// ==UserScript==
// @name         PL - Tab title as tor filename (blob enforced)
// @version      1.4
// @author       SH0D4N
// @tag          pornolab
// @tag          pornolab.net
// @description  Force torrent filename from tab title on Pornolab.net (overrides server filename via Blob)
// @match        https://pornolab.net/forum/viewtopic.php?t=*
// @match        https://pornolab.net/forum/viewforum.php?f=*
// @match        https://pornolab.net/forum/tracker.php*
// @grant        none
// @run-at       document-idle
// @namespace    vm-pl-title-filename
// ==/UserScript==

(function () {
  'use strict';

  const SITE_TAG = 'pornolab.net';
  const MAX_FILENAME_CHARS = 240; // safe limit for filename (without path)
  const TORRENT_EXT = '.torrent';

  // Click delegation – also catches dynamically inserted links.
  document.addEventListener('click', async (ev) => {
    const a = ev.target.closest('a');
    if (!a) return;

    if (!isTorrentDownloadLink(a)) return;

    // Respect middle/Ctrl/Shift/Alt/meta – in those cases do nothing
    if (ev.defaultPrevented || ev.button === 1 || ev.metaKey || ev.ctrlKey || ev.shiftKey || ev.altKey) return;

    ev.preventDefault();

    try {
      const url = new URL(a.href, location.href);
      const fileId = url.searchParams.get('t') || url.searchParams.get('id') || '';
      const title = getCleanTitle();
      const base = `[${SITE_TAG}]${fileId ? '_' + fileId : ''}_${title}`;
      const filename = toFilename(base, MAX_FILENAME_CHARS, TORRENT_EXT);

      // Download as Blob, create an object URL, and download with our filename
      const resp = await fetch(url.toString(), { credentials: 'same-origin' });
      if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
      const blob = await resp.blob();

      const blobUrl = URL.createObjectURL(blob);
      triggerDownload(blobUrl, filename);
      URL.revokeObjectURL(blobUrl);
    } catch (e) {
      console.error('[vm-pl-title-filename] Download fallback failed:', e);
      // Fallback: if Blob download fails, let the original behavior happen
      location.href = a.href;
    }
  }, true); // capture=true, so it runs before the page’s handlers

  function isTorrentDownloadLink(a) {
    const href = (a.getAttribute('href') || '').toLowerCase();
    return href.includes('/dl.php') || a.classList.contains('dl-stub');
  }

  function getCleanTitle() {
    // “Tab title” without “ :: PornoLab.Net” at the end
    const clean = document.title.replace(/\s*::\s*PornoLab\.Net\s*$/i, '').trim();
    return clean || 'torrent';
  }

  function toFilename(base, maxChars, ext) {
    let name = sanitizeFilename(base);

    // remove duplicate extension
    if (name.toLowerCase().endsWith(ext)) {
      name = name.slice(0, -ext.length);
    }

    // shorten so it fits with extension
    const maxBase = Math.max(1, maxChars - ext.length);
    if (name.length > maxBase) {
      name = name.slice(0, maxBase).replace(/[.\s]+$/g, '');
    }
    return name + ext;
  }

  function sanitizeFilename(input) {
    // normalize whitespace
    let s = input.replace(/\s+/g, ' ').trim();

    // forbidden characters in Windows
    s = s.replace(/[\\/:*?"<>|]/g, '-').replace(/[\x00-\x1F\x7F]/g, '');

    // avoid reserved device names
    s = s.split(/([._\s-]+)/).map((part, i) => (i % 2 ? part : avoidReserved(part))).join('');

    // remove trailing dots/spaces
    s = s.replace(/[.\s]+$/g, '');
    return s || 'torrent';
  }

  function avoidReserved(stem) {
    const res = new Set([
      'CON','PRN','AUX','NUL',
      'COM1','COM2','COM3','COM4','COM5','COM6','COM7','COM8','COM9',
      'LPT1','LPT2','LPT3','LPT4','LPT5','LPT6','LPT7','LPT8','LPT9'
    ]);
    return res.has(stem.toUpperCase()) ? stem + '-' : stem;
  }

  function triggerDownload(href, filename) {
    const a = document.createElement('a');
    a.href = href;
    a.download = filename; // force filename thanks to blob: URL
    a.style.display = 'none';
    document.body.appendChild(a);
    a.click();
    a.remove();
  }
})();

```