feat: aggregateAttributes

packages/website-ue/src/core/blitz/aggregateAttributes.ts

@@ -0,0 +1,51 @@
+import {
+  TankAttributeChange_AttributeName,
+  TankAttributeChange_Modifier,
+  type TankAttributeChange,
+} from "@protos/blitz_static_tank_upgrade_single_stage";
+import { times } from "lodash-es";
+
+function patch(
+  changes: TankAttributeChange[],
+  attributes: Partial<Record<TankAttributeChange_AttributeName, number>>
+) {
+  for (const { attribute_name, value, modifier } of changes) {
+    switch (modifier) {
+      case TankAttributeChange_Modifier.MODIFIER_OVERRIDE:
+        attributes[attribute_name] = value;
+        break;
+
+      case TankAttributeChange_Modifier.MODIFIER_MULTIPLY: {
+        if (!(attribute_name in attributes)) {
+          throw new Error(
+            `Missing attribute ${TankAttributeChange_AttributeName[attribute_name]} to modify`
+          );
+        }
+      }
+
+      case TankAttributeChange_Modifier.MODIFIER_MULTIPLY: {
+        attributes[attribute_name]! *= value;
+        break;
+      }
+
+      default:
+        throw new Error(
+          `Unhandled modified ${TankAttributeChange_Modifier[modifier]}`
+        );
+    }
+  }
+}
+
+export function aggregateAttributes(
+  base: TankAttributeChange[],
+  stages: TankAttributeChange[][],
+  stage: number
+) {
+  const attributes: Partial<Record<TankAttributeChange_AttributeName, number>> =
+    {};
+
+  patch(base, attributes);
+  times(stage, (index) => patch(stages[index], attributes));
+
+  return attributes;
+}