feat: expose updateDemand and restock on Villager (#12608)

build-data/paper.at

@@ -419,6 +419,7 @@ public net.minecraft.world.entity.npc.Villager increaseMerchantCareer()V
 public net.minecraft.world.entity.npc.Villager numberOfRestocksToday
 public net.minecraft.world.entity.npc.Villager releaseAllPois()V
 public net.minecraft.world.entity.npc.Villager setUnhappy()V
+public net.minecraft.world.entity.npc.Villager updateDemand()V
 public net.minecraft.world.entity.npc.WanderingTrader getWanderTarget()Lnet/minecraft/core/BlockPos;
 public net.minecraft.world.entity.player.Abilities flyingSpeed
 public net.minecraft.world.entity.player.Abilities walkingSpeed

paper-api/src/main/java/org/bukkit/entity/Villager.java

@@ -391,4 +391,21 @@ public interface Villager extends AbstractVillager {
      * reputation regardless of its impact and the player associated.
      */
     public void clearReputations();
+
+    /**
+     * Updates the demand for Villager offers.
+     * Demand can rise and fall based on how often offers are traded.
+     * They can fall when an item is not traded for a while, or rise when the item is resupplied next.
+     * Demand is used to calculate the price of items in the Villager's offers.
+     * <br>
+     * <b>Note: Demand is stored per item and not per Villager.</b>
+     */
+    public void updateDemand();
+
+    /**
+     * Resets uses of all offers for the Villager. This also internally calls {@link #updateDemand()}.
+     * Calling this will trigger a {@link org.bukkit.event.entity.VillagerReplenishTradeEvent} for each offer that is restocked.
+     * Demand is still updated even if all events are canceled.
+     */
+    public void restock();
 }

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftVillager.java

@@ -380,4 +380,14 @@ public class CraftVillager extends CraftAbstractVillager implements Villager {
     public void clearReputations() {
         getHandle().getGossips().gossips.clear();
     }
+
+    @Override
+    public void updateDemand() {
+        getHandle().updateDemand();
+    }
+
+    @Override
+    public void restock() {
+        getHandle().restock();
+    }
 }