// ==UserScript==
// @name         Instagram s9e Stealthgram Link Inserter
// @namespace    https://stealthgram.com/
// @version      2024.08.05
// @description  Seamlessly insert Stealthgram media links under s9e Instagram embeds on any page, with duplicate prevention and dynamic embed handling
// @match        *://*www.thecoli.com/threads/*
// @match        *://*/threads/*
// @grant        none
// ==/UserScript==

(function() {
  'use strict';

  const debug = false; // Set to true for console.log debugging

  function log(msg) { if (debug) console.log('[Stealthgram userscript]', msg); }

  function getInstagramMediaId(iframe) {
    if (!iframe || !iframe.src) return null;
    const match = iframe.src.match(/#([A-Za-z0-9_-]{5,})/);
    return match ? match[1] : null;
  }

  function insertStealthgramLink(iframe, mediaId) {
    if (!iframe || !mediaId) return;
    if (iframe.getAttribute('data-stealthgram-done')) return;

    // Add <br> and then link
    const br = document.createElement('br');
    const link = document.createElement('a');
    link.href = 'https://stealthgram.com/media/' + mediaId;
    link.textContent = 'Stealthgram link';
    link.target = '_blank';
    link.rel = 'noopener noreferrer';
    link.className = 'stealthgram-link';
    link.style = 'font-size:90%;font-family:monospace;';
    iframe.insertAdjacentElement('afterend', br);
    br.insertAdjacentElement('afterend', link);
    iframe.setAttribute('data-stealthgram-done', '1');
    log('Inserted for ' + mediaId);
  }

  let throttleTimeout;
  function processEmbeds() {
    if (throttleTimeout) return;
    throttleTimeout = setTimeout(() => {
      throttleTimeout = null;
      const embeds = document.querySelectorAll('iframe[data-s9e-mediaembed="instagram"]');
      for (let iframe of embeds) {
        const mediaId = getInstagramMediaId(iframe);
        if (mediaId) insertStealthgramLink(iframe, mediaId);
      }
    }, 200);
  }

  processEmbeds();

  // Observe for dynamically-added embeds
  const observer = new MutationObserver(() => { processEmbeds(); });
  observer.observe(document.body, {childList: true, subtree: true});

  log('Instagram Stealthgram userscript loaded.');
})();