Player slot for managing item correspondence between players

src/games/stendhal/server/entity/item/OwnedItem.java

@@ -28,7 +28,7 @@
 public abstract class OwnedItem extends Item {
 
 	// slots to which item cannot be equipped if it has an owner
-	private List<String> ownedBlacklistSlots = Arrays.asList("trade");
+	private List<String> ownedBlacklistSlots = Arrays.asList("mailbox", "trade");
 	// slots to which non-owners cannot equip
 	private List<String> ownerOnlySlots;
 

src/games/stendhal/server/entity/player/PlayerRPClass.java

@@ -1,6 +1,6 @@
 /* $Id$ */
 /***************************************************************************
- *                   (C) Copyright 2003-2023 - Marauroa                    *
+ *                   (C) Copyright 2003-2024 - Marauroa                    *
  ***************************************************************************
  ***************************************************************************
  *                                                                         *
@@ -89,6 +89,9 @@ static void generateRPClass() {
 		player.addRPSlot("bank_nalwor", 30, Definition.HIDDEN);
 		player.addRPSlot("zaras_chest_ados", 30, Definition.HIDDEN);
 
+		// mail system
+		player.addRPSlot("mailbox", 1, Definition.HIDDEN);
+
 		// Kills recorder - needed for quest
 		player.addRPSlot("!kills", 1, Definition.HIDDEN);
 

src/games/stendhal/server/entity/slot/Mailbox.java

@@ -0,0 +1,182 @@
+/***************************************************************************
+ *                    Copyright © 2024 - Faiumoni e. V.                    *
+ ***************************************************************************
+ ***************************************************************************
+ *                                                                         *
+ *   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 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+package games.stendhal.server.entity.slot;
+
+import java.sql.SQLException;
+
+import org.apache.log4j.Logger;
+
+import games.stendhal.server.entity.item.Item;
+import games.stendhal.server.entity.item.OwnedItem;
+import games.stendhal.server.entity.player.Player;
+import marauroa.common.game.RPSlot;
+import marauroa.common.game.SlotOwner;
+import marauroa.server.db.DBTransaction;
+import marauroa.server.db.TransactionPool;
+import marauroa.server.game.db.CharacterDAO;
+import marauroa.server.game.db.DAORegister;
+
+
+/**
+ * Slot for managing item correspondence between players.
+ *
+ * FIXME:
+ * - might be better to use two class properties "inbox"/"outbox"
+ * - should not be able to send item to player if their inbox is already occupied
+ * - might be better to use slot(s) not attached to a specific player
+ */
+public class Mailbox extends PlayerSlot {
+
+	private static final Logger logger = Logger.getLogger(Mailbox.class);
+
+	public static enum MailboxResult {
+		CONTENTS_EMPTY,
+		CANNOT_CARRY,
+		INVALID_ITEM,
+		OWNED_ITEM,
+		RECEIVER_NOT_FOUND,
+		RECEIVER_ACCEPTED,
+		RECEIVER_DENIED,
+		ABORTER_ACCEPTED,
+		ABORTER_DENIED,
+		SQL_ERROR
+	}
+
+	/** Name of player meant to receive contents. */
+	private String target;
+
+
+	public Mailbox() {
+		super("mailbox");
+	}
+
+	/**
+	 * Retrieves targeted receiver.
+	 *
+	 * @return
+	 *   Name of player to receive item.
+	 */
+	public String getTarget() {
+		return target;
+	}
+
+	@Override
+	public int getCapacity() {
+		return 1;
+	}
+
+	/**
+	 * Configures player meant to received contents.
+	 *
+	 * @param target
+	 *   Player name.
+	 * @param item
+	 *   Item to add to slot.
+	 * @return
+	 *   Mailbox action result.
+	 * @throws SQLException
+	 */
+	public MailboxResult requestSend(final String target, final Item item) {
+		if (item == null) {
+			return MailboxResult.INVALID_ITEM;
+		}
+		if (item.isBound() || (item instanceof OwnedItem && ((OwnedItem) item).hasOwner())) {
+			return MailboxResult.OWNED_ITEM;
+		}
+		final DBTransaction transaction = TransactionPool.get().beginWork();
+		final CharacterDAO characterDAO = DAORegister.get().get(CharacterDAO.class);
+		String accountName;
+		try {
+			accountName = characterDAO.getAccountName(transaction, target);
+			if (accountName == null) {
+				return MailboxResult.RECEIVER_NOT_FOUND;
+			}
+			this.target = accountName;
+			// NOTE: does this also remove it from the source slot?
+			add(item);
+			return MailboxResult.RECEIVER_ACCEPTED;
+		} catch (final SQLException e) {
+			logger.error("Error occurred when looking up account for character \"" + target + "\"", e);
+		}
+		return MailboxResult.SQL_ERROR;
+	}
+
+	/**
+	 * Requests retrieval of contents.
+	 *
+	 * @param player
+	 *   Player making request.
+	 * @return
+	 *   Mailbox action result.
+	 */
+	public MailboxResult requestReceive(final Player player) {
+		if (target == null) {
+			logger.warn("Target receiver not assigned for " + this);
+			return MailboxResult.RECEIVER_DENIED;
+		}
+		final String name = player.getName();
+		if (!name.equals(target)) {
+			logger.warn("Requested contents of " + this + " for player " + name);
+			return MailboxResult.RECEIVER_DENIED;
+		}
+		final Item item = (Item) getFirst();
+		if (item == null) {
+			logger.warn("Requested contents of empty " + this);
+			return MailboxResult.CONTENTS_EMPTY;
+		}
+		final RPSlot slot = player.getSlotToEquip(item);
+		if (slot == null) {
+			return MailboxResult.CANNOT_CARRY;
+		}
+		// NOTE: does this also remove it from the mailbox slot?
+		slot.add(item);
+		if (getFirst() != null) {
+			logger.warn("Contents received but contents not empty in " + this);
+		}
+		// reset receiver
+		target = null;
+		return MailboxResult.RECEIVER_ACCEPTED;
+	}
+
+	/**
+	 * Aborts request to send item and returns to sender.
+	 *
+	 * @param player
+	 *   Player requesting abort.
+	 * @return
+	 *   Mailbox action result.
+	 */
+	public MailboxResult requestAbort(final Player player) {
+		final String name = player.getName();
+		final SlotOwner owner = getOwner();
+		if (!name.equals(owner.get("name"))) {
+			return MailboxResult.ABORTER_DENIED;
+		}
+		final Item item = (Item) getFirst();
+		if (item == null) {
+			logger.warn("Requested contents of empty " + this);
+			return MailboxResult.CONTENTS_EMPTY;
+		}
+		final RPSlot slot = player.getSlotToEquip(item);
+		if (slot == null) {
+			return MailboxResult.CANNOT_CARRY;
+		}
+		// NOTE: does this also remove it from the mailbox slot?
+		slot.add(item);
+		if (getFirst() != null) {
+			logger.warn("Contents received but contents not empty in " + this);
+		}
+		// reset receiver
+		target = null;
+		return MailboxResult.ABORTER_ACCEPTED;
+	}
+}