// ==UserScript==
// @name         柳大师 - 学习助手（v10.9.3）
// @namespace    local.liudashi.study-helper
// @version      10.9.3
// @description  视频+课件+测验 任务队列 + 自动翻页 + AI答题
// @author       柳大师
// @match        *://*.chaoxing.com/*
// @match        *://*.fanya.chaoxing.com/*
// @match        *://i.chaoxing.com/*
// @match        *://passport2.chaoxing.com/*
// @match        *://*.zhihuishu.com/*
// @match        *://*.icourse163.org/*
// @match        *://*.xuetangx.com/*
// @match        *://*.icve.com.cn/*
// @match        *://*.ulearning.cn/*
// @match        *://*.cnmooc.org/*
// @match        *://*.edu.cn/*
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_xmlhttpRequest
// @grant        GM_registerMenuCommand
// @connect      open.bigmodel.cn
// @connect      api.deepseek.com
// @connect      dashscope.aliyuncs.com
// @connect      api.gomooc.net
// @connect      *
// @run-at       document-idle
// ==/UserScript==

(function () {
    'use strict';
    if (window._sh_script_injected) return;
    window._sh_script_injected = true;

    const BRAND = '柳大师';
    const VERSION = '10.9.2';
    const IS_TOP = window.top === window.self;

    function getGreeting() {
        const h = new Date().getHours();
        if (h < 6) return '凌晨好';
        if (h < 11) return '上午好';
        if (h < 13) return '中午好';
        if (h < 18) return '下午好';
        return '晚上好';
    }
    const sleep = ms => new Promise(r => setTimeout(r, ms));
    const rand = (a, b) => a + Math.random() * (b - a);
    const log = (...a) => console.log(`[${BRAND}]`, ...a);

    const LOCK_KEY = 'sh_video_lock_v8';
    const FRAME_ID = 'f_' + Math.random().toString(36).slice(2, 10) + '_' + Date.now();
    let HOST = null, ROOT = null, BALL_EL = null, PANEL_EL = null;

    function readLock() { try { const r = localStorage.getItem(LOCK_KEY); if (!r) return null; const d = JSON.parse(r); return (Date.now() - d.heartbeat > 30000) ? null : d; } catch (e) { return null; } }
    function writeLock(d) { try { localStorage.setItem(LOCK_KEY, JSON.stringify(d)); } catch (e) {} }
    function clearLock() { try { if (readLock()?.frameId === FRAME_ID) localStorage.removeItem(LOCK_KEY); } catch (e) {} }
    function acquireLock(src) { const now = Date.now(); let d = readLock(); if (!d) { writeLock({ frameId: FRAME_ID, src: src || '', heartbeat: now }); return true; } if (d.frameId === FRAME_ID) { d.heartbeat = now; writeLock(d); return true; } return false; }
    function lockHeldByOther() { const d = readLock(); return d && d.frameId !== FRAME_ID; }
    setInterval(() => { const d = readLock(); if (d?.frameId === FRAME_ID) { d.heartbeat = Date.now(); writeLock(d); } }, 10000);

    const AI_PROVIDERS = {
        zhipu: { name: '智谱 GLM-4-Flash', url: 'https://open.bigmodel.cn/api/paas/v4/chat/completions', model: 'glm-4-flash', tip: '完全免费 · 手机号注册', registerUrl: 'https://open.bigmodel.cn/' },
        deepseek: { name: 'DeepSeek', url: 'https://api.deepseek.com/v1/chat/completions', model: 'deepseek-chat', tip: '注册送额度', registerUrl: 'https://platform.deepseek.com/' },
        qwen: { name: '通义千问', url: 'https://dashscope.aliyuncs.com/compatible-mode/v1/chat/completions', model: 'qwen-turbo', tip: '新用户免费额度', registerUrl: 'https://dashscope.console.aliyun.com/' },
    };

    const CONFIG = {
        enabled: GM_getValue('sh_enabled', true),
        autoPlay: GM_getValue('sh_autoPlay', true),
        autoNext: GM_getValue('sh_autoNext', true),
        autoAnswer: GM_getValue('sh_autoAnswer', true),
        aiEnabled: GM_getValue('sh_aiEnabled', true),
        autoSubmit: GM_getValue('sh_autoSubmit', false),
        stealthMode: GM_getValue('sh_stealthMode', true),
        muteFallback: GM_getValue('sh_muteFallback', true),
        playbackRate: GM_getValue('sh_playbackRate', 1.5),
        nextDelay: GM_getValue('sh_nextDelay', 10),
        darkMode: GM_getValue('sh_darkMode', false),
        aiProvider: GM_getValue('sh_aiProvider', 'zhipu'),
        aiKeys: GM_getValue('sh_aiKeys', {}),
        enableFreeBank: GM_getValue('sh_enableFreeBank', true),
        ballPos: GM_getValue('sh_ballPos', { side: 'right', top: 100 }),
    };
    function saveConfig() { try { Object.keys(CONFIG).forEach(k => GM_setValue('sh_' + k, CONFIG[k])); } catch (e) {} }
    function domGet(id) { try { return ROOT?.getElementById(id); } catch (e) { return null; } }
    function domQueryAll(sel) { try { return ROOT ? Array.from(ROOT.querySelectorAll(sel)) : []; } catch (e) { return []; } }

    function loadBank() { try { return GM_getValue('sh_qbank', {}); } catch (e) { return {}; } }
    function saveBank(b) { try { GM_setValue('sh_qbank', b); } catch (e) {} }
    function hashQ(t) { const c = (t || '').replace(/\s+/g, '').slice(0, 200); let h = 0; for (let i = 0; i < c.length; i++) { h = ((h << 5) - h) + c.charCodeAt(i); h |= 0; } return 'q_' + Math.abs(h).toString(36); }
    function queryBank(t) { const b = loadBank(); const e = b[hashQ(t)]; return e ? e.a : null; }
    function recordBank(t, a, type, src) {
        if (!t || !a) return false;
        const b = loadBank(); const k = hashQ(t); const ex = b[k];
        if (ex && ex.src === 'system' && ex.a === a) return false;
        if (ex && ex.src === 'system' && src === 'ai') return false;
        b[k] = { q: t.slice(0, 300), a, type: type || 'radio', t: Date.now(), src: src || 'ai' };
        const keys = Object.keys(b);
        if (keys.length > 5000) { keys.sort((x, y) => (b[x].t || 0) - (b[y].t || 0)); keys.slice(0, 1000).forEach(kk => delete b[kk]); }
        saveBank(b); return true;
    }
    function deleteBankEntry(k) { const b = loadBank(); if (b[k]) { delete b[k]; saveBank(b); return true; } return false; }
    function listBank(f) { const b = loadBank(); let arr = Object.entries(b).map(([k, v]) => ({ key: k, ...v })); if (f) { const s = f.toLowerCase(); arr = arr.filter(it => (it.q || '').toLowerCase().includes(s) || (it.a || '').toLowerCase().includes(s)); } return arr.sort((a, b) => (b.t || 0) - (a.t || 0)); }
    function bankStats() { const b = loadBank(); let sys = 0, ai = 0, man = 0; Object.values(b).forEach(v => { if (v.src === 'system') sys++; else if (v.src === 'manual') man++; else ai++; }); return { total: Object.keys(b).length, sys, ai, man }; }

    const TASK_CARD_SELECTORS = [
        '.ans-job-item', '.posCatalog_select', '.chapter_item', '.catalog_points', '.jobItem',
        '[class*="ans-job"]', '[class*="job-item"]', '[class*="catalog_points"]',
    ];
    const COMPLETED_MARKERS = [
        '.icon_Completed', '.ans-job-icon-come', '.ans-job-icon.ans-job-icon-come',
        '.icon-dui', '.icon-success', '[class*="complete"]', '[class*="finish"]',
        '[class*="done"]', '[class*="success"]', '[class*="dui"]', '[class*="passed"]', '[class*="checked"]',
    ];
    const PPT_FRAME_HINTS = /ppt|slide|panview|document|pdf|doc|viewer|office/i;
    const PPT_NEXT_BTN_SELECTORS = [
        '.ppt_next', '.nextBtn', '.next-btn', '.btn-next', '.slide-next',
        '[title*="下一页"]', '[aria-label*="下一页"]', '[class*="next-page"]',
        '[class*="nextPage"]', '[class*="next_page"]', '.arrow-right', '.arrowRight',
        '.icon-next', '[class*="arrow"][class*="right"]', 'a[data-page="next"]',
    ];

    function isGreenColor(str) {
        if (!str) return false;
        if (str.includes('green') || str.includes('success') || str.includes('complete') || str.includes('done')) return true;
        const m = str.match(/rgba?\((\d+),\s*(\d+),\s*(\d+)/);
        if (m) { const [r, g, b] = m.slice(1, 4).map(Number); return g > 120 && g > r * 1.15 && g > b * 1.15; }
        return false;
    }
    function isCardCompleted(card) {
        if (!card) return false;
        for (const sel of COMPLETED_MARKERS) {
            const marks = card.querySelectorAll(sel);
            for (const mark of marks) {
                const st = getComputedStyle(mark);
                if (isGreenColor(st.color) || isGreenColor(st.backgroundColor) || isGreenColor(st.borderColor)) return true;
                try { const bf = getComputedStyle(mark, '::before'); if (/["']?[✓✔√]/.test(bf.content || '')) return true; if (isGreenColor(bf.color) || isGreenColor(bf.backgroundColor)) return true; } catch (e) {}
                const lb = (mark.getAttribute('aria-label') || mark.getAttribute('title') || '').trim();
                if (/完成|已学|已看/.test(lb)) return true;
            }
        }
        const textEls = card.querySelectorAll('span, div, em, i, p, b, strong, label');
        for (const el of textEls) {
            const t = (el.textContent || '').trim();
            if (t.length > 15) continue;
            if (/^(任务点已完成|已完成|已学完|完成学习|学习完成|通过|已通过)$/.test(t)) {
                const st = getComputedStyle(el);
                if (isGreenColor(st.color)) return true;
                const p = el.parentElement;
                if (p) { const ps = getComputedStyle(p); if (isGreenColor(ps.color) || isGreenColor(ps.backgroundColor)) return true; }
            }
        }
        return false;
    }

    function getCardType(card) {
        if (!card) return 'unknown';
        if (card.querySelector('video')) return 'video';
        const iframes = card.querySelectorAll('iframe');
        for (const f of iframes) {
            if (/video|media|player|ananas/i.test(f.src || '')) return 'video';
            if (PPT_FRAME_HINTS.test(f.src || '')) {
                try {
                    const idoc = f.contentDocument || f.contentWindow?.document;
                    if (idoc && (idoc.querySelector('video'))) return 'video';
                } catch (e) {}
                return 'ppt';
            }
        }
        const text = card.textContent || '';
        if (/测验|答题|选择题|判断题|考试|考核/.test(text)) return 'quiz';
        if (/视频|视屏|课程视频|观看/.test(text)) return 'video';
        if (/课件|文档|阅读|ppt|PPT|幻灯片|PPT课件/.test(text)) return 'ppt';
        if (/pdf|PDF/.test(text)) return 'doc';
        const cls = (card.className || '').toString();
        if (/video/i.test(cls)) return 'video';
        if (/ppt|slide|courseware/i.test(cls)) return 'ppt';
        if (/doc|read|pdf/i.test(cls)) return 'doc';
        if (/quiz|exam|test/i.test(cls)) return 'quiz';
        return 'unknown';
    }

    function scanTaskCards() {
        const cardSet = new Set();
        for (const sel of TASK_CARD_SELECTORS) { try { document.querySelectorAll(sel).forEach(el => cardSet.add(el)); } catch (e) {} }
        const cards = [...cardSet].sort((a, b) => {
            const p = a.compareDocumentPosition(b);
            if (p & Node.DOCUMENT_POSITION_FOLLOWING) return -1;
            if (p & Node.DOCUMENT_POSITION_PRECEDING) return 1;
            return 0;
        });
        const queue = [];
        for (const card of cards) {
            const rect = card.getBoundingClientRect();
            if (rect.width < 50 || rect.height < 20) continue;
            if (isCardCompleted(card)) { const v = card.querySelector('video'); if (v) v.dataset.shTaskDone = '1'; continue; }
            const type = getCardType(card);
            if (type === 'unknown' && !card.querySelector('video') && !card.querySelector('iframe')) { card.dataset.shSkipped = '1'; continue; }
            queue.push({ card, type, video: card.querySelector('video'), text: (card.textContent || '').trim().slice(0, 60) });
        }
        return queue;
    }

    let CURRENT_TASK = null, IS_SWITCHING = false, VIDEO_ENDED_AT = 0, LAST_ACTION = 0, LAST_SCAN_AT = 0;
    const SCAN_INTERVAL = 3000;
    const QUIZ_TIMEOUT = 5 * 60 * 1000;
    const PPT_STALL_TIMEOUT = 90 * 1000;

    function findVideoInCard(card) {
        if (!card) return null;
        let v = card.querySelector('video');
        if (v) return v;
        const ifr = card.querySelectorAll('iframe');
        for (const f of ifr) { try { const d = f.contentDocument || f.contentWindow?.document; if (d) { v = d.querySelector('video'); if (v) return v; } } catch (e) {} }
        return null;
    }

    function findPptFrame(card) {
        if (!card) return null;
        const iframes = [...card.querySelectorAll('iframe')];
        for (const f of iframes) {
            if (PPT_FRAME_HINTS.test(f.src || '')) return f;
        }
        for (const f of iframes) {
            try { const d = f.contentDocument; if (d && d.body) return f; } catch (e) {}
        }
        if (card.querySelector('[class*="slide"], [class*="ppt"], [class*="panview"]')) return null;
        return null;
    }

    function tryClickPptNext(pageDoc) {
        if (!pageDoc) return false;
        for (const sel of PPT_NEXT_BTN_SELECTORS) {
            try {
                const btns = pageDoc.querySelectorAll(sel);
                for (const b of btns) {
                    const style = pageDoc.defaultView ? pageDoc.defaultView.getComputedStyle(b) : null;
                    if (style && (style.display === 'none' || style.visibility === 'hidden')) continue;
                    if (b.disabled) continue;
                    const txt = (b.textContent || '').trim();
                    const title = (b.getAttribute('title') || b.getAttribute('aria-label') || '').trim();
                    if (/上一页|prev|previous/i.test(txt + ' ' + title)) continue;
                    try { b.click(); return true; } catch (e) {}
                    try {
                        b.dispatchEvent(new MouseEvent('click', { bubbles: true, cancelable: true, view: pageDoc.defaultView || window }));
                        return true;
                    } catch (e) {}
                }
            } catch (e) {}
        }
        try {
            const allClickable = pageDoc.querySelectorAll('a, button, span, div[onclick]');
            for (const el of allClickable) {
                const t = (el.textContent || '').trim();
                if (t.length > 10) continue;
                if (/^(下一页|下一张|继续|next)$/i.test(t)) {
                    try { el.click(); return true; } catch (e) {}
                }
            }
        } catch (e) {}
        return false;
    }

    function tryPressPptKey(pageDoc) {
        if (!pageDoc) return;
        const win = pageDoc.defaultView || window;
        const targets = [pageDoc.body, pageDoc.documentElement].filter(Boolean);
        const keys = ['ArrowRight', 'PageDown', ' ', 'Right'];
        keys.forEach(k => {
            targets.forEach(t => {
                try {
                    t.dispatchEvent(new KeyboardEvent('keydown', { key: k, keyCode: k === 'ArrowRight' ? 39 : k === 'PageDown' ? 34 : 32, bubbles: true }));
                    t.dispatchEvent(new KeyboardEvent('keyup', { key: k, keyCode: k === 'ArrowRight' ? 39 : k === 'PageDown' ? 34 : 32, bubbles: true }));
                } catch (e) {}
            });
            try {
                win.dispatchEvent(new KeyboardEvent('keydown', { key: k, bubbles: true }));
                win.dispatchEvent(new KeyboardEvent('keyup', { key: k, bubbles: true }));
            } catch (e) {}
        });
    }

    async function handlePptTask(task) {
        if (isCardCompleted(task.card)) return 'done';
        const frame = findPptFrame(task.card);
        let pageDoc = null;
        try { pageDoc = frame ? (frame.contentDocument || frame.contentWindow?.document) : null; } catch (e) { pageDoc = null; }
        if (!pageDoc) pageDoc = task.card.ownerDocument;
        if (tryClickPptNext(pageDoc)) return 'clicked';
        if (pageDoc !== task.card.ownerDocument) {
            if (tryClickPptNext(task.card.ownerDocument)) return 'clicked';
        }
        tryPressPptKey(pageDoc);
        return 'key';
    }

    async function pollLoop() {
        if (!CONFIG.enabled || !CONFIG.autoPlay || IS_SWITCHING) return;
        if (lockHeldByOther()) { document.querySelectorAll('video').forEach(v => { if (!v.paused) try { v.pause(); } catch (e) {} }); return; }

        const now = Date.now();
        if (now - LAST_SCAN_AT > SCAN_INTERVAL) {
            LAST_SCAN_AT = now;
            if (CURRENT_TASK && CURRENT_TASK.card && isCardCompleted(CURRENT_TASK.card)) { await finishTask(CURRENT_TASK, true); return; }
        }

        if (CURRENT_TASK) {
            const task = CURRENT_TASK;

            if (task.type === 'quiz') {
                if (!task.card || !document.contains(task.card)) { log('📤 quiz 卡片已移除，释放'); releaseTask(); return; }
                if (task.startTime && (now - task.startTime > QUIZ_TIMEOUT)) { log('⏱ quiz 超时释放'); releaseTask(); return; }
                if (isCardCompleted(task.card)) { await finishTask(task, true); return; }
                return;
            }

            if (task.type === 'ppt' || task.type === 'doc') {
                if (!task.card || !document.contains(task.card)) { log('📤 ppt 卡片已移除，释放'); releaseTask(); return; }
                if (isCardCompleted(task.card)) { log('✅ 课件完成'); await finishTask(task, true); return; }
                if (task.lastActionTime && (now - task.lastActionTime > PPT_STALL_TIMEOUT) && (now - task.startTime > PPT_STALL_TIMEOUT * 2)) {
                    log('⚠️ 课件长时间无进展，释放任务'); releaseTask(); return;
                }
                if (!task.lastActionTime || now - task.lastActionTime > 2500) {
                    task.lastActionTime = now;
                    const result = await handlePptTask(task);
                    if (result === 'done') { await finishTask(task, true); return; }
                    log('📄 课件翻页:', result);
                }
                updateStatus('课件翻页中');
                return;
            }

            const v = task.video;
            if (!v || !document.contains(v)) {
                if (task.card && isCardCompleted(task.card)) await finishTask(task, true);
                else releaseTask();
                return;
            }
            const cardDone = task.card && isCardCompleted(task.card);
            const ended = v.ended || (v.duration && v.currentTime / v.duration >= 0.99);
            if (ended && !VIDEO_ENDED_AT) { VIDEO_ENDED_AT = Date.now(); updateStatus('等待任务点变绿'); }
            if (cardDone) { const n = Date.now(); if (n - LAST_ACTION < 1000) return; LAST_ACTION = n; await finishTask(task); return; }
            if (ended && VIDEO_ENDED_AT && Date.now() - VIDEO_ENDED_AT > 90000) { log('⚠️ 视频超时强制通过'); await finishTask(task, true); return; }
            if (v.paused && !ended) { try { await v.play(); applyRateDynamic(v, CONFIG.playbackRate); updateStatus('播放中'); } catch (e) { v.muted = true; try { await v.play(); } catch (e2) {} } }
            else if (!ended) { applyRateDynamic(v, CONFIG.playbackRate); updateStatus('播放中'); }
            return;
        }

        const queue = scanTaskCards();
        if (!queue.length) {
            const quizCount = document.querySelectorAll('.TiMu').length;
            const videoCount = document.querySelectorAll('video').length;
            if (quizCount > 0 && videoCount === 0) return;
            if (IS_TOP) await goNext();
            return;
        }

        const head = queue[0];
        log(`▶ [${head.type}]`, head.text);

        if (head.type === 'video') {
            const v = findVideoInCard(head.card) || head.video;
            if (!v) { if (head.card) head.card.dataset.shTried = '1'; return; }
            if (!acquireLock(v.currentSrc || 'video')) return;
            CURRENT_TASK = head;
            CURRENT_TASK.video = v;
            CURRENT_TASK.startTime = Date.now();
            VIDEO_ENDED_AT = 0;
            try { head.card.click(); } catch (e) {}
            await sleep(1500);
            await playVideoElement(v);
            return;
        } else if (head.type === 'ppt' || head.type === 'doc') {
            CURRENT_TASK = head;
            CURRENT_TASK.video = null;
            CURRENT_TASK.startTime = Date.now();
            CURRENT_TASK.lastActionTime = 0;
            log('📄 进入课件任务');
            try { head.card.click(); } catch (e) {}
            await sleep(2000);
            const result = await handlePptTask(head);
            if (result === 'done') await finishTask(head, true);
            return;
        } else if (head.type === 'quiz') {
            CURRENT_TASK = head;
            CURRENT_TASK.video = null;
            CURRENT_TASK.startTime = Date.now();
            log('📝 进入测验任务');
            try { head.card.click(); } catch (e) {}
            return;
        }
    }

    async function playVideoElement(v) {
        if (!v) return;
        applyRateDynamic(v, CONFIG.playbackRate);
        try { await v.play(); updateStatus('播放中'); }
        catch (e) { if (CONFIG.muteFallback && !v.muted) { v.muted = true; try { await v.play(); updateStatus('播放中(静音)'); } catch (e2) {} } }
    }

    async function finishTask(task, force = false) {
        if (!task) return;
        if (task.card) try { task.card.dataset.shTaskDone = '1'; } catch (e) {}
        if (task.video) try { task.video.dataset.shTaskDone = '1'; task.video.pause(); } catch (e) {}
        const delay = 3000 + Math.random() * 12000;
        updateStatus(`延时 ${(delay / 1000).toFixed(0)}s`);
        clearLock();
        releaseTask();
        await sleep(delay);
        setTimeout(() => pollLoop().catch(() => {}), 100);
    }
    function releaseTask() {
        if (CURRENT_TASK?.video) try { CURRENT_TASK.video.dataset.shActive = '0'; } catch (e) {}
        CURRENT_TASK = null;
        VIDEO_ENDED_AT = 0;
    }

    let lastNext = 0;
    async function goNext() {
        const now = Date.now(); if (now - lastNext < 30000) return; lastNext = now;
        IS_SWITCHING = true; updateStatus('切换中...');
        const cooldown = CONFIG.stealthMode ? rand(180000, 480000) : 0;
        await sleep(CONFIG.nextDelay * 1000 + cooldown);
        tryClickNext();
        setTimeout(() => { IS_SWITCHING = false; setTimeout(() => pollLoop().catch(() => {}), 3000); }, 8000);
    }
    function tryClickNext() {
        const sels = ['.next', '.next-btn', '.nextSection', '.next-section', '.chapter-next', '.section-next', '#nextBtn', '[class*="nextBtn"]', '[class*="next"] button', '.nextChapter', '.next-chapter', '[title*="下一"]', 'a[href*="next"]'];
        for (const s of sels) { const b = document.querySelector(s); if (b && b.offsetParent !== null && !b.disabled) { b.click(); return true; } }
        for (const el of document.querySelectorAll('a,button,span,div[onclick]')) {
            const t = (el.textContent || '').trim();
            if (t && t.length <= 20 && /^下一[节章课]|继续学习|next$/i.test(t) && el.offsetParent !== null) { el.click(); return true; }
        }
        return false;
    }

    async function queryFreeBank(q) {
        if (!CONFIG.enableFreeBank) return null;
        return new Promise(res => {
            GM_xmlhttpRequest({
                method: 'GET', url: `https://api.gomooc.net/api.php?question=${encodeURIComponent(q)}`, timeout: 5000,
                onload: r => { try { const d = JSON.parse(r.responseText); const a = d.answer || (d.data && d.data.answer); res(a || null); } catch (e) { res(null); } },
                onerror: () => res(null), ontimeout: () => res(null)
            });
        });
    }

    async function callAI(q, opts, type) {
        if (!CONFIG.aiEnabled) return null;
        const prov = AI_PROVIDERS[CONFIG.aiProvider];
        const key = (CONFIG.aiKeys || {})[CONFIG.aiProvider];
        if (!prov || !key) { log(`❌ 未配置 ${prov?.name || 'AI'} 的 Key`); return null; }

        let sys, usr;
        if (type === 'radio' || type === 'checkbox') {
            const optTexts = opts.map(o => o.text || o);
            const isJudge = opts.length === 2 && optTexts.some(t => /对|错|是|否|正确|错误/.test(t));
            if (isJudge) {
                sys = `你是一位答题助手。用户会给你一道判断题。必须严格遵守：\n1. 只输出一个字："对" 或 "错"\n2. 不要输出任何解释、标点、其他文字\n3. 如果题目有乱码，根据上下文推测原题再判断\n示例输出："对"`;
                usr = `判断题：${q}\n\n只回答"对"或"错"：`;
            } else {
                const optText = opts.map((o, i) => `${String.fromCharCode(65 + i)}. ${o.text || o}`).join('\n');
                sys = `你是一位答题助手。用户会给你一道选择题。必须严格遵守：\n1. 只输出选项字母，如 "A" 或 "AC" 或 "ABD"\n2. 不要输出任何解释、标点、其他文字\n3. 单选题只输出 1 个字母，多选题输出所有正确字母不带空格\n4. 如果题目有乱码，根据上下文推测原题再作答\n示例输出："A"`;
                usr = `题目：${q}\n\n选项：\n${optText}\n\n只回答选项字母：`;
            }
        } else if (type === 'blank') {
            sys = `你是一位答题助手。填空题必须严格遵守：\n1. 只输出答案内容，多个空用 || 分隔\n2. 不要输出任何解释、题号、"答案："等前缀\n3. 如果题目有乱码，根据上下文推测原题再作答\n示例输出："北京" 或 "异步电动机||变频调速"`;
            usr = `填空题：${q}\n\n只回答答案内容：`;
        } else {
            sys = `你是一位答题助手。只输出答案内容，不要解释。`;
            usr = `题目：${q}\n答案：`;
        }

        log(`🤖 调用 ${prov.name}`);
        const res = await new Promise(r => {
            GM_xmlhttpRequest({
                method: 'POST', url: prov.url,
                headers: { 'Content-Type': 'application/json', 'Authorization': `Bearer ${key}` },
                data: JSON.stringify({ model: prov.model, messages: [{ role: 'system', content: sys }, { role: 'user', content: usr }], max_tokens: 200, temperature: 0.1 }),
                timeout: 20000,
                onload: x => {
                    log('📥 AI 状态:', x.status);
                    try {
                        const d = JSON.parse(x.responseText);
                        if (d.error) { log('❌ AI 错误:', JSON.stringify(d.error).slice(0, 200)); r(null); return; }
                        const t = d.choices[0].message.content.trim();
                        log('✅ AI 原始返回:', t);
                        r(t);
                    } catch (e) { log('❌ 解析失败:', e.message); r(null); }
                },
                onerror: () => { log('❌ AI 网络错误'); r(null); },
                ontimeout: () => { log('❌ AI 超时'); r(null); }
            });
        });
        if (!res) return null;
        return extractAnswerFromText(res, type, opts);
    }

    function extractAnswerFromText(text, type, opts) {
        if (!text) return null;
        const t = String(text).trim();
        if (type === 'radio' || type === 'checkbox') {
            const optTexts = (opts || []).map(o => o.text || o);
            const isJudge = (opts || []).length === 2 && optTexts.some(o => /对|错|是|否|正确|错误/.test(o));
            if (isJudge) {
                if (/(?:答案|正确答案)[：:是\s]*错/.test(t) || /^错/.test(t) || /判断为错|应该是错|答案是错/.test(t)) return '错';
                if (/(?:答案|正确答案)[：:是\s]*对/.test(t) || /^对/.test(t) || /判断为对|应该是对|答案是对/.test(t)) return '对';
                if (/[×✘]/.test(t)) return '错';
                if (/[√✔]/.test(t)) return '对';
                const hasErr = /错误/.test(t), hasCorr = /正确/.test(t);
                if (hasErr && !hasCorr) return '错';
                if (hasCorr && !hasErr) return '对';
                return t.slice(0, 3);
            }
            const m1 = t.match(/(?:答案|正确答案|选|应选|答案为|答案是)[：:是\s]*([A-D]{1,4})/i);
            if (m1) return m1[1].toUpperCase();
            const m2 = t.match(/^[A-D]{1,4}$/);
            if (m2) return t.toUpperCase();
            const letters = t.match(/[A-D]/g);
            if (letters && letters.length > 0 && letters.length <= 4) return [...new Set(letters)].sort().join('');
            return t.slice(0, 20);
        }
        if (type === 'blank' || type === 'short') {
            let a = t.replace(/^(?:答案|正确答案|答案为|答案是)[：:是\s]*/, '').trim();
            a = a.replace(/^["'「『]/, '').replace(/["'」』]$/, '');
            return a || null;
        }
        return t;
    }

    function inViewport(el) { const r = el.getBoundingClientRect(); return r.width > 0 && r.height > 0 && r.bottom > 0 && r.right > 0 && r.top < innerHeight && r.left < innerWidth; }
    function isQuestionText(t) { if (!t || t.length < 3) return false; const cn = t.match(/[\u4e00-\u9fa5]/g); if (cn && cn.length / t.length >= 0.1) return true; return /^[a-zA-Z0-9\s.,;:'"!?()\-]+$/.test(t) && t.length > 8; }
    const Q_SELS = ['.TiMu', '.question-item', '.topic-item', '[class*="question"]', '[class*="exam-item"]', '.pop-question', '.quiz-item', '.ans-video-question', '[class*