// ==UserScript==
// @name        4chan pixeldrain URL parser
// @namespace   4chanpixeldrainparse
// @match       https://boards.4chan.org/*/thread/*
// @grant       none
// @version     1.0.3
// @author      Anonymous
// @description Parse pixeldrain URLs on 4chan
// @updateURL   https://gist.github.com/raw/6fedeaacb169bc89bc5186bd00741b4a/4chan-pixeldrain.user.js
// @downloadURL https://gist.github.com/raw/6fedeaacb169bc89bc5186bd00741b4a/4chan-pixeldrain.user.js
// ==/UserScript==
(async function () {
  const RE_PIXELDRAIN_URL_SUFFIX = /com\/\s?([a-z])\s?\/\s?([a-zA-Z0-9]{8})/;
  const RE_PIXELDRAIN_URL_PLAINTEXT = new RegExp(`(?:https?://)?pixeldrain\\s+\\.?${RE_PIXELDRAIN_URL_SUFFIX.source}`, 'gim');
  const RE_PIXELDRAIN_URL_A = new RegExp(`href="https?://pixeldrain">https://pixeldrain</a>\\s*${RE_PIXELDRAIN_URL_SUFFIX.source}`, 'gim');
  const ids = {};

  function processPost(post) {
    if (post.textContent.includes('pixeldrain') && (post.innerHTML.match(RE_PIXELDRAIN_URL_PLAINTEXT) || post.innerHTML.match(RE_PIXELDRAIN_URL_A))) {
      post.innerHTML = post.innerHTML.replaceAll(RE_PIXELDRAIN_URL_PLAINTEXT, `<a class="linkify" rel="noreferrer noopener" target="_blank" href="https://pixeldrain.com/$1/$2">https://pixeldrain.com/$1/$2</a>`);
      post.innerHTML = post.innerHTML.replaceAll(RE_PIXELDRAIN_URL_A, `href="https://pixeldrain.com/$1/$2">https://pixeldrain.com/$1/$2</a>`);
    }
  }

  function* getPosts(root) {
    for (const post of Array.from(root.querySelectorAll('.postMessage')).reverse()) {
      if (post.id in ids) {
        continue;
      }
      ids[post.id] = true;
      yield post;
    }
  }

  function processAllPosts(root) {
    for (const post of getPosts(root)) {
      processPost(post);
    }
  }

  window.addEventListener('load', async () => {
    setTimeout(async () => {
      processAllPosts(document.body);
    }, 5000);
  });

  document.addEventListener('PostsInserted', async (evt) => {
    processAllPosts(evt.target);
  });
})();