Merge pull request #2221 from kacpherek/fix/villager-trade-trigger

🤖 Agent: Read against the vanilla 26.3 sources (Fire the villager_trade advancement trigger on trades) and proven in contrib-gate-21's union of 72 kacpherek PRs: 95 parity harnesses on playhorizon and the Mac mini, clippy, 1534 tests, lan_e2e 23 checks in-frame and with --server-thread. Thanks @kacpherek!

crates/horizon-client/src/game/advancements.rs

@@ -708,6 +708,27 @@ impl Game<'_> {
         let it = item_view(stack);
         self.trigger(name, |c, w| adv::item_entity(c, &me, target, &it, w));
     }
+    /// `TradeTrigger`: the villager and the item the trade gave.
+    pub(super) fn trigger_trade(&mut self, villager: &EntityView, stack: &ItemStack) {
+        let me = self.player_entity();
+        let villager = villager.clone();
+        let it = item_view(stack);
+        self.trigger("minecraft:villager_trade", move |c, w| {
+            let pctx = adv::Entities {
+                this: Some(&me),
+                origin: me.position,
+                tool: None,
+                block_pos: None,
+            };
+            let vctx = adv::Entities {
+                this: Some(&villager),
+                ..pctx
+            };
+            adv::conditions(&c["player"], &pctx, w)
+                && adv::conditions(&c["villager"], &vctx, w)
+                && adv::item(&c["item"], &it, w)
+        });
+    }
     /// `EnterBlockTrigger`: the block, its state properties and the player.
     pub(super) fn trigger_enter_block(&mut self, state: horizon_world::registry::BlockStateId) {
         let Some(definition) = self.pack.assets.registry.state(state).cloned() else {

crates/horizon-client/src/game/lan_trading.rs

@@ -277,7 +277,12 @@ impl Game<'_> {
             g.carried = menu.carried.take();
         }
         self.register_exploration_maps(made);
-        gm.merchant.session = self.merchant_apply(session, gm.merchant.mob);
+        let (session, traded) = self.merchant_apply(session, gm.merchant.mob);
+        gm.merchant.session = session;
+        if !traded.is_empty() {
+            // The guest's own statistic and advancements.
+            self.as_guest(host, conn, |g| g.merchant_traded(gm.merchant.mob, &traded));
+        }
         self.drop_guest_items(host, gi, dropped);
         self.lan_send_offers(host, conn, &mut gm, false);
         self.lan_send_merchant_content(host, conn, &mut gm);

crates/horizon-client/src/game/trading.rs

@@ -398,18 +398,21 @@ impl Game<'_> {
             .as_ref()
             .and_then(|s| s.merchant.as_ref())
             .and_then(|m| m.mob);
-        let session = self.merchant_apply(session, mob);
+        let (session, traded) = self.merchant_apply(session, mob);
+        self.merchant_traded(mob, &traded);
         if let Some(m) = self.station.as_mut().and_then(|s| s.merchant.as_mut()) {
             m.session = session;
         }
     }
-    /// What a menu click's session did, applied to the world and its mob.
+    /// What a menu click's session did, applied to the world and its mob;
+    /// with the result of each trade made, for `merchant_traded`.
     pub(super) fn merchant_apply(
         &mut self,
         session: Box<merchant::Session>,
         mob: Option<u32>,
-    ) -> Box<merchant::Session> {
+    ) -> (Box<merchant::Session>, Vec<ItemStack>) {
         let mut session = session;
+        let mut traded = Vec::new();
         let events = std::mem::take(&mut session.events);
         let (villager, origin) = (session.villager, session.origin);
         if let Some(m) = mob.and_then(|id| self.mobs.iter_mut().find(|m| m.id == id)) {
@@ -438,11 +441,26 @@ impl Game<'_> {
                     };
                     self.audio.play(sound, Some(origin), 1.0, pitch);
                 }
-                merchant::Event::Traded(_) => self.stats.custom("traded_with_villager", 1),
+                merchant::Event::Traded(index) => {
+                    traded.extend(session.offers.get(index).map(|o| o.result.clone()));
+                }
                 merchant::Event::TradeSound => {}
             }
         }
-        session
+        (session, traded)
+    }
+    /// `MerchantResultSlot.checkTakeAchievements` and `AbstractVillager.notifyTrade`
+    /// for each trade made: the statistic and the `villager_trade` trigger.
+    pub(super) fn merchant_traded(&mut self, mob: Option<u32>, results: &[ItemStack]) {
+        for result in results {
+            self.stats.custom("traded_with_villager", 1);
+            let villager = mob
+                .and_then(|id| self.mobs.iter().find(|m| m.id == id))
+                .map(|m| self.mob_entity(m));
+            if let Some(villager) = villager {
+                self.trigger_trade(&villager, result);
+            }
+        }
     }
     /// `Villager.customServerAiStep`: the TRADE reputation event of the last
     /// trade, a tick later; the prices follow the new reputation.