/**
* HTML -> Markdown conversion, the same stack pi-web-access popularized:
* Readability (article extraction) + Turndown (HTML -> Markdown), with
* linkedom providing a DOM in Node without a browser.
*/
import { Readability } from '@mozilla/readability';
import { parseHTML } from 'linkedom';
import TurndownService from 'turndown';
const turndown = new TurndownService({
headingStyle: 'atx',
codeBlockStyle: 'fenced',
});
export interface HtmlToMarkdownResult {
title: string;
markdown: string;
/** true when Readability found no article and we fell back to the whole body */
lowQuality: boolean;
}
export function htmlToMarkdown(html: string, raw: boolean): HtmlToMarkdownResult {
const { document } = parseHTML(html);
const documentTitle = document.title?.trim() ?? '';
if (raw) {
// Keep everything: tables, code blocks, nav - whole .
const body = document.body;
const markdown = body ? turndown.turndown(body.innerHTML) : '';
return { title: documentTitle, markdown, lowQuality: true };
}
const reader = new Readability(document as Document);
const article = reader.parse();
if (!article || typeof article.content !== 'string' || article.content.length === 0) {
// No article found (SPA shell, bare text, exotic markup) - fall back to
// the whole body so we never return nothing, but flag the low quality.
const body = document.body;
const fallback = body ? turndown.turndown(body.innerHTML) : '';
return { title: documentTitle, markdown: fallback, lowQuality: true };
}
const markdown = turndown.turndown(article.content);
return { title: article.title || documentTitle, markdown, lowQuality: false };
}