Using a default implementation of IPlayerManager and IOffPlayer with minimal functionnalities, for standalone apps (discord bots, ...)

Core/src/main/java/fr/pandacube/lib/core/players/IPlayerManager.java

@@ -22,7 +22,26 @@ import net.md_5.bungee.api.chat.BaseComponent;
 
 public abstract class IPlayerManager<OP extends IOnlinePlayer, OF extends IOffPlayer> {
 	private static IPlayerManager<?, ?> instance;
-	public static synchronized IPlayerManager<?, ?> getInstance() { return instance; }
+	
+	public static synchronized IPlayerManager<?, ?> getInstance() {
+		if (instance == null) {
+			try {
+				new StandalonePlayerManager(); // will set the instance value itself (see IPlayerManager constructor)
+			} catch (DBInitTableException e) {
+				throw new RuntimeException(e);
+			}
+		}
+		return instance;
+	}
+	
+	private static synchronized void setInstance(IPlayerManager<?, ?> newInstance) {
+		if (instance != null && !(instance instanceof StandalonePlayerManager)) {
+			throw new IllegalStateException("only one instance of playerManager is possible");
+		}
+		instance = newInstance;
+	}
+	
+	
 	
 	
 	private Map<UUID, OP> onlinePlayers = Collections.synchronizedMap(new HashMap<>());
@@ -33,9 +52,7 @@ public abstract class IPlayerManager<OP extends IOnlinePlayer, OF extends IOffPl
 	
 	
 	public IPlayerManager() throws DBInitTableException {
-		synchronized (IPlayerManager.class) {
-			instance = this;
-		}
+		setInstance(this);
 
 		DB.initTable(SQLPlayer.class);
 		DB.initTable(SQLPlayerConfig.class);

Core/src/main/java/fr/pandacube/lib/core/players/StandaloneOffPlayer.java

@@ -0,0 +1,38 @@
+package fr.pandacube.lib.core.players;
+
+import java.util.UUID;
+
+/* package */ class StandaloneOffPlayer implements IOffPlayer {
+	
+	private final UUID uniqueId;
+	
+	public StandaloneOffPlayer(UUID id) {
+		if (id == null) throw new IllegalArgumentException("id cannot be null");
+		uniqueId = id;
+	}
+
+	@Override
+	public UUID getUniqueId() {
+		return uniqueId;
+	}
+
+	@Override
+	public boolean isOnline() {
+		return false;
+	}
+
+	@Override
+	public IOnlinePlayer getOnlineInstance() {
+		return null;
+	}
+	
+	private String displayName = null;
+	
+	@Override
+	public String getDisplayName() {
+		if (displayName == null)
+			displayName = getDisplayNameFromPermissionSystem();
+		return displayName;
+	}
+
+}

Core/src/main/java/fr/pandacube/lib/core/players/StandalonePlayerManager.java

@@ -0,0 +1,32 @@
+package fr.pandacube.lib.core.players;
+
+import java.util.UUID;
+
+import fr.pandacube.lib.core.chat.Chat;
+import fr.pandacube.lib.core.db.DBInitTableException;
+import fr.pandacube.lib.core.util.Log;
+import net.kyori.adventure.text.Component;
+
+/**
+ * A standalone player manager, using an implementation of {@link IPlayerManager}
+ * that does not manage online players. This is used to ease access to players data
+ * on standalone applications (web api, discord bot, ...)
+ *
+ */
+/* package */ class StandalonePlayerManager extends IPlayerManager<IOnlinePlayer, StandaloneOffPlayer> {
+
+	public StandalonePlayerManager() throws DBInitTableException {
+		super();
+	}
+
+	@Override
+	protected StandaloneOffPlayer newOffPlayerInstance(UUID p) {
+		return new StandaloneOffPlayer(p);
+	}
+	
+	@Override
+	protected void sendMessageToConsole(Component message) {
+		Log.info(Chat.chatComponent(message).getLegacyText());
+	}
+	
+}