PaperMC/paper-server/nms-patches/net/minecraft/world/food/FoodMetaData.patch

--- a/net/minecraft/world/food/FoodMetaData.java
+++ b/net/minecraft/world/food/FoodMetaData.java
@@ -7,15 +7,33 @@
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.GameRules;
 
+// CraftBukkit start
+import net.minecraft.network.protocol.game.PacketPlayOutUpdateHealth;
+import net.minecraft.server.level.EntityPlayer;
+// CraftBukkit end
+
 public class FoodMetaData {
 
     public int foodLevel = 20;
     public float saturationLevel = 5.0F;
     public float exhaustionLevel;
     private int tickTimer;
+    // CraftBukkit start
+    private EntityHuman entityhuman;
+    public int saturatedRegenRate = 10;
+    public int unsaturatedRegenRate = 80;
+    public int starvationRate = 80;
+    // CraftBukkit end
     private int lastFoodLevel = 20;
 
-    public FoodMetaData() {}
+    public FoodMetaData() { throw new AssertionError("Whoopsie, we missed the bukkit."); } // CraftBukkit start - throw an error
+
+    // CraftBukkit start - added EntityHuman constructor
+    public FoodMetaData(EntityHuman entityhuman) {
+        org.apache.commons.lang.Validate.notNull(entityhuman);
+        this.entityhuman = entityhuman;
+    }
+    // CraftBukkit end
 
     private void add(int i, float f) {
         this.foodLevel = Math.min(i + this.foodLevel, 20);
@@ -30,7 +48,17 @@
         FoodInfo foodinfo = (FoodInfo) itemstack.get(DataComponents.FOOD);
 
         if (foodinfo != null) {
-            this.add(foodinfo.nutrition(), foodinfo.saturation());
+            // CraftBukkit start
+            int oldFoodLevel = foodLevel;
+
+            org.bukkit.event.entity.FoodLevelChangeEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callFoodLevelChangeEvent(entityhuman, foodinfo.nutrition() + oldFoodLevel, itemstack);
+
+            if (!event.isCancelled()) {
+                this.add(event.getFoodLevel() - oldFoodLevel, foodinfo.saturation());
+            }
+
+            ((EntityPlayer) entityhuman).getBukkitEntity().sendHealthUpdate();
+            // CraftBukkit end
         }
 
     }
@@ -44,7 +72,15 @@
             if (this.saturationLevel > 0.0F) {
                 this.saturationLevel = Math.max(this.saturationLevel - 1.0F, 0.0F);
             } else if (enumdifficulty != EnumDifficulty.PEACEFUL) {
-                this.foodLevel = Math.max(this.foodLevel - 1, 0);
+                // CraftBukkit start
+                org.bukkit.event.entity.FoodLevelChangeEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callFoodLevelChangeEvent(entityhuman, Math.max(this.foodLevel - 1, 0));
+
+                if (!event.isCancelled()) {
+                    this.foodLevel = event.getFoodLevel();
+                }
+
+                ((EntityPlayer) entityhuman).connection.send(new PacketPlayOutUpdateHealth(((EntityPlayer) entityhuman).getBukkitEntity().getScaledHealth(), this.foodLevel, this.saturationLevel));
+                // CraftBukkit end
             }
         }
 
@@ -52,23 +88,25 @@
 
         if (flag && this.saturationLevel > 0.0F && entityhuman.isHurt() && this.foodLevel >= 20) {
             ++this.tickTimer;
-            if (this.tickTimer >= 10) {
+            if (this.tickTimer >= this.saturatedRegenRate) { // CraftBukkit
                 float f = Math.min(this.saturationLevel, 6.0F);
 
-                entityhuman.heal(f / 6.0F);
-                this.addExhaustion(f);
+                entityhuman.heal(f / 6.0F, org.bukkit.event.entity.EntityRegainHealthEvent.RegainReason.SATIATED); // CraftBukkit - added RegainReason
+                // this.addExhaustion(f); CraftBukkit - EntityExhaustionEvent
+                entityhuman.causeFoodExhaustion(f, org.bukkit.event.entity.EntityExhaustionEvent.ExhaustionReason.REGEN); // CraftBukkit - EntityExhaustionEvent
                 this.tickTimer = 0;
             }
         } else if (flag && this.foodLevel >= 18 && entityhuman.isHurt()) {
             ++this.tickTimer;
-            if (this.tickTimer >= 80) {
-                entityhuman.heal(1.0F);
-                this.addExhaustion(6.0F);
+            if (this.tickTimer >= this.unsaturatedRegenRate) { // CraftBukkit - add regen rate manipulation
+                entityhuman.heal(1.0F, org.bukkit.event.entity.EntityRegainHealthEvent.RegainReason.SATIATED); // CraftBukkit - added RegainReason
+                // this.a(6.0F); CraftBukkit - EntityExhaustionEvent
+                entityhuman.causeFoodExhaustion(6.0f, org.bukkit.event.entity.EntityExhaustionEvent.ExhaustionReason.REGEN); // CraftBukkit - EntityExhaustionEvent
                 this.tickTimer = 0;
             }
         } else if (this.foodLevel <= 0) {
             ++this.tickTimer;
-            if (this.tickTimer >= 80) {
+            if (this.tickTimer >= this.starvationRate) { // CraftBukkit - add regen rate manipulation
                 if (entityhuman.getHealth() > 10.0F || enumdifficulty == EnumDifficulty.HARD || entityhuman.getHealth() > 1.0F && enumdifficulty == EnumDifficulty.NORMAL) {
                     entityhuman.hurt(entityhuman.damageSources().starve(), 1.0F);
                 }