// ==UserScript==
// @name         pixiv fanbox no lazy loading image
// @namespace    https://nanaya.net
// @version      2.1.2
// @description  Lazy loading is bad for environment. Disable it.
// @author       nanaya
// @match        https://*.fanbox.cc/*
// @grant        none
// @run-at       document-start
// @downloadURL  https://hg.nanaya.net/ec-userscripts/raw-file/tip/pixiv-fanbox-unlazy.user.js
// ==/UserScript==

'use strict';

function unlazy () {
  const imageUrlPrefix = 'https://downloads.fanbox.cc/images/post/';

  function disableEventLink (event) {
    event.stopPropagation();
  }

  function fix (link) {
    const href = link.href;

    // basic sanity check
    if (typeof href !== 'string' || !href.startsWith(imageUrlPrefix)) {
      return;
    }

    // don't run again if already run on passed link
    if (link._ecUserscript) {
      return;
    }
    link._ecUserscript = true;

    link.addEventListener('click', disableEventLink);
    const image = document.createElement('img');
    image.style.width = '100%';
    image.src = href;
    link.replaceChildren(image);
  }

  function run (node) {
    if (!(node instanceof window.HTMLElement)) return;

    fix(node);
    for (const link of node.querySelectorAll(`[href^="${imageUrlPrefix}"]`)) {
      fix(link);
    }
  }

  function onMutate (mutations) {
    for (const mutation of mutations) {
      for (const node of mutation.addedNodes) {
        run(node);
      }
    }
  }

  const observer = new window.MutationObserver(onMutate);
  observer.observe(document, { childList: true, subtree: true });
  run(document.body);
}

unlazy();