// ==UserScript==
// @name         Email Copy Button for All Sites
// @name:zh-CN   全站邮箱一键复制
// @namespace    http://tampermonkey.net/
// @version      1.9
// @description  Automatically detects email addresses on any webpage and adds a one-click copy button. Supports plain text emails, mailto links, input field values (e.g. read-only forms, admin dashboards), table cells, drawer/modal content, aria attributes, and title attributes. Includes deduplication, trailing punctuation trim, and rescan on DOM updates for SPA/dynamic pages.
// @description:zh-CN 在任意网页自动识别邮箱地址并添加一键复制按钮，支持纯文本邮箱、mailto 链接及表单输入框内的邮箱值（兼容组件库只读表单、表格详情、抽屉弹窗等后台系统），兼容 React / Next.js 动态渲染页面，修复重复按钮、正则误匹配、滚动懒加载等问题。
// @author       Nosy Swab
// @match        *://*/*
// @exclude      https://apps.sfc.hk/*
// @run-at       document-end
// @grant        none
// @license      MIT
// @icon         data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy5zvcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCA2NkNCIgd2lkdGg9IjY0IiBoZWlnaHQ9IjY0Ij48cmVjdCB3aWR0aD0iNjQiIGhlaWdodD0iNjQiIHJ4PSI4IiBmaWxsPSIjMTg0OGZmIi8+PHBhdGggZD0iTTMyIDIwYzYuNjMgMCAxMiA1LjM3IDEyIDEycy01LjM3IDEyLTEyIDEyLTEyLTUuMzctMTItMTIgNS4zNy0xMiAxMi0xMnptMCA0Yy00LjQxIDAtOCAzLjU5LTggOHMzLjU5IDggOCA4IDgtMy41OSA4LTgtMy41OS04LTgtOHoiIGZpbGw9IndoaXRlIi8+PHBhdGggZD0iTTE2IDQ0YzAtOC44NCA3LjE2LTE2IDE2LTE2czE2IDcuMTYgMTYgMTZ2NGgtMzJ2LTR6IiBmaWxsPSJ3aGl0ZSIvPjwvc3ZnPg==
// ==/UserScript==

(function () {
  'use strict';

  if (location.hostname === 'apps.sfc.hk') return;

  var EMAIL_RE   = /[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}/;
  var EMAIL_RE_G = /[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}/g;

  // Clean trailing punctuation/brackets from extracted email
  function cleanEmail(raw) {
    return raw.replace(/[),;:.'"\]>]+$/, '').trim();
  }

  // Marker to avoid inserting duplicate buttons
  var MARKER = 'data-email-btn-injected';

  function makeBtn(email) {
    var btn = document.createElement('button');
    btn.textContent = '\uD83D\uDCCB';
    btn.title = 'Copy: ' + email;
    btn.setAttribute(MARKER, '1');
    btn.style.cssText = [
      'display:inline-flex',
      'align-items:center',
      'justify-content:center',
      'margin-left:4px',
      'padding:1px 5px',
      'font-size:12px',
      'line-height:1',
      'border:1px solid #d9d9d9',
      'border-radius:4px',
      'background:#fff',
      'cursor:pointer',
      'vertical-align:middle',
      'transition:background 0.15s',
      'flex-shrink:0'
    ].join(';');
    btn.addEventListener('mouseenter', function () { btn.style.background = '#f0f0f0'; });
    btn.addEventListener('mouseleave', function () { btn.style.background = '#fff'; });
    btn.addEventListener('click', function (e) {
      e.preventDefault();
      e.stopPropagation();
      navigator.clipboard.writeText(email).then(function () {
        var orig = btn.textContent;
        btn.textContent = '\u2713';
        btn.style.background = '#52c41a';
        btn.style.color = '#fff';
        btn.style.borderColor = '#52c41a';
        setTimeout(function () {
          btn.textContent = orig;
          btn.style.background = '#fff';
          btn.style.color = '';
          btn.style.borderColor = '#d9d9d9';
        }, 1500);
      }).catch(function () {
        var ta = document.createElement('textarea');
        ta.value = email;
        ta.style.cssText = 'position:fixed;opacity:0;top:0;left:0';
        document.body.appendChild(ta);
        ta.select();
        document.execCommand('copy');
        document.body.removeChild(ta);
      });
    });
    return btn;
  }

  // ── Inject into plain text nodes ──────────────────────────────────────
  var SKIP_TAGS = new Set([
    'SCRIPT','STYLE','NOSCRIPT','CODE','PRE','SVG','CANVAS',
    'HEAD','TEMPLATE','TEXTAREA'
  ]);

  function injectIntoTextNode(node) {
    var text = node.nodeValue;
    if (!text || !EMAIL_RE.test(text)) return;
    var parent = node.parentNode;
    if (!parent) return;
    if (SKIP_TAGS.has(parent.tagName)) return;
    if (parent.getAttribute && parent.getAttribute(MARKER)) return;
    // Avoid double-processing
    if (parent.hasAttribute && parent.hasAttribute(MARKER)) return;

    var parts = text.split(EMAIL_RE_G);
    var matches = text.match(EMAIL_RE_G);
    if (!matches) return;

    var frag = document.createDocumentFragment();
    parts.forEach(function (part, i) {
      frag.appendChild(document.createTextNode(part));
      if (matches[i]) {
        var email = cleanEmail(matches[i]);
        frag.appendChild(document.createTextNode(email));
        frag.appendChild(makeBtn(email));
      }
    });
    parent.setAttribute(MARKER, '1');
    parent.replaceChild(frag, node);
  }

  // ── Inject after mailto links ──────────────────────────────────────────
  function injectMailtoLinks(root) {
    var links = (root.querySelectorAll ? root : document)
      .querySelectorAll('a[href^="mailto:"]');
    links.forEach(function (a) {
      if (a.getAttribute(MARKER)) return;
      var email = cleanEmail(a.href.replace('mailto:', '').split('?')[0]);
      if (!email) return;
      a.setAttribute(MARKER, '1');
      a.insertAdjacentElement('afterend', makeBtn(email));
    });
  }

  // ── Inject into input/textarea values ─────────────────────────────────
  function injectInputValues(root) {
    var fields = (root.querySelectorAll ? root : document)
      .querySelectorAll('input[value], input[readonly], input[disabled], textarea[readonly], textarea[disabled]');
    fields.forEach(function (el) {
      if (el.getAttribute(MARKER)) return;
      var val = el.value || el.getAttribute('value') || '';
      var m = val.match(EMAIL_RE);
      if (!m) return;
      var email = cleanEmail(m[0]);
      el.setAttribute(MARKER, '1');
      // insert button after the field if parent allows
      var parent = el.parentNode;
      if (parent && !SKIP_TAGS.has(parent.tagName)) {
        var btn = makeBtn(email);
        el.insertAdjacentElement('afterend', btn);
      }
    });
  }

  // ── Inject into title / aria-label / data-* attributes ────────────────
  function injectAttrHints(root) {
    var attrs = ['title', 'aria-label', 'placeholder', 'data-email', 'data-value'];
    attrs.forEach(function (attr) {
      var els = (root.querySelectorAll ? root : document)
        .querySelectorAll('[' + attr + ']');
      els.forEach(function (el) {
        var key = MARKER + '-attr-' + attr;
        if (el.getAttribute(key)) return;
        var val = el.getAttribute(attr) || '';
        var m = val.match(EMAIL_RE);
        if (!m) return;
        var email = cleanEmail(m[0]);
        el.setAttribute(key, '1');
        el.insertAdjacentElement('afterend', makeBtn(email));
      });
    });
  }

  // ── Walk text nodes ────────────────────────────────────────────────────
  function walkTextNodes(root) {
    var walker = document.createTreeWalker(
      root,
      NodeFilter.SHOW_TEXT,
      {
        acceptNode: function (node) {
          if (SKIP_TAGS.has(node.parentElement && node.parentElement.tagName)) {
            return NodeFilter.FILTER_REJECT;
          }
          return NodeFilter.FILTER_ACCEPT;
        }
      },
      false
    );
    var nodes = [];
    var n;
    while ((n = walker.nextNode())) nodes.push(n);
    nodes.forEach(injectIntoTextNode);
  }

  // ── Full scan on a root element ────────────────────────────────────────
  function scanRoot(root) {
    try {
      walkTextNodes(root);
      injectMailtoLinks(root);
      injectInputValues(root);
      injectAttrHints(root);
    } catch (e) {
      // silently ignore per-node errors
    }
  }

  // ── Initial scan ──────────────────────────────────────────────────────
  scanRoot(document.body);

  // Delayed second pass for late-mounting components
  setTimeout(function () { scanRoot(document.body); }, 1200);
  setTimeout(function () { scanRoot(document.body); }, 3000);

  // ── MutationObserver for SPA / dynamic content ────────────────────────
  var pending = false;
  var observer = new MutationObserver(function (mutations) {
    if (pending) return;
    pending = true;
    requestAnimationFrame(function () {
      pending = false;
      mutations.forEach(function (mut) {
        mut.addedNodes.forEach(function (node) {
          if (node.nodeType === 1) {
            // Element node — scan it and its subtree
            if (!SKIP_TAGS.has(node.tagName)) {
              scanRoot(node);
            }
          } else if (node.nodeType === 3) {
            // Text node
            injectIntoTextNode(node);
          }
        });
      });
    });
  });

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

  // ── Rescan visible area on scroll (throttled) — catches virtual scroll ─
  var scrollTimer = null;
  window.addEventListener('scroll', function () {
    clearTimeout(scrollTimer);
    scrollTimer = setTimeout(function () {
      // Only re-scan input/textarea values on scroll as text nodes are handled by MO
      injectInputValues(document.body);
      injectAttrHints(document.body);
    }, 400);
  }, { passive: true });

})();