Reddit expand media and comments

Shows pictures and some videos right after the link, loads and expands comment threads.

Versione datata 13/11/2019. Vedi la nuova versione l'ultima versione.

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(Ho già un gestore di script utente, lasciamelo installare!)

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Dovrai installare un'estensione come ad esempio Stylus per installare questo stile.

Dovrai installare un'estensione come ad esempio Stylus per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

Dovrai installare un'estensione per la gestione degli stili utente per installare questo stile.

(Ho già un gestore di stile utente, lasciamelo installare!)

// ==UserScript==
// @name           Reddit expand media and comments
// @description    Shows pictures and some videos right after the link, loads and expands comment threads.

// @version        0.3.0

// @author         wOxxOm
// @namespace      wOxxOm.scripts
// @license        MIT License

// @match          *://*.reddit.com/*

// @grant          GM_addStyle
// @grant          GM_xmlhttpRequest

// @connect        imgur.com
// @connect        gfycat.com
// @connect        gyazo.com
// @connect        streamable.com
// @connect        instagram.com
// @connect        ibb.co
// @connect        prntscr.com
// @connect        prnt.sc
// @connect        images.app.goo.gl
// @connect        www.google.com
// ==/UserScript==

'use strict';

const CLASS = 'reddit-inline-media';
const CLASS_ALBUM = CLASS + '-album';
const OVERFLOW_ATTR = 'data-overflow';
const MORE_SELECTOR = '[id^="moreComments-"] p, .morecomments a';
const REQUEST_THROTTLE_MS = unsafeWindow.reddit ? 500 : 100;

const RULES = [{
  u: [
    'imgur.com/a/',
    'imgur.com/gallery/',
  ],
  r: /(a|gallery)\/(\w+)(#\w+)?$/,
  s: 'https://imgur.com/ajaxalbums/getimages/$2/hit.json?all=true',
  q: json =>
    json.data.images.map(img =>
      img && `https://i.imgur.com/${img.hash}${img.ext}`),
}, {
  u: 'imgur.com/',
  r: /.com\/\w+$/,
  q: 'link[rel="image_src"], meta[name="twitter:player:stream"]',
}, {
  u: '//streamable.com/',
  r: /\.com\/.+/,
  q: 'video',
}, {
  u: '//gfycat.com/',
  r: /.com\/.+/,
  q: 'source[src*=".webm"]',
}, {
  u: '//gyazo.com/',
  r: /\.com\/\w{32,}/,
  q: 'meta[name="twitter:image"]',
  xhr: true,
}, {
  u: [
    'instagram.com/p/',
    '//ibb.co/',
    '//images.app.goo.gl/',
  ],
  q: 'meta[property="og:image"]',
}, {
  u: '//prntscr.com/',
  r: /\.com\/(\w+)$/i,
  s: 'https://prnt.sc/$1',
  q: 'meta[property="og:image"]',
  xhr: true,
}, {
  u: '//prnt.sc/',
  r: /\.sc\/\w+$/i,
  q: 'meta[property="og:image"]',
  xhr: true,
}, {
  u: [
    '//youtu.be/',
    '//youtube.com/',
    '//www.youtube.com/',
  ],
  r: /\/\/[^/]+?(?:\.be\/|\.com\/.*?[&?/]v[=/])([^&?/#]+)/,
  s: 'https://i.ytimg.com/vi/$1/default.jpg',
}, {
  u: '//pbs.twimg.com/media/',
  r: /.+?\?format=\w+/,
}, {
  u: '.gifv',
  r: /(.+?)\.gifv(\?.*)?$/i,
  s: '$1.mp4$2',
}, {
  // keep this one at the end of the list
  r: /\.(jpe?g|png|gif|webm|mp4)(\?.*)?$/i,
}];

// language=CSS
GM_addStyle(`
  .${CLASS} {
    max-width: 100%;
    display: block;
  }
  .${CLASS}[data-src] {
    padding-top: 400px;
  }
  .${CLASS}:hover {
    outline: 2px solid #3bbb62;
  }
  .${CLASS_ALBUM} {
    overflow-y: auto;
    max-height: calc(100vh - 100px);
    margin: .5em 0;
  }
  .${CLASS_ALBUM}[${OVERFLOW_ATTR}] {
    -webkit-mask-image: linear-gradient(white 75%, transparent);
    mask-image: linear-gradient(white 75%, transparent);
  }
  .${CLASS_ALBUM}[${OVERFLOW_ATTR}]:hover {
    -webkit-mask-image: none;
    mask-image: none;
  }
  .${CLASS_ALBUM} > :nth-child(n + 2) {
    margin-top: 1em;
  }
`);

const isChrome = navigator.userAgent.includes('Chrom');
const more = [];
const toStop = new Set();

let scrollObserver = lazyCreateObserver(onScroll, {rootMargin: '200% 0px'},
  obs => (scrollObserver = obs));

let albumObserver = lazyCreateObserver(onScroll, {rootMargin: '200px 0px'},
  obs => (albumObserver = obs));

new MutationObserver(onMutation)
  .observe(document.body, {subtree: true, childList: true});

onMutation([{
  addedNodes: [document.body],
}]);

function onMutation(mutations) {
  var items = [];
  var someElementsAdded;
  for (var i = 0, m; (m = mutations[i++]);) {
    for (var j = 0, added = m.addedNodes, node; (node = added[j++]);) {
      if (!node.localName)
        continue;
      someElementsAdded = true;
      if (node.localName === 'a') {
        var rule = findMatchingRule(node);
        if (rule)
          items.push(rule);
        continue;
      }
      if (!node.firstElementChild)
        continue;
      var aa = node.getElementsByTagName('a');
      for (var k = 0, a; (a = aa[k++]);) {
        const data = findMatchingRule(a);
        if (data)
          items.push(data);
      }
    }
  }
  if (someElementsAdded && !observeShowMore.timer)
    observeShowMore.timer = setTimeout(observeShowMore, 500);
  if (items.length)
    setTimeout(maybeExpand, 0, items);
}

function onScroll(entries, observer) {
  const stoppingScheduled = toStop.size > 0;
  for (const e of entries) {
    let el = e.target;
    if (el.localName === 'ins') {
      toggleAttribute(el.parentNode, OVERFLOW_ATTR, !e.isIntersecting);
      continue;
    }
    if (!e.isIntersecting) {
      const rect = e.boundingClientRect;
      if ((rect.bottom < -200 || rect.top > innerHeight + 200) &&
          el.src && !el.dataset.src && el[GM_info.script.name])
        toStop.add(el);
      continue;
    }
    if (stoppingScheduled)
      toStop.delete(el);
    const isImage = el.localName === 'img';
    if (isImage && el.dataset.src || el.localName === 'video') {
      el.src = el.dataset.src;
      el[GM_info.script.name] = {observer};
      el.addEventListener(isImage ? 'load' : 'loadedmetadata', unobserveOnLoad);
      delete el.dataset.src;
      continue;
    }
    if (el.localName === 'a') {
      // switch to an unfocusable element to prevent the link
      // from stealing focus and scrolling the view
      const el2 = document.createElement('span');
      el2.setAttribute('onclick', el.getAttribute('onclick'));
      el2.setAttribute('id', el.id);
      el.parentNode.replaceChild(el2, el);
      el = el2;
    }
    expandNextComment(el);
  }
  if (!stoppingScheduled && toStop.size)
    requestAnimationFrame(stopOffscreenImages);
}

function stopOffscreenImages() {
  for (const el of toStop) {
    delete el[GM_info.script.name];
    el.dataset.src = el.src;
    el.removeAttribute('src');
    el.removeEventListener('load', unobserveOnLoad);
  }
  toStop.clear();
}

function findMatchingRule(a) {
  let url = a.href;
  for (const rule of RULES) {
    const {u} = rule;
    if (u && !(Array.isArray(u) ? u.find(includedInThis, url) : url.includes(u)))
      continue;
    const {r} = rule;
    const m = !r || url.match(r);
    if (!m)
      continue;
    if (r && rule.s)
      url = url.slice(0, m.index + m[0].length).replace(r, rule.s).slice(m.index);
    return {
      a,
      url,
      rule,
    };
  }
}

function maybeExpand(items) {
  for (const item of items) {
    const {a, rule} = item;
    const {href} = a;
    const text = a.textContent.trim();
    if (
      text &&
      !a.getElementsByTagName('img')[0] &&
      (
        !text.startsWith('http') ||
        !text.endsWith('...') ||
        !/^https?:\/\/\S+?\.{3}$/.test(text)
      ) &&
      !a.closest(
        '.scrollerItem,' +
        '[contenteditable="true"],' +
        `a[href="${href}"] + * a[href="${href}"],` +
        `img[src="${href}"] + * a[href="${href}"]`) &&
      (
        // don't process insides of a post except for its text
        !a.closest('[data-test-id="post-content"]') ||
        a.closest('[data-click-id="text"]')
      )
    ) {
      try {
        (rule.q ? expandRemote : expand)(item);
      } catch (e) {
        // console.debug(e, item);
      }
    }
  }
}

function expand({a, url = a.href, isAlbum}, observer = scrollObserver) {
  const isVideo = /(webm|gifv|mp4)(\?.*)?$/i.test(url);
  const el = document.createElement(isVideo ? 'video' : 'img');
  el.dataset.src = url;
  el.className = CLASS;
  a.insertAdjacentElement(isAlbum ? 'beforeEnd' : 'afterEnd', el);
  if (isVideo) {
    el.controls = true;
    el.preload = 'metadata';
    if (isChrome)
      el.addEventListener('click', playOnClick);
  }
  observer.observe(el);
  return !isAlbum && el;
}

async function expandRemote(item) {
  const {url, rule} = item;
  const r = await download(url);
  const isJSON = /^content-type:.*?json\s*$/mi.test(r.responseHeaders);
  const doc = isJSON ?
    tryJSONparse(r.response) :
    new DOMParser().parseFromString(r.response, 'text/html');
  switch (typeof rule.q) {
    case 'string': {
      if (!isJSON)
        expandRemoteFromSelector(doc, item);
      return;
    }
    case 'function': {
      let urls;
      try {
        urls = await rule.q(doc, r.response, item);
      } catch (e) {}
      if (urls && urls.length) {
        urls = Array.isArray(urls) ? urls : [urls];
        expandFromUrls(urls, item);
      }
      return;
    }
  }
}

async function expandRemoteFromSelector(doc, {rule, url, a}) {
  if (!doc)
    return;
  const el = doc.querySelector(rule.q);
  if (!el)
    return;
  let imageUrl = el.href || el.src || el.content;
  if (!imageUrl)
    return;
  if (rule.xhr)
    imageUrl = await downloadAsBase64({imageUrl, url});
  if (imageUrl)
    expand({a, url: imageUrl});
}

function expandFromUrls(urls, {a}) {
  let observer;
  const isAlbum = urls.length > 1;
  if (isAlbum) {
    observer = albumObserver;
    a = a.insertAdjacentElement('afterEnd', document.createElement('div'));
    a.className = CLASS_ALBUM;
  }
  for (const url of urls) {
    if (url)
      a = expand({a, url, isAlbum}, observer) || a;
  }
  if (isAlbum) {
    new IntersectionObserver(onScroll, {root: a})
      .observe(a.appendChild(document.createElement('ins')));
  }
}

function expandNextComment(el) {
  if (el)
    more.push(el);
  else
    more.shift();
  if (more.length === 1 || !el && more.length) {
    more[0].dispatchEvent(new MouseEvent('click', {bubbles: true}));
    setTimeout(expandNextComment, REQUEST_THROTTLE_MS);
  }
}

function observeShowMore() {
  observeShowMore.timer = 0;
  if (document.querySelector(MORE_SELECTOR)) {
    for (const el of document.querySelectorAll(MORE_SELECTOR)) {
      scrollObserver.observe(el);
    }
  }
}

function playOnClick(event, el, wasPaused) {
  if (!el) {
    setTimeout(playOnClick, 0, event, this, this.paused);
  } else if (el.paused === wasPaused) {
    wasPaused ? el.play() : el.pause();
  }
}

function tryJSONparse(str) {
  try {
    return JSON.parse(str);
  } catch (e) {
    return undefined;
  }
}

function download(options) {
  if (typeof options === 'string')
    options = {url: options};
  return new Promise((resolve, reject) => {
    GM_xmlhttpRequest(Object.assign({
      method: 'GET',
      onload: resolve,
      onerror: reject,
    }, options));
  });
}

async function downloadAsBase64({imageUrl, url}) {
  let blob = (await download({
    url: imageUrl,
    headers: {
      'Referer': url,
    },
    responseType: 'blob',
  })).response;

  if (blob.type !== getMimeType(imageUrl))
    blob = blob.slice(0, blob.size, getMimeType(imageUrl));

  return new Promise(resolve => {
    Object.assign(new FileReader(), {
      onload: e => resolve(e.target.result),
    }).readAsDataURL(blob);
  });
}

function getMimeType(url) {
  const ext = (url.match(/\.(\w+)(\?.*)?$|$/)[1] || '').toLowerCase();
  return 'image/' + (ext === 'jpg' ? 'jpeg' : ext);
}

function toggleAttribute(el, name, state) {
  if (state && !el.hasAttribute(name))
    el.setAttribute(name, '');
  else
    el.removeAttribute(name);
}

function lazyCreateObserver(onIntersect, options, onCreate) {
  return new Proxy({}, {
    get(_target, k) {
      const observer = new IntersectionObserver(onIntersect, options);
      onCreate(observer);
      const v = observer[k];
      return typeof v === 'function' ? v.bind(observer) : v;
    },
  });
}

function unobserveOnLoad() {
  this.removeEventListener('load', unobserveOnLoad);
  const {observer} = this[GM_info.script.name] || {};
  if (observer)
    observer.unobserve(this);
  delete this[GM_info.script.name];
}

function includedInThis(needle) {
  return this.includes(needle);
}