// ==UserScript==
// @name         Imgur.com → Imgur.lol
// @namespace    https://luke.gg/
// @version      1.3
// @description  i.imgur.com -> imgur.lol
// @author       luke
// @match        *://*/*
// @run-at       document-start
// @grant        none
// ==/UserScript==

(function() {
  'use strict';

  const OLD_DOMAIN = /i\.(imgur\.com)/gi;
  const NEW_DOMAIN = 'imgur.lol';

  /** ---- Stage 1: Early interception for preloaded elements ---- **/
  // Override common URL-creating functions
  const origCreateElement = Document.prototype.createElement;
  Document.prototype.createElement = function(tag) {
    const el = origCreateElement.call(this, tag);
    const observer = new MutationObserver(() => rewriteAttributes(el));
    observer.observe(el, { attributes: true });
    return el;
  };

  // Rewrite all URL-like attributes of an element
  function rewriteAttributes(node) {
    if (!node || !node.attributes) return;
    for (const attr of node.attributes) {
      if (typeof attr.value === 'string' && attr.value.includes('imgur.com')) {
        const newVal = attr.value.replace(OLD_DOMAIN, NEW_DOMAIN);
        if (newVal !== attr.value) node.setAttribute(attr.name, newVal);
      }
    }
  }

  /** ---- Stage 2: Text & Attribute replacement after DOM loads ---- **/
  function rewriteAll(root=document.body) {
    if (!root) return;

    // Elements
    const walker = document.createTreeWalker(root, NodeFilter.SHOW_ELEMENT);
    while (walker.nextNode()) rewriteAttributes(walker.currentNode);

    // Text nodes
    const textWalker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT);
    while (textWalker.nextNode()) {
      const node = textWalker.currentNode;
      if (node.nodeValue.includes('imgur.com')) {
        node.nodeValue = node.nodeValue.replace(OLD_DOMAIN, NEW_DOMAIN);
      }
    }
  }

  /** ---- Stage 3: Dynamic mutation observer ---- **/
  const mo = new MutationObserver(muts => {
    for (const m of muts) {
      for (const node of m.addedNodes) {
        if (node.nodeType === 1) { // element
          rewriteAll(node);
        } else if (node.nodeType === 3) { // text
          if (node.nodeValue.includes('imgur.com')) {
            node.nodeValue = node.nodeValue.replace(OLD_DOMAIN, NEW_DOMAIN);
          }
        }
      }
    }
  });

  /** ---- Stage 4: Apply once DOM is ready ---- **/
  function init() {
    rewriteAll();
    mo.observe(document.body, { childList: true, subtree: true });
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', init);
  } else {
    init();
  }

  /** ---- Stage 5: Intercept navigation clicks ---- **/
  document.addEventListener('click', ev => {
    const a = ev.target.closest('a[href]');
    if (a && a.href.includes('imgur.com')) {
      a.href = a.href.replace(OLD_DOMAIN, NEW_DOMAIN);
    }
  }, true);

})();