1 files changed, 55 insertions, 0 deletions
diff --git a/packages/shared/utils/listUtils.ts b/packages/shared/utils/listUtils.ts
new file mode 100644
index 00000000..1dd3d476
--- /dev/null
+++ b/packages/shared/utils/listUtils.ts
@@ -0,0 +1,55 @@
+import { ZBookmarkList } from "../types/lists";
+
+export interface ZBookmarkListTreeNode {
+  item: ZBookmarkList;
+  children: ZBookmarkListTreeNode[];
+}
+
+export type ZBookmarkListRoot = Record<string, ZBookmarkListTreeNode>;
+
+export function listsToTree(lists: ZBookmarkList[]) {
+  const idToList = lists.reduce<Record<string, ZBookmarkList>>((acc, list) => {
+    acc[list.id] = list;
+    return acc;
+  }, {});
+
+  const root: ZBookmarkListRoot = {};
+
+  // Prepare all refs
+  const refIdx = lists.reduce<Record<string, ZBookmarkListTreeNode>>(
+    (acc, l) => {
+      acc[l.id] = {
+        item: l,
+        children: [],
+      };
+      return acc;
+    },
+    {},
+  );
+
+  // Build the tree
+  lists.forEach((list) => {
+    const node = refIdx[list.id];
+    if (list.parentId) {
+      refIdx[list.parentId].children.push(node);
+    } else {
+      root[list.id] = node;
+    }
+  });
+
+  const allPaths: ZBookmarkList[][] = [];
+  const dfs = (node: ZBookmarkListTreeNode, path: ZBookmarkList[]) => {
+    const list = idToList[node.item.id];
+    const newPath = [...path, list];
+    allPaths.push(newPath);
+    node.children.forEach((child) => {
+      dfs(child, newPath);
+    });
+  };
+
+  Object.values(root).forEach((node) => {
+    dfs(node, []);
+  });
+
+  return { allPaths, root };
+}