onenote-manager

/** Extract readable text from a OneNote one:T inline HTML fragment (ported
 * from local-onenote-mcp's HTMLTextExtractor). */

import { Parser } from "htmlparser2";

const NEWLINE_ON_OPEN = new Set(["br", "p", "div", "li", "tr", "h1", "h2", "h3", "h4", "h5", "h6"]);
const NEWLINE_ON_CLOSE = new Set(["p", "div", "li", "tr", "h1", "h2", "h3", "h4", "h5", "h6"]);

export function htmlFragmentToText(fragment: string): string {
  const parts: string[] = [];
  const newline = () => {
    if (parts.length === 0 || !parts[parts.length - 1].endsWith("\n")) parts.push("\n");
  };
  const parser = new Parser(
    {
      onopentag: (name) => {
        if (NEWLINE_ON_OPEN.has(name.toLowerCase())) newline();
      },
      onclosetag: (name) => {
        if (NEWLINE_ON_CLOSE.has(name.toLowerCase())) newline();
      },
      ontext: (text) => {
        if (text) parts.push(text);
      },
    },
    { decodeEntities: true },
  );
  parser.write(fragment || "");
  parser.end();
  let value = parts.join("");
  value = value.replace(/\x00/g, "");
  value = value.replace(/[ \t]+\n/g, "\n");
  value = value.replace(/\n{3,}/g, "\n\n");
  return value.trim();
}