2 files changed, 67 insertions, 0 deletions
diff --git a/src/main/java/gregtech/api/interfaces/IGT_RecipeMap.java b/src/main/java/gregtech/api/interfaces/IGT_RecipeMap.java
new file mode 100644
index 0000000000..69f87161d1
--- /dev/null
+++ b/src/main/java/gregtech/api/interfaces/IGT_RecipeMap.java
@@ -0,0 +1,64 @@
+package gregtech.api.interfaces;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.function.Function;
+
+import javax.annotation.Nonnull;
+
+import gregtech.api.util.GT_Recipe;
+import gregtech.api.util.GT_RecipeBuilder;
+import gregtech.api.util.GT_Utility;
+
+/**
+ * Represents the target of a recipe adding action, usually, but not necessarily, is a recipe map itself.
+ */
+public interface IGT_RecipeMap {
+
+    /**
+     * Add a downstream recipe map that will get to handle the original builder.
+     * 
+     * @param downstream
+     */
+    void addDownstream(IGT_RecipeMap downstream);
+
+    /**
+     * Actually add the recipe represented by the builder. CAN modify the builder's internal states!!!
+     */
+    @Nonnull
+    Collection<GT_Recipe> doAdd(GT_RecipeBuilder builder);
+
+    /**
+     * Return a variant of this recipe map that will perform a deep copy on input recipe builder before doing anything
+     * to it.
+     *
+     * The returned recipe map will not have any downstreams, but can accept new downstreams.
+     */
+    default IGT_RecipeMap deepCopyInput() {
+        return newRecipeMap(b -> doAdd(b.copy()));
+    }
+
+    static IGT_RecipeMap newRecipeMap(Function<? super GT_RecipeBuilder, Collection<GT_Recipe>> func) {
+        return new IGT_RecipeMap() {
+
+            private final Collection<IGT_RecipeMap> downstreams = new ArrayList<>();
+
+            @Override
+            public void addDownstream(IGT_RecipeMap downstream) {
+                downstreams.add(downstream);
+            }
+
+            @Nonnull
+            @Override
+            public Collection<GT_Recipe> doAdd(GT_RecipeBuilder builder) {
+                List<Collection<GT_Recipe>> ret = new ArrayList<>();
+                ret.add(func.apply(builder));
+                for (IGT_RecipeMap downstream : downstreams) {
+                    ret.add(downstream.doAdd(builder));
+                }
+                return GT_Utility.concat(ret);
+            }
+        };
+    }
+}
diff --git a/src/main/java/gregtech/api/interfaces/internal/IGT_RecipeAdder.java b/src/main/java/gregtech/api/interfaces/internal/IGT_RecipeAdder.java
index bda2523811..149600b426 100644
--- a/src/main/java/gregtech/api/interfaces/internal/IGT_RecipeAdder.java
+++ b/src/main/java/gregtech/api/interfaces/internal/IGT_RecipeAdder.java
@@ -5,6 +5,7 @@ import net.minecraftforge.fluids.Fluid;
 import net.minecraftforge.fluids.FluidStack;
 
 import gregtech.api.util.GT_Recipe;
+import gregtech.api.util.GT_RecipeBuilder;
 
 public interface IGT_RecipeAdder {
 
@@ -960,4 +961,6 @@ public interface IGT_RecipeAdder {
      */
     GT_Recipe addIC2ReactorFuelCell(ItemStack input, ItemStack output, boolean aMox, float aHeat, float aEnergy,
             int aCells);
+
+    GT_RecipeBuilder stdBuilder();
 }