// Translator credits and promo lines that sites paste into every chapter
// ("Translator: …", "Discord: https://…", "Join the Discord…", ko-fi/Patreon).
// A paragraph is dropped only when it is short and the whole thing is promo, so
// story text that happens to mention a word like "discord" stays.
// The illustrator's reader.js carries the same rule for in-app reading.
const MAX_PROMO_LENGTH = 200;
const URL = /https?:\/\/\S+|\b(dsc|discord)\.gg\/\S*/gi;
const MAX_LINK_LABEL = 60; // "Discord: <url>", "Ko-Fi: <url>", but not prose with a link
const PROMO = [
  /^(discord|patreon|ko-?fi)\b\s*:?/i,
  /\b(join|support)\b.{0,40}\b(discord|patreon|ko-?fi)\b/i,
  /\bko-?fi\b|\bpatreon\b/i,
  /^(translators?|translated by|translation|editors?|edited by|editing|proofreaders?|proofread by|tl|tln|pr|ed)(\s*\/\s*\w+)*\s*[:-]/i,
  /\bread (the )?(latest|advanced?|more) chapters?\b/i,
];

export const isPromo = text => {
  const t = text.replace(/\s+/g, ' ').trim();
  if (!t || t.length > MAX_PROMO_LENGTH) return false;
  const label = t.replace(URL, '').trim();
  if (label.length < t.length && label.length <= MAX_LINK_LABEL) return true;
  return PROMO.some(r => r.test(t));
};

/** Remove promo paragraphs from a cheerio document; returns how many. */
export const stripPromo = $ => {
  let removed = 0;
  $('p, div, h3, h4, h5, h6, li').each((_, el) => {
    const node = $(el);
    // Innermost blocks only, so a wrapper holding the whole chapter is never dropped.
    if (node.find('p, div, li').length) return;
    if (isPromo(node.text())) {
      node.remove();
      removed++;
    }
  });
  return removed;
};