✨ feat: initial app

apps/web/store/editor-store-helpers.ts

@@ -0,0 +1,42 @@
+import type { Layer, Project } from "@pien-studio/types";
+
+export const HISTORY_LIMIT = 120;
+
+export type HistoryState = {
+  past: Project[];
+  present: Project;
+  future: Project[];
+};
+
+export function deepClone<T>(value: T): T {
+  if (typeof globalThis.structuredClone === "function") {
+    return globalThis.structuredClone(value);
+  }
+  return JSON.parse(JSON.stringify(value)) as T;
+}
+
+export function cloneProject(project: Project): Project {
+  return deepClone(project);
+}
+
+export function cloneLayer(layer: Layer): Layer {
+  return deepClone(layer);
+}
+
+export function makeHistory(project: Project): HistoryState {
+  return { past: [], present: cloneProject(project), future: [] };
+}
+
+export function computeHistoryFlags(history: HistoryState) {
+  return { canUndo: history.past.length > 0, canRedo: history.future.length > 0 };
+}
+
+export function capHistory(items: Project[]): Project[] {
+  if (items.length <= HISTORY_LIMIT) return items;
+  return items.slice(items.length - HISTORY_LIMIT);
+}
+
+export function resolveSelectedLayerId(project: Project, preferred: string | null): string | null {
+  if (preferred && project.layers.some((layer) => layer.id === preferred)) return preferred;
+  return project.layers[0]?.id ?? null;
+}