provide chat options

src/games/stendhal/common/constants/Events.java

@@ -62,4 +62,6 @@ public final class Events {
 	public static final String BESTIARY = Actions.BESTIARY;
 
 	public static final String OUTFIT_LIST = "show_outfit_list";
+
+	public static final String CHAT_OPTIONS = "chat_options";
 }

src/games/stendhal/server/core/engine/RPClassGenerator.java

@@ -66,6 +66,7 @@
 import games.stendhal.server.events.BestiaryEvent;
 import games.stendhal.server.events.BuddyLoginEvent;
 import games.stendhal.server.events.BuddyLogoutEvent;
+import games.stendhal.server.events.ChatOptionsEvent;
 import games.stendhal.server.events.ExamineEvent;
 import games.stendhal.server.events.GlobalVisualEffectEvent;
 import games.stendhal.server.events.GroupChangeEvent;
@@ -284,6 +285,9 @@ public void createRPClassesWithoutBaking() {
 		if (!RPClass.hasRPClass("healed")) {
 			HealedEvent.generateRPClass();
 		}
+		if (!RPClass.hasRPClass(Events.CHAT_OPTIONS)) {
+			ChatOptionsEvent.generateRPClass();
+		}
 		if (!RPClass.hasRPClass(Events.IMAGE)) {
 			ImageEffectEvent.generateRPClass();
 		}

src/games/stendhal/server/entity/npc/fsm/Engine.java

@@ -32,6 +32,7 @@
 import games.stendhal.server.entity.npc.EventRaiser;
 import games.stendhal.server.entity.npc.SpeakerNPC;
 import games.stendhal.server.entity.player.Player;
+import games.stendhal.server.events.ChatOptionsEvent;
 
 /**
  * a finite state machine.
@@ -602,15 +603,17 @@ private void executeTransition(final Player player, final Sentence sentence, fin
 		}
 
 		currentState = nextState;
-        if (currentState == ConversationStates.ATTENDING) {
-        	speakerNPC.setIdea("attending");
-        } else if (currentState != ConversationStates.IDLE) {
-        	speakerNPC.setIdea("awaiting");
-        }
+		if (currentState == ConversationStates.ATTENDING) {
+			speakerNPC.setIdea("attending");
+		} else if (currentState != ConversationStates.IDLE) {
+			speakerNPC.setIdea("awaiting");
+		}
 		if (trans.getAction() != null) {
 			trans.getAction().fire(player, sentence, new EventRaiser(speakerNPC));
 		}
 
+		player.addEvent(new ChatOptionsEvent(speakerNPC, player, currentState));
+		player.notifyWorldAboutChanges();
 		speakerNPC.notifyWorldAboutChanges();
 	}
 

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

@@ -40,6 +40,7 @@ static void generateRPClass() {
 		player.addAttribute("text", Type.LONG_STRING, Definition.VOLATILE);
 //		player.addAttribute("private_text", Type.LONG_STRING, (byte) (Definition.HIDDEN | Definition.VOLATILE));
 
+		player.addRPEvent(Events.CHAT_OPTIONS, Definition.PRIVATE);
 		player.addRPEvent(Events.PRIVATE_TEXT, Definition.PRIVATE);
 		player.addRPEvent(Events.PLAYER_LOGGED_ON, Definition.PRIVATE);
 		player.addRPEvent(Events.PLAYER_LOGGED_OUT, Definition.PRIVATE);

src/games/stendhal/server/events/ChatOptionsEvent.java

@@ -0,0 +1,91 @@
+/***************************************************************************
+ *                   (C) Copyright 2023-2023 - Stendhal                    *
+ ***************************************************************************
+ ***************************************************************************
+ *                                                                         *
+ *   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.events;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import com.google.common.base.Joiner;
+
+import games.stendhal.common.constants.Events;
+import games.stendhal.common.parser.ConversationParser;
+import games.stendhal.common.parser.Expression;
+import games.stendhal.common.parser.Sentence;
+import games.stendhal.server.entity.npc.ConversationStates;
+import games.stendhal.server.entity.npc.SpeakerNPC;
+import games.stendhal.server.entity.npc.fsm.Transition;
+import games.stendhal.server.entity.player.Player;
+import marauroa.common.game.Definition.Type;
+import marauroa.common.game.RPClass;
+import marauroa.common.game.RPEvent;
+
+public class ChatOptionsEvent extends RPEvent {
+
+	private static final String NPC = "npc";
+	private static final String OPTIONS = "options";
+
+	public ChatOptionsEvent(SpeakerNPC npc, Player player, ConversationStates currentState) {
+		super(Events.CHAT_OPTIONS);
+		put(NPC, npc.getName());
+
+		List<String> chatOptions = buildChatOptions(npc, player, currentState);
+		put(OPTIONS, Joiner.on("|~|").join(chatOptions));
+	}
+
+	/**
+	 * builds a list of the available chat options
+	 *
+	 * @param npc SpeakerNPC the player is talking to
+	 * @param player player (to check conditions)
+	 * @param currentState current state of the SpeakerNPC's state machine
+	 * @return list of chat options
+	 */
+	private List<String> buildChatOptions(SpeakerNPC npc, Player player, ConversationStates currentState) {
+		List<String> res = new LinkedList<>();
+		Sentence sentence = ConversationParser.parse("");
+
+		final List<Transition> transitions = npc.getTransitions();
+		for (final Transition transition : transitions) {
+			if (transition.getState() != currentState) {
+				continue;
+			}
+
+			for(Expression expr : transition.getTriggers()) {
+				if (transition.getCondition() != null) {
+					if (!transition.getCondition().fire(player, sentence, npc)) {
+						continue;
+					}
+				}
+
+				String trigger = expr.getNormalized();
+				String options = "";
+				if (trigger.equals("buy") || trigger.equals("sell") || trigger.equals("")) {
+					options = "params";
+				}
+				res.add(trigger + "|*|" + trigger + "|*|" + options);
+				break;
+			}
+		}
+
+
+		return res;
+	}
+
+	/**
+	 * Creates the rpclass.
+	 */
+	public static void generateRPClass() {
+		final RPClass rpclass = new RPClass(Events.CHAT_OPTIONS);
+		rpclass.addAttribute(NPC, Type.STRING);
+		rpclass.addAttribute(OPTIONS, Type.VERY_LONG_STRING);
+	}
+}