// ==UserScript==
// @name         Via 网页翻译（Bilibili Index-Translate）
// @namespace    via.index.translate
// @version      1.9.10
// @description  右侧按钮组：整页外文译中文（双语/仅译文）+ 图片识图翻译 + 模型切换。引擎：Bilibili Index-Translate
// @author       NoteGPT
// @match        http://*/*
// @match        https://*/*
// @run-at       document-end
// @grant        none
// @license MIT
// ==/UserScript==

/*  v1.9.0 相对 1.8.3 的修复
 *  1. 长按切「仅译文」失效：长按后浏览器仍会补发 click，导致刚开就被关掉。改为抑制合成 click。
 *  2. 三个按钮重叠：图片按钮 bottom 与文字按钮 top 相撞（手机上重叠 17px）。改为统一按钮坞纵向排列。
 *  3. 图片翻译主路径必失败：接口不接受远程 URL（30s 超时 504），原来总是掉到需登录的第三方 OCR。
 *     改为 canvas 压缩 → base64 内联直传（实测 4s 出结果），跨域被污染时自动走 weserv 代理重取。
 *  4. 还原不干净：原元素上残留 vtx-hide 类。现在一并清除。
 *  5. 并发 3 + 间隔 150ms 会撞 503 风暴。改为全局限流闸门 + 指数退避 + 抖动。
 *  6. 被用户停止后仍提示「翻译完成」。改为按实际状态提示。
 *  7. 跳过导航/页头用 className 子串匹配，会误判（如 canvas 含 nav）。改为按类名分词精确匹配。
 *  8. 杂项：重复注册 mouseup、图片拦截未阻断页面自身处理、识图建议用 35B。
 */

(function () {
  'use strict';

  if (window.__vtxInjected) return;
  // 不在 iframe 里运行，避免多出一套按钮
  if (window.top !== window.self) return;
  window.__vtxInjected = true;

  /* ================== 可调参数 ================== */
  var CFG = {
    api: 'https://index-translate.bilibili.com/v1/chat/completions',
    model: 'Index-Translate-35B-A3B',
    batchChars: 900,     // 单次请求携带的字符数（实测 >1000 容易超时/漏译）
    segMax: 1000,        // 单段超长则按句子切开
    gap: 180,            // 批次之间的间隔（毫秒）
    concurrency: 3,      // 并发批次数量（配合限流闸门，3 较稳）
    retry: 3,            // 单请求最大尝试次数
    maxBlocks: 600,
    maxChars: 60000,
    imgMaxSide: 1400,    // 识图前把图片最长边压到这么多像素
    imgQuality: 0.82     // 识图 JPEG 质量
  };

  var MODELS = [
    { id: 'Index-Translate-2B', short: '2B', label: '快速（2B，文字够用，识图较差）' },
    { id: 'Index-Translate-9B', short: '9B', label: '均衡（9B）' },
    { id: 'Index-Translate-35B-A3B', short: '35B', label: '高质量（35B）' }
  ];

  function loadModel() {
    try {
      var saved = localStorage.getItem('vtx_model');
      if (saved) {
        for (var i = 0; i < MODELS.length; i++) {
          if (MODELS[i].id === saved) { CFG.model = saved; return i; }
        }
      }
    } catch (e) { }
    return 2;
  }
  function saveModel(idx) {
    CFG.model = MODELS[idx].id;
    try { localStorage.setItem('vtx_model', CFG.model); } catch (e) { }
  }
  var modelIdx = loadModel();

  /* ================== 常量 ================== */
  var BLOCK_TAGS = {
    P: 1, DIV: 1, LI: 1, UL: 1, OL: 1, DL: 1, DT: 1, DD: 1, H1: 1, H2: 1, H3: 1, H4: 1, H5: 1, H6: 1,
    SECTION: 1, ARTICLE: 1, ASIDE: 1, HEADER: 1, FOOTER: 1, MAIN: 1, NAV: 1, BLOCKQUOTE: 1,
    FIGURE: 1, FIGCAPTION: 1, TABLE: 1, THEAD: 1, TBODY: 1, TFOOT: 1, TR: 1, TD: 1, TH: 1,
    FORM: 1, FIELDSET: 1, ADDRESS: 1, DETAILS: 1, SUMMARY: 1, BODY: 1
  };
  var SKIP_TAGS = {
    SCRIPT: 1, STYLE: 1, NOSCRIPT: 1, IFRAME: 1, SVG: 1, CANVAS: 1, VIDEO: 1, AUDIO: 1,
    TEXTAREA: 1, INPUT: 1, SELECT: 1, OPTION: 1, BUTTON: 1, CODE: 1, PRE: 1, KBD: 1, SAMP: 1,
    TEMPLATE: 1, HEAD: 1, META: 1, LINK: 1
  };
  // 这些容器里的文字属于站点导航／页脚，不翻译（按类名分词精确匹配，避免误伤）
  var CHROME_RE = /^(nav|navbar|navigation|navi|menu|menubar|submenu|topbar|header|masthead|footer|sidebar|breadcrumb|site-nav|main-nav|site-header|page-header|site-footer|page-footer)([-_]|$)/;

  var PROMPT_BATCH = [
    'Translate each numbered line into Simplified Chinese (简体中文).',
    'Output rules:',
    '1. Output exactly one line per input line, in the same order, no blank lines.',
    '2. Keep the "N|||" prefix exactly as in the input, then put the translation after it.',
    '3. Output the translation only: no explanation, no notes, no quotes, no markdown.',
    '4. Keep numbers, URLs, emails, file paths and code identifiers unchanged.',
    ''
  ].join('\n');

  var PROMPT_SINGLE = 'Translate the following text into Simplified Chinese. Output only the translation, without quotes or any explanation:\n\n';

  // 注意：模板里绝对不能出现 <占位符>，模型会把尖括号里的占位符原样输出
  var PROMPT_IMAGE = '识别图片中的文字并翻译成简体中文。用下面两个标记分段输出，标记各占一行：\n【原文】\n【译文】';

  /* ================== 状态 ================== */
  var S = { running: false, cancel: false, hasResult: false, onlyMode: false, total: 0, done: 0, unreadable: 0, failed: 0 };
  var IMG = { mode: false, loading: false };
  var GATE = { until: 0 };
  var NET = { dead: false };
  var CTRL = null;  // AbortController，停止时取消在飞请求
  var CREATED = { blocks: [], modified: [] };  // 记录脚本创建/修改的元素，避免误删网页原有内容

  /* ================== 工具函数 ================== */
  function sleep(ms) { return new Promise(function (res) { setTimeout(res, ms); }); }
  function norm(s) { return String(s || '').replace(/\s+/g, ' ').trim(); }

  var LETTER_RE = /[A-Za-z\u00C0-\u024F\u0370-\u03FF\u0400-\u04FF\u0590-\u05FF\u0600-\u06FF\u0E00-\u0E7F\u3040-\u30FF\uAC00-\uD7AF]/;
  var HAN_RE = /[\u3400-\u4DBF\u4E00-\u9FFF]/g;
  var KANA_RE = /[\u3040-\u30FF]/;

  function needTranslate(t) {
    if (!t || t.length < 2) return false;
    if (!LETTER_RE.test(t)) return false;
    if (KANA_RE.test(t)) return true;
    var han = (t.match(HAN_RE) || []).length;
    if (han > 0 && han / t.length > 0.3) return false;
    return true;
  }

  function splitSeg(text, max) {
    var out = [];
    var rest = String(text);
    while (rest.length > max) {
      var head = rest.slice(0, max + 1);
      var cut = -1;
      var re = /[.!?;:。！？；：]["'”’)\]]?\s/g;
      var m;
      while ((m = re.exec(head)) !== null) {
        if (m.index + 1 >= max * 0.35) cut = m.index + m[0].length;
      }
      if (cut <= 0) {
        var sp = rest.slice(0, max).lastIndexOf(' ');
        cut = sp > max * 0.4 ? sp : max;
      }
      out.push(rest.slice(0, cut).trim());
      rest = rest.slice(cut).trim();
    }
    if (rest) out.push(rest);
    return out.length ? out : [text];
  }

  function parseNumbered(content, n) {
    var res = new Array(n);
    var lines = String(content).replace(/\r/g, '').split('\n');
    for (var i = 0; i < lines.length; i++) {
      var m = lines[i].match(/^\s*(\d{1,3})\s*[|｜]{1,3}\s*([\s\S]*)$/);
      if (m) {
        var k = parseInt(m[1], 10) - 1;
        if (k >= 0 && k < n && !res[k]) {
          var v = m[2].trim();
          if (v) res[k] = v;
        }
      }
    }
    for (var j = 0; j < n; j++) if (!res[j]) return null;
    return res;
  }

  function parseByLines(content, n) {
    var arr = String(content).replace(/\r/g, '').split('\n')
      .map(function (s) { return s.replace(/^\s*\d{1,3}\s*[|｜]{1,3}\s*/, '').trim(); })
      .filter(function (s) { return s.length > 0; });
    if (arr.length !== n) return null;
    return arr;
  }

  // 清洗单条译文；结果里没有汉字且原文含拉丁字母，视为「没翻译」丢弃
  function cleanOne(c, src) {
    var t = String(c || '').trim();
    t = t.replace(/^["'“”‘’]+|["'“”‘’]+$/g, '').trim();
    t = t.replace(/^译文[:：]\s*/, '').trim();
    if (!t) return '';
    if (!/[\u4e00-\u9fff]/.test(t)) {
      if (!src || /[A-Za-z]{3,}/.test(src)) return '';
      return t;
    }
    return t;
  }

  /* ================== 网络请求 ================== */
  function waitGate() {
    var d = GATE.until - Date.now();
    return d > 0 ? sleep(d) : Promise.resolve();
  }
  function coolDown(ms) {
    GATE.until = Math.max(GATE.until, Date.now() + ms);
  }

  function post(body, timeoutMs, ignoreGlobal) {
    var ac = new AbortController();
    var timer = setTimeout(function () { ac.abort(); }, timeoutMs || 25000);
    var onGlobalAbort = function () { ac.abort(); };
    if (!ignoreGlobal && CTRL && CTRL.signal) {
      if (CTRL.signal.aborted) ac.abort();
      else CTRL.signal.addEventListener('abort', onGlobalAbort);
    }
    return fetch(CFG.api, {
      method: 'POST', mode: 'cors', credentials: 'omit',
      signal: ac.signal,
      headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(body)
    }).then(function (r) {
      if (!r.ok) {
        var err = new Error('HTTP ' + r.status);
        err.status = r.status;
        throw err;
      }
      return r.json();
    }).then(function (d) {
      var c = d && d.choices && d.choices[0] && d.choices[0].message && d.choices[0].message.content;
      if (!c || !String(c).trim()) throw new Error('empty');
      return String(c);
    }).finally(function () {
      clearTimeout(timer);
      if (!ignoreGlobal && CTRL && CTRL.signal) CTRL.signal.removeEventListener('abort', onGlobalAbort);
    });
  }

  function request(prompt, attempt) {
    attempt = attempt || 1;
    if (NET.dead) return Promise.reject(new Error('net-dead'));
    if (S.cancel) { var e = new Error('cancelled'); e.name = 'AbortError'; return Promise.reject(e); }
    return waitGate().then(function () {
      if (S.cancel) { var e2 = new Error('cancelled'); e2.name = 'AbortError'; throw e2; }
      return post({
        model: CFG.model, temperature: 0.1, stream: false,
        messages: [
          { role: 'system', content: '你是专业翻译引擎。把用户给的英文内容翻译成简体中文。只输出译文本身，不要解释。' },
          { role: 'user', content: prompt }
        ]
      });
    }).catch(function (err) {
      // 用户主动取消（CTRL.abort 或 S.cancel 置位），不重试
      if (err.name === 'AbortError' && (S.cancel || (CTRL && CTRL.signal.aborted))) throw err;
      // 请求超时（ac.abort 但 CTRL 未取消），当作网络错误重试
      // 页面 CSP 的 connect-src 或断网会让 fetch 直接抛 TypeError，重试没有意义
      var isNetErr = !err.status && (err.name === 'TypeError' || err.name === 'AbortError' ||
        /Failed to fetch|NetworkError|Load failed|net-dead/i.test(err.message || ''));
      if (isNetErr && !(CTRL && CTRL.signal.aborted)) {
        // 超时也重试，但不标记 NET.dead（只是这一次慢）
        if (err.name === 'AbortError') {
          if (attempt >= CFG.retry) throw err;
          return sleep(1000).then(function () { return request(prompt, attempt + 1); });
        }
        NET.dead = true; throw err;
      }
      if (err.name === 'AbortError') throw err;
      // 限流类错误：整体冷却，且退避时间随次数递增
      if (!err.status || err.status === 429 || err.status >= 500) {
        coolDown(900 * attempt + Math.round(Math.random() * 400));
      }
      if (attempt >= CFG.retry) throw err;
      return sleep(700 * attempt + Math.round(Math.random() * 300))
        .then(function () { return request(prompt, attempt + 1); });
    });
  }

  // 逐条翻译（批量失败时的兜底）
  function translateIndividually(items) {
    var out = new Array(items.length);
    var nextIdx = 0;
    function worker() {
      if (S.cancel || NET.dead) return Promise.resolve();
      var i = nextIdx++;
      if (i >= items.length) return Promise.resolve();
      var k = i;
      return request(PROMPT_SINGLE + items[k].chunk.src, 1).then(function (c) {
        out[k] = cleanOne(c, items[k].chunk.src);
      }).catch(function () { out[k] = ''; })
        .then(function () { return sleep(160); })
        .then(worker);
    }
    var starts = [];
    for (var w = 0; w < Math.min(CFG.concurrency, items.length); w++) starts.push(worker());
    return Promise.all(starts).then(function () { return out; });
  }

  function translateBatch(items) {
    var n = items.length;
    if (n === 1) {
      return request(PROMPT_SINGLE + items[0].chunk.src, 1)
        .then(function (c) { return [cleanOne(c, items[0].chunk.src)]; })
        .catch(function () { return []; });
    }
    var lines = items.map(function (it, i) {
      return (i + 1) + '|||' + String(it.chunk.src).replace(/\s*\n\s*/g, ' ');
    });
    return request(PROMPT_BATCH + lines.join('\n'), 1).then(function (c) {
      var arr = parseNumbered(c, n) || parseByLines(c, n);
      if (!arr) return null;
      return arr.map(function (s, i) { return cleanOne(s, items[i] && items[i].chunk.src); });
    }).catch(function (err) {
      if (S.cancel) return [];
      return null;
    }).then(function (res) {
      if (res || S.cancel || NET.dead) return res || [];
      return translateIndividually(items);
    });
  }

  /* ================== 页面文本抽取 ================== */
  function isVisible(el) {
    var r = el.getBoundingClientRect();
    // 小于 2px 的块基本是屏读辅助元素（如 Skip to main content），不翻
    if (r.width < 2 || r.height < 2) return false;
    var cs;
    try { cs = window.getComputedStyle(el); } catch (e) { return true; }
    if (!cs) return true;
    if (cs.display === 'none' || cs.visibility === 'hidden' || cs.opacity === '0') return false;
    return true;
  }

  function isChrome(el) {
    var p = el;
    while (p && p !== document.body) {
      var pt = p.tagName;
      if (pt === 'NAV' || pt === 'HEADER' || pt === 'FOOTER' || pt === 'ASIDE') return true;
      var cls = (typeof p.className === 'string') ? p.className : '';
      if (cls) {
        var toks = cls.toLowerCase().split(/\s+/);
        for (var i = 0; i < toks.length; i++) {
          if (toks[i] && CHROME_RE.test(toks[i])) return true;
        }
      }
      p = p.parentNode;
    }
    return false;
  }

  function collect() {
    var out = [];
    function walk(el) {
      if (!el || el.nodeType !== 1) return;
      if (SKIP_TAGS[el.tagName]) return;
      if (el.id && el.id.indexOf('vtx-') === 0) return;
      if (el.className && typeof el.className === 'string' && el.className.indexOf('vtx-') === 0) return;
      if (el.getAttribute && el.getAttribute('contenteditable') === 'true') return;
      if (el.getAttribute && el.getAttribute('aria-hidden') === 'true') return;
      if (el.classList && el.classList.contains('vtx-done')) return;
      if (isChrome(el)) return;

      var kids = el.children;
      var hasBlockChild = false;
      var hasImgChild = false;
      for (var i = 0; i < kids.length; i++) {
        var ct = kids[i].tagName;
        if (BLOCK_TAGS[ct]) { hasBlockChild = true; break; }
        if (ct === 'IMG') hasImgChild = true;
      }

      if (hasBlockChild) {
        for (var j = 0; j < kids.length; j++) walk(kids[j]);
        return;
      }
      // 含图片的卡片：继续往下找文字子节点，不把图片 alt 混进翻译文本
      if (hasImgChild) {
        for (var k2 = 0; k2 < kids.length; k2++) {
          if (kids[k2].tagName !== 'IMG') walk(kids[k2]);
        }
        var directText = '';
        for (var n = 0; n < el.childNodes.length; n++) {
          if (el.childNodes[n].nodeType === 3) directText += el.childNodes[n].nodeValue;
        }
        directText = norm(directText);
        if (needTranslate(directText) && isVisible(el)) out.push({ el: el, text: directText });
        return;
      }
      var t = norm(el.textContent);
      if (!needTranslate(t)) return;
      if (!isVisible(el)) return;
      out.push({ el: el, text: t });
    }
    if (document.body) walk(document.body);
    return out;
  }

  /* ================== 样式 ================== */
  function injectStyle() {
    if (document.getElementById('vtx-style')) return;
    var st = document.createElement('style');
    st.id = 'vtx-style';
    st.textContent =
      // 按钮坞：三个按钮竖向排列，整体可拖动
      '#vtx-dock{position:fixed;right:5px;top:50%;transform:translateY(-50%);z-index:2147483645;' +
      'display:flex;flex-direction:column;align-items:flex-end;gap:8px;touch-action:none;}' +
      '#vtx-dock>div{width:40px;min-height:52px;padding:6px 0;box-sizing:border-box;' +
      'display:flex;align-items:center;justify-content:center;' +
      'color:#fff;font:600 15px/1.15 -apple-system,"PingFang SC","Helvetica Neue",Arial,sans-serif;' +
      'border-radius:14px 4px 4px 14px;box-shadow:0 2px 8px rgba(0,0,0,.22);cursor:pointer;' +
      'opacity:.9;-webkit-tap-highlight-color:transparent;-webkit-user-select:none;user-select:none;' +
      'letter-spacing:0;text-align:center;}' +
      '#vtx-dock.vtx-left{right:auto;left:5px;align-items:flex-start;}' +
      '#vtx-dock.vtx-left>div{border-radius:4px 14px 14px 4px;}' +
      '#vtx-fab{background:rgba(0,161,214,.92);}' +
      '#vtx-imgfab{background:rgba(230,126,34,.92);}' +
      '#vtx-modelfab{background:rgba(90,90,90,.92);font-size:11px;min-height:30px;width:36px;}' +
      '@media (min-width:768px){#vtx-dock>div{width:36px;min-height:46px;font-size:13px;}' +
      '#vtx-modelfab{width:32px;min-height:26px;font-size:10px;}}' +
      '#vtx-dock>div:active{opacity:1;}' +
      '#vtx-fab.vtx-run{background:rgba(251,114,153,.95);font-size:12px;}' +
      '#vtx-fab.vtx-done{background:rgba(70,150,95,.95);}' +
      '#vtx-fab.vtx-only{background:rgba(155,89,182,.95);}' +
      '#vtx-imgfab.vtx-on{background:rgba(230,126,34,1);box-shadow:0 0 0 3px rgba(230,126,34,.35);}' +
      // 译文块
      '.vtx-block{display:block;margin:6px 0 8px;padding:6px 9px;border-left:3px solid #00a1d6;' +
      'background:rgba(0,161,214,.09);border-radius:0 4px 4px 0;font-size:14px;line-height:1.65;' +
      'min-height:1em;color:#222 !important;text-align:left;word-break:break-word;}' +
      'body.vtx-only .vtx-hide{display:none !important;}' +
      'body.vtx-only .vtx-block{margin:0 0 6px;padding:0;border-left:none;' +
      'background:transparent;border-radius:0;font-size:16px;line-height:1.7;}' +
      'body.vtx-imgmode img{outline:2px dashed rgba(230,126,34,.6);outline-offset:-2px;}' +
      // 图片翻译面板
      '#vtx-panel{position:fixed;left:8px;right:8px;bottom:8px;z-index:2147483646;' +
      'max-height:55vh;overflow-y:auto;background:#fff;color:#222;border-radius:12px;' +
      'box-shadow:0 -4px 24px rgba(0,0,0,.25);padding:14px 14px 10px;box-sizing:border-box;' +
      'font:14px/1.6 -apple-system,"PingFang SC",Arial,sans-serif;display:none;}' +
      '#vtx-panel.vtx-show{display:block;}' +
      '#vtx-panel .vtx-panel-title{font-weight:700;font-size:13px;color:#e67e22;margin-bottom:8px;}' +
      '#vtx-panel .vtx-panel-sec{margin:8px 0;}' +
      '#vtx-panel .vtx-panel-label{font-size:12px;color:#888;margin-bottom:2px;}' +
      '#vtx-panel .vtx-panel-body{white-space:pre-wrap;word-break:break-word;}' +
      '#vtx-panel .vtx-panel-close{position:absolute;top:8px;right:12px;font-size:20px;color:#999;' +
      'cursor:pointer;line-height:1;padding:2px 4px;}' +
      '#vtx-toast{position:fixed;left:50%;bottom:16%;transform:translateX(-50%);z-index:2147483647;' +
      'max-width:80%;padding:8px 14px;border-radius:18px;background:rgba(0,0,0,.78);color:#fff;' +
      'font:14px/1.4 -apple-system,"PingFang SC",Arial,sans-serif;text-align:center;' +
      'pointer-events:none;opacity:1;transition:opacity .35s;}';
    (document.head || document.documentElement).appendChild(st);
  }

  function toast(msg, duration) {
    duration = duration || 2200;
    if (window.via && typeof window.via.toast === 'function') {
      try { window.via.toast(String(msg)); return; } catch (e) { }
    }
    var t = document.getElementById('vtx-toast');
    if (!t) {
      t = document.createElement('div'); t.id = 'vtx-toast'; document.body.appendChild(t);
    }
    t.textContent = String(msg);
    t.style.opacity = '1';
    clearTimeout(toast._t);
    toast._t = setTimeout(function () {
      t.style.opacity = '0';
      setTimeout(function () { if (t.parentNode) t.parentNode.removeChild(t); }, 400);
    }, duration);
  }

  /* ================== 拖拽 ================== */
  var dock = null;

  function makeDraggable(el) {
    var lpTimer = null, lpFiredAt = 0;
    var dragging = false, moved = false, pressed = false;
    var sx = 0, sy = 0;
    function clearLp() { if (lpTimer) { clearTimeout(lpTimer); lpTimer = null; } }
    function pt(e) { return (e.touches && e.touches.length) ? e.touches[0] : e; }

    function doMove(e) {
      if (!pressed) return;
      var p = pt(e);
      if (!p || typeof p.clientX !== 'number') return;
      var dx = p.clientX - sx, dy = p.clientY - sy;
      if (!dragging && !moved && Math.sqrt(dx * dx + dy * dy) > 12) {
        dragging = true; moved = true; clearLp();
        var r = el.getBoundingClientRect();
        el.style.right = 'auto';
        el.style.left = r.left + 'px';
        el.style.top = r.top + 'px';
        el.style.transform = 'none';
      }
      if (dragging) {
        if (e.cancelable) e.preventDefault();
        // 每帧以当前指针为基准，避免累加误差
        var r2 = el.getBoundingClientRect();
        var nl = Math.max(0, Math.min(window.innerWidth - r2.width, r2.left + dx));
        var nt = Math.max(0, Math.min(window.innerHeight - r2.height, r2.top + dy));
        el.style.left = nl + 'px'; el.style.top = nt + 'px';
        sx = p.clientX; sy = p.clientY;
      }
    }

    function finishDrag() {
      pressed = false;
      if (!dragging) return;
      dragging = false;
      var r = el.getBoundingClientRect();
      var centerX = r.left + r.width / 2;
      el.style.top = Math.max(6, Math.min(window.innerHeight - r.height - 6, r.top)) + 'px';
      if (centerX < window.innerWidth / 2) {
        el.classList.add('vtx-left');
        el.style.left = '5px'; el.style.right = 'auto';
      } else {
        el.classList.remove('vtx-left');
        el.style.right = '5px'; el.style.left = 'auto';
      }
    }

    document.addEventListener('mouseup', finishDrag, true);
    document.addEventListener('mousemove', doMove, true);
    document.addEventListener('touchmove', doMove, { passive: false });
    document.addEventListener('touchend', function () { if (dragging) finishDrag(); }, true);

    return {
      onDown: function (e, longPressCb) {
        var p = pt(e); if (!p) return;
        sx = p.clientX; sy = p.clientY;
        pressed = true; dragging = false; moved = false;
        clearLp();
        if (longPressCb) {
          lpTimer = setTimeout(function () {
            lpTimer = null; lpFiredAt = Date.now();
            longPressCb();
          }, 500);
        }
      },
      onUp: function () { clearLp(); finishDrag(); },
      // 长按结束后浏览器还会补发一次 click，必须吞掉
      justLongPressed: function () {
        if (lpFiredAt && (Date.now() - lpFiredAt < 900)) { lpFiredAt = 0; return true; }
        return false;
      },
      wasMoved: function () { return moved; },
      resetMoved: function () { moved = false; }
    };
  }

  function bindButton(btn, drag, onTap, longPressCb) {
    btn.addEventListener('touchstart', function (e) { drag.onDown(e, longPressCb); }, { passive: true });
    btn.addEventListener('touchend', function () { drag.onUp(); }, false);
    btn.addEventListener('touchcancel', function () { drag.onUp(); }, false);
    btn.addEventListener('mousedown', function (e) { drag.onDown(e, longPressCb); }, false);
    btn.addEventListener('mouseup', function () { drag.onUp(); }, false);
    btn.addEventListener('click', function (e) {
      e.preventDefault(); e.stopPropagation();
      if (drag.justLongPressed()) return;      // 长按后补发的 click，忽略
      if (drag.wasMoved()) { drag.resetMoved(); return; }
      onTap();
    }, false);
  }

  /* ================== 文字翻译按钮 ================== */
  var fab = null;

  function setFab(txt, mode) {
    if (!fab) return;
    fab.textContent = txt;
    fab.className = mode === 'run' ? 'vtx-run' : (mode === 'only' ? 'vtx-only' : (mode === 'done' ? 'vtx-done' : ''));
  }

  function refreshFab() {
    if (S.running) return;
    if (!S.hasResult) { setFab('译', ''); return; }
    setFab('原', S.onlyMode ? 'only' : 'done');
  }

  function createDock() {
    var existing = document.getElementById('vtx-dock');
    if (existing) { dock = existing; fab = document.getElementById('vtx-fab'); return; }
    dock = document.createElement('div');
    dock.id = 'vtx-dock';

    fab = document.createElement('div');
    fab.id = 'vtx-fab';
    fab.setAttribute('role', 'button');
    fab.setAttribute('aria-label', '翻译本页');
    fab.textContent = '译';

    dock.appendChild(fab);
    (document.body || document.documentElement).appendChild(dock);
  }

  /* ================== 仅译文模式 ================== */
  function toggleOnlyMode() {
    if (S.running) { toast('翻译中，请先停止'); return; }
    if (!S.hasResult) { toast('先翻译，再长按按钮切仅译文'); return; }
    S.onlyMode = !S.onlyMode;
    if (S.onlyMode) {
      document.body.classList.add('vtx-only');
      toast('仅显示译文（长按切回双语）');
    } else {
      document.body.classList.remove('vtx-only');
      toast('已切回双语对照');
    }
    refreshFab();
  }

  /* ================== 图片翻译 ================== */
  var imgFab = null;

  function resolveImgUrl(imgEl) {
    var src = imgEl.currentSrc || imgEl.src ||
              imgEl.getAttribute('data-src') ||
              imgEl.getAttribute('data-original') ||
              imgEl.getAttribute('data-lazy-src') || '';
    if (!src) return '';
    if (src.indexOf(',') > -1 && src.indexOf(' ') > -1) src = src.trim().split(/\s+/)[0];
    if (src.charAt(0) === '/' && src.charAt(1) === '/') src = location.protocol + src;
    else if (src.charAt(0) === '/') src = location.origin + src;
    return src;
  }

  function proxied(url) {
    if (!url || url.indexOf('data:') === 0) return '';
    return 'https://images.weserv.nl/?url=' + encodeURIComponent(url.replace(/^https?:\/\//, ''));
  }

  function loadForCanvas(url) {
    return new Promise(function (resolve, reject) {
      var im = new Image();
      im.crossOrigin = 'anonymous';
      var timer = setTimeout(function () {
        im.onload = im.onerror = null;
        reject(new Error('图片加载超时'));
      }, 15000);
      im.onload = function () { clearTimeout(timer); resolve(im); };
      im.onerror = function () { clearTimeout(timer); reject(new Error('load fail')); };
      im.src = url;
    });
  }

  // 把图片压成 base64（接口只吃内联图片，远程 URL 会 504）
  function toDataUrl(imgEl) {
    var first = resolveImgUrl(imgEl);
    if (!first) return Promise.reject(new Error('读不到图片地址'));
    var list = [first];
    var p = proxied(first);
    if (p) list.push(p);

    function attempt(i) {
      if (i >= list.length) return Promise.reject(new Error('图片无法读取（跨域限制）'));
      return loadForCanvas(list[i]).then(function (im) {
        var w = im.naturalWidth || im.width, h = im.naturalHeight || im.height;
        if (!w || !h) throw new Error('bad size');
        var scale = Math.min(1, CFG.imgMaxSide / Math.max(w, h));
        var cw = Math.max(1, Math.round(w * scale)), ch = Math.max(1, Math.round(h * scale));
        var cv = document.createElement('canvas');
        cv.width = cw; cv.height = ch;
        var ctx = cv.getContext('2d');
        ctx.fillStyle = '#fff'; ctx.fillRect(0, 0, cw, ch);
        ctx.drawImage(im, 0, 0, cw, ch);
        var data;
        try { data = cv.toDataURL('image/jpeg', CFG.imgQuality); }
        catch (e) { throw new Error('tainted'); }   // 画布被跨域污染
        if (!data || data.indexOf('data:image') !== 0) throw new Error('encode fail');
        return data;
      }).catch(function () { return attempt(i + 1); });
    }
    return attempt(0);
  }

  function biliImageTranslate(dataUrl, attempt) {
    attempt = attempt || 1;
    var model = (CFG.model === 'Index-Translate-2B') ? 'Index-Translate-35B-A3B' : CFG.model;
    return waitGate().then(function () {
      return post({
        model: model, temperature: 0.1, stream: false,
        messages: [{
          role: 'user',
          content: [
            { type: 'text', text: PROMPT_IMAGE },
            { type: 'image_url', image_url: { url: dataUrl } }
          ]
        }]
      }, 20000, true);
    }).catch(function (err) {
      if (attempt >= CFG.retry) throw err;
      if (!err.status || err.status === 429 || err.status >= 500) {
        coolDown(900 * attempt + Math.round(Math.random() * 400));
      }
      return sleep(700 * attempt + Math.round(Math.random() * 300))
        .then(function () { return biliImageTranslate(dataUrl, attempt + 1); });
    });
  }

  // 解析识图结果：兼容【原文】/【译文】与「原文：/译文：」两种写法，可重复出现多组
  function parseImageResult(text) {
    var t = String(text || '').replace(/\r/g, '');
    t = t.replace(/【\s*原文\s*】/g, '\n@@O@@\n')
         .replace(/【\s*译文\s*】/g, '\n@@T@@\n')
         .replace(/(^|\n)[ \t]*原文[ \t]*[：:]/g, '$1\n@@O@@\n')
         .replace(/(^|\n)[ \t]*译文[ \t]*[：:]/g, '$1\n@@T@@\n');

    // 去掉模型照抄回来的模板占位符
    function stripPH(s) {
      return String(s).split('\n').filter(function (ln) {
        var x = ln.trim();
        if (!x) return false;
        if (/^[<＜][^>＞]*[>＞]$/.test(x)) return false;
        if (/^(识别到的原文|识别到的文字|中文翻译|原文|译文|待翻译内容)$/.test(x)) return false;
        return true;
      }).join('\n').trim();
    }

    var origs = [], trans = [];
    var parts = t.split(/@@([OT])@@/);
    for (var i = 1; i < parts.length; i += 2) {
      var tag = parts[i];
      var body = stripPH(parts[i + 1] || '');
      if (!body) continue;
      if (tag === 'O') origs.push(body); else trans.push(body);
    }
    var o = origs.join('\n').trim();
    var r = trans.join('\n').trim();
    if (!r && /[\u4e00-\u9fff]/.test(t)) r = t.trim();   // 模型只给了译文时的兜底
    return { orig: o, trans: r };
  }

  function panelSet(orig, trans) {
    var p = document.getElementById('vtx-panel');
    if (!p) return;
    if (orig !== null) p.querySelector('[data-orig]').textContent = orig;
    if (trans !== null) p.querySelector('[data-trans]').textContent = trans;
  }

  function showPanel(orig, trans) {
    var p = document.getElementById('vtx-panel');
    if (!p) {
      p = document.createElement('div');
      p.id = 'vtx-panel';
      p.innerHTML =
        '<div class="vtx-panel-close">×</div>' +
        '<div class="vtx-panel-title">图片翻译</div>' +
        '<div class="vtx-panel-sec"><div class="vtx-panel-label">识别原文</div><div class="vtx-panel-body" data-orig></div></div>' +
        '<div class="vtx-panel-sec"><div class="vtx-panel-label">译文</div><div class="vtx-panel-body" data-trans></div></div>';
      document.body.appendChild(p);
      p.querySelector('.vtx-panel-close').addEventListener('click', function (e) {
        e.stopPropagation();
        p.classList.remove('vtx-show');
      });
    }
    p.querySelector('[data-orig]').textContent = orig;
    p.querySelector('[data-trans]').textContent = trans;
    p.classList.add('vtx-show');
  }

  function ocrAndTranslate(imgEl) {
    if (IMG.loading) { toast('正在处理上一张，请稍候'); return; }
    IMG.loading = true;
    showPanel('识别中…', '翻译中…');

    toDataUrl(imgEl).then(function (dataUrl) {
      return biliImageTranslate(dataUrl);
    }).then(function (raw) {
      var r = parseImageResult(raw);
      panelSet(r.orig || '（未识别到文字）', r.trans || '（翻译失败）');
      IMG.loading = false;
    }).catch(function (err) {
      var msg = (err && err.name === 'AbortError') ? '请求超时'
        : (err && err.message) ? err.message : String(err);
      panelSet(null, '翻译失败：' + msg.substring(0, 60));
      IMG.loading = false;
      toast('图片翻译失败：' + msg.substring(0, 40), 4000);
    });
  }

  function toggleImgMode() {
    IMG.mode = !IMG.mode;
    if (IMG.mode) {
      document.body.classList.add('vtx-imgmode');
      imgFab.classList.add('vtx-on');
      imgFab.textContent = '关';
      toast('图片翻译：点页面上的图片');
    } else {
      document.body.classList.remove('vtx-imgmode');
      imgFab.classList.remove('vtx-on');
      imgFab.textContent = '图';
      var p = document.getElementById('vtx-panel');
      if (p) p.classList.remove('vtx-show');
    }
  }

  /* ================== 模型切换 ================== */
  var modelFab = null;
  function cycleModel() {
    modelIdx = (modelIdx + 1) % MODELS.length;
    saveModel(modelIdx);
    modelFab.textContent = MODELS[modelIdx].short;
    toast('模型：' + MODELS[modelIdx].label, 2600);
  }

  /* ================== 渲染 ================== */
  function renderNode(node) {
    if (node.block) return;
    var text = node.chunks.map(function (c) { return c.out || ''; }).join('').trim();
    if (!text || text.length < 2) {
      S.unreadable++;
      node.el.classList.add('vtx-done');
      CREATED.modified.push(node.el);
      return;
    }
    try {
      var el = node.el;
      var box = document.createElement('div');
      box.className = 'vtx-block';
      box.setAttribute('data-vtx', '1');
      box.textContent = text;
      // 表格单元格内追加 div（单元格本身可以放 div）
      if (el.tagName === 'TD' || el.tagName === 'TH') {
        el.appendChild(box);
      } else if (el.tagName === 'TR') {
        // 整行：插到整个表格后面
        var tbl = el.closest('table');
        if (tbl && tbl.nextSibling) tbl.parentNode.insertBefore(box, tbl.nextSibling);
        else if (tbl) tbl.parentNode.appendChild(box);
        else if (el.nextSibling) el.parentNode.insertBefore(box, el.nextSibling);
        else el.parentNode.appendChild(box);
      } else if (el.nextSibling) {
        el.parentNode.insertBefore(box, el.nextSibling);
      } else {
        el.parentNode.appendChild(box);
      }
      el.classList.add('vtx-hide');
      el.classList.add('vtx-done');
      CREATED.blocks.push(box);
      CREATED.modified.push(el);
      node.block = box;
    } catch (e) { }
  }

  function restore() {
    for (var i = 0; i < CREATED.blocks.length; i++) {
      var b = CREATED.blocks[i];
      if (b.parentNode) b.parentNode.removeChild(b);
    }
    for (var h = 0; h < CREATED.modified.length; h++) {
      var el = CREATED.modified[h];
      el.classList.remove('vtx-hide');
      el.classList.remove('vtx-done');
    }
    CREATED.blocks = []; CREATED.modified = [];
    document.body.classList.remove('vtx-only');
    document.body.classList.remove('vtx-imgmode');
    IMG.mode = false;
    IMG.loading = false;
    if (imgFab) { imgFab.classList.remove('vtx-on'); imgFab.textContent = '图'; }
    var p = document.getElementById('vtx-panel');
    if (p) p.classList.remove('vtx-show');
    S.hasResult = false;
    S.onlyMode = false;
    refreshFab();
    toast('已还原原文');
  }

  /* ================== 主流程 ================== */
  function onFab() {
    if (S.running) { S.cancel = true; if (CTRL) { try { CTRL.abort(); } catch (e) {} } setFab('…', 'run'); return; }
    if (S.onlyMode) {                 // 仅译文模式下短点 = 切回双语
      S.onlyMode = false;
      document.body.classList.remove('vtx-only');
      refreshFab();
      return;
    }
    if (S.hasResult) { restore(); return; }
    start();
  }

  function start() {
    if (typeof fetch !== 'function') { toast('当前浏览器内核过旧'); return; }
    var found = collect();
    if (!found.length) { toast('没有需要翻译的外文内容'); return; }

    var nodes = [], queue = [], usedChars = 0;
    for (var i = 0; i < found.length && nodes.length < CFG.maxBlocks; i++) {
      var text = found[i].text;
      if (usedChars >= CFG.maxChars) break;
      var parts = splitSeg(text, CFG.segMax);
      var node = { el: found[i].el, chunks: [], block: null, pending: parts.length };
      for (var p = 0; p < parts.length; p++) {
        var chunk = { src: parts[p], out: '' };
        node.chunks.push(chunk);
        queue.push({ node: node, chunk: chunk });
        usedChars += parts[p].length;
      }
      nodes.push(node);
    }

    // 第一批故意很小（≤160 字符），让第一条译文尽快出现
    var batches = [], cur = [], curLen = 0;
    for (var q = 0; q < queue.length; q++) {
      var len = queue[q].chunk.src.length;
      var isFirst = (batches.length === 0);
      var limit = isFirst ? 160 : CFG.batchChars;
      if (cur.length && (curLen + len > limit || (isFirst && cur.length >= 2))) {
        batches.push(cur); cur = []; curLen = 0;
      }
      cur.push(queue[q]);
      curLen += len;
    }
    if (cur.length) batches.push(cur);

    S.running = true; S.cancel = false;
    S.total = queue.length; S.done = 0; S.unreadable = 0; S.failed = 0;
    NET.dead = false;
    CTRL = (typeof AbortController !== 'undefined') ? new AbortController() : null;
    setFab('…', 'run');
    toast('翻译 ' + nodes.length + ' 段，点按钮停止');

    var bi = 0;
    function stop(finished) {
      S.running = false;
      var any = false;
      for (var k = 0; k < nodes.length; k++) { if (nodes[k].block) { any = true; break; } }
      S.hasResult = any; S.onlyMode = false;
      refreshFab();
      CTRL = null;
      if (NET.dead && !any) {
        // 全失败时清掉残留的 vtx-done，否则下次翻译会跳过这些元素
        for (var m = 0; m < CREATED.modified.length; m++) {
          CREATED.modified[m].classList.remove('vtx-done');
          CREATED.modified[m].classList.remove('vtx-hide');
        }
        CREATED.modified = []; CREATED.blocks = [];
        toast('本页安全策略（CSP）或网络阻止了翻译请求', 5000);
      } else if (finished && any) {
        var okChunks = S.done - S.failed;
        var base = (NET.dead ? '网络受限，仅完成 ' : '完成 ') + okChunks + ' 段';
        var tail = S.failed > 0 ? '，失败 ' + S.failed + ' 段' : '｜长按切仅译文';
        toast(base + tail, 2800);
      } else if (any) {
        toast('已停止，点按钮还原');
      } else {
        for (var m2 = 0; m2 < CREATED.modified.length; m2++) {
          CREATED.modified[m2].classList.remove('vtx-done');
          CREATED.modified[m2].classList.remove('vtx-hide');
        }
        CREATED.modified = []; CREATED.blocks = [];
        toast('没有翻译出内容');
      }
    }

    function worker() {
      if (S.cancel || NET.dead || bi >= batches.length) return Promise.resolve();
      var batch = batches[bi++];
      return translateBatch(batch).then(function (res) {
        if (S.cancel) return;
        for (var k = 0; k < batch.length; k++) {
          var item = batch[k];
          item.chunk.out = (res && res[k]) ? String(res[k]).trim() : '';
          if (!item.chunk.out) S.failed++;
          item.node.pending--;
          if (item.node.pending <= 0) renderNode(item.node);
          S.done++;
        }
        setFab(Math.round(S.done / S.total * 100) + '%', 'run');
        return sleep(CFG.gap);
      }).catch(function () { return sleep(900); })
        .then(function () { return worker(); });
    }

    var workers = [];
    var nWorkers = Math.min(CFG.concurrency, batches.length);
    for (var w = 0; w < nWorkers; w++) workers.push(worker());
    Promise.all(workers).then(function () { stop(!S.cancel); });
  }

  /* ================== 启动 ================== */
  function init() {
    injectStyle();
    createDock();

    var drag = makeDraggable(dock);

    bindButton(fab, drag, onFab, toggleOnlyMode);

    imgFab = document.createElement('div');
    imgFab.id = 'vtx-imgfab';
    imgFab.setAttribute('role', 'button');
    imgFab.setAttribute('aria-label', '图片翻译');
    imgFab.textContent = '图';
    dock.appendChild(imgFab);

    modelFab = document.createElement('div');
    modelFab.id = 'vtx-modelfab';
    modelFab.setAttribute('role', 'button');
    modelFab.title = '点击切换翻译模型';
    modelFab.textContent = MODELS[modelIdx].short;
    dock.appendChild(modelFab);

    bindButton(imgFab, drag, toggleImgMode, null);
    bindButton(modelFab, drag, cycleModel, null);

    // 图片模式下拦截图片点击（捕获阶段，且阻止页面自身的点击处理）
    document.addEventListener('click', function (e) {
      if (!IMG.mode) return;
      var t = e.target;
      while (t && t !== document.body) {
        if (t.tagName === 'IMG') {
          e.preventDefault(); e.stopPropagation(); e.stopImmediatePropagation();
          ocrAndTranslate(t);
          return;
        }
        if (t.id && t.id.indexOf('vtx-') === 0) return;
        t = t.parentNode;
      }
    }, true);
  }

  if (document.body) init();
  else document.addEventListener('DOMContentLoaded', init, false);
})();