// ==UserScript==
// @name         Auto Link Button for All Sites
// @name:zh-CN   全站纯文本网址一键转链接
// @namespace    https://auto-link-button.local/
// @version      1.1.0
// @description  Automatically detects plain-text URLs (www.xxx / http(s)://xxx / bare domains with common TLDs) anywhere on a page and turns them into clickable links that open in a new tab. Existing hyperlinks, code blocks, inputs and editable areas are left untouched.
// @description:zh-CN  自动识别网页中纯文本形式的网址（www.xxx / http(s)://xxx / 带常见后缀的裸域名），一键转换为可点击超链接，新标签页打开。已有 <a> 链接、代码块、输入框、可编辑区域均不受影响。
// @author       you
// @match        *://*/*
// @icon         data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cg fill='none' stroke='%230A84FF' stroke-width='2.2' stroke-linecap='round'%3E%3Crect x='3' y='9' width='10' height='6' rx='3' transform='rotate(-40 8 12)'/%3E%3Crect x='11' y='9' width='10' height='6' rx='3' transform='rotate(-40 16 12)'/%3E%3C/g%3E%3C/svg%3E
// @run-at       document-idle
// @grant        none
// @license      MIT
// ==/UserScript==

(function () {
  'use strict';

  // 常见 TLD 白名单，用于裸域名（无 www / http 前缀）匹配，降低误判率
  // 例如 "e.g." "Fig.1" "v2.3" 这类不会被误当成网址
  const TLDS = [
    'com','net','org','edu','gov','mil','info','biz','name','pro',
    'io','co','ai','app','dev','xyz','top','site','online','store',
    'hk','cn','tw','sg','jp','kr','uk','us','ca','au','nz','de','fr',
    'it','es','nl','se','no','fi','dk','ch','at','be','ie','pl','ru',
    'in','id','th','vn','ph','my','br','mx','za','ae','sa','il',
    'me','tv','cc','ws','ly','gg','so','to','fm','io','gl','vc',
    'edu.hk','gov.hk','org.hk','com.hk','com.cn','com.tw','co.uk','co.jp','co.kr','com.sg','com.au'
  ]
    .sort((a, b) => b.length - a.length) // 长的（多级 TLD）优先匹配
    .join('|');

  const URL_REGEX = new RegExp(
    String.raw`\bhttps?:\/\/[^\s<>"'\)\]]+` + // 1) http(s):// 完整 URL
    String.raw`|\bwww\.[\w-]+(?:\.[\w-]+)+(?:\/[^\s<>"'\)\]]*)?` + // 2) www. 开头
    String.raw`|(?<![\w@.\/])(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+(?:${TLDS})(?![\w-])(?:\/[^\s<>"'\)\]]*)?`, // 3) 裸域名 + 有效 TLD
    'gi'
  );

  function isSkippableAncestor(el) {
    if (!el) return false;
    const skipEl = el.closest('a, script, style, textarea, input, code, pre, [contenteditable="true"]');
    return !!skipEl;
  }

  function linkify(textNode) {
    const text = textNode.nodeValue;
    if (!text) return;
    URL_REGEX.lastIndex = 0;
    if (!URL_REGEX.test(text)) return;
    URL_REGEX.lastIndex = 0;

    const frag = document.createDocumentFragment();
    let lastIndex = 0;
    let match;
    let hit = false;

    while ((match = URL_REGEX.exec(text)) !== null) {
      let url = match[0];
      const start = match.index;

      // 去掉网址末尾常见的标点残留，如 "www.gavekal.com," 或 "(www.gavekal.com)"
      const trailingPunct = /[.,;:!?，。；：！？]+$/;
      const trimmed = url.replace(trailingPunct, '');
      const diff = url.length - trimmed.length;
      url = trimmed;

      if (start > lastIndex) {
        frag.appendChild(document.createTextNode(text.slice(lastIndex, start)));
      }

      const a = document.createElement('a');
      a.href = url.startsWith('http') ? url : `http://${url}`;
      a.textContent = url;
      a.target = '_blank';
      a.rel = 'noopener noreferrer';
      a.style.color = '#0645AD';
      a.style.textDecoration = 'underline';
      frag.appendChild(a);
      hit = true;

      lastIndex = start + url.length + diff;
      if (diff > 0) {
        frag.appendChild(document.createTextNode(text.slice(start + url.length, lastIndex)));
      }
    }

    if (!hit) return;

    if (lastIndex < text.length) {
      frag.appendChild(document.createTextNode(text.slice(lastIndex)));
    }

    textNode.parentNode.replaceChild(frag, textNode);
  }

  function walk(root) {
    const walker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT, {
      acceptNode(node) {
        if (!node.nodeValue || !node.nodeValue.trim()) return NodeFilter.FILTER_SKIP;
        if (isSkippableAncestor(node.parentElement)) return NodeFilter.FILTER_REJECT;
        return NodeFilter.FILTER_ACCEPT;
      },
    });

    const targets = [];
    let n;
    while ((n = walker.nextNode())) targets.push(n);
    targets.forEach(linkify);
  }

  // 初次扫描（注意：root 若本身就是 <a> 内部的 text node 会在 walk 内被跳过，
  // 但若 root 本身是新插入的元素节点，需要先判断该元素本身是否在可跳过祖先内）
  function safeWalk(root) {
    if (root.nodeType === Node.ELEMENT_NODE) {
      if (isSkippableAncestor(root) || root.closest?.('a')) return;
      walk(root);
    } else if (root.nodeType === Node.TEXT_NODE) {
      if (!isSkippableAncestor(root.parentElement)) linkify(root);
    }
  }

  walk(document.body);

  let debounceTimer = null;
  const pending = new Set();
  const observer = new MutationObserver((mutations) => {
    for (const m of mutations) {
      m.addedNodes.forEach((node) => pending.add(node));
    }
    clearTimeout(debounceTimer);
    debounceTimer = setTimeout(() => {
      pending.forEach(safeWalk);
      pending.clear();
    }, 200);
  });

  observer.observe(document.body, { childList: true, subtree: true });
})();