feat(beta): public spaces

apps/client/src/features/public-space/utils/docs-tree.ts

@@ -0,0 +1,39 @@
+import { SharedPageTreeNode } from "@/features/share/utils.ts";
+
+// Preorder walk of the whole tree, matching the sidebar's visual order. Drives
+// prev/next navigation independently of which nodes are expanded.
+export function flattenTreePreorder(
+  nodes: SharedPageTreeNode[],
+): SharedPageTreeNode[] {
+  const out: SharedPageTreeNode[] = [];
+  const walk = (list: SharedPageTreeNode[]) => {
+    for (const node of list) {
+      out.push(node);
+      if (node.children?.length) walk(node.children);
+    }
+  };
+  walk(nodes);
+  return out;
+}
+
+// Ancestors of the node with the given slugId, root-first, excluding the node
+// itself. Null when the slugId is not in the tree.
+export function findAncestorTrail(
+  nodes: SharedPageTreeNode[],
+  slugId: string,
+): SharedPageTreeNode[] | null {
+  const walk = (
+    list: SharedPageTreeNode[],
+    trail: SharedPageTreeNode[],
+  ): SharedPageTreeNode[] | null => {
+    for (const node of list) {
+      if (node.slugId === slugId) return trail;
+      if (node.children?.length) {
+        const found = walk(node.children, [...trail, node]);
+        if (found) return found;
+      }
+    }
+    return null;
+  };
+  return walk(nodes, []);
+}