Configurable minimum demand for trades

Addresses MC-163962 where villager demand decreases indefinitely. Paper adds a patch to fix this by preventing demand from going below zero. This patch adds a config option to allow the minimum demand to instead be configurable.

patches/server/0229-Configurable-minimum-demand-for-trades.patch

@@ -1,61 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Totorewa <76272501+totorewa@users.noreply.github.com>
-Date: Fri, 7 Jan 2022 21:34:57 +1300
-Subject: [PATCH] Configurable minimum demand for trades
-
-Addresses MC-163962 where villager demand decreases indefinitely. Paper
-adds a patch to fix this by preventing demand from going below zero.
-This patch adds a config option to allow the minimum demand to instead
-be configurable.
-
-diff --git a/net/minecraft/world/entity/npc/Villager.java b/net/minecraft/world/entity/npc/Villager.java
-index fcaf3db893d14b8359bddc1cc69da82e533ebc87..e03066a9e336fb67f729a84404ef8b37208fa77d 100644
---- a/net/minecraft/world/entity/npc/Villager.java
-+++ b/net/minecraft/world/entity/npc/Villager.java
-@@ -548,7 +548,7 @@ public class Villager extends AbstractVillager implements ReputationEventHandler
-         while (iterator.hasNext()) {
-             MerchantOffer merchantrecipe = (MerchantOffer) iterator.next();
- 
--            merchantrecipe.updateDemand();
-+            merchantrecipe.updateDemand(this.level().purpurConfig.villagerMinimumDemand); // Purpur
-         }
- 
-     }
-diff --git a/net/minecraft/world/item/trading/MerchantOffer.java b/net/minecraft/world/item/trading/MerchantOffer.java
-index 0efc8d997b34302c3e0a5d7ec73a11a940dbeefe..af157881d440b34cfe79fbc9b03cc9ef28515eb8 100644
---- a/net/minecraft/world/item/trading/MerchantOffer.java
-+++ b/net/minecraft/world/item/trading/MerchantOffer.java
-@@ -131,7 +131,12 @@ public class MerchantOffer {
-     }
- 
-     public void updateDemand() {
--        this.demand = Math.max(0, this.demand + this.uses - (this.maxUses - this.uses)); // Paper - Fix MC-163962
-+        // Purpur start
-+        this.updateDemand(0);
-+    }
-+    public void updateDemand(int minimumDemand) {
-+        this.demand = Math.max(minimumDemand, this.demand + this.uses - (this.maxUses - this.uses)); // Paper - Fix MC-163962
-+        // Purpur end
-     }
- 
-     public ItemStack assemble() {
-diff --git a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
-index fc11b643c938cf7d7bd088825dfd89afef15401d..fa09bd0e91d3c71d960e316f792323b763569b6e 100644
---- a/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
-+++ b/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java
-@@ -2914,6 +2914,7 @@ public class PurpurWorldConfig {
-     public boolean villagerTakeDamageFromWater = false;
-     public boolean villagerAllowTrading = true;
-     public boolean villagerAlwaysDropExp = false;
-+    public int villagerMinimumDemand = 0;
-     private void villagerSettings() {
-         villagerRidable = getBoolean("mobs.villager.ridable", villagerRidable);
-         villagerRidableInWater = getBoolean("mobs.villager.ridable-in-water", villagerRidableInWater);
-@@ -2936,6 +2937,7 @@ public class PurpurWorldConfig {
-         villagerTakeDamageFromWater = getBoolean("mobs.villager.takes-damage-from-water", villagerTakeDamageFromWater);
-         villagerAllowTrading = getBoolean("mobs.villager.allow-trading", villagerAllowTrading);
-         villagerAlwaysDropExp = getBoolean("mobs.villager.always-drop-exp", villagerAlwaysDropExp);
-+        villagerMinimumDemand = getInt("mobs.villager.minimum-demand", villagerMinimumDemand);
-     }
- 
-     public boolean vindicatorRidable = false;

purpur-server/minecraft-patches/sources/net/minecraft/world/entity/npc/Villager.java.patch

@@ -22,6 +22,15 @@
                  this.startTrading(player);
              }
  
+@@ -503,7 +_,7 @@
+ 
+     private void updateDemand() {
+         for (MerchantOffer merchantOffer : this.getOffers()) {
+-            merchantOffer.updateDemand();
++            merchantOffer.updateDemand(this.level().purpurConfig.villagerMinimumDemand); // Purpur - Configurable minimum demand for trades
+         }
+     }
+ 
 @@ -707,7 +_,7 @@
  
      @Override

purpur-server/minecraft-patches/sources/net/minecraft/world/item/trading/MerchantOffer.java.patch

@@ -0,0 +1,16 @@
+--- a/net/minecraft/world/item/trading/MerchantOffer.java
++++ b/net/minecraft/world/item/trading/MerchantOffer.java
+@@ -143,7 +_,12 @@
+     }
+ 
+     public void updateDemand() {
+-        this.demand = Math.max(0, this.demand + this.uses - (this.maxUses - this.uses)); // Paper - Fix MC-163962
++        // Purpur start - Configurable minimum demand for trades
++        this.updateDemand(0);
++    }
++    public void updateDemand(int minimumDemand) {
++        this.demand = Math.max(minimumDemand, this.demand + this.uses - (this.maxUses - this.uses)); // Paper - Fix MC-163962
++        // Purpur end - Configurable minimum demand for trades
+     }
+ 
+     public ItemStack assemble() {

purpur-server/src/main/java/org/purpurmc/purpur/PurpurWorldConfig.java

@@ -2913,6 +2913,7 @@ public class PurpurWorldConfig {
     public boolean villagerTakeDamageFromWater = false;
     public boolean villagerAllowTrading = true;
     public boolean villagerAlwaysDropExp = false;
+    public int villagerMinimumDemand = 0;
     private void villagerSettings() {
         villagerRidable = getBoolean("mobs.villager.ridable", villagerRidable);
         villagerRidableInWater = getBoolean("mobs.villager.ridable-in-water", villagerRidableInWater);
@@ -2935,6 +2936,7 @@ public class PurpurWorldConfig {
         villagerTakeDamageFromWater = getBoolean("mobs.villager.takes-damage-from-water", villagerTakeDamageFromWater);
         villagerAllowTrading = getBoolean("mobs.villager.allow-trading", villagerAllowTrading);
         villagerAlwaysDropExp = getBoolean("mobs.villager.always-drop-exp", villagerAlwaysDropExp);
+        villagerMinimumDemand = getInt("mobs.villager.minimum-demand", villagerMinimumDemand);
     }
 
     public boolean vindicatorRidable = false;