Tore out the old engine, left some wounds

app/imports/api/engine/computation/buildComputation/computeInactiveStatus.js

@@ -0,0 +1,28 @@
+import walkDown from '/imports/api/engine/computation/utility/walkdown.js';
+
+export default function computeInactiveStatus(node){
+  const prop = node.node;
+  if (isActive(prop)) return;
+  // Unequipped items disable their children, but are not disabled themselves
+  // All notes do the same
+  if (prop.type !== 'item' && prop.type !== 'note' ){
+    prop.inactive = true;
+    prop.deactivatedBySelf = true;
+  }
+  // Mark children as inactive due to ancestor
+  walkDown(node.children, child => {
+    child.node.inactive = true;
+    child.node.deactivatedByAncestor = true;
+  });
+}
+
+function isActive(prop){
+  if (prop.disabled) return false;
+  switch (prop.type){
+    case 'buff': return !!prop.applied;
+    case 'item': return !!prop.equipped;
+    case 'spell': return !!prop.prepared || !!prop.alwaysPrepared;
+    case 'note': return false;
+    default: return true;
+  }
+}