import { z } from 'zod';
import { browserManager } from '../browser/BrowserManager.js';
import { toolError, toolSuccess } from '../utils/errors.js';
import {
buildTreeIndex,
assembleTree,
pruneToDepth,
countNodes,
cdpAXNodeToSummary,
} from '../utils/axTree.js';
import type { CdpAXNode, GetFullAXTreeResponse } from '../browser/types.js';
export const getAccessibilityTreeSchema = {
interestingOnly: z
.boolean()
.optional()
.default(true)
.describe(
'If true, prunes nodes that are not interesting (hidden, presentational). ' +
'Set false to get the raw full tree. Default: true'
),
maxDepth: z
.number()
.int()
.positive()
.optional()
.default(10)
.describe('Maximum tree depth to return. Default: 10'),
useFullTree: z
.boolean()
.optional()
.default(false)
.describe(
'If true, uses CDP Accessibility.getFullAXTree (more complete but slower). ' +
'If false, uses page.accessibility.snapshot(). Default: false'
),
};
export async function getAccessibilityTreeHandler(args: {
interestingOnly?: boolean;
maxDepth?: number;
useFullTree?: boolean;
}): Promise<ReturnType<typeof toolSuccess | typeof toolError>> {
try {
const { page, cdpSession } = browserManager.requireConnection();
const interestingOnly = args.interestingOnly ?? true;
const maxDepth = args.maxDepth ?? 10;
const useFullTree = args.useFullTree ?? false;
let tree: unknown;
let nodeCount = 0;
if (useFullTree) {
// Use CDP Accessibility.getFullAXTree for the raw complete tree
const result = await cdpSession.send(
'Accessibility.getFullAXTree',
{}
) as GetFullAXTreeResponse;
const nodes: CdpAXNode[] = result.nodes;
const filtered = interestingOnly
? nodes.filter((n) => !n.ignored)
: nodes;
// Find root node (no parentId or parentId not in set)
const nodeIds = new Set(filtered.map((n) => n.nodeId));
const root = filtered.find((n) => !n.parentId || !nodeIds.has(n.parentId));
if (!root) {
return toolSuccess({
tree: null,
nodeCount: 0,
message: 'No root node found in accessibility tree.',
});
}
const index = buildTreeIndex(filtered);
const assembled = assembleTree(root, index, 0, maxDepth);
tree = pruneToDepth(assembled, maxDepth);
nodeCount = countNodes(assembled);
} else {
// Use Puppeteer's higher-level accessibility snapshot
const snapshot = await page.accessibility.snapshot({
interestingOnly,
});
if (!snapshot) {
return toolSuccess({
tree: null,
nodeCount: 0,
message: 'Accessibility snapshot returned null. The page may not have loaded.',
});
}
tree = snapshot;
// Count nodes in the snapshot
nodeCount = countSnapshotNodes(snapshot as unknown as Record<string, unknown>);
}
const title = await page.title().catch(() => '');
const url = page.url();
return toolSuccess({
url,
title,
nodeCount,
maxDepth,
interestingOnly,
tree,
});
} catch (error) {
return toolError(error);
}
}
function countSnapshotNodes(node: Record<string, unknown>): number {
const children = node['children'] as Record<string, unknown>[] | undefined;
if (!children || children.length === 0) return 1;
return 1 + children.reduce((sum, child) => sum + countSnapshotNodes(child), 0);
}
