import getReadingTime from 'reading-time';
import { toString as mdToString } from 'mdast-util-to-string';

const ELLIPSIS = '\u2026';

export default function() {
  return function (tree, { data }) {
    const textOnPage = mdToString(tree);

    const readingTime = getReadingTime(textOnPage);
    data.astro.frontmatter.readingTime = readingTime.text;

    const description = textOnPage.slice(0, 100) + ELLIPSIS;
    data.astro.frontmatter.description = description;
  };
}