// ==UserScript==
// @name         中国矿业大学-实验慕课小助手 (labsafe专版 v4.0)
// @namespace    http://labsafe.cumt.edu.cn/
// @version      4.0
// @description  默认2倍速、自动答题提交、修复目录假跳转(行级坐标去重+精确节数递进+可视化高亮框验证)
// @match        *://labsafe.cumt.edu.cn/*
// @match        *://dygx.cumt.edu.cn/*
// @match        *://*.cumt.edu.cn/*
// @run-at       document-end
// @grant        none
// @license MIT
// ==/UserScript==

(function () {
    'use strict';

    if (window.__CUMT_LABSAFE_V4__) return;
    window.__CUMT_LABSAFE_V4__ = true;

    const CONFIG = {
        running: true,
        targetRate: parseFloat(localStorage.getItem('cumt_v4_rate')) || 2.0,
        lockRate: true,
        quizMode: 'rotate',
        customSubmitSelector: localStorage.getItem('cumt_v4_submit_sel') || '',
        // 存储绑定目录的几何与选择器特征
        bindMeta: JSON.parse(localStorage.getItem('cumt_v4_bind_meta') || 'null'),
        currentIndex: parseInt(localStorage.getItem('cumt_v4_cur_idx') || '0', 10),
        totalCount: 0,
        lastJumpTime: 0,
        lastQuizHash: '',
        tryOptionIndex: 0,
        internalRateChanging: false
    };

    function getAllDocuments() {
        const docs = [document];
        document.querySelectorAll('iframe').forEach(ifr => {
            try {
                if (ifr.contentDocument) docs.push(ifr.contentDocument);
            } catch (e) {}
        });
        return docs;
    }

    function isVisible(el) {
        if (!el || !el.getBoundingClientRect) return false;
        if (el.closest && el.closest('#cumt-helper-panel')) return false;
        const style = window.getComputedStyle(el);
        if (style.display === 'none' || style.visibility === 'hidden' || parseFloat(style.opacity) === 0) {
            return false;
        }
        const rect = el.getBoundingClientRect();
        return rect.width > 4 && rect.height > 4;
    }

    // 强力真实点击：同时派发鼠标事件序列 + 原生 el.click()（原生 click 会自动向父级冒泡触发 Vue @click）
    function fireNativeClick(el) {
        if (!el) return false;
        try {
            const win = el.ownerDocument.defaultView || window;
            const rect = el.getBoundingClientRect();
            const clientX = rect.left + rect.width / 2;
            const clientY = rect.top + rect.height / 2;
            ['pointerdown', 'mousedown', 'pointerup', 'mouseup'].forEach(type => {
                el.dispatchEvent(new win.MouseEvent(type, {
                    bubbles: true,
                    cancelable: true,
                    view: win,
                    clientX,
                    clientY
                }));
            });
            // 关键：调用原生 click() 方法，确保 Vue / React / 原生 a 标签 100% 触发
            if (typeof el.click === 'function') {
                el.click();
            } else {
                el.dispatchEvent(new win.MouseEvent('click', { bubbles: true, cancelable: true, view: win }));
            }
            if (el.tagName === 'INPUT') {
                el.checked = true;
                el.dispatchEvent(new win.Event('change', { bubbles: true }));
                el.dispatchEvent(new win.Event('input', { bubbles: true }));
            }
            return true;
        } catch (e) {
            try { el.click(); } catch (err) {}
            return true;
        }
    }

    // 获取当前播放视频的特征签名（用于校验点击后视频是否真正发生了切换）
    function getVideoSignature() {
        const docs = getAllDocuments();
        for (const doc of docs) {
            const v = doc.querySelector('video');
            if (v) {
                return `${location.href}|${v.currentSrc || v.src || ''}|${v.duration || 0}`;
            }
        }
        return location.href;
    }

    // 提取元素的静态类名（剔除动态高亮类名）
    function getStaticClasses(el) {
        if (!el || !el.className || typeof el.className !== 'string') return [];
        return el.className.trim().split(/\s+/).filter(c =>
            c && !/(^|[-_])(active|current|playing|selected|on|hover|focus|open|expand|checked|this)($|[-_])/i.test(c)
        );
    }

    function buildSimpleSelector(el) {
        if (!el || el.nodeType !== 1) return '';
        let sel = el.tagName.toLowerCase();
        const cls = getStaticClasses(el);
        if (cls.length > 0) {
            sel += '.' + cls.slice(0, 2).map(c => CSS.escape(c)).join('.');
        }
        return sel;
    }

    // ==================== 核心：智能提取目录列表（纵向坐标行级去重） ====================
    // 给定用户点击的目录元素 clickedEl，构建可匹配整列目录每一节对应位置的元数据
    function createBindMeta(clickedEl) {
        const rect = clickedEl.getBoundingClientRect();
        const leafSel = buildSimpleSelector(clickedEl);
        const parentEl = clickedEl.parentElement;
        const parentSel = parentEl && parentEl.tagName !== 'BODY' ? buildSimpleSelector(parentEl) : '';
        const grandEl = parentEl ? parentEl.parentElement : null;
        const grandSel = grandEl && grandEl.tagName !== 'BODY' ? buildSimpleSelector(grandEl) : '';

        let fullSel = leafSel;
        if (parentSel) fullSel = `${parentSel} > ${fullSel}`;
        if (grandSel) fullSel = `${grandSel} > ${fullSel}`;

        return {
            selector: fullSel,
            fallbackSelector: parentSel ? `${parentSel} > ${clickedEl.tagName.toLowerCase()}` : leafSel,
            left: Math.round(rect.left),
            width: Math.round(rect.width),
            height: Math.round(rect.height),
            tagName: clickedEl.tagName
        };
    }

    // 根据绑定元数据，获取页面上所有课程小节（按纵向行坐标严格去重，每行只保留 1 个节点）
    function getBoundLessonItems() {
        if (!CONFIG.bindMeta) return [];
        const meta = CONFIG.bindMeta;
        const docs = getAllDocuments();

        for (const doc of docs) {
            let rawNodes = Array.from(doc.querySelectorAll(meta.selector)).filter(isVisible);
            if (rawNodes.length < 2 && meta.fallbackSelector) {
                rawNodes = Array.from(doc.querySelectorAll(meta.fallbackSelector)).filter(isVisible);
            }

            // 过滤条件：必须与绑定元素处于同一侧边栏列（水平 X 坐标相近），排除顶栏或其它区域无关元素
            const colFiltered = rawNodes.filter(el => {
                const r = el.getBoundingClientRect();
                const sameColumn = Math.abs(r.left - meta.left) < 120;
                const reasonableHeight = r.height >= 12 && r.height <= 120;
                const hasText = (el.innerText || el.textContent || '').trim().length > 0;
                return sameColumn && reasonableHeight && hasText;
            });

            // 关键：按垂直高度（top）排序，并将同一水平行（top 相差小于 12px）的多个元素合并去重！
            colFiltered.sort((a, b) => a.getBoundingClientRect().top - b.getBoundingClientRect().top);

            const deduped = [];
            for (const el of colFiltered) {
                const r = el.getBoundingClientRect();
                if (deduped.length === 0) {
                    deduped.push(el);
                } else {
                    const prev = deduped[deduped.length - 1];
                    const prevRect = prev.getBoundingClientRect();
                    // 如果两个元素在同一行（垂直高度差 < 12px）或存在包含关系，只保留宽度更接近点击目标的那一个
                    if (Math.abs(r.top - prevRect.top) < 12 || prev.contains(el) || el.contains(prev)) {
                        if (Math.abs(r.width - meta.width) < Math.abs(prevRect.width - meta.width)) {
                            deduped[deduped.length - 1] = el;
                        }
                    } else {
                        deduped.push(el);
                    }
                }
            }

            if (deduped.length > 0) {
                CONFIG.totalCount = deduped.length;
                updateIndexDisplay();
                return deduped;
            }
        }
        return [];
    }

    // 对目标目录项执行穿透式点击（先点目标本身，若 350ms 后视频未切换，再点同行内的标题/链接/按钮）
    function clickLessonTarget(targetEl, indexLabel) {
        if (!targetEl) return;

        // 闪烁橙色边框提示正在点击哪一节
        const oldOutline = targetEl.style.outline;
        targetEl.style.outline = '3px solid #f97316';
        setTimeout(() => { targetEl.style.outline = oldOutline || ''; }, 2500);

        targetEl.scrollIntoView({ behavior: 'smooth', block: 'center' });
        const beforeSig = getVideoSignature();

        // 第一阶段：直接点击绑定的精确元素（事件会自动向上冒泡到行容器）
        fireNativeClick(targetEl);
        setStatus(`⏭️ 正在切换至第 ${indexLabel} 节: ${(targetEl.innerText || '').trim().slice(0, 14)}...`);

        // 第二阶段：350ms 后检查视频是否已切换；若未切换，穿透点击该行容器内的所有可交互子节点
        setTimeout(() => {
            const afterSig = getVideoSignature();
            if (afterSig === beforeSig) {
                const rowContainer = targetEl.closest('li, dd, .el-tree-node__content, .el-menu-item, [class*="item"], [class*="lesson"], [class*="video"], [class*="catalog"]') || targetEl.parentElement || targetEl;
                const clickables = rowContainer.querySelectorAll('a, button, [class*="title"], [class*="name"], [class*="play"], span');
                clickables.forEach(sub => {
                    if (sub !== targetEl && isVisible(sub)) {
                        fireNativeClick(sub);
                    }
                });
                // 补充触发双击（部分树形组件需要 dblclick 或对行容器直接 click）
                if (rowContainer !== targetEl) fireNativeClick(rowContainer);
            }
        }, 350);
    }

    // ==================== 1. 自动跳转下一节 ====================
    function goToNextVideo(isManual = false) {
        const now = Date.now();
        if (!isManual && now - CONFIG.lastJumpTime < 5000) return false;
        CONFIG.lastJumpTime = now;

        const docs = getAllDocuments();

        // 先关闭可能阻挡切集的确认弹窗
        for (const doc of docs) {
            const modalBtn = doc.querySelector('.el-message-box__btns .el-button--primary, .el-dialog__footer .el-button--primary, .layui-layer-btn0, .ant-modal-footer .ant-btn-primary');
            if (modalBtn && isVisible(modalBtn)) {
                fireNativeClick(modalBtn);
            }
        }

        // 优先使用绑定的目录列表，严格按 CONFIG.currentIndex + 1 顺序推进
        const items = getBoundLessonItems();
        if (items.length > 0) {
            const nextIdx = CONFIG.currentIndex + 1;
            if (nextIdx < items.length) {
                CONFIG.currentIndex = nextIdx;
                localStorage.setItem('cumt_v4_cur_idx', String(nextIdx));
                updateIndexDisplay();
                clickLessonTarget(items[nextIdx], `${nextIdx + 1}/${items.length}`);
                return true;
            } else {
                setStatus(`🎉 当前目录全部 ${items.length} 节已播完！`);
                return false;
            }
        }

        // 若尚未绑定目录，尝试寻找页面上显式的“下一节/下一集”按钮
        for (const doc of docs) {
            const allBtns = doc.querySelectorAll('button, a, span, div, li');
            const nextRegex = /^(下一节|下一集|下一课|下一个|下一视频|继续下一节)$/;
            for (const btn of allBtns) {
                if (!isVisible(btn)) continue;
                const txt = (btn.innerText || btn.textContent || '').replace(/\s+/g, '');
                if (nextRegex.test(txt)) {
                    fireNativeClick(btn);
                    setStatus(`⏭️ 已点击「${txt}」`);
                    return true;
                }
            }
        }

        setStatus('⚠️ 请先点下方紫色【🎯绑定当前节】再点右侧正在播的这节标题');
        return false;
    }

    // ==================== 2. 自动答题与点击提交 ====================
    function findSubmitButton(doc) {
        if (CONFIG.customSubmitSelector) {
            const btns = Array.from(doc.querySelectorAll(CONFIG.customSubmitSelector)).filter(isVisible);
            if (btns.length > 0) return btns[btns.length - 1];
        }

        const knownSelectors = [
            '.el-dialog__footer .el-button--primary',
            '.el-message-box__btns .el-button--primary',
            '.ant-modal-footer .ant-btn-primary',
            '.layui-layer-btn0',
            'button[type="submit"]'
        ];
        for (const sel of knownSelectors) {
            const btns = Array.from(doc.querySelectorAll(sel)).filter(isVisible);
            if (btns.length > 0) return btns[btns.length - 1];
        }

        const candidates = doc.querySelectorAll('button, a, input[type="button"], div[class*="btn"], span[class*="btn"], .el-button, .ant-btn, .btn');
        const targetRegex = /^(提交|提交答案|确认提交|确定|确认|继续|继续学习|完成|下一题|回答|我知道了)$/;

        for (const el of candidates) {
            if (!isVisible(el)) continue;
            const txt = (el.innerText || el.value || el.textContent || '').replace(/\s+/g, '');
            if (targetRegex.test(txt)) return el;
        }
        return null;
    }

    function checkAndSolveQuiz() {
        const docs = getAllDocuments();
        for (const doc of docs) {
            const options = Array.from(doc.querySelectorAll(
                'input[type="radio"], input[type="checkbox"], .el-radio, .el-checkbox, .ant-radio-wrapper, .ant-checkbox-wrapper, .layui-form-radio, .layui-form-checkbox, [class*="option-item"], [class*="question-option"]'
            )).filter(el => isVisible(el) || (el.parentElement && isVisible(el.parentElement)));

            if (options.length > 0) {
                setStatus('📝 检测到弹题，正在作答...');
                const quizBox = options[0].closest('.el-dialog, .ant-modal, .layui-layer, .modal, form, [class*="quiz"], [class*="question"], body');
                const currentHash = (quizBox ? quizBox.innerText.slice(0, 60) : '') + options.length;

                if (currentHash !== CONFIG.lastQuizHash) {
                    CONFIG.lastQuizHash = currentHash;
                    CONFIG.tryOptionIndex = 0;
                }

                const idx = CONFIG.quizMode === 'first' ? 0 : (CONFIG.tryOptionIndex % options.length);
                const targetOption = options[idx];
                const clickTarget = isVisible(targetOption) ? targetOption : targetOption.parentElement;

                fireNativeClick(clickTarget);
                if (targetOption.tagName === 'INPUT' && targetOption !== clickTarget) {
                    fireNativeClick(targetOption);
                }

                const isCheckbox = targetOption.type === 'checkbox' || /checkbox/i.test(targetOption.className);
                if (isCheckbox && options.length > 1 && idx === 0) {
                    const secondTarget = isVisible(options[1]) ? options[1] : options[1].parentElement;
                    setTimeout(() => fireNativeClick(secondTarget), 150);
                }

                setTimeout(() => {
                    const submitBtn = findSubmitButton(doc);
                    if (submitBtn) {
                        fireNativeClick(submitBtn);
                        setStatus(`✅ 已选第 ${idx + 1} 项并点击提交`);
                        setTimeout(() => {
                            const confirmBtn = findSubmitButton(doc);
                            if (confirmBtn) fireNativeClick(confirmBtn);
                        }, 1000);
                    } else {
                        setStatus('⚠️ 已选答案，请点下方【🎯绑定提交】');
                    }
                    CONFIG.tryOptionIndex++;
                }, 550);

                return true;
            }
        }
        return false;
    }

    // ==================== 3. 视频倍速与自动连播监控 ====================
    function applyPlaybackRate(video, rate) {
        if (!video) return;
        CONFIG.internalRateChanging = true;
        video.playbackRate = rate;
        setTimeout(() => { CONFIG.internalRateChanging = false; }, 200);
    }

    function monitorVideo() {
        const docs = getAllDocuments();
        let foundVideo = false;

        // 同步刷新目录总节数显示
        if (CONFIG.bindMeta && CONFIG.totalCount === 0) {
            getBoundLessonItems();
        }

        for (const doc of docs) {
            const videos = doc.querySelectorAll('video');
            for (const video of videos) {
                foundVideo = true;
                video.muted = true;

                if (!video.__cumt_v4_bound__) {
                    video.__cumt_v4_bound__ = true;

                    video.addEventListener('ratechange', () => {
                        if (!CONFIG.internalRateChanging && video.playbackRate > 0) {
                            if (video.playbackRate === 1.0 && CONFIG.targetRate !== 1.0 && video.currentTime < 3) {
                                applyPlaybackRate(video, CONFIG.targetRate);
                            } else {
                                CONFIG.targetRate = video.playbackRate;
                                localStorage.setItem('cumt_v4_rate', CONFIG.targetRate);
                                const rateSelect = document.getElementById('cumt-rate-select');
                                if (rateSelect) rateSelect.value = String(CONFIG.targetRate);
                            }
                        }
                    });

                    video.addEventListener('ended', () => {
                        if (CONFIG.running) {
                            setStatus('🎉 本节播放完毕，正在切换下一节...');
                            setTimeout(() => goToNextVideo(false), 1000);
                        }
                    });
                }

                if (CONFIG.lockRate && Math.abs(video.playbackRate - CONFIG.targetRate) > 0.05) {
                    applyPlaybackRate(video, CONFIG.targetRate);
                }

                if (video.ended || (video.duration > 10 && video.currentTime >= video.duration - 0.6)) {
                    setStatus('🎉 本节已完成，准备切换下一节...');
                    goToNextVideo(false);
                    return;
                }

                if (video.paused) {
                    video.play().catch(() => {
                        const playBtn = doc.querySelector('.vjs-big-play-button, .prism-big-play-btn, .dplayer-play-icon, .el-icon-video-play, [class*="play-btn"]');
                        if (playBtn && isVisible(playBtn)) fireNativeClick(playBtn);
                    });
                }

                const pct = video.duration ? Math.round((video.currentTime / video.duration) * 100) : 0;
                setStatus(`▶️ 播放中 (${pct}%) | 倍速: ${video.playbackRate}x`);
            }
        }

        if (!foundVideo) {
            setStatus('🔍 等待进入视频播放页...');
        }
    }

    // ==================== 4. 悬浮控制面板与目录拾取器 ====================
    function updateIndexDisplay() {
        const el = document.getElementById('cumt-idx-display');
        if (!el) return;
        if (CONFIG.bindMeta && CONFIG.totalCount > 0) {
            el.textContent = `第 ${CONFIG.currentIndex + 1} / ${CONFIG.totalCount} 节`;
            el.style.color = '#4ade80';
        } else {
            el.textContent = '未绑定目录';
            el.style.color = '#fbbf24';
        }
    }

    function createPanel() {
        const panel = document.createElement('div');
        panel.id = 'cumt-helper-panel';
        panel.style.cssText = `
            position: fixed; right: 18px; bottom: 18px; z-index: 2147483647;
            width: 280px; background: #1e293b; color: #f8fafc;
            border-radius: 10px; padding: 12px; font-size: 13px;
            font-family: system-ui, -apple-system, sans-serif;
            box-shadow: 0 8px 24px rgba(0,0,0,0.4); border: 1px solid #334155;
            line-height: 1.5; user-select: none;
        `;

        panel.innerHTML = `
            <div style="display:flex;justify-content:space-between;align-items:center;margin-bottom:8px;padding-bottom:6px;border-bottom:1px solid #334155;">
                <strong style="font-size:14px;color:#38bdf8;">⚡ 矿大安全课助手 v4.0</strong>
                <button id="cumt-toggle-btn" style="background:#22c55e;color:#fff;border:none;border-radius:4px;padding:2px 8px;cursor:pointer;font-size:12px;">运行中</button>
            </div>
            <div id="cumt-status" style="background:#0f172a;padding:6px 8px;border-radius:6px;margin-bottom:8px;font-size:12px;color:#cbd5e1;word-break:break-all;">
                正在初始化...
            </div>
            <div style="display:flex;justify-content:space-between;align-items:center;margin-bottom:6px;background:#0f172a;padding:4px 8px;border-radius:6px;">
                <span>当前定位：</span>
                <div style="display:flex;align-items:center;gap:6px;">
                    <button id="cumt-idx-prev" style="background:#334155;color:#fff;border:none;border-radius:3px;padding:0 6px;cursor:pointer;" title="定位减1">-</button>
                    <strong id="cumt-idx-display" style="font-size:12px;color:#fbbf24;">未绑定目录</strong>
                    <button id="cumt-idx-next" style="background:#334155;color:#fff;border:none;border-radius:3px;padding:0 6px;cursor:pointer;" title="定位加1">+</button>
                </div>
            </div>
            <div style="display:flex;justify-content:space-between;align-items:center;margin-bottom:6px;">
                <span>播放倍速：</span>
                <select id="cumt-rate-select" style="background:#0f172a;color:#38bdf8;border:1px solid #475569;border-radius:4px;padding:2px 6px;font-size:12px;font-weight:bold;">
                    <option value="2">2.0x (默认高速)</option>
                    <option value="1.5">1.5x</option>
                    <option value="1.25">1.25x</option>
                    <option value="1">1.0x</option>
                    <option value="0">跟随网页原生设置</option>
                </select>
            </div>
            <div style="display:grid;grid-template-columns:1fr 1fr;gap:6px;margin-bottom:6px;">
                <button id="cumt-pick-list" style="background:#8b5cf6;color:#fff;border:none;border-radius:5px;padding:6px;cursor:pointer;font-size:12px;font-weight:bold;">🎯 绑定当前节</button>
                <button id="cumt-test-next" style="background:#0ea5e9;color:#fff;border:none;border-radius:5px;padding:6px;cursor:pointer;font-size:12px;font-weight:bold;">⏭️ 立即跳下一节</button>
            </div>
            <div style="display:grid;grid-template-columns:1fr 1fr;gap:6px;">
                <button id="cumt-pick-submit" style="background:#3b82f6;color:#fff;border:none;border-radius:5px;padding:5px;cursor:pointer;font-size:12px;">🎯 绑定提交键</button>
                <button id="cumt-clear-bind" style="background:#475569;color:#cbd5e1;border:none;border-radius:5px;padding:5px;cursor:pointer;font-size:12px;">🔄 重置绑定</button>
            </div>
        `;
        document.body.appendChild(panel);
        updateIndexDisplay();

        // 节数微调按钮
        document.getElementById('cumt-idx-prev').onclick = () => {
            if (CONFIG.currentIndex > 0) {
                CONFIG.currentIndex--;
                localStorage.setItem('cumt_v4_cur_idx', String(CONFIG.currentIndex));
                updateIndexDisplay();
            }
        };
        document.getElementById('cumt-idx-next').onclick = () => {
            if (CONFIG.currentIndex + 1 < CONFIG.totalCount) {
                CONFIG.currentIndex++;
                localStorage.setItem('cumt_v4_cur_idx', String(CONFIG.currentIndex));
                updateIndexDisplay();
            }
        };

        const rateSelect = document.getElementById('cumt-rate-select');
        rateSelect.value = CONFIG.lockRate ? String(CONFIG.targetRate) : '0';
        rateSelect.onchange = function () {
            const val = parseFloat(this.value);
            if (val === 0) {
                CONFIG.lockRate = false;
                setStatus('👌 已交由网页原生播放器控制倍速');
            } else {
                CONFIG.lockRate = true;
                CONFIG.targetRate = val;
                localStorage.setItem('cumt_v4_rate', val);
                getAllDocuments().forEach(doc => {
                    doc.querySelectorAll('video').forEach(v => applyPlaybackRate(v, val));
                });
                setStatus(`⚡ 倍速已设为 ${val}x`);
            }
        };

        document.getElementById('cumt-toggle-btn').onclick = function () {
            CONFIG.running = !CONFIG.running;
            this.textContent = CONFIG.running ? '运行中' : '已暂停';
            this.style.background = CONFIG.running ? '#22c55e' : '#ef4444';
            setStatus(CONFIG.running ? '▶️ 已恢复自动运行' : '⏸️ 脚本已暂停');
        };

        document.getElementById('cumt-test-next').onclick = () => {
            goToNextVideo(true);
        };

        document.getElementById('cumt-clear-bind').onclick = () => {
            CONFIG.customSubmitSelector = '';
            CONFIG.bindMeta = null;
            CONFIG.currentIndex = 0;
            CONFIG.totalCount = 0;
            localStorage.removeItem('cumt_v4_submit_sel');
            localStorage.removeItem('cumt_v4_bind_meta');
            localStorage.removeItem('cumt_v4_cur_idx');
            updateIndexDisplay();
            setStatus('🗑️ 已清除绑定，请重新点【🎯绑定当前节】');
        };

        document.getElementById('cumt-pick-submit').onclick = () => startPicker('submit');
        document.getElementById('cumt-pick-list').onclick = () => startPicker('list');
    }

    function setStatus(msg) {
        const el = document.getElementById('cumt-status');
        if (el) el.textContent = msg;
    }

    // 监听用户在网页目录上的手动点击，自动同步更新“当前第几节”
    document.addEventListener('click', (e) => {
        if (!CONFIG.bindMeta || (e.target.closest && e.target.closest('#cumt-helper-panel'))) return;
        const items = getBoundLessonItems();
        if (items.length > 0) {
            const clickedRect = e.target.getBoundingClientRect();
            const matchIdx = items.findIndex(item => {
                if (item === e.target || item.contains(e.target) || e.target.contains(item)) return true;
                const r = item.getBoundingClientRect();
                return Math.abs(r.top - clickedRect.top) < 12 && Math.abs(r.left - clickedRect.left) < 120;
            });
            if (matchIdx !== -1 && matchIdx !== CONFIG.currentIndex) {
                CONFIG.currentIndex = matchIdx;
                localStorage.setItem('cumt_v4_cur_idx', String(matchIdx));
                updateIndexDisplay();
            }
        }
    }, true);

    // 可视化拾取器
    function startPicker(type) {
        setStatus(
            type === 'submit'
                ? '👆 请点击弹窗上的【提交/确定】按钮...'
                : '👆 请点击课程目录中【正在播放的这一节标题文字】...'
        );
        const docs = getAllDocuments();
        let lastHover = null;

        function onMove(e) {
            if (e.target.closest && e.target.closest('#cumt-helper-panel')) return;
            if (lastHover && lastHover !== e.target) {
                lastHover.style.outline = lastHover.__old_outline__ || '';
            }
            lastHover = e.target;
            lastHover.__old_outline__ = lastHover.style.outline;
            lastHover.style.outline = '3px solid #ef4444';
        }

        function onClick(e) {
            if (e.target.closest && e.target.closest('#cumt-helper-panel')) return;
            e.preventDefault();
            e.stopPropagation();

            if (lastHover) lastHover.style.outline = lastHover.__old_outline__ || '';
            cleanup();

            if (type === 'submit') {
                const sel = buildSimpleSelector(e.target);
                CONFIG.customSubmitSelector = sel;
                localStorage.setItem('cumt_v4_submit_sel', sel);
                setStatus(`✅ 已绑定提交按钮: ${sel}`);
                fireNativeClick(e.target);
            } else {
                const meta = createBindMeta(e.target);
                CONFIG.bindMeta = meta;
                localStorage.setItem('cumt_v4_bind_meta', JSON.stringify(meta));

                const items = getBoundLessonItems();
                const targetTop = e.target.getBoundingClientRect().top;
                let idx = items.findIndex(item => Math.abs(item.getBoundingClientRect().top - targetTop) < 12);
                if (idx === -1) idx = 0;

                CONFIG.currentIndex = idx;
                CONFIG.totalCount = items.length;
                localStorage.setItem('cumt_v4_cur_idx', String(idx));
                updateIndexDisplay();

                // 用绿色虚线框短暂高亮所有识别出的课程小节，方便肉眼确认
                items.forEach((item, i) => {
                    const old = item.style.outline;
                    item.style.outline = i === idx ? '3px solid #38bdf8' : '2px dashed #22c55e';
                    setTimeout(() => { item.style.outline = old || ''; }, 3000);
                });

                setStatus(`✅ 识别到 ${items.length} 节课程(已绿框高亮)，当前第 ${idx + 1} 节`);
            }
        }

        function cleanup() {
            docs.forEach(d => {
                d.removeEventListener('mousemove', onMove, true);
                d.removeEventListener('click', onClick, true);
            });
        }

        docs.forEach(d => {
            d.addEventListener('mousemove', onMove, true);
            d.addEventListener('click', onClick, true);
        });
    }

    // ==================== 启动主循环 ====================
    createPanel();
    setInterval(() => {
        if (!CONFIG.running) return;
        const hasQuiz = checkAndSolveQuiz();
        if (!hasQuiz) {
            monitorVideo();
        }
    }, 1800);
})();