feat: NPC reactions gated by conditions, applying effects

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Semesterprojekt/src/main/java/thb/jeanluc/adventure/command/impl/GiveCommand.java

@@ -1,6 +1,8 @@
 package thb.jeanluc.adventure.command.impl;
 
 import thb.jeanluc.adventure.command.Command;
+import thb.jeanluc.adventure.game.Conditions;
+import thb.jeanluc.adventure.game.Effects;
 import thb.jeanluc.adventure.game.GameContext;
 import thb.jeanluc.adventure.model.Npc;
 import thb.jeanluc.adventure.model.NpcReaction;
@@ -44,12 +46,17 @@ public class GiveCommand implements Command {
         }
 
         NpcReaction reaction = reactionOpt.get();
+        if (!Conditions.all(reaction.getRequires(), ctx)) {
+            ctx.getIo().write(npc.getName() + " isn't ready for that yet.");
+            return;
+        }
         if (reaction.getConsumes() != null) {
             ctx.getPlayer().removeItem(reaction.getConsumes().getId());
         }
         if (reaction.getGives() != null) {
             ctx.getPlayer().addItem(reaction.getGives());
         }
+        Effects.applyAll(reaction.getEffects(), ctx);
         ctx.getIo().write(npc.getName() + ": " + reaction.getResponse());
     }
 

Semesterprojekt/src/main/java/thb/jeanluc/adventure/loader/ReferenceResolver.java

@@ -155,6 +155,8 @@ public class ReferenceResolver {
                         .consumes(consumes)
                         .gives(gives)
                         .response(r.response())
+                        .requires(ConditionDto.toModelList(r.requires()))
+                        .effects(EffectDto.toModelList(r.effects()))
                         .build();
                 npc.putReaction(r.onReceive(), reaction);
             }

Semesterprojekt/src/main/java/thb/jeanluc/adventure/loader/dto/ReactionDto.java

@@ -1,5 +1,7 @@
 package thb.jeanluc.adventure.loader.dto;
 
+import java.util.List;
+
 /**
  * YAML representation of a single NPC reaction.
  *
@@ -7,11 +9,19 @@ package thb.jeanluc.adventure.loader.dto;
  * @param response  text the NPC says after the exchange
  * @param gives     id of the item handed back; nullable
  * @param consumes  id of the item taken from the player; nullable
+ * @param requires  conditions that must hold; nullable
+ * @param effects   effects applied after a successful exchange; nullable
  */
 public record ReactionDto(
         String onReceive,
         String response,
         String gives,
-        String consumes
+        String consumes,
+        List<ConditionDto> requires,
+        List<EffectDto> effects
 ) {
+    /** Backward-compatible constructor without requires/effects. */
+    public ReactionDto(String onReceive, String response, String gives, String consumes) {
+        this(onReceive, response, gives, consumes, null, null);
+    }
 }

Semesterprojekt/src/main/java/thb/jeanluc/adventure/model/NpcReaction.java

@@ -4,6 +4,8 @@ import lombok.Builder;
 import lombok.Getter;
 import thb.jeanluc.adventure.model.item.Item;
 
+import java.util.List;
+
 /**
  * A single trigger/response pair on an NPC. When the player gives the
  * NPC an item matching {@link #consumes}, the NPC writes {@link #response}
@@ -21,4 +23,10 @@ public class NpcReaction {
 
     /** Text the NPC says after a successful exchange. */
     private final String response;
+
+    /** Conditions that must hold for the exchange; null/empty = always. */
+    private final List<Condition> requires;
+
+    /** Effects applied after a successful exchange; null = none. */
+    private final List<Effect> effects;
 }

Semesterprojekt/src/test/java/thb/jeanluc/adventure/command/impl/ReactionEffectsTest.java

@@ -0,0 +1,42 @@
+package thb.jeanluc.adventure.command.impl;
+
+import org.junit.jupiter.api.Test;
+import thb.jeanluc.adventure.game.GameContext;
+import thb.jeanluc.adventure.io.TestIO;
+import thb.jeanluc.adventure.model.Condition;
+import thb.jeanluc.adventure.model.Effect;
+import thb.jeanluc.adventure.model.Npc;
+import thb.jeanluc.adventure.model.NpcReaction;
+import thb.jeanluc.adventure.model.Player;
+import thb.jeanluc.adventure.model.Room;
+import thb.jeanluc.adventure.model.item.PlainItem;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ReactionEffectsTest {
+    @Test
+    void reactionRequiresFlagAndAppliesEffects() {
+        Room room = new Room("k", "K", "d");
+        Npc man = Npc.shell("man", "Old Man", "stooped", "hi");
+        man.putReaction("fuse", NpcReaction.builder()
+                .requires(List.of(new Condition(Condition.Type.FLAG, "cellar_drained")))
+                .effects(List.of(new Effect(Effect.Type.SET_FLAG, "fuse_installed")))
+                .response("Done.")
+                .build());
+        room.addNpc(man);
+        Player player = new Player(room, 0);
+        player.addItem(PlainItem.builder().id("fuse").name("Fuse").description("d").build());
+        TestIO io = new TestIO();
+        GameContext ctx = new GameContext(null, player, io);
+
+        new GiveCommand().execute(ctx, List.of("fuse", "man"));
+        assertThat(ctx.getState().isSet("fuse_installed")).isFalse(); // requires not met
+
+        ctx.getState().set("cellar_drained");
+        new GiveCommand().execute(ctx, List.of("fuse", "man"));
+        assertThat(ctx.getState().isSet("fuse_installed")).isTrue();
+        assertThat(io.allOutput()).contains("Done.");
+    }
+}