1 files changed, 88 insertions, 0 deletions
diff --git a/src/main/java/gregtech/api/multitileentity/WeakTargetRef.java b/src/main/java/gregtech/api/multitileentity/WeakTargetRef.java
new file mode 100644
index 0000000000..1509384f5e
--- /dev/null
+++ b/src/main/java/gregtech/api/multitileentity/WeakTargetRef.java
@@ -0,0 +1,88 @@
+package gregtech.api.multitileentity;
+
+import java.lang.ref.WeakReference;
+
+import net.minecraft.tileentity.TileEntity;
+import net.minecraft.util.ChunkCoordinates;
+import net.minecraft.world.World;
+
+import gregtech.api.multitileentity.interfaces.IMultiTileEntity;
+
+public class WeakTargetRef<T extends IMultiTileEntity> {
+
+    protected final ChunkCoordinates position = new ChunkCoordinates(0, -1, 0);
+    protected final Class<?> targetClass;
+    protected boolean shouldCache;
+    protected WeakReference<T> target = new WeakReference<>(null);
+    protected World world = null;
+
+    public WeakTargetRef(Class<?> targetClass, boolean shouldCache) {
+        this.targetClass = targetClass;
+        this.shouldCache = shouldCache;
+    }
+
+    public WeakTargetRef(T target, boolean shouldCache) {
+        this(target.getClass(), shouldCache);
+        setTarget(target);
+    }
+
+    public void setTarget(T newTarget) {
+        if (!targetClass.isInstance(newTarget)) {
+            throw new IllegalArgumentException("Target is not of the correct type");
+        }
+        position.set(newTarget.getXCoord(), newTarget.getYCoord(), newTarget.getZCoord());
+        world = newTarget.getWorld();
+    }
+
+    public void setWorld(World world) {
+        this.world = world;
+    }
+
+    public void setPosition(ChunkCoordinates position) {
+        this.position.set(position.posX, position.posY, position.posZ);
+    }
+
+    public void setPosition(int x, int y, int z) {
+        this.position.set(x, y, z);
+    }
+
+    public void setShouldCache(boolean shouldCache) {
+        this.shouldCache = shouldCache;
+    }
+
+    public T get() {
+        if (!shouldCache) {
+            return resolveTarget();
+        }
+        T result = target.get();
+        if (result == null || result.isDead()) {
+            result = resolveTarget();
+            if (result != null) {
+                target = new WeakReference<>(result);
+            } else {
+                target.clear();
+            }
+        }
+        return result;
+    }
+
+    @SuppressWarnings("unchecked")
+    protected T resolveTarget() {
+        if (world != null && position.posX >= 0 && world.blockExists(position.posX, position.posY, position.posZ)) {
+            final TileEntity te = world.getTileEntity(position.posX, position.posY, position.posZ);
+            return this.targetClass.isInstance(te) ? (T) te : null;
+        }
+        return null;
+    }
+
+    public ChunkCoordinates getPosition() {
+        return position;
+    }
+
+    public void invalidate() {
+        target.clear();
+        world = null;
+        position.set(0, -1, 0);
+    }
+
+}