SPIGOT-4833: Allow access to LivingEntity memories

src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java

@@ -46,6 +46,8 @@ import org.bukkit.craftbukkit.CraftWorld;
 import org.bukkit.craftbukkit.inventory.CraftEntityEquipment;
 import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.craftbukkit.potion.CraftPotionUtil;
+import org.bukkit.craftbukkit.entity.memory.CraftMemoryKey;
+import org.bukkit.craftbukkit.entity.memory.CraftMemoryMapper;
 import org.bukkit.entity.AbstractArrow;
 import org.bukkit.entity.DragonFireball;
 import org.bukkit.entity.Egg;
@@ -69,6 +71,7 @@ import org.bukkit.entity.ThrownPotion;
 import org.bukkit.entity.TippedArrow;
 import org.bukkit.entity.Trident;
 import org.bukkit.entity.WitherSkull;
+import org.bukkit.entity.memory.MemoryKey;
 import org.bukkit.event.entity.EntityPotionEffectEvent;
 import org.bukkit.event.player.PlayerTeleportEvent;
 import org.bukkit.inventory.EntityEquipment;
@@ -582,4 +585,14 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
     public boolean isCollidable() {
         return getHandle().collides;
     }
+
+    @Override
+    public <T> T getMemory(MemoryKey<T> memoryKey) {
+        return (T) getHandle().getBehaviorController().getMemory(CraftMemoryKey.fromMemoryKey(memoryKey)).map(CraftMemoryMapper::fromNms).orElse(null);
+    }
+
+    @Override
+    public <T> void setMemory(MemoryKey<T> memoryKey, T t) {
+        getHandle().getBehaviorController().setMemory(CraftMemoryKey.fromMemoryKey(memoryKey), CraftMemoryMapper.toNms(t));
+    }
 }

src/main/java/org/bukkit/craftbukkit/entity/memory/CraftMemoryKey.java

@@ -0,0 +1,19 @@
+package org.bukkit.craftbukkit.entity.memory;
+
+import net.minecraft.server.IRegistry;
+import net.minecraft.server.MemoryModuleType;
+import org.bukkit.craftbukkit.util.CraftNamespacedKey;
+import org.bukkit.entity.memory.MemoryKey;
+
+public final class CraftMemoryKey {
+
+    private CraftMemoryKey() {}
+
+    public static <T, U> MemoryModuleType<U> fromMemoryKey(MemoryKey<T> memoryKey) {
+        return (MemoryModuleType<U>) IRegistry.MEMORY_MODULE_TYPE.get(CraftNamespacedKey.toMinecraft(memoryKey.getKey()));
+    }
+
+    public static <T, U> MemoryKey<U> toMemoryKey(MemoryModuleType<T> memoryModuleType) {
+        return MemoryKey.getByKey(CraftNamespacedKey.fromMinecraft(IRegistry.MEMORY_MODULE_TYPE.getKey(memoryModuleType)));
+    }
+}

src/main/java/org/bukkit/craftbukkit/entity/memory/CraftMemoryMapper.java

@@ -0,0 +1,42 @@
+package org.bukkit.craftbukkit.entity.memory;
+
+import net.minecraft.server.BlockPosition;
+import net.minecraft.server.GlobalPos;
+import org.bukkit.Bukkit;
+import org.bukkit.Location;
+import org.bukkit.craftbukkit.CraftServer;
+import org.bukkit.craftbukkit.CraftWorld;
+
+public final class CraftMemoryMapper {
+
+    private CraftMemoryMapper() {}
+
+    public static Object fromNms(Object object) {
+        if (object instanceof GlobalPos) {
+            return fromNms((GlobalPos) object);
+        } else if (object instanceof Long) {
+            return object;
+        }
+
+        throw new UnsupportedOperationException("Do not know how to map " + object);
+    }
+
+    public static Object toNms(Object object) {
+        if (object instanceof Location) {
+            return toNms((Location) object);
+        }
+
+        throw new UnsupportedOperationException("Do not know how to map " + object);
+    }
+
+    public static Location fromNms(GlobalPos globalPos) {
+        // PAIL: globalPos.a() -> getDimensionManager()
+        // PAIL: globalPos.b() -> getBlockPosition()
+        return new org.bukkit.Location(((CraftServer) Bukkit.getServer()).getServer().getWorldServer(globalPos.a()).getWorld(), globalPos.b().getX(), globalPos.b().getY(), globalPos.b().getZ());
+    }
+
+    public static GlobalPos toNms(Location location) {
+        // PAIL: GlobalPos.a(DmensionManager, BlockPosition) -> create()
+        return GlobalPos.a(((CraftWorld) location.getWorld()).getHandle().getWorldProvider().getDimensionManager(), new BlockPosition(location.getX(), location.getY(), location.getZ()));
+    }
+}

src/test/java/org/bukkit/entity/memory/CraftMemoryKeyTest.java

@@ -0,0 +1,75 @@
+package org.bukkit.entity.memory;
+
+import net.minecraft.server.GlobalPos;
+import net.minecraft.server.IRegistry;
+import net.minecraft.server.MemoryModuleType;
+import org.bukkit.Location;
+import org.bukkit.craftbukkit.entity.memory.CraftMemoryKey;
+import org.bukkit.support.AbstractTestingBase;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class CraftMemoryKeyTest extends AbstractTestingBase {
+
+    @Test
+    public void shouldConvertBukkitHomeKeyToNMSRepresentation() {
+        MemoryModuleType<GlobalPos> nmsHomeKey = CraftMemoryKey.fromMemoryKey(MemoryKey.HOME);
+        Assert.assertEquals("MemoryModuleType should be HOME", MemoryModuleType.HOME, nmsHomeKey);
+    }
+
+    @Test
+    public void shouldConvertBukkitJobSiteKeyToNMSRepresentation() {
+        MemoryModuleType<GlobalPos> nmsHomeKey = CraftMemoryKey.fromMemoryKey(MemoryKey.JOB_SITE);
+        Assert.assertEquals("MemoryModuleType should be JOB_SITE", MemoryModuleType.JOB_SITE, nmsHomeKey);
+    }
+
+    @Test
+    public void shouldConvertBukkitMeetingPointKeyToNMSRepresentation() {
+        MemoryModuleType<GlobalPos> nmsHomeKey = CraftMemoryKey.fromMemoryKey(MemoryKey.MEETING_POINT);
+        Assert.assertEquals("MemoryModuleType should be MEETING_POINT", MemoryModuleType.MEETING_POINT, nmsHomeKey);
+    }
+
+    @Test
+    public void shouldConvertNMSHomeKeyToBukkitRepresentation() {
+        MemoryKey<Location> bukkitHomeKey = CraftMemoryKey.toMemoryKey(MemoryModuleType.HOME);
+        Assert.assertEquals("MemoryModuleType should be HOME", MemoryKey.HOME, bukkitHomeKey);
+    }
+
+    @Test
+    public void shouldConvertNMSJobSiteKeyToBukkitRepresentation() {
+        MemoryKey<Location> bukkitJobSiteKey = CraftMemoryKey.toMemoryKey(MemoryModuleType.JOB_SITE);
+        Assert.assertEquals("MemoryKey should be JOB_SITE", MemoryKey.JOB_SITE, bukkitJobSiteKey);
+    }
+
+    @Test
+    public void shouldConvertNMSMeetingPointKeyToBukkitRepresentation() {
+        MemoryKey<Location> bukkitHomeKey = CraftMemoryKey.toMemoryKey(MemoryModuleType.MEETING_POINT);
+        Assert.assertEquals("MemoryKey should be MEETING_POINT", MemoryKey.MEETING_POINT, bukkitHomeKey);
+    }
+
+    @Test
+    public void shouldReturnNullWhenBukkitRepresentationOfKeyisNotAvailable() {
+        MemoryKey bukkitNoKey = CraftMemoryKey.toMemoryKey(MemoryModuleType.MOBS);
+        Assert.assertNull("MemoryModuleType should be null", bukkitNoKey);
+    }
+
+    @Test
+    public void shouldReturnNullWhenBukkitRepresentationOfKeyisNotAvailableAndSerializerIsNotPresent() {
+        for (MemoryModuleType<?> memoryModuleType : IRegistry.MEMORY_MODULE_TYPE) {
+            if (!memoryModuleType.a().isPresent()) { // PAIL: a() -> getSerializer()
+                MemoryKey bukkitNoKey = CraftMemoryKey.toMemoryKey(memoryModuleType);
+                Assert.assertNull("MemoryModuleType should be null", bukkitNoKey);
+            }
+        }
+    }
+
+    @Test
+    public void shouldReturnAnInstanceOfMemoryKeyWhenBukkitRepresentationOfKeyisAvailableAndSerializerIsPresent() {
+        for (MemoryModuleType<?> memoryModuleType : IRegistry.MEMORY_MODULE_TYPE) {
+            if (memoryModuleType.a().isPresent()) { // PAIL: a() -> getSerializer()
+                MemoryKey bukkitNoKey = CraftMemoryKey.toMemoryKey(memoryModuleType);
+                Assert.assertNotNull("MemoryModuleType should not be null", bukkitNoKey);
+            }
+        }
+    }
+}