkit.event.Listener;
 import org.bukkit.plugin.Plugin;
@@ -20,6 +22,9 @@
  * Contains methods used in order to utilize the Citizens API.
  */
 public final class CitizensAPI {
+
+    private static SchedulerAdapter scheduler;
+
     private CitizensAPI() {
     }
 
@@ -195,6 +200,21 @@ public static void setImplementation(CitizensPlugin implementation) {
         instance = implementation;
     }
 
+    /**
+     * The new scheduler that works on Folia and Spigot
+     * @return scheduler Folia or Spigot
+     */
+    public static SchedulerAdapter getScheduler() {
+        if (scheduler == null) {
+            if (SpigotUtil.isFoliaServer()) {
+                scheduler = new net.citizensnpcs.api.util.schedulers.adapter.FoliaScheduler(getPlugin());
+            } else {
+                scheduler = new net.citizensnpcs.api.util.schedulers.adapter.SpigotScheduler(getPlugin());
+            }
+        }
+        return scheduler;
+    }
+
     /**
      * Shuts down any resources currently being held.
      */

src/main/java/net/citizensnpcs/api/LocationLookup.java

@@ -10,6 +10,7 @@
 import java.util.concurrent.Future;
 import java.util.function.BiConsumer;
 
+import net.citizensnpcs.api.util.schedulers.SchedulerRunnable;
 import org.bukkit.Bukkit;
 import org.bukkit.GameMode;
 import org.bukkit.Location;
@@ -20,7 +21,6 @@
 import org.bukkit.event.player.PlayerQuitEvent;
 import org.bukkit.event.world.WorldUnloadEvent;
 import org.bukkit.potion.PotionEffectType;
-import org.bukkit.scheduler.BukkitRunnable;
 
 import com.google.common.collect.Collections2;
 import com.google.common.collect.Iterables;
@@ -31,7 +31,7 @@
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.api.npc.NPCRegistry;
 
-public class LocationLookup extends BukkitRunnable {
+public class LocationLookup extends SchedulerRunnable {
     private final Map<String, PerPlayerMetadata<?>> metadata = Maps.newHashMap();
     private Future<Map<UUID, PhTreeF<NPC>>> npcFuture = null;
     private Map<UUID, PhTreeF<NPC>> npcWorlds = Maps.newHashMap();
@@ -123,7 +123,7 @@ public Iterable<Player> getNearbyVisiblePlayers(Entity base, Location location,
 
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public void onJoin(PlayerJoinEvent event) {
-        Bukkit.getScheduler().scheduleSyncDelayedTask(CitizensAPI.getPlugin(), () -> {
+        CitizensAPI.getScheduler().runEntityTask(event.getPlayer(), () -> {
             updateWorld(event.getPlayer().getWorld());
             for (PerPlayerMetadata meta : metadata.values()) {
                 if (meta.onJoin != null) {
@@ -134,7 +134,7 @@ public void onJoin(PlayerJoinEvent event) {
     }
 
     public void onQuit(PlayerQuitEvent event) {
-        Bukkit.getScheduler().scheduleSyncDelayedTask(CitizensAPI.getPlugin(), () -> {
+        CitizensAPI.getScheduler().runEntityTask(event.getPlayer(), () -> {
             updateWorld(event.getPlayer().getWorld());
             for (PerPlayerMetadata<?> meta : metadata.values()) {
                 meta.sent.remove(event.getPlayer().getUniqueId());
@@ -173,12 +173,14 @@ public void run() {
             Map<UUID, Collection<TreeFactory.Node<NPC>>> map = Maps.newHashMap();
             Location loc = new Location(null, 0, 0, 0);
             for (NPC npc : sourceRegistry) {
-                if (!npc.isSpawned())
-                    continue;
-                npc.getEntity().getLocation(loc);
-                Collection<TreeFactory.Node<NPC>> nodes = map.computeIfAbsent(npc.getEntity().getWorld().getUID(),
-                        uid -> Lists.newArrayList());
-                nodes.add(new TreeFactory.Node<>(new double[] { loc.getX(), loc.getY(), loc.getZ() }, npc));
+                CitizensAPI.getScheduler().runEntityTask(npc.getEntity(), () -> {
+                    if (!npc.isSpawned())
+                        return;
+                    npc.getEntity().getLocation(loc);
+                    Collection<TreeFactory.Node<NPC>> nodes = map.computeIfAbsent(npc.getEntity().getWorld().getUID(),
+                            uid -> Lists.newArrayList());
+                    nodes.add(new TreeFactory.Node<>(new double[] { loc.getX(), loc.getY(), loc.getZ() }, npc));
+                });
             }
             npcFuture = ForkJoinPool.commonPool().submit(new TreeFactory<>(map));
         }

src/main/java/net/citizensnpcs/api/astar/pathfinder/AsyncChunkSnapshotBlockSource.java

@@ -2,6 +2,8 @@
 
 import java.util.concurrent.Callable;
 
+import net.citizensnpcs.api.CitizensAPI;
+import net.citizensnpcs.api.util.SpigotUtil;
 import org.bukkit.Bukkit;
 import org.bukkit.ChunkSnapshot;
 import org.bukkit.Location;
@@ -24,10 +26,11 @@ protected ChunkSnapshot getChunkObject(int x, int z) {
         // TODO: pre-load multiple chunks on cache miss
         Callable<ChunkSnapshot> call = () -> world.getChunkAt(x, z).getChunkSnapshot(false, false, false);
         try {
-            if (!Bukkit.isPrimaryThread()) {
+            if (!SpigotUtil.isFoliaServer() && !Bukkit.isPrimaryThread()) {
                 return Bukkit.getScheduler().callSyncMethod(null, call).get();
-            } else
-                return call.call();
+            }
+            return call.call();
+
         } catch (Exception e) {
             e.printStackTrace();
         }

src/main/java/net/citizensnpcs/api/astar/pathfinder/DoorExaminer.java

@@ -2,6 +2,7 @@
 
 import java.util.List;
 
+import net.citizensnpcs.api.util.schedulers.SchedulerRunnable;
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.Material;
@@ -86,7 +87,7 @@ private void close(NPC npc, Block point) {
         @Override
         public void onReached(NPC npc, Block point) {
             Location doorCentre = point.getLocation().add(0.5, 0, 0.5);
-            new BukkitRunnable() {
+            new SchedulerRunnable() {
                 @Override
                 public void run() {
                     if (!npc.getNavigator().isNavigating()) {
@@ -101,7 +102,7 @@ public void run() {
                         cancel();
                     }
                 }
-            }.runTaskTimer(CitizensAPI.getPlugin(), 3, 1);
+            }.runRegionTaskTimer(CitizensAPI.getPlugin(), doorCentre, 3, 1);
         }
 
         private void open(NPC npc, Block point, Material type) {

src/main/java/net/citizensnpcs/api/gui/InputMenus.java

@@ -252,7 +252,7 @@ public void onPlayerChat(AsyncPlayerChatEvent event) {
                 HandlerList.unregisterAll(this);
                 String chat = event.getMessage();
                 event.setCancelled(true);
-                Bukkit.getScheduler().scheduleSyncDelayedTask(CitizensAPI.getPlugin(), () -> {
+                CitizensAPI.getScheduler().runEntityTask(event.getPlayer(), () -> {
                     if (chat.equals("\"\"") || chat.equals("''") || chat.equals("null")) {
                         callback.accept("");
                     } else {

src/main/java/net/citizensnpcs/api/gui/InventoryMenu.java

@@ -438,7 +438,7 @@ public void run() {
 
     private void runViewerModifier(Runnable run) {
         if (delayViewerChanges) {
-            Bukkit.getScheduler().scheduleSyncDelayedTask(CitizensAPI.getPlugin(), run);
+            CitizensAPI.getScheduler().runTask(run);
         } else {
             run.run();
         }

src/main/java/net/citizensnpcs/api/npc/AbstractNPC.java

@@ -504,17 +504,17 @@ private void teleport(final Entity entity, Location location, int delay, Telepor
         final Entity passenger = entity.getPassenger();
         entity.eject();
         if (!location.getWorld().equals(entity.getWorld())) {
-            Bukkit.getScheduler().scheduleSyncDelayedTask(CitizensAPI.getPlugin(),
-                    () -> entity.teleport(location, cause), delay++);
+            CitizensAPI.getScheduler().runEntityTaskLater(entity,
+                    () -> SpigotUtil.teleportAsync(entity, location, cause), delay++);
         } else {
-            entity.teleport(location, cause);
+            SpigotUtil.teleportAsync(entity, location, cause);
         }
         if (passenger == null)
             return;
         teleport(passenger, location, delay++, cause);
         Runnable task = () -> entity.setPassenger(passenger);
         if (!location.getWorld().equals(entity.getWorld())) {
-            Bukkit.getScheduler().scheduleSyncDelayedTask(CitizensAPI.getPlugin(), task, delay);
+            CitizensAPI.getScheduler().runEntityTaskLater(entity, task, delay);
         } else {
             task.run();
         }

src/main/java/net/citizensnpcs/api/util/SpigotUtil.java

@@ -8,17 +8,16 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.WeakHashMap;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.regex.Pattern;
 
-import org.bukkit.Bukkit;
-import org.bukkit.Keyed;
-import org.bukkit.Material;
-import org.bukkit.NamespacedKey;
-import org.bukkit.World;
+import org.bukkit.*;
 import org.bukkit.enchantments.Enchantment;
+import org.bukkit.entity.Entity;
 import org.bukkit.entity.EntityType;
 import org.bukkit.entity.Player;
+import org.bukkit.event.player.PlayerTeleportEvent;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryView;
 import org.bukkit.inventory.ItemStack;
@@ -277,6 +276,18 @@ public static ItemStack parseItemStack(ItemStack base, String item) {
         return base;
     }
 
+    public static CompletableFuture<Boolean> teleportAsync(Entity entity, Location location) {
+        return ASYNC_TELEPORT ? entity.teleportAsync(location) : CompletableFuture.completedFuture(entity.teleport(location));
+    }
+
+    public static CompletableFuture<Boolean> teleportAsync(Entity entity, Location location, PlayerTeleportEvent.TeleportCause cause) {
+        return ASYNC_TELEPORT ? entity.teleportAsync(location, cause) : CompletableFuture.completedFuture(entity.teleport(location, cause));
+    }
+
+    public static boolean isFoliaServer() {
+        return FOLIA_SERVER;
+    }
+
     private static ChronoUnit toChronoUnit(TimeUnit tu) {
         switch (tu) {
             case NANOSECONDS:
@@ -306,12 +317,26 @@ private static ChronoUnit toChronoUnit(TimeUnit tu) {
     private static boolean SUPPORT_WORLD_HEIGHT = true;
     private static boolean SUPPORTS_KEYED;
     private static Boolean using1_13API;
+    private static boolean FOLIA_SERVER = false;
+    private static boolean ASYNC_TELEPORT = false;
 
     static {
         try {
             Class.forName("org.bukkit.Keyed");
             SUPPORTS_KEYED = true;
         } catch (ClassNotFoundException e) {
         }
+        try {
+            Class.forName("io.papermc.paper.threadedregions.RegionizedServer");
+            FOLIA_SERVER = true;
+        } catch (ClassNotFoundException ignored) {
+            FOLIA_SERVER = false;
+        }
+        try {
+            Entity.class.getMethod("teleportAsync", Location.class, PlayerTeleportEvent.TeleportCause.class);
+            ASYNC_TELEPORT = true;
+        } catch (NoSuchMethodException exception) {
+            ASYNC_TELEPORT = false;
+        }
     }
 }