/** Shared Markdown parsing and depth-first traversal for documentation gates. */

import { fromMarkdown } from 'mdast-util-from-markdown'
import { gfmFromMarkdown } from 'mdast-util-gfm'
import { gfm } from 'micromark-extension-gfm'
import type { Nodes } from 'mdast'

/** Parse GitHub-flavored Markdown with the repository's standard extensions. */
export function parseMarkdown(source: string): Nodes {
  return fromMarkdown(source, { extensions: [gfm()], mdastExtensions: [gfmFromMarkdown()] })
}

/**
 * Visit a Markdown tree depth-first; returning false prunes a node's children.
 * @param node - current tree node.
 * @param visitor - callback invoked before each node's children.
 */
export function visitMarkdown(node: Nodes, visitor: (node: Nodes) => boolean | void): void {
  if (visitor(node) === false) return
  if ('children' in node) {
    for (const child of node.children) visitMarkdown(child, visitor)
  }
}