Added interface for other plugins

src/main/java/com/onaple/epicboundaries/EpicBoundaries.java

@@ -5,12 +5,15 @@
 import com.onaple.epicboundaries.commands.CreateInstanceCommand;
 import com.onaple.epicboundaries.data.access.InstanceDao;
 import com.onaple.epicboundaries.event.CopyWorldEvent;
+import com.onaple.epicboundaries.service.IInstanceService;
+import com.onaple.epicboundaries.service.InstanceService;
 import org.slf4j.Logger;
 import org.spongepowered.api.Sponge;
 import org.spongepowered.api.command.args.GenericArguments;
 import org.spongepowered.api.command.spec.CommandSpec;
 import org.spongepowered.api.event.Listener;
 import org.spongepowered.api.event.game.state.GameInitializationEvent;
+import org.spongepowered.api.event.game.state.GamePreInitializationEvent;
 import org.spongepowered.api.plugin.Plugin;
 import org.spongepowered.api.plugin.PluginContainer;
 import org.spongepowered.api.scheduler.Task;
@@ -81,6 +84,11 @@ public void onServerStart(GameInitializationEvent event) {
         logger.info("EPICBOUNDARIES initialized.");
     }
 
+    @Listener
+    public void onGamePreInitialization(GamePreInitializationEvent event) {
+        Sponge.getServiceManager().setProvider(this, IInstanceService.class, new InstanceService());
+    }
+
     /**
      * Action occuring when a world has just been copied
      * @param event World copied event

src/main/java/com/onaple/epicboundaries/service/IInstanceService.java

@@ -0,0 +1,10 @@
+package com.onaple.epicboundaries.service;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface IInstanceService {
+    boolean apparate(String worldName, String playerName);
+    int apparate(String worldName, List<String> playerName);
+    Optional<String> createInstance(String worldToCopy, String playerName);
+}

src/main/java/com/onaple/epicboundaries/service/InstanceService.java

@@ -0,0 +1,71 @@
+package com.onaple.epicboundaries.service;
+
+import com.onaple.epicboundaries.WorldAction;
+import org.spongepowered.api.Sponge;
+
+import java.util.List;
+import java.util.Optional;
+
+public class InstanceService implements IInstanceService {
+    /**
+     * Try to transfer a player to a given world
+     * @param worldName Name of the world
+     * @param playerName Name of the player
+     * @return True if player has been transferred
+     */
+    @Override
+    public boolean apparate(String worldName, String playerName) {
+        return Sponge.getServer().loadWorld(worldName).map(world ->
+            Sponge.getServer().getPlayer(playerName).map(player -> {
+                WorldAction worldAction = new WorldAction();
+                worldAction.transferPlayerToWorld(player, world);
+                return true;
+            }).orElse(false)
+        ).orElse(false);
+    }
+
+    /**
+     * Try to transfer a group of players to a given world
+     * @param worldName Name of the world
+     * @param playerNames Names of the players
+     * @return Successful transfer count
+     */
+    @Override
+    public int apparate(String worldName, List<String> playerNames) {
+        return Sponge.getServer().loadWorld(worldName).map(world -> {
+            int playerTransferCount = 0;
+            WorldAction worldAction = new WorldAction();
+            for(String playerName : playerNames) {
+                playerTransferCount += Sponge.getServer().getPlayer(playerName).map(player -> {
+                    worldAction.transferPlayerToWorld(player, world);
+                    return 1;
+                }).orElse(0);
+            }
+            return playerTransferCount;
+        }).orElse(0);
+    }
+
+    /**
+     * Try to create an instance from a world and transfer a player to it
+     * @param worldToCopy World to copy
+     * @param playerName Name of the player to transfer
+     * @return Optional of world name, if copy successfully initiated
+     */
+    @Override
+    public Optional<String> createInstance(String worldToCopy, String playerName) {
+        if (worldToCopy.equals(Sponge.getServer().getDefaultWorldName())) {
+            return Optional.empty();
+        }
+        Sponge.getServer().getWorldProperties(worldToCopy).ifPresent(worldProperties -> {
+            String uuid, newWorldName;
+            do {
+                uuid = java.util.UUID.randomUUID().toString();
+                newWorldName = uuid;
+            } while (Sponge.getServer().getWorldProperties(newWorldName).isPresent());
+            WorldAction worldAction = new WorldAction();
+            worldAction.copyWorld(worldProperties, newWorldName);
+            worldAction.addPlayerToTransferQueue(playerName, newWorldName);
+        });
+        return Optional.empty();
+    }
+}