CraftBukkit/nms-patches/net/minecraft/world/level/block/entity/TileEntityBeacon.patch

--- a/net/minecraft/world/level/block/entity/TileEntityBeacon.java
+++ b/net/minecraft/world/level/block/entity/TileEntityBeacon.java
@@ -46,6 +46,11 @@
 import net.minecraft.world.level.levelgen.HeightMap;
 import net.minecraft.world.phys.AxisAlignedBB;
 
+// CraftBukkit start
+import org.bukkit.craftbukkit.potion.CraftPotionUtil;
+import org.bukkit.potion.PotionEffect;
+// CraftBukkit end
+
 public class TileEntityBeacon extends TileEntity implements ITileInventory, INamableTileEntity {
 
     private static final int MAX_LEVELS = 4;
@@ -71,6 +76,15 @@
     public IChatBaseComponent name;
     public ChestLock lockKey;
     private final IContainerProperties dataAccess;
+    // CraftBukkit start - add fields and methods
+    public PotionEffect getPrimaryEffect() {
+        return (this.primaryPower != null) ? CraftPotionUtil.toBukkit(new MobEffect(this.primaryPower, getLevel(this.levels), getAmplification(levels, primaryPower, secondaryPower), true, true)) : null;
+    }
+
+    public PotionEffect getSecondaryEffect() {
+        return (hasSecondaryEffect(levels, primaryPower, secondaryPower)) ? CraftPotionUtil.toBukkit(new MobEffect(this.secondaryPower, getLevel(this.levels), getAmplification(levels, primaryPower, secondaryPower), true, true)) : null;
+    }
+    // CraftBukkit end
 
     @Nullable
     static Holder<MobEffectList> filterEffect(@Nullable Holder<MobEffectList> holder) {
@@ -251,38 +265,77 @@
         super.setRemoved();
     }
 
-    private static void applyEffects(World world, BlockPosition blockposition, int i, @Nullable Holder<MobEffectList> holder, @Nullable Holder<MobEffectList> holder1) {
-        if (!world.isClientSide && holder != null) {
-            double d0 = (double) (i * 10 + 10);
+    // CraftBukkit start - split into components
+    private static byte getAmplification(int i, @Nullable Holder<MobEffectList> holder, @Nullable Holder<MobEffectList> holder1) {
+        {
             byte b0 = 0;
 
             if (i >= 4 && Objects.equals(holder, holder1)) {
                 b0 = 1;
             }
 
+            return b0;
+        }
+    }
+
+    private static int getLevel(int i) {
+        {
             int j = (9 + i * 2) * 20;
+            return j;
+        }
+    }
+
+    public static List getHumansInRange(World world, BlockPosition blockposition, int i) {
+        {
+            double d0 = (double) (i * 10 + 10);
+
             AxisAlignedBB axisalignedbb = (new AxisAlignedBB(blockposition)).inflate(d0).expandTowards(0.0D, (double) world.getHeight(), 0.0D);
             List<EntityHuman> list = world.getEntitiesOfClass(EntityHuman.class, axisalignedbb);
+
+            return list;
+        }
+    }
+
+    private static void applyEffect(List list, @Nullable Holder<MobEffectList> holder, int j, int b0) {
+        {
             Iterator iterator = list.iterator();
 
             EntityHuman entityhuman;
 
             while (iterator.hasNext()) {
                 entityhuman = (EntityHuman) iterator.next();
-                entityhuman.addEffect(new MobEffect(holder, j, b0, true, true));
+                entityhuman.addEffect(new MobEffect(holder, j, b0, true, true), org.bukkit.event.entity.EntityPotionEffectEvent.Cause.BEACON);
             }
+        }
+    }
 
+    private static boolean hasSecondaryEffect(int i, @Nullable Holder<MobEffectList> holder, @Nullable Holder<MobEffectList> holder1) {
+        {
             if (i >= 4 && !Objects.equals(holder, holder1) && holder1 != null) {
-                iterator = list.iterator();
-
-                while (iterator.hasNext()) {
-                    entityhuman = (EntityHuman) iterator.next();
-                    entityhuman.addEffect(new MobEffect(holder1, j, 0, true, true));
-                }
+                return true;
             }
 
+            return false;
+        }
+    }
+
+    private static void applyEffects(World world, BlockPosition blockposition, int i, @Nullable Holder<MobEffectList> holder, @Nullable Holder<MobEffectList> holder1) {
+        if (!world.isClientSide && holder != null) {
+            double d0 = (double) (i * 10 + 10);
+            byte b0 = getAmplification(i, holder, holder1);
+
+            int j = getLevel(i);
+            List list = getHumansInRange(world, blockposition, i);
+
+            applyEffect(list, holder, j, b0);
+
+            if (hasSecondaryEffect(i, holder, holder1)) {
+                applyEffect(list, holder1, j, 0);
+            }
         }
+
     }
+    // CraftBukkit end
 
     public static void playSound(World world, BlockPosition blockposition, SoundEffect soundeffect) {
         world.playSound((EntityHuman) null, blockposition, soundeffect, SoundCategory.BLOCKS, 1.0F, 1.0F);
@@ -316,7 +369,7 @@
         if (nbttagcompound.contains(s, 8)) {
             MinecraftKey minecraftkey = MinecraftKey.tryParse(nbttagcompound.getString(s));
 
-            return minecraftkey == null ? null : (Holder) BuiltInRegistries.MOB_EFFECT.getHolder(minecraftkey).map(TileEntityBeacon::filterEffect).orElse((Object) null);
+            return minecraftkey == null ? null : (Holder) BuiltInRegistries.MOB_EFFECT.getHolder(minecraftkey).orElse(null); // CraftBukkit - persist manually set non-default beacon effects (SPIGOT-3598)
         } else {
             return null;
         }
@@ -327,6 +380,7 @@
         super.loadAdditional(nbttagcompound, holderlookup_a);
         this.primaryPower = loadEffect(nbttagcompound, "primary_effect");
         this.secondaryPower = loadEffect(nbttagcompound, "secondary_effect");
+        this.levels = nbttagcompound.getInt("Levels"); // CraftBukkit - SPIGOT-5053, use where available
         if (nbttagcompound.contains("CustomName", 8)) {
             this.name = parseCustomNameSafe(nbttagcompound.getString("CustomName"), holderlookup_a);
         }