Implement chainable splitter system

src/js/game/systems/chainable_splitter.js

@@ -1,10 +1,12 @@
 import { GameSystemWithFilter } from "../game_system_with_filter";
 import { ChainableSplitterComponent } from "../components/chainable_splitter";
+import { enumDirectionToVector, enumDirection } from "../../core/vector";
 import { Entity } from "../entity";
 import { DrawParameters } from "../../core/draw_parameters";
 import { formatBigNumber, lerp } from "../../core/utils";
 import { Loader } from "../../core/loader";
 import { enumLayer } from "../root";
+import { BaseItem } from "../base_item";
 
 export class ChainableSplitterSystem extends GameSystemWithFilter {
     constructor(root) {
@@ -15,19 +17,64 @@ export class ChainableSplitterSystem extends GameSystemWithFilter {
         for (let i = 0; i < this.allEntities.length; ++i) {
             const entity = this.allEntities[i];
             const splitterComp = entity.components.ChainableSplitter;
-
             if (splitterComp.inputItem === null) {
                 continue;
             }
 
-            const ejectorComp = entity.components.ItemEjector;
-
-            const nextSlot = ejectorComp.getFirstFreeSlot(enumLayer.regular);
-            if (nextSlot !== null) {
-                if (ejectorComp.tryEject(nextSlot, splitterComp.inputItem)) {
-                    splitterComp.inputItem = null;
-                }
+            const leftEdgeEntity = this.getLeftEdgeEntity(entity);
+            this.reset = true;
+            if (this.tryEject(leftEdgeEntity, splitterComp.inputItem)) {
+                splitterComp.inputItem = null;
             }
         }
     }
+
+    /**
+     *
+     * @param {Entity} entity
+     * @returns {Entity}
+     */
+    getLeftEdgeEntity(entity) {
+        const leftEntity = this.getAdjacentEntity(entity, enumDirection.left);
+        if (leftEntity === null || !leftEntity.components.ChainableSplitter) {
+            return entity;
+        }
+
+        return this.getLeftEdgeEntity(leftEntity);
+    }
+
+    /**
+     *
+     * @param {Entity} entity
+     * @param {BaseItem} item
+     * @returns {boolean}
+     */
+    tryEject(entity, item) {
+        const splitterComp = entity.components.ChainableSplitter;
+        if (!splitterComp.ejected) {
+            this.reset = false;
+            const ejectComp = entity.components.ItemEjector;
+
+            if (ejectComp.canEjectOnSlot(0)) {
+                if (ejectComp.tryEject(0, item)) {
+                    splitterComp.ejected = true;
+                    return true;
+                }
+            }
+        }
+
+        const rightEntity = this.getAdjacentEntity(entity, enumDirection.right);
+        if (
+            rightEntity !== null &&
+            rightEntity.components.ChainableSplitter &&
+            this.tryEject(rightEntity, item)
+        ) {
+            return true;
+        }
+
+        if (this.reset) {
+            splitterComp.ejected = false;
+        }
+        return false;
+    }
 }