// ==UserScript==
// @name         实验室安全习题集（自建题库 · 独立版）
// @namespace    https://labsafety.local/sqb
// @version      1.1.7
// @description  把课程树里所有视频题目按章节重绘成习题集（一章一张小卷），人工作答后由脚本代填/代交；考试场景整卷重绘并能代为交卷
// @author       智能学习助手
// @license      MIT
// @match        https://sa.ycit.edu.cn/*
// @tag          学习辅助
// @tag          题库
// @tag          效率工具
// @run-at       document-start
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_addStyle
// @noframes
// ==/UserScript==

/*
 * 实验室安全习题集 —— 把课程树里的视频题目重绘成按章节分类的习题集。
 *
 * 能做什么：
 *   1. 一键采集整棵课程树（会自动展开章节、自动切下一节）的全部题目，按章节分桶存成本地题库；
 *   2. 主面板按章节生成数字按钮，点开就是这一章的小卷（卡片全展开），直接作答；
 *   3. 每章可单独「提交本章」，也可在面板上「全部提交」；提交前的作答会写回平台；
 *   4. 考试场景：开考后自动识别整张试卷并重绘，作答后由脚本代填并代为交卷，交卷得分会回读到面板日志；
 *   5. 视频控制（倍速 / 自动续播 / 不许暂停 / 播完切下一节）默认全关，需要时在「设置」里开。
 *
 * 数据：题库与作答存在本地（GM 存储），刷新不丢；「全部清空」会把题库一起清掉。
 * 定位：辅助学习工具，人工作答，脚本只负责采集、代填和代提交，不推断答案。
 * 已知限制：平台命中前端缓存时不发请求，该节可能取不到 courseId 而被跳过；接口不下发正确答案，因此只区分已答/未答，不判对错。
 */

(function () {
    'use strict';

    // ============================ 0. 常量 ============================
    const SCRIPT_INFO = { name: '实验室安全习题集', version: '1.1.7' };
    const NS = 'sqb_';                       // GM 键前缀（与旧脚本隔离）
    const Z = 2147483000;                    // 浮层 z-index（压过平台弹窗）
    const API_QUESTION = '/api/jeecg-boot/jcedutec/courseSource/queryCourseQuestionRelaByMainId';
    const API_SUBMIT = '/api/jeecg-boot/jcedutec/courseSource/submitAnswer';
    const KIND_TEXT = { '1': '判断题', '2': '单选题', '3': '多选题' };
    const LETTERS = ['A', 'B', 'C', 'D', 'E', 'F'];

    // ============================ 1. 存储层 ============================
    function gmGet(key, def) {
        try {
            if (typeof GM_getValue === 'function') {
                const v = GM_getValue(key, undefined);
                if (v !== undefined && v !== null) return v;
            }
        } catch (e) { /* 回落 localStorage */ }
        try {
            const raw = localStorage.getItem(NS + key);
            return raw === null ? def : JSON.parse(raw);
        } catch (e) { return def; }
    }
    function gmSet(key, val) {
        try {
            if (typeof GM_setValue === 'function') { GM_setValue(key, val); return; }
        } catch (e) { /* 回落 localStorage */ }
        try { localStorage.setItem(NS + key, JSON.stringify(val)); } catch (e) { /* 配额满时静默 */ }
    }

    // ============================ 2. 配置 ============================
    // 采集默认参数，均可在「设置」里调
    const DEFAULTS = {
        expandChapters: true,   // 采集前自动展开所有章节
        autoNext: true,         // 采完一课自动切下一课
        stepDelay: 600,         // 切课后的等待（毫秒）
        idWait: 9000,           // 等待课程 id 变化的上限（毫秒）
        // 视频控制：全部默认关闭，避免与其它脚本抢 video
        videoSpeed: 1,
        autoPlayVideo: false,
        autoSwitchVideo: false,
        noPause: false,
        // 提交
        submitDelay: 180
    };
    let cfg = Object.assign({}, DEFAULTS, gmGet('cfg', {}));
    function saveCfg() { gmSet('cfg', cfg); }

    // ============================ 3. 运行时状态 ============================
    const S = {
        token: null,          // x-access-token
        courseId: null,       // 当前视频对应的课程 id
        courseIdAt: 0,        // 最近一次写入 courseId 的时间戳（兜底判据用）
        graphId: null,        // 章节树根 id
        running: false,
        stopFlag: false,
        courseIndex: -1,
        totalCourses: 0,
        examSink: null,       // startExam 响应回调
        examSubmitSink: null, // submitExam 判分响应回调
        _lines: []
    };

    const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

    function log(msg) {
        try { console.log('[SQB] ' + msg); } catch (e) { /* 控制台不可用时忽略 */ }
        const line = '[' + new Date().toTimeString().slice(0, 8) + '] ' + msg;
        S._lines.push(line);
        if (S._lines.length > 300) S._lines.shift();
        const el = document.getElementById('sqb-log');
        if (el) {
            el.textContent = S._lines.slice(-8).join('\n');
            el.scrollTop = el.scrollHeight;
        }
    }

    function toast(msg, ms) {
        let box = document.getElementById('sqb-toast');
        if (!box) {
            box = document.createElement('div');
            box.id = 'sqb-toast';
            document.body.appendChild(box);
        }
        box.textContent = msg;
        box.classList.add('on');
        clearTimeout(box._timer);
        box._timer = setTimeout(() => box.classList.remove('on'), ms || 2600);
    }

    // ============================ 4. 网络钩子 ============================
    // 平台切课是 SPA，URL 不变；只能从 courseSource 请求里认出当前课程 id。
    function installHook() {
        const pickId = (url) => {
            if (!url || url.indexOf('courseSource') < 0) return;
            const m = String(url).match(/[?&]id=(\d{6,})/);
            if (m) {
                if (m[1] !== S.courseId) S.courseId = m[1];
                S.courseIdAt = Date.now();
            }
            const g = String(url).match(/[?&]graphId=(\d+)/);
            if (g && g[1]) S.graphId = g[1];
        };

        try {
            const origFetch = window.fetch;
            if (typeof origFetch === 'function') {
                window.fetch = function (input, init) {
                    let url = '';
                    try {
                        url = typeof input === 'string' ? input : (input && input.url) || '';
                        if (init && init.headers) {
                            const h = init.headers;
                            const v = typeof h.get === 'function' ? h.get('x-access-token') : h['x-access-token'];
                            if (v) S.token = v;
                        }
                        pickId(url);
                    } catch (e) { /* 忽略 */ }
                    const p = origFetch.apply(this, arguments);
                    // 考试整卷 / 交卷判分：旁挂一份响应副本，不改动原响应
                    if (p && typeof p.then === 'function') {
                        const kind = url.indexOf('/jcedutec/exam/startExam') >= 0 ? 'start'
                            : url.indexOf('/jcedutec/exam/submitExam') >= 0 ? 'submit' : '';
                        if (kind) {
                            p.then((res) => {
                                try {
                                    res.clone().json().then((data) => {
                                        if (kind === 'start' && typeof S.examSink === 'function') S.examSink(data);
                                        if (kind === 'submit' && typeof S.examSubmitSink === 'function') S.examSubmitSink(data);
                                    }).catch(() => {});
                                } catch (e) { /* 忽略 */ }
                            }).catch(() => {});
                        }
                    }
                    return p;
                };
            }
        } catch (e) { /* 忽略 */ }

        try {
            const origOpen = XMLHttpRequest.prototype.open;
            const origSend = XMLHttpRequest.prototype.send;
            const origSet = XMLHttpRequest.prototype.setRequestHeader;
            XMLHttpRequest.prototype.open = function (m, u) {
                try { this.__sqbUrl = u; pickId(u); } catch (e) { /* 忽略 */ }
                return origOpen.apply(this, arguments);
            };
            XMLHttpRequest.prototype.setRequestHeader = function (k, v) {
                try {
                    if (String(k).toLowerCase() === 'x-access-token' && v) S.token = v;
                    pickId(this.__sqbUrl);
                } catch (e) { /* 忽略 */ }
                return origSet.apply(this, arguments);
            };
            XMLHttpRequest.prototype.send = function () {
                try {
                    const u = String(this.__sqbUrl || '');
                    const kind = u.indexOf('/jcedutec/exam/startExam') >= 0 ? 'start'
                        : u.indexOf('/jcedutec/exam/submitExam') >= 0 ? 'submit' : '';
                    if (kind) {
                        this.addEventListener('load', () => {
                            let data = this.response;
                            if (typeof data === 'string') { try { data = JSON.parse(data); } catch (e) { data = null; } }
                            if (kind === 'start' && data && typeof S.examSink === 'function') S.examSink(data);
                            if (kind === 'submit' && data && typeof S.examSubmitSink === 'function') S.examSubmitSink(data);
                        }, { once: true });
                    }
                } catch (e) { /* 忽略 */ }
                return origSend.apply(this, arguments);
            };
        } catch (e) { /* 忽略 */ }

        // token 兜底：Vuex 持久化在 localStorage
        try {
            const raw = localStorage.getItem('pro__Access-Token');
            if (raw) {
                const o = JSON.parse(raw);
                if (o && o.value) S.token = o.value;
            }
        } catch (e) { /* 忽略 */ }

        // graphId 兜底：当前 URL 查询参数
        try {
            const p = new URL(location.href).searchParams;
            if (p.get('graphId')) S.graphId = p.get('graphId');
        } catch (e) { /* 忽略 */ }
    }

    // ============================ 5. 接口 ============================
    async function apiGet(path) {
        const headers = {};
        if (S.token) headers['x-access-token'] = S.token;
        const sep = path.indexOf('?') >= 0 ? '&' : '?';
        const r = await fetch(path + sep + '_t=' + Date.now(), { headers, credentials: 'include' });
        return r.json().catch(() => ({}));
    }
    async function apiPost(path, body) {
        const headers = { 'Content-Type': 'application/json' };
        if (S.token) headers['x-access-token'] = S.token;
        const r = await fetch(path, { method: 'POST', headers, body: JSON.stringify(body), credentials: 'include' });
        return r.json().catch(() => ({}));
    }
    async function fetchQuestions(courseId, graphId) {
        const j = await apiGet(API_QUESTION + '?id=' + courseId + '&graphId=' + graphId);
        return Array.isArray(j.result) ? j.result : [];
    }

    // ============================ 6. 题目归一化 ============================
    // 平台字段：id / kind / stem / optiona..f / analysis / type_dictText
    function normalize(q, seq) {
        const options = [];
        ['a', 'b', 'c', 'd', 'e', 'f'].forEach((ch, i) => {
            const v = q['option' + ch];
            if (v !== null && v !== undefined && String(v).trim() !== '') {
                options.push({ letter: LETTERS[i], text: String(v).replace(/\s+/g, ' ').trim() });
            }
        });
        const kind = String(q.kind !== undefined && q.kind !== null ? q.kind : '2');
        return {
            id: String(q.id),
            seq: seq,
            kind: kind,
            kindText: KIND_TEXT[kind] || ('类型' + kind),
            stem: String(q.stem || q.question || '').replace(/\s+/g, ' ').trim(),
            options: options,
            analysis: q.analysis ? String(q.analysis).replace(/\s+/g, ' ').trim() : ''
        };
    }

    // ============================ 7. 课程树 ============================
    function getCourseNodes() {
        return Array.prototype.slice.call(document.querySelectorAll('.ant-tree-child-tree li'));
    }
    function nodeTitle(li) {
        const w = li.querySelector('.ant-tree-node-content-wrapper');
        return ((w && (w.getAttribute('title') || w.textContent)) || '').replace(/\s+/g, ' ').trim();
    }
    function isSelected(li) { return li.classList.contains('ant-tree-treenode-selected'); }

    async function expandAllChapters() {
        const closed = document.querySelectorAll('.ant-tree > .ant-tree-treenode-switcher-close');
        if (!closed.length) { log('章节已全部展开'); return; }
        log('展开 ' + closed.length + ' 个章节…');
        for (let i = 0; i < closed.length; i++) {
            const sw = closed[i].querySelector('.ant-tree-switcher');
            if (sw) { sw.click(); await sleep(350); }
        }
        await sleep(800);
        log('展开完成，课程节点 ' + getCourseNodes().length + ' 个');
    }

    // 点击节点并等待课程 id 变化
    async function gotoCourse(li) {
        const prev = S.courseId;
        const prevAt = S.courseIdAt;
        const w = li.querySelector('.ant-tree-node-content-wrapper');
        if (!w) return null;
        w.click();
        const deadline = Date.now() + (Number(cfg.idWait) || 9000);
        while (Date.now() < deadline) {
            await sleep(250);
            if (S.courseId && S.courseId !== prev) return S.courseId;
        }
        // 兜底：id 没变但确实发过请求（同一课被重新请求）
        if (S.courseId && S.courseIdAt > prevAt) return S.courseId;
        return null;   // 超时：可能该课已被缓存、没发请求
    }

    // 【实测结构，2026-11-03 真机 courseDetail 页】
    //   .ant-tree > li                       = 章节（13 个，**没有单独的根节点**）
    //   章节内 .ant-tree-child-tree > li     = 小节（合计 121 个）
    //   章节 li 的 class 是 ant-tree-treenode-switcher-open；小节是叶子，不带 childTree
    // ⇒ 归属关系只能靠「章节 li → 其 childTree 的直接 li」，不能用节点深度判定。
    function chapterLessons(chLi) {
        const ct = chLi.querySelector('.ant-tree-child-tree');
        if (!ct) return [];
        return Array.prototype.slice.call(ct.children).filter((el) => el.tagName === 'LI');
    }
    function groupChapters() {
        return Array.prototype.slice.call(document.querySelectorAll('.ant-tree > li'))
            .map((ch) => ({ li: ch, title: nodeTitle(ch), lessons: chapterLessons(ch) }))
            .filter((g) => g.lessons.length);   // 未展开的空章丢掉
    }

    // 章节按钮上的数字：取章节名第一段数字（"01安全概述" → "1"，去掉前导零），取不到用序号
    function chapterNumber(title, fallback) {
        const m = String(title || '').match(/\d+/);
        if (!m) return String(fallback);
        return m[0].replace(/^0+(?=\d)/, '');
    }

    // ============================ 8. 题库 ============================
    // { v, at, graphId, chapters: [ { num, title, lessons: [ { name, courseId, questions } ] } ] }
    const Bank = {
        data: null,
        load() {
            const raw = gmGet('bank', null);
            this.data = raw && raw.chapters ? raw : { v: 1, at: 0, graphId: '', chapters: [] };
            this.normalize();
            return this.data;
        },
        // 章号归一：去掉前导零（"02" → "2"）并合并同号章节
        // 必要性：早期版本存的是 "02"，后来的版本算出来是 "2"，不归一会并存成两个按钮
        normalize() {
            const map = new Map();
            (this.data.chapters || []).forEach((c) => {
                const num = String(c.num === null || c.num === undefined ? '' : c.num).replace(/^0+(?=\d)/, '') || '0';
                if (!map.has(num)) map.set(num, { num: num, title: c.title || ('第 ' + num + ' 章'), lessons: [] });
                const target = map.get(num);
                (c.lessons || []).forEach((l) => {
                    if (!target.lessons.some((x) => String(x.courseId) === String(l.courseId))) target.lessons.push(l);
                });
            });
            this.data.chapters = Array.from(map.values()).sort((a, b) => (Number(a.num) || 0) - (Number(b.num) || 0));
            this.save();
        },
        save() { this.data.at = Date.now(); gmSet('bank', this.data); },
        reset() {
            this.data = { v: 1, at: Date.now(), graphId: S.graphId || '', chapters: [] };
            this.save();
        },
        chapter(num) {
            const key = String(num === null || num === undefined ? '' : num).replace(/^0+(?=\d)/, '');
            return this.data.chapters.find((c) => String(c.num).replace(/^0+(?=\d)/, '') === key) || null;
        },
        upsertChapter(bucket) {
            // 章号归一后再比对，避免 "02" 与 "2" 并存
            const num = String(bucket.num || '').replace(/^0+(?=\d)/, '') || '0';
            const target = Object.assign({}, bucket, { num: num });
            const idx = this.data.chapters.findIndex((c) => String(c.num).replace(/^0+(?=\d)/, '') === num);
            if (idx >= 0) this.data.chapters[idx] = target;
            else this.data.chapters.push(target);
            this.data.chapters.sort((a, b) => (Number(a.num) || 0) - (Number(b.num) || 0));
            this.data.graphId = this.data.graphId || S.graphId || '';
            this.save();
        },
        questionsOf(chapter) {
            const seen = new Set();
            const out = [];
            (chapter.lessons || []).forEach((lesson) => {
                (lesson.questions || []).forEach((q) => {
                    if (seen.has(q.id)) return;
                    seen.add(q.id);
                    out.push({ q: q, lesson: lesson });
                });
            });
            return out;
        },
        stats() {
            let lessons = 0, questions = 0;
            this.data.chapters.forEach((c) => {
                lessons += (c.lessons || []).length;
                questions += this.questionsOf(c).length;
            });
            return { chapters: this.data.chapters.length, lessons: lessons, questions: questions };
        }
    };

    // ============================ 9. 作答记录 ============================
    // { [题目id]: { letters: ['A'], submitted: bool, at: 时间戳 } }
    const Answers = {
        data: null,
        timer: null,
        load() { this.data = gmGet('answers', {}) || {}; },
        save() {
            clearTimeout(this.timer);
            this.timer = setTimeout(() => gmSet('answers', this.data), 220);
        },
        saveNow() { clearTimeout(this.timer); gmSet('answers', this.data); },
        get(id) { return this.data[String(id)] || null; },
        letters(id) {
            const rec = this.get(id);
            return rec && Array.isArray(rec.letters) ? rec.letters : [];
        },
        toggle(q, letter) {
            const id = String(q.id);
            const rec = this.data[id] || { letters: [], submitted: false, at: 0 };
            if (String(q.kind) === '3') {
                const i = rec.letters.indexOf(letter);
                if (i >= 0) rec.letters.splice(i, 1);
                else rec.letters.push(letter);
                rec.letters.sort();
            } else {
                rec.letters = rec.letters[0] === letter ? [] : [letter];
            }
            rec.at = Date.now();
            rec.submitted = false;
            this.data[id] = rec;
            this.save();
            return rec.letters;
        },
        markSubmitted(id) {
            const rec = this.data[String(id)];
            if (rec) { rec.submitted = true; rec.at = Date.now(); }
            else this.data[String(id)] = { letters: [], submitted: true, at: Date.now() };
            this.save();
        },
        countOf(chapter) {
            const list = Bank.questionsOf(chapter);
            let answered = 0, submitted = 0;
            list.forEach((item) => {
                const rec = this.get(item.q.id);
                if (rec && rec.letters && rec.letters.length) {
                    answered++;
                    if (rec.submitted) submitted++;
                }
            });
            return { total: list.length, answered: answered, submitted: submitted };
        },
        clearChapter(chapter) {
            Bank.questionsOf(chapter).forEach((item) => { delete this.data[item.q.id]; });
            this.saveNow();
        },
        clearAll() { this.data = {}; this.saveNow(); }
    };

    // ============================ 10. 采集器 ============================
    const seen = new Set();     // 已采集的课程名，避免重复

    // 【改动】产出写进 Bank，而不是 push 到内存数组
    async function collectOne(li, index, bucket) {
        const name = nodeTitle(li);
        if (!name) return null;
        if (seen.has(name)) { log('跳过（已采集）：' + name); return null; }

        log('→ (' + (index + 1) + ') ' + name);
        const cid = await gotoCourse(li);
        if (!cid) { log('  ✗ 未捕获到课程 id，跳过'); return null; }
        await sleep(Number(cfg.stepDelay) || 600);

        let raw = [];
        try { raw = await fetchQuestions(cid, S.graphId); }
        catch (e) { log('  ✗ 拉题失败：' + (e && e.message)); }
        const questions = raw.map((q, i) => normalize(q, i + 1));

        const item = { name: name, courseId: cid, questions: questions };
        seen.add(name);
        bucket.lessons.push(item);
        log('  ✓ ' + questions.length + ' 题');
        return item;
    }

    async function startCollect() {
        if (S.running) return;
        if (!S.token) log('未捕获到 x-access-token，将直接带 cookie 请求（若失败请刷新一次页面）');
        if (!S.graphId) {
            log('未取到 graphId｜根节点=' + document.querySelectorAll('.ant-tree > li').length +
                '｜childTree节点=' + getCourseNodes().length);
            toast('未取到 graphId：请进入「我的课程 → 某门课」详情页（地址带 graphId=）再采集');
            return;
        }

        S.running = true;
        S.stopFlag = false;
        UI.syncCollectButtons();
        log('开始采集｜graphId=' + S.graphId);

        try {
            if (cfg.expandChapters) await expandAllChapters();
            const groups = groupChapters();
            S.totalCourses = groups.reduce((n, g) => n + g.lessons.length, 0);
            if (!groups.length) {
                log('✗ 未找到章节节点｜childTree节点=' + getCourseNodes().length +
                    '｜antTree节点=' + document.querySelectorAll('.ant-tree li').length);
                toast('未找到课程节点，请看面板日志');
                return;
            }
            log('解析到 ' + groups.length + ' 章 / ' + S.totalCourses + ' 节');

            let done = 0;
            for (let ci = 0; ci < groups.length; ci++) {
                if (S.stopFlag) { log('已手动停止'); break; }
                const g = groupChapters()[ci] || groups[ci];
                if (!g) continue;
                const num = chapterNumber(g.title, ci + 1);
                const bucket = { num: num, title: g.title, lessons: [] };
                log('—— 第 ' + num + ' 章｜' + g.title + '｜' + g.lessons.length + ' 节');

                for (let i = 0; i < g.lessons.length; i++) {
                    if (S.stopFlag) { log('已手动停止'); break; }
                    const name = nodeTitle(g.lessons[i]);
                    // 节点可能在切课后被重渲染：在当前 DOM 同章里按名字重新定位
                    const nowG = groupChapters()[ci];
                    const pool = nowG ? nowG.lessons : [];
                    const li = pool.find((x) => nodeTitle(x) === name) || g.lessons[i];
                    if (!li || !document.contains(li)) { log('  ✗ 节点已失效，跳过：' + name); continue; }

                    S.courseIndex = done;
                    done++;
                    UI.setProgress(done, S.totalCourses, name);
                    await collectOne(li, i, bucket);
                    if (!cfg.autoNext) { log('已关闭自动切换，停在当前课'); break; }
                }
                // 逐章落盘：中途停止也不丢已采内容
                if (bucket.lessons.length) Bank.upsertChapter(bucket);
                UI.renderGrid();
                UI.renderStats();
                // 关掉「自动切下一节」时，采完当前章就整体停下
                if (!cfg.autoNext) break;
            }
            const st = Bank.stats();
            log('采集结束：' + st.chapters + ' 章 / ' + st.lessons + ' 节 / ' + st.questions + ' 题');
            toast('采集结束：' + st.lessons + ' 节，' + st.questions + ' 题');
        } catch (e) {
            log('✗ 异常：' + (e && e.message));
        } finally {
            S.running = false;
            UI.syncCollectButtons();
            UI.renderGrid();
            UI.renderStats();
        }
    }

    const Collector = {
        start() { startCollect(); },
        stop() { S.stopFlag = true; log('收到停止指令…'); },
        get running() { return S.running; }
    };

    // ============================ 11. 提交 ============================
    async function submitItems(items) {
        const graphId = Bank.data.graphId || S.graphId || '';
        let ok = 0, fail = 0, skip = 0;
        for (const item of items) {
            const letters = Array.isArray(item.letters) ? item.letters : [];
            if (!letters.length) { skip++; continue; }
            const option = String(item.q.kind) === '3' ? letters.slice() : letters[0];
            let res = null;
            try {
                res = await apiPost(API_SUBMIT, {
                    questionId: item.q.id, id: item.courseId, graphId: graphId, option: option
                });
            } catch (e) { res = null; }
            if (res && (res.success === true || res.code === 200)) { ok++; Answers.markSubmitted(item.q.id); }
            else fail++;
            await sleep(Number(cfg.submitDelay) || 180);
        }
        return { ok: ok, fail: fail, skip: skip };
    }

    function itemsOfChapter(chapter) {
        return Bank.questionsOf(chapter).map((item) => ({
            q: item.q,
            letters: Answers.letters(item.q.id),
            courseId: item.lesson.courseId
        }));
    }

    const Submitter = {
        async chapter(chapter) {
            const items = itemsOfChapter(chapter).filter((it) => it.letters.length);
            if (!items.length) { toast('本章还没有作答，无法提交'); return; }
            toast('提交第 ' + chapter.num + ' 章：' + items.length + ' 题…', 6000);
            const r = await submitItems(items);
            log('第 ' + chapter.num + ' 章提交：成功 ' + r.ok + ' / 失败 ' + r.fail);
            toast('第 ' + chapter.num + ' 章：成功 ' + r.ok + '，失败 ' + r.fail);
            UI.renderGrid(); UI.renderStats();
            if (UI.overlayChapter) UI.renderOverlayBody();
        },
        async all() {
            const chapters = Bank.data.chapters.slice();
            if (!chapters.length) { toast('题库为空，先采集'); return; }
            const all = [];
            chapters.forEach((c) => { all.push.apply(all, itemsOfChapter(c).filter((it) => it.letters.length)); });
            if (!all.length) { toast('还没有任何作答，无法提交'); return; }
            toast('全部提交：' + all.length + ' 题…', 8000);
            const r = await submitItems(all);
            log('全部提交：成功 ' + r.ok + ' / 失败 ' + r.fail);
            toast('全部提交完成：成功 ' + r.ok + '，失败 ' + r.fail);
            UI.renderGrid(); UI.renderStats();
        }
    };

    // ============================ 12. 答案提供者插槽 ============================
    // v1 恒 null。后续接 AI 或错题弹窗只改这里。
    const AnswerProvider = {
        async provide(_question) { return null; }
    };

    // ============================ 13. 考试模块 ============================
    const Exam = {
        records: [],
        recordId: '',
        active: false,
        capture(data) {
            try {
                const result = (data && data.result) || null;
                const records = result && result.records;
                if (!Array.isArray(records) || !records.length) return;
                if (this.recordId && this.recordId === String(result.id || '') && this.active) return;
                this.recordId = String(result.id || '');
                this.records = records.map((r, i) => normalize(r, i + 1));
                this.active = true;
                log('捕获考试卷：' + this.records.length + ' 题');
                UI.renderExamPane();
                UI.openExamOverlay();
            } catch (e) { log('整卷解析失败：' + (e && e.message)); }
        },
        // 交卷判分回执（submitExam 响应旁挂）。拿到后把纸面收掉，避免误二次提交。
        onResult(data) {
            try {
                const r = (data && data.result) || null;
                if (!data || data.success !== true || !r) return;
                if (this._resultSeen === String(r.id || '')) return;
                this._resultSeen = String(r.id || '');
                const score = r.score;
                const pass = String(r.isQualified) === '1';
                if (score === null || score === undefined) {
                    log('交卷完成：等待评分');
                    toast('已交卷，等待评分结果', 5000);
                } else {
                    log('交卷完成：得分 ' + score + (r.isQualified !== undefined && r.isQualified !== null ? '（' + (pass ? '合格' : '未合格') + '）' : ''));
                    toast('交卷完成：得分 ' + score, 6000);
                }
                // 纸面已失效：清空卷面并收起浮层，避免对着旧卷再点一次提交
                this.records = [];
                this.active = false;
                UI.closeOverlay();
                UI.renderExamPane();
            } catch (e) { /* 忽略 */ }
        },

        findVm() {
            const root = document.querySelector('#app') && document.querySelector('#app').__vue__;
            const stack = root ? [root] : [];
            const seenVm = new Set();
            while (stack.length) {
                const vm = stack.pop();
                if (!vm || seenVm.has(vm)) continue;
                seenVm.add(vm);
                if (Array.isArray(vm.records) && vm.records.length && vm.param && typeof vm.submit === 'function') return vm;
                const kids = vm.$children || [];
                for (let i = 0; i < kids.length; i++) stack.push(kids[i]);
            }
            return null;
        },
        pullFromVm() {
            const vm = this.findVm();
            if (!vm) return false;
            this.records = vm.records.map((r, i) => normalize(r, i + 1));
            this.recordId = String(vm.recordId || '');
            this.active = true;
            log('从页面实例补全考卷：' + this.records.length + ' 题');
            UI.renderExamPane();
            return true;
        },
        fill(vm) {
            let n = 0;
            this.records.forEach((q) => {
                const letters = Answers.letters(q.id);
                if (!letters.length) return;
                const value = String(q.kind) === '3' ? letters.slice() : letters[0];
                if (typeof vm.$set === 'function') vm.$set(vm.param, q.id, value);
                else vm.param[q.id] = value;
                n++;
            });
            return n;
        },
        // 页面「当前显示题」用的是另一套绑定（vm.model + vm.option/vm.options），
        // 只写 vm.param 不动它 ⇒ 点提交时页面会拿旧绑定覆盖当前题，白丢一题。
        // 否则提交时页面会拿旧绑定覆盖当前题。
        syncDisplayed(vm) {
            if (!vm || !vm.model) return;
            const curId = String(vm.model.id || '');
            const value = vm.param ? vm.param[curId] : null;
            if (String(vm.model.kind) === '3') {
                vm.options = Array.isArray(value) ? value.slice() : [];
                vm.option = '';
            } else {
                vm.option = typeof value === 'string' ? value : '';
                vm.options = [];
            }
        },
        confirmDialog() {
            return new Promise((resolve) => {
                let settled = false;
                const finish = (ok) => {
                    if (settled) return;
                    settled = true;
                    observer.disconnect();
                    clearTimeout(timer);
                    resolve(ok);
                };
                const tryConfirm = () => {
                    const dialog = Array.prototype.slice.call(document.querySelectorAll('.ant-modal-confirm'))
                        .reverse()
                        .find((el) => el.getClientRects().length > 0 && /是否提交|确认提交试卷/.test(el.textContent || ''));
                    if (!dialog) return;
                    const buttons = Array.prototype.slice.call(dialog.querySelectorAll('button'));
                    const btn = buttons.find((b) => !b.disabled && /^(确定|确认|OK)$/i.test(b.textContent.trim().replace(/\s+/g, '')))
                        || dialog.querySelector('button.ant-btn-primary:not([disabled])');
                    if (!btn) return;
                    btn.click();
                    finish(true);
                };
                const observer = new MutationObserver(tryConfirm);
                observer.observe(document.body, { childList: true, subtree: true });
                const timer = setTimeout(() => finish(false), 2500);
                tryConfirm();
            });
        },
        async submit() {
            if (!this.records.length && !this.pullFromVm()) { toast('未找到正在进行的考试'); return; }
            const vm = this.findVm();
            if (!vm) { toast('无法访问考试页面，请保持在考试页后重试'); return; }
            const filled = this.fill(vm);
            if (!filled) { toast('还没有作答，无法提交'); return; }
            // 跳到最后一题并把当前题的绑定值拉齐，再交卷
            const last = this.records[this.records.length - 1];
            if (last) {
                const n = this.records.length;
                vm.index = n - 1;
                vm.seria = '第' + n + '题';
                vm.model = Object.assign({}, last);
                vm.model.kind_text = String(last.kind) === '1' ? '判断题' : String(last.kind) === '3' ? '多选题' : '单选题';
                this.syncDisplayed(vm);
                if (typeof vm.$nextTick === 'function') await new Promise((r) => vm.$nextTick(r));
            }
            await sleep(120);
            if (typeof vm.submit !== 'function') { toast('页面没有提交入口，请手动交卷'); return; }
            const confirmation = this.confirmDialog();
            try { vm.submit(); } catch (e) { log('提交异常：' + (e && e.message)); }
            const ok = await confirmation;
            toast(ok ? '已提交，等待评分结果' : '提交已发起，请页面上确认', 5000);
            log('考试提交：填入 ' + filled + ' 题｜确认 ' + (ok ? '成功' : '未捕捉到'));
        }
    };

    // ============================ 14. 视频控制（自有版移植，默认全关） ============================
    const Video = {
        timer: null,
        pick() {
            return document.querySelector('video') || document.querySelector('#cc_F7B76307B77D90F213358DE27D943A99');
        },
        tick() {
            const v = this.pick();
            if (!v) return;
            const speed = Number(cfg.videoSpeed) || 1;
            if (speed !== 1 && Math.abs(v.playbackRate - speed) > 0.001) v.playbackRate = speed;
            if (cfg.noPause && v.paused && !v.ended) v.play().catch(() => {});
            else if (cfg.autoPlayVideo && v.paused && !v.ended) v.play().catch(() => {});
        },
        start() {
            this.stop();
            const need = (Number(cfg.videoSpeed) || 1) !== 1 || cfg.noPause || cfg.autoPlayVideo;
            if (!need) return;
            this.timer = setInterval(() => this.tick(), 600);
            log('视频控制已启动（倍速 ' + (Number(cfg.videoSpeed) || 1) + 'x）');
        },
        stop() {
            if (this.timer) { clearInterval(this.timer); this.timer = null; }
        },
        async onEnded() {
            if (!cfg.autoSwitchVideo) return;
            const cur = document.querySelector('.ant-tree .ant-tree-node-content-wrapper.ant-tree-node-selected');
            const li = cur && cur.closest('li');
            if (!li) return;
            const ul = li.parentElement;
            const ch = ul && ul.tagName === 'UL' ? ul.parentElement.closest('li') : null;
            if (!ch) return;
            let kids = ch.querySelector(':scope > ul');
            const list = kids ? Array.prototype.slice.call(kids.children).filter((x) => x.tagName === 'LI') : [];
            const idx = list.indexOf(li);
            if (idx < 0 || idx >= list.length - 1) { log('本章已到末节，不自动切换'); return; }
            const w = list[idx + 1].querySelector('.ant-tree-node-content-wrapper');
            if (w) { w.click(); log('自动切下一节：' + nodeTitle(list[idx + 1])); }
        },
        bind() {
            document.addEventListener('ended', (e) => {
                if (e && e.target && e.target.tagName === 'VIDEO') this.onEnded();
            }, true);
        }
    };

    // ============================ 15. 样式 ============================
    const CSS = `
#sqb-panel, #sqb-overlay, #sqb-toast { box-sizing: border-box; }
#sqb-panel button, #sqb-overlay button, #sqb-panel input, #sqb-panel select { font-family: inherit; }
#sqb-overlay .sqb-of .meta { color: #8a9099; font-size: 12px; }
#sqb-panel {
    --sqb-radius: 20px;
    --sqb-accent: #1677ff;
    position: fixed; top: 120px; right: 20px; width: 360px;
    background: #fff; color: #1f2329; border: 1px solid rgba(0,0,0,.08);
    border-radius: var(--sqb-radius); box-shadow: 0 12px 40px rgba(15,23,42,.16);
    z-index: ${Z}; font: 13px/1.55 -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
    overflow: hidden; user-select: none;
}
#sqb-panel.min { width: 168px; }
#sqb-panel.min .sqb-tabs, #sqb-panel.min .sqb-body { display: none; }
#sqb-panel .sqb-head { display: flex; align-items: center; justify-content: space-between; padding: 12px 14px; border-bottom: 1px solid rgba(0,0,0,.06); cursor: move; }
#sqb-panel .sqb-title { font-weight: 500; font-size: 13.5px; }
#sqb-panel .sqb-ver { color: #8a9099; font-size: 11px; margin-left: 6px; }
#sqb-panel .sqb-min { border: 0; background: #f2f3f5; color: #4e5969; width: 22px; height: 22px; border-radius: 7px; cursor: pointer; line-height: 1; }
#sqb-panel .sqb-tabs { display: flex; gap: 4px; padding: 8px 10px; border-bottom: 1px solid rgba(0,0,0,.06); }
#sqb-panel .sqb-tabs button { flex: 1; border: 0; background: transparent; color: #4e5969; padding: 6px 0; border-radius: 8px; cursor: pointer; font-size: 12.5px; }
#sqb-panel .sqb-tabs button.on { background: rgba(22,119,255,.1); color: var(--sqb-accent); font-weight: 500; }
#sqb-panel .sqb-body { padding: 12px 14px 14px; max-height: 70vh; overflow: auto; }
#sqb-panel .sqb-pane { display: none; }
#sqb-panel .sqb-pane.on { display: block; }
#sqb-panel .sqb-stats { display: flex; gap: 6px; margin-bottom: 10px; }
#sqb-panel .sqb-stats div { flex: 1; background: #f7f8fa; border-radius: 10px; padding: 7px 6px; text-align: center; }
#sqb-panel .sqb-stats b { display: block; font-size: 15px; color: var(--sqb-accent); font-weight: 500; }
#sqb-panel .sqb-stats i { font-style: normal; color: #8a9099; font-size: 10.5px; }
#sqb-panel .sqb-row { display: flex; gap: 6px; margin-bottom: 8px; }
#sqb-panel .sqb-btn { flex: 1; border: 1px solid rgba(0,0,0,.1); background: #fff; color: #1f2329; padding: 7px 0; border-radius: 9px; cursor: pointer; font-size: 12.5px; }
#sqb-panel .sqb-btn.pri { background: var(--sqb-accent); border-color: var(--sqb-accent); color: #fff; }
#sqb-panel .sqb-btn.warn { color: #d4380d; border-color: rgba(212,56,13,.3); }
#sqb-panel .sqb-btn:disabled { opacity: .5; cursor: not-allowed; }
#sqb-panel .sqb-grid { display: flex; flex-wrap: wrap; gap: 6px; margin: 4px 0 10px; }
#sqb-panel .sqb-chip { width: 40px; height: 38px; border-radius: 10px; cursor: pointer; border: 1px solid rgba(0,0,0,.1); background: #fff; color: #4e5969; font-size: 13px; font-weight: 500; position: relative; padding: 0 0 10px; box-sizing: border-box; }
#sqb-panel .sqb-chip.empty { padding-bottom: 0; }
#sqb-panel .sqb-chip.empty { border-style: dashed; color: #b8bcc4; }
#sqb-panel .sqb-chip.has { border-color: rgba(22,119,255,.45); color: var(--sqb-accent); }
#sqb-panel .sqb-chip.done { background: var(--sqb-accent); border-color: var(--sqb-accent); color: #fff; }
/* 当前正在看的那一章：实线蓝边 + 淡蓝底 + 外发光，与「有作答」(半透明蓝边) 区分开 */
#sqb-panel .sqb-chip.sel { border-color: var(--sqb-accent); background: rgba(22,119,255,.1); box-shadow: 0 0 0 2px rgba(22,119,255,.25); color: var(--sqb-accent); font-weight: 600; }
#sqb-panel .sqb-chip.done.sel { background: var(--sqb-accent); color: #fff; box-shadow: 0 0 0 2px rgba(22,119,255,.4); }
#sqb-panel .sqb-chip em { position: absolute; left: 0; right: 0; bottom: 2px; text-align: center; font-style: normal; font-size: 9px; line-height: 1; letter-spacing: -.2px; opacity: .68; }
#sqb-panel .sqb-sw { display: flex; align-items: center; justify-content: space-between; padding: 5px 0; color: #4e5969; font-size: 12.5px; }
#sqb-panel .sqb-sw input[type=checkbox] { accent-color: var(--sqb-accent); }
#sqb-panel .sqb-sw input[type=number], #sqb-panel .sqb-sw select { width: 78px; border: 1px solid rgba(0,0,0,.12); border-radius: 7px; padding: 3px 6px; font-size: 12px; color: #1f2329; background: #fff; }
#sqb-panel .sqb-log { margin-top: 8px; max-height: 108px; overflow: auto; background: #f7f8fa; border-radius: 9px; padding: 7px 8px; color: #6b7280; font: 11px/1.6 ui-monospace, Consolas, monospace; white-space: pre-wrap; word-break: break-all; }
#sqb-panel .sqb-hint { color: #8a9099; font-size: 11.5px; line-height: 1.6; }
#sqb-toast { position: fixed; left: 50%; bottom: 36px; transform: translate(-50%, 12px); background: rgba(31,35,41,.92); color: #fff; padding: 9px 16px; border-radius: 10px; font: 13px/1.5 -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif; z-index: ${Z + 1}; opacity: 0; pointer-events: none; transition: opacity .18s ease, transform .18s ease; max-width: 70vw; }
#sqb-toast.on { opacity: 1; transform: translate(-50%, 0); }
#sqb-overlay { position: fixed; inset: 0; background: rgba(15,23,42,.42); z-index: ${Z - 1}; display: none; align-items: center; justify-content: center; padding: 24px; font: 13.5px/1.6 -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif; }
#sqb-overlay.on { display: flex; }
#sqb-overlay .sqb-card { width: 100%; max-width: 1000px; height: 88vh; background: #fff; border-radius: 20px; display: flex; flex-direction: column; overflow: hidden; box-shadow: 0 24px 80px rgba(15,23,42,.32); }
#sqb-overlay .sqb-oh { padding: 16px 20px; border-bottom: 1px solid rgba(0,0,0,.07); display: flex; align-items: center; gap: 10px; }
#sqb-overlay .sqb-oh h3 { margin: 0; font-size: 15px; font-weight: 500; }
#sqb-overlay .sqb-oh .meta { color: #8a9099; font-size: 12px; }
#sqb-overlay .sqb-oh .spacer { flex: 1; }
#sqb-overlay .sqb-oh button { border: 1px solid rgba(0,0,0,.1); background: #fff; color: #4e5969; border-radius: 9px; padding: 6px 12px; cursor: pointer; font-size: 12.5px; }
#sqb-overlay .sqb-ob { flex: 1; overflow: auto; padding: 16px 20px; background: #fbfbfc; }
#sqb-overlay .sqb-of { padding: 12px 20px; border-top: 1px solid rgba(0,0,0,.07); display: flex; gap: 8px; align-items: center; background: #fff; }
#sqb-overlay .sqb-of .spacer { flex: 1; }
#sqb-overlay .sqb-of button { border: 1px solid rgba(0,0,0,.1); background: #fff; color: #1f2329; border-radius: 10px; padding: 8px 16px; cursor: pointer; font-size: 13px; }
#sqb-overlay .sqb-of button.pri { background: #1677ff; border-color: #1677ff; color: #fff; }
#sqb-overlay .sqb-of button.warn { color: #d4380d; border-color: rgba(212,56,13,.3); }
#sqb-overlay .sqb-of button:disabled { opacity: .4; cursor: not-allowed; }
#sqb-overlay .sqb-q { background: #fff; border: 1px solid rgba(0,0,0,.07); border-radius: 14px; padding: 14px 16px; margin-bottom: 10px; }
#sqb-overlay .sqb-qh { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
#sqb-overlay .sqb-no { width: 24px; height: 24px; border-radius: 8px; background: rgba(22,119,255,.1); color: #1677ff; font-size: 12px; font-weight: 500; display: flex; align-items: center; justify-content: center; }
#sqb-overlay .sqb-kind { font-size: 11.5px; color: #8a9099; background: #f2f3f5; border-radius: 6px; padding: 1px 7px; }
#sqb-overlay .sqb-flag { font-size: 11.5px; color: #0f9d58; margin-left: auto; }
#sqb-overlay .sqb-stem { color: #1f2329; margin-bottom: 10px; white-space: pre-wrap; }
#sqb-overlay .sqb-opts { display: flex; flex-direction: column; gap: 6px; }
#sqb-overlay .sqb-opt { display: flex; gap: 9px; align-items: flex-start; text-align: left; border: 1px solid rgba(0,0,0,.1); background: #fff; border-radius: 10px; padding: 9px 11px; cursor: pointer; font: inherit; color: #1f2329; }
#sqb-overlay .sqb-opt:hover { border-color: rgba(22,119,255,.45); }
#sqb-overlay .sqb-opt.on { border-color: #1677ff; background: rgba(22,119,255,.06); }
#sqb-overlay .sqb-lt { width: 20px; height: 20px; flex: 0 0 20px; border-radius: 6px; background: #f2f3f5; color: #4e5969; font-size: 12px; display: flex; align-items: center; justify-content: center; }
#sqb-overlay .sqb-opt.on .sqb-lt { background: #1677ff; color: #fff; }
#sqb-overlay .sqb-an { margin-top: 9px; color: #6b7280; font-size: 12.5px; background: #f7f8fa; border-radius: 9px; padding: 8px 10px; }
`;

    function esc(s) {
        return String(s === null || s === undefined ? '' : s)
            .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
            .replace(/"/g, '&quot;').replace(/'/g, '&#39;');
    }

    // ============================ 16. UI ============================
    const UI = {
        overlayChapter: null,
        overlayMode: '',

        buildPanel() {
            if (document.getElementById('sqb-panel')) return;
            const el = document.createElement('div');
            el.id = 'sqb-panel';
            el.innerHTML = [
                '<div class="sqb-head">',
                '  <div class="sqb-title">习题集<span class="sqb-ver">v' + SCRIPT_INFO.version + '</span></div>',
                '  <button class="sqb-min" title="收起 / 展开">—</button>',
                '</div>',
                '<div class="sqb-tabs">',
                '  <button data-tab="bank" class="on">习题集</button>',
                '  <button data-tab="exam">试卷</button>',
                '  <button data-tab="cfg">设置</button>',
                '</div>',
                '<div class="sqb-body">',
                '  <div class="sqb-pane on" data-pane="bank">',
                '    <div class="sqb-stats">',
                '      <div><b id="sqb-st-ch">0</b><i>章节</i></div>',
                '      <div><b id="sqb-st-q">0</b><i>题目</i></div>',
                '      <div><b id="sqb-st-a">0/0</b><i>已答</i></div>',
                '    </div>',
                '    <div class="sqb-row">',
                '      <button class="sqb-btn pri" id="sqb-collect">开始采集</button>',
                '      <button class="sqb-btn" id="sqb-collect-stop" disabled>停止</button>',
                '    </div>',
                '    <div class="sqb-grid" id="sqb-grid"></div>',
                '    <div class="sqb-row">',
                '      <button class="sqb-btn pri" id="sqb-submit-all">全部提交</button>',
                '      <button class="sqb-btn warn" id="sqb-clear-all">全部清空</button>',
                '    </div>',
                '    <div class="sqb-log" id="sqb-log">就绪。先进「我的课程 → 某门课」详情页，再点「开始采集」。</div>',
                '  </div>',
                '  <div class="sqb-pane" data-pane="exam">',
                '    <div class="sqb-hint" id="sqb-exam-status">未检测到考试。开考后会自动展开整张试卷。</div>',
                '    <div class="sqb-row" style="margin-top:10px">',
                '      <button class="sqb-btn pri" id="sqb-exam-open">展开整张试卷</button>',
                '      <button class="sqb-btn" id="sqb-exam-submit">提交整卷</button>',
                '    </div>',
                '    <div class="sqb-hint">「提交整卷」会把你在整卷界面里的作答写回页面并代为交卷；没作答的题不会写。</div>',
                '  </div>',
                '  <div class="sqb-pane" data-pane="cfg">',
                '    <div class="sqb-sw"><label>采集前自动展开章节</label><input type="checkbox" id="sqb-cf-expand"></div>',
                '    <div class="sqb-sw"><label>采完自动切下一节</label><input type="checkbox" id="sqb-cf-autonext"></div>',
                '    <div class="sqb-sw"><label>切课后等待</label><input type="number" id="sqb-cf-step" min="100" step="100"></div>',
                '    <div class="sqb-sw"><label>等 courseId 上限</label><input type="number" id="sqb-cf-idwait" min="1500" step="500"></div>',
                '    <div class="sqb-sw"><label>播放倍速</label><select id="sqb-cf-speed"></select></div>',
                '    <div class="sqb-sw"><label>自动续播（暂停就抢回）</label><input type="checkbox" id="sqb-cf-autoplay"></div>',
                '    <div class="sqb-sw"><label>不许暂停</label><input type="checkbox" id="sqb-cf-nopause"></div>',
                '    <div class="sqb-sw"><label>播完自动切下一节</label><input type="checkbox" id="sqb-cf-autoswitch"></div>',
                '    <div class="sqb-hint" style="margin-top:6px">视频控制默认全部关闭，避免与其它脚本抢同一个 video 元素。改完立即生效。</div>',
                '    <div class="sqb-row" style="margin-top:10px">',
                '      <button class="sqb-btn warn" id="sqb-bank-reset">清空题库</button>',
                '    </div>',
                '  </div>',
                '</div>'
            ].join('');
            document.body.appendChild(el);

            const tabs = Array.prototype.slice.call(el.querySelectorAll('.sqb-tabs button'));
            const panes = Array.prototype.slice.call(el.querySelectorAll('.sqb-pane'));
            tabs.forEach((btn) => {
                btn.addEventListener('click', () => {
                    tabs.forEach((b) => b.classList.toggle('on', b === btn));
                    panes.forEach((p) => p.classList.toggle('on', p.dataset.pane === btn.dataset.tab));
                });
            });

            el.querySelector('.sqb-min').addEventListener('click', () => {
                el.classList.toggle('min');
                el.querySelector('.sqb-min').textContent = el.classList.contains('min') ? '＋' : '—';
            });

            const head = el.querySelector('.sqb-head');
            let drag = null;
            head.addEventListener('mousedown', (e) => {
                if (e.target.tagName === 'BUTTON') return;
                const r = el.getBoundingClientRect();
                drag = { x: e.clientX - r.left, y: e.clientY - r.top };
            });
            document.addEventListener('mousemove', (e) => {
                if (!drag) return;
                el.style.left = Math.max(0, e.clientX - drag.x) + 'px';
                el.style.top = Math.max(0, e.clientY - drag.y) + 'px';
                el.style.right = 'auto';
            });
            document.addEventListener('mouseup', () => { drag = null; });

            el.querySelector('#sqb-collect').addEventListener('click', () => Collector.start());
            el.querySelector('#sqb-collect-stop').addEventListener('click', () => Collector.stop());
            el.querySelector('#sqb-submit-all').addEventListener('click', () => Submitter.all());
            el.querySelector('#sqb-clear-all').addEventListener('click', () => {
                if (!confirm('清空全部？章节按钮会一起消失，题库与作答都会清掉，需要重新采集。')) return;
                Answers.clearAll();
                Bank.reset();                       // 题库一起清 ⇒ 章节小按钮随之消失
                this.closeOverlay();                // 若浮层开着，一并关掉
                this.renderGrid();
                this.renderStats();
                toast('已清空：章节按钮已移除');
            });

            el.querySelector('#sqb-exam-open').addEventListener('click', () => {
                if (!Exam.records.length) Exam.pullFromVm();
                if (!Exam.records.length) { toast('未找到正在进行的考试'); return; }
                this.openExamOverlay();
            });
            el.querySelector('#sqb-exam-submit').addEventListener('click', () => Exam.submit());

            const speedSel = el.querySelector('#sqb-cf-speed');
            [1, 1.25, 1.5, 1.75, 2, 2.5, 3].forEach((v) => {
                const o = document.createElement('option');
                o.value = String(v); o.textContent = v + 'x';
                speedSel.appendChild(o);
            });
            speedSel.value = String(Number(cfg.videoSpeed) || 1);
            speedSel.addEventListener('change', () => { cfg.videoSpeed = Number(speedSel.value) || 1; saveCfg(); Video.start(); });

            const bindSw = (id, key, after) => {
                const box = el.querySelector(id);
                box.checked = !!cfg[key];
                box.addEventListener('change', () => { cfg[key] = box.checked; saveCfg(); if (after) after(); });
            };
            bindSw('#sqb-cf-expand', 'expandChapters');
            bindSw('#sqb-cf-autonext', 'autoNext');
            bindSw('#sqb-cf-autoplay', 'autoPlayVideo', () => Video.start());
            bindSw('#sqb-cf-nopause', 'noPause', () => Video.start());
            bindSw('#sqb-cf-autoswitch', 'autoSwitchVideo');

            const bindNum = (id, key, min) => {
                const box = el.querySelector(id);
                box.value = String(cfg[key]);
                box.addEventListener('change', () => {
                    cfg[key] = Math.max(min, parseInt(box.value, 10) || DEFAULTS[key]);
                    box.value = String(cfg[key]);
                    saveCfg();
                });
            };
            bindNum('#sqb-cf-step', 'stepDelay', 100);
            bindNum('#sqb-cf-idwait', 'idWait', 1500);

            el.querySelector('#sqb-bank-reset').addEventListener('click', () => {
                if (!confirm('清空题库（题目全删，作答记录保留）？')) return;
                Bank.reset();
                this.renderGrid(); this.renderStats();
                toast('题库已清空');
            });

            this.renderGrid();
            this.renderStats();
        },

        renderStats() {
            const st = Bank.stats();
            let answered = 0;
            Bank.data.chapters.forEach((c) => { answered += Answers.countOf(c).answered; });
            const set = (id, v) => { const e = document.getElementById(id); if (e) e.textContent = v; };
            set('sqb-st-ch', st.chapters);
            set('sqb-st-q', st.questions);
            set('sqb-st-a', answered + '/' + st.questions);
        },

        renderGrid() {
            const grid = document.getElementById('sqb-grid');
            if (!grid) return;
            grid.innerHTML = '';
            const chapters = Bank.data.chapters;
            if (!chapters.length) {
                grid.innerHTML = '<div class="sqb-hint">题库为空。点「开始采集」把整棵课程树的题目收下来。</div>';
                return;
            }
            chapters.forEach((ch) => {
                const cnt = Answers.countOf(ch);
                const btn = document.createElement('button');
                btn.className = 'sqb-chip';
                btn.textContent = String(ch.num);
                btn.title = ch.title + '（' + cnt.total + ' 题，已答 ' + cnt.answered + '）';
                if (!cnt.total) btn.classList.add('empty');
                else if (cnt.answered >= cnt.total) btn.classList.add('done');
                else if (cnt.answered > 0) btn.classList.add('has');
                // 当前正打开的那一章高亮（翻页时跟着走）
                if (this.overlayChapter && String(this.overlayChapter.num) === String(ch.num)) btn.classList.add('sel');
                // 角标显示「已答/总题数」，没题的章不显示（本身已是虚线空态）
                if (cnt.total) {
                    const em = document.createElement('em');
                    em.textContent = cnt.answered + '/' + cnt.total;
                    btn.appendChild(em);
                }
                btn.addEventListener('click', () => UI.openChapterOverlay(ch.num));
                grid.appendChild(btn);
            });
        },

        // 作答后刷新面板计数与章节按钮角标（合并 140ms 内的连续点击，避免每题重绘）
        refreshCounters() {
            clearTimeout(this._ct);
            this._ct = setTimeout(() => { this.renderGrid(); this.renderStats(); }, 140);
        },

        syncCollectButtons() {
            const start = document.getElementById('sqb-collect');
            const stop = document.getElementById('sqb-collect-stop');
            if (start) { start.disabled = S.running; start.textContent = S.running ? '采集中…' : '开始采集'; }
            if (stop) stop.disabled = !S.running;
        },

        setProgress(cur, total, name) {
            const el = document.getElementById('sqb-log');
            if (el) el.title = cur + '/' + total + ' ' + name;
        },

        ensureOverlay() {
            if (document.getElementById('sqb-overlay')) return document.getElementById('sqb-overlay');
            const el = document.createElement('div');
            el.id = 'sqb-overlay';
            el.innerHTML = [
                '<div class="sqb-card">',
                '  <div class="sqb-oh">',
                '    <h3 id="sqb-ov-title">习题集</h3>',
                '    <span class="meta" id="sqb-ov-meta"></span>',
                '    <span class="spacer"></span>',
                '    <button id="sqb-ov-close">关闭</button>',
                '  </div>',
                '  <div class="sqb-ob" id="sqb-ov-body"></div>',
                '  <div class="sqb-of">',
                '    <span class="meta" id="sqb-ov-progress"></span>',
                '    <span class="spacer"></span>',
                '    <button id="sqb-ov-prev">上一章</button>',
                '    <button id="sqb-ov-next">下一章</button>',
                '    <button class="warn" id="sqb-ov-clear">清空</button>',
                '    <button class="pri" id="sqb-ov-submit">提交</button>',
                '  </div>',
                '</div>'
            ].join('');
            document.body.appendChild(el);
            el.querySelector('#sqb-ov-close').addEventListener('click', () => UI.closeOverlay());
            el.querySelector('#sqb-ov-prev').addEventListener('click', () => UI.prevChapter());
            el.querySelector('#sqb-ov-next').addEventListener('click', () => UI.nextChapter());
            el.querySelector('#sqb-ov-submit').addEventListener('click', () => {
                if (UI.overlayMode === 'exam') Exam.submit();
                else if (UI.overlayChapter) Submitter.chapter(UI.overlayChapter);
            });
            el.querySelector('#sqb-ov-clear').addEventListener('click', () => {
                if (UI.overlayMode === 'exam') {
                    Exam.records.forEach((q) => { delete Answers.data[q.id]; });
                    Answers.saveNow();
                } else if (UI.overlayChapter) {
                    Answers.clearChapter(UI.overlayChapter);
                }
                UI.renderOverlayBody();
                UI.renderGrid();
                UI.renderStats();
            });
            el.addEventListener('click', (e) => { if (e.target === el) UI.closeOverlay(); });
            return el;
        },

        closeOverlay() {
            const el = document.getElementById('sqb-overlay');
            if (el) el.classList.remove('on');
            this.overlayChapter = null;
            this.overlayMode = '';
            this.renderGrid();
            this.renderStats();
        },

        openChapterOverlay(num) {
            const ch = Bank.chapter(num);
            if (!ch) { toast('该章节未采集到题目'); return; }
            this.overlayMode = 'chapter';
            this.overlayChapter = ch;
            const el = this.ensureOverlay();
            el.querySelector('#sqb-ov-title').textContent = ch.title || ('第 ' + ch.num + ' 章');
            el.querySelector('#sqb-ov-meta').textContent = '第 ' + ch.num + ' 章';
            el.querySelector('#sqb-ov-submit').textContent = '提交本章';
            el.querySelector('#sqb-ov-clear').textContent = '清空本章';
            // 「上一章 / 下一章」：按题库章序走，跳过 0 题的章（空章翻进去只有一句"没采到题目"）
            const setNav = (id, target, word, noneText) => {
                const b = el.querySelector(id);
                b.style.display = '';
                b.disabled = !target;
                b.title = target ? (word + '：' + (target.title || ('第 ' + target.num + ' 章'))) : noneText;
            };
            setNav('#sqb-ov-prev', this.findPrevChapter(ch), '上一章', '前面没有别的章节了');
            setNav('#sqb-ov-next', this.findNextChapter(ch), '下一章', '后面没有别的章节了');
            el.classList.add('on');
            this.renderOverlayBody();
            this.renderGrid();                 // 让主面板对应章节按钮高亮
            const body = document.getElementById('sqb-ov-body');
            if (body) body.scrollTop = 0;
        },

        // 找"上一张有题的卷子"：从当前章往前扫，跳过 0 题的章；没有则返回 null
        findPrevChapter(ch) {
            const list = Bank.data.chapters;
            const i = list.findIndex((c) => String(c.num) === String(ch.num));
            if (i < 0) return null;
            for (let k = i - 1; k >= 0; k--) {
                if (Answers.countOf(list[k]).total > 0) return list[k];
            }
            return null;
        },

        // 找"下一张有题的卷子"：从当前章往后扫，跳过 0 题的章；没有则返回 null
        findNextChapter(ch) {
            const list = Bank.data.chapters;
            const i = list.findIndex((c) => String(c.num) === String(ch.num));
            if (i < 0) return null;
            for (let k = i + 1; k < list.length; k++) {
                if (Answers.countOf(list[k]).total > 0) return list[k];
            }
            return null;
        },

        prevChapter() {
            if (this.overlayMode !== 'chapter' || !this.overlayChapter) return;
            const prv = this.findPrevChapter(this.overlayChapter);
            if (!prv) { toast('前面没有别的章节了'); return; }
            this.openChapterOverlay(prv.num);
        },

        nextChapter() {
            if (this.overlayMode !== 'chapter' || !this.overlayChapter) return;
            const nxt = this.findNextChapter(this.overlayChapter);
            if (!nxt) { toast('后面没有别的章节了'); return; }
            this.openChapterOverlay(nxt.num);
        },

        openExamOverlay() {
            if (!Exam.records.length) { toast('未找到正在进行的考试'); return; }
            this.overlayMode = 'exam';
            this.overlayChapter = null;
            const el = this.ensureOverlay();
            el.querySelector('#sqb-ov-title').textContent = '整张试卷';
            el.querySelector('#sqb-ov-meta').textContent = '共 ' + Exam.records.length + ' 题';
            el.querySelector('#sqb-ov-submit').textContent = '提交整卷';
            el.querySelector('#sqb-ov-clear').textContent = '清空作答';
            el.querySelector('#sqb-ov-next').style.display = 'none';   // 整卷没有"下一章"
            el.querySelector('#sqb-ov-prev').style.display = 'none';   // 整卷也没有"上一章"
            el.classList.add('on');
            this.renderOverlayBody();
            this.renderGrid();                 // 整卷模式：主面板不高亮任何一章
        },

        renderOverlayBody() {
            const body = document.getElementById('sqb-ov-body');
            const prog = document.getElementById('sqb-ov-progress');
            if (!body) return;
            let list = [];
            if (this.overlayMode === 'exam') list = Exam.records.map((q) => ({ q: q, lesson: null }));
            else if (this.overlayChapter) list = Bank.questionsOf(this.overlayChapter);
            if (!list.length) {
                body.innerHTML = '<div class="sqb-hint">这一章没有采到题目。</div>';
                if (prog) prog.textContent = '';
                return;
            }
            let answered = 0;
            const html = list.map((item, idx) => {
                const q = item.q;
                const letters = Answers.letters(q.id);
                if (letters.length) answered++;
                const rec = Answers.get(q.id);
                const opts = (q.options || []).map((o) => {
                    const on = letters.indexOf(o.letter) >= 0 ? ' on' : '';
                    return '<button class="sqb-opt' + on + '" data-qid="' + esc(q.id) + '" data-letter="' + o.letter + '">' +
                        '<span class="sqb-lt">' + o.letter + '</span><span>' + esc(o.text) + '</span></button>';
                }).join('');
                const flag = rec && rec.submitted ? '<span class="sqb-flag">已提交</span>' : '';
                const an = q.analysis ? '<div class="sqb-an">' + esc(q.analysis) + '</div>' : '';
                return '<div class="sqb-q" data-qid="' + esc(q.id) + '">' +
                    '<div class="sqb-qh"><span class="sqb-no">' + (idx + 1) + '</span>' +
                    '<span class="sqb-kind">' + (q.kindText || '') + '</span>' + flag + '</div>' +
                    '<div class="sqb-stem">' + esc(q.stem) + '</div>' +
                    '<div class="sqb-opts">' + opts + '</div>' + an + '</div>';
            }).join('');
            body.innerHTML = html;
            if (prog) prog.textContent = '已答 ' + answered + ' / ' + list.length;

            const qmap = new Map();
            list.forEach((item) => qmap.set(String(item.q.id), item.q));
            Array.prototype.slice.call(body.querySelectorAll('.sqb-opt')).forEach((btn) => {
                btn.addEventListener('click', () => {
                    const q = qmap.get(String(btn.dataset.qid));
                    if (!q) return;
                    Answers.toggle(q, btn.dataset.letter);
                    const card = body.querySelector('.sqb-q[data-qid="' + q.id + '"]');
                    if (card) {
                        const now = Answers.letters(q.id);
                        Array.prototype.slice.call(card.querySelectorAll('.sqb-opt')).forEach((b) => {
                            b.classList.toggle('on', now.indexOf(b.dataset.letter) >= 0);
                        });
                        const flag = card.querySelector('.sqb-flag');
                        if (flag) flag.remove();
                    }
                    if (prog) {
                        let a = 0;
                        list.forEach((item) => { if (Answers.letters(item.q.id).length) a++; });
                        prog.textContent = '已答 ' + a + ' / ' + list.length;
                    }
                    this.refreshCounters();
                });
            });
        },

        renderExamPane() {
            const el = document.getElementById('sqb-exam-status');
            if (el) el.textContent = Exam.records.length
                ? '已识别试卷：共 ' + Exam.records.length + ' 题，可点「展开整张试卷」重开。'
                : '未检测到考试。开考后会自动展开整张试卷。';
        }
    };

    // ============================ 17. 启动 ============================
    function boot() {
        Bank.load();
        Answers.load();

        if (typeof GM_addStyle === 'function') GM_addStyle(CSS);
        else {
            const st = document.createElement('style');
            st.textContent = CSS;
            document.head.appendChild(st);
        }

        UI.buildPanel();
        UI.syncCollectButtons();
        UI.renderExamPane();
        Video.bind();
        Video.start();
        S.examSink = (data) => Exam.capture(data);
        S.examSubmitSink = (data) => Exam.onResult(data);

        log('已启动 ' + SCRIPT_INFO.name + ' v' + SCRIPT_INFO.version +
            '｜graphId=' + (S.graphId || '未取到') + '｜题库 ' + Bank.stats().chapters + ' 章');
        if (!S.graphId) log('提示：先进「我的课程 → 某门课」详情页，再点「开始采集」');
    }

    installHook();
    if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', boot);
    else boot();

    window.__SQB__ = () => ({
        version: SCRIPT_INFO.version,
        token: !!S.token,
        graphId: S.graphId,
        courseId: S.courseId,
        running: S.running,
        bank: Bank.stats(),
        answers: Object.keys(Answers.data || {}).length,
        exam: { active: Exam.active, records: Exam.records.length },
        cfg: Object.assign({}, cfg)
    });
})();