// ==UserScript==
// @name         WeLearn 自动刷课脚本（小屏返回修复V3）
// @namespace    http://tampermonkey.net/
// @version      7.3
// @description  修复小屏二级页面返回：遮罩点击+history.back，全量播放+面板+持久化+防挂机
// @match        https://welearn.sflep.com/student/StudyCourse.aspx*
// @grant        none
// @run-at       document-idle
// ==/UserScript==

(function() {
    'use strict';

    // ========== 配置 ==========
    const SCROLL_INTERVAL_MS = 2000;
    const CHECK_PLAY_END_MS = 2000;
    const CHAPTER_WAIT_MS = 8000;
    const ELEMENT_WAIT_MAX = 60;
    const ELEMENT_WAIT_STEP = 1000;
    const MEDIA_LOAD_TIMEOUT = 20000;
    const PROGRESS_TIMEOUT = 20000;
    const MAX_RETRIES = 2;
    const PROGRESS_STALL_COUNT = 4;
    const MIN_PLAY_DURATION = 5000;
    const MAX_RECOVER_ATTEMPTS = 3;
    const MAX_CHAPTER_INDEX = 4;
    const TOPIC_REVIEW_INTERVAL_MIN = 2;
    const TOPIC_REVIEW_INTERVAL_MAX = 3;
    const TOPIC_READ_DURATION_MIN = 5000;
    const TOPIC_READ_DURATION_MAX = 10000;
    const MOUSEOVER_INTERVAL = 30000;
    const RETURN_DELAY = 4000;           // 等待后尝试返回
    const RETURN_CHECK_INTERVAL = 500;

    const LS_KEY = 'welearn_auto_course_data';

    // ========== 全局状态 ==========
    let scrollTaskRunning = false;
    let scrollAbortController = null;
    let viewportKeeperRAF = null;
    let viewportKeeperInterval = null;
    let audioContextUnlocked = false;
    let mouseoverIntervalId = null;

    let state = {
        completedRounds: 0,
        currentChapterIdx: 0,
        remainingMediaQueue: [],
        openedTopics: []
    };

    let isLoopRunning = false;
    let abortController = null;
    let currentActivity = '空闲';
    let panelContainer = null;

    // ========== 工具函数 ==========
    const randomInt = (min, max) => Math.floor(Math.random() * (max - min + 1)) + min;
    const sleep = (ms, signal) => new Promise((resolve, reject) => {
        const timer = setTimeout(resolve, ms);
        if (signal) signal.addEventListener('abort', () => { clearTimeout(timer); reject(new Error('Aborted')); });
    });

    async function waitForElement(selector, scope, timeout = ELEMENT_WAIT_MAX) {
        for (let i = 0; i < timeout; i++) {
            if (!scope) { await sleep(ELEMENT_WAIT_STEP); continue; }
            const el = scope.querySelector(selector);
            if (el) return el;
            await sleep(ELEMENT_WAIT_STEP);
        }
        return null;
    }

    function getIframeDocument() {
        const iframe = document.querySelector('iframe[src*="e-textbook"], iframe[src*="readoor"]');
        return iframe?.contentDocument || null;
    }

    function getScrollContainer() {
        const doc = getIframeDocument();
        return doc?.querySelector('.text_middle_center') || doc?.querySelector('.el-scrollbar__wrap') || null;
    }

    function getTopicTitle(topicElement) {
        const titleEl = topicElement.querySelector('.title_name') || topicElement.querySelector('.el-collapse-item__title');
        return titleEl ? titleEl.textContent.trim() : '';
    }

    function getRealVideoItems() {
        const doc = getIframeDocument();
        if (!doc) return [];
        const allItems = Array.from(doc.querySelectorAll('.el-collapse-item'));
        return allItems.filter(item => {
            const hasCover = item.querySelector('.def_img_box');
            const hasVideoBox = item.querySelector('.video_box');
            const isExam = item.querySelector('[class*="exam"]') ||
                           item.innerHTML.includes('submitQuestion') ||
                           item.querySelector('.exam-box') ||
                           item.querySelector('.test-box');
            return (hasCover || hasVideoBox) && !isExam;
        });
    }

    function getAudioItems() {
        const doc = getIframeDocument();
        return doc ? Array.from(doc.querySelectorAll('.audio_deft_box')) : [];
    }

    function getNonMediaCollapseItems() {
        const doc = getIframeDocument();
        if (!doc) return [];
        const allItems = Array.from(doc.querySelectorAll('.el-collapse-item'));
        const videoItems = getRealVideoItems();
        return allItems.filter(item => {
            const isVideo = videoItems.includes(item);
            const containsAudioBox = item.querySelector('.audio_deft_box');
            return !isVideo && !containsAudioBox;
        });
    }

    function getAllChapterLeafNodes() {
        const doc = getIframeDocument();
        return doc ? Array.from(doc.querySelectorAll('.el-tree-node.is_chapter.noChildren')) : [];
    }

    // ========== 持久化 ==========
    function loadState() {
        try {
            const data = localStorage.getItem(LS_KEY);
            if (data) {
                const parsed = JSON.parse(data);
                state.completedRounds = parsed.completedRounds || 0;
                state.currentChapterIdx = parsed.currentChapterIdx ?? 0;
                state.remainingMediaQueue = parsed.remainingMediaQueue || [];
                state.openedTopics = parsed.openedTopics || [];
            }
        } catch (e) {}
    }

    function saveState() {
        try {
            localStorage.setItem(LS_KEY, JSON.stringify(state));
        } catch (e) {}
    }

    function markTopicOpened(topicElement) {
        const title = getTopicTitle(topicElement);
        if (title && !state.openedTopics.includes(title)) {
            state.openedTopics.push(title);
            saveState();
        }
    }

    // ========== 焦点伪造 + 防挂机 ==========
    function setupFocusSpoofing() {
        try { Object.defineProperty(document, 'hasFocus', { value: () => true, writable: false, configurable: false }); } catch (e) {}
        window.addEventListener('blur', e => { e.stopImmediatePropagation(); window.focus(); }, true);
        window.addEventListener('focus', e => e.stopImmediatePropagation(), true);
        setTimeout(() => {
            const doc = getIframeDocument();
            if (doc?.defaultView) {
                const win = doc.defaultView;
                try { Object.defineProperty(win.document, 'hasFocus', { value: () => true, writable: false, configurable: false }); } catch (e) {}
                win.addEventListener('blur', e => { e.stopImmediatePropagation(); win.focus(); }, true);
                win.addEventListener('focus', e => e.stopImmediatePropagation(), true);
            }
        }, 2000);
    }

    function startMouseoverSimulation() {
        if (mouseoverIntervalId) return;
        mouseoverIntervalId = setInterval(() => {
            const doc = getIframeDocument();
            if (doc?.body) {
                doc.body.dispatchEvent(new MouseEvent('mouseover', {
                    bubbles: true, cancelable: true, view: doc.defaultView
                }));
                try {
                    if (parent && parent.document && parent.document.body) {
                        parent.document.body.click();
                    }
                } catch (e) {}
            }
        }, MOUSEOVER_INTERVAL);
    }

    function stopMouseoverSimulation() {
        if (mouseoverIntervalId) { clearInterval(mouseoverIntervalId); mouseoverIntervalId = null; }
    }

    // ========== 防离开检测 ==========
    function preventLeavingDetection() {
        try {
            Object.defineProperty(document, 'hidden', { get: () => false, configurable: false });
            Object.defineProperty(document, 'visibilityState', { get: () => 'visible', configurable: false });
        } catch (e) {}
        window.addEventListener('visibilitychange', e => e.stopImmediatePropagation(), true);
    }

    function preventLeavingInIframe(doc) {
        if (!doc) return;
        try {
            Object.defineProperty(doc, 'hidden', { get: () => false, configurable: false });
            Object.defineProperty(doc, 'visibilityState', { get: () => 'visible', configurable: false });
        } catch (e) {}
        doc.addEventListener('visibilitychange', e => e.stopImmediatePropagation(), true);
    }

    // ========== 音频上下文 ==========
    function unlockAudioContexts() {
        if (typeof AudioContext !== 'undefined') {
            if (!window.__audioContexts) window.__audioContexts = [];
            window.__audioContexts.forEach(ctx => { if (ctx.state === 'suspended') ctx.resume().catch(() => {}); });
        }
        audioContextUnlocked = true;
    }

    function hijackAudioContextCreation(win) {
        if (!win?.AudioContext) return;
        const Orig = win.AudioContext;
        win.AudioContext = function(...args) {
            const ctx = new Orig(...args);
            if (!win.__audioContexts) win.__audioContexts = [];
            win.__audioContexts.push(ctx);
            return ctx;
        };
        win.AudioContext.prototype = Orig.prototype;
    }

    // ========== 章节操作 ==========
    async function ensureDrawerOpen() {
        const doc = getIframeDocument();
        if (!doc) return;
        if (doc.querySelector('.el-drawer.open')) return;
        const menuBtn = await waitForElement('.ymhicon.ymh-ebookopen', doc, 5);
        if (menuBtn) { menuBtn.click(); await sleep(2000); }
    }

    async function clickChapterNode(chapterEl) {
        const doc = getIframeDocument();
        if (!doc || !chapterEl) return false;
        await ensureDrawerOpen();
        chapterEl.scrollIntoView?.({ block: 'nearest', behavior: 'auto' });
        await sleep(300);
        const content = chapterEl.querySelector('.el-tree-node__content');
        if (content) { content.click(); return true; }
        return false;
    }

    async function goToChapter(idx) {
        const chapters = getAllChapterLeafNodes();
        if (idx < 0 || idx >= chapters.length) return false;
        const success = await clickChapterNode(chapters[idx]);
        if (success) {
            state.currentChapterIdx = idx;
            const videos = getRealVideoItems();
            const audios = getAudioItems();
            const fullList = [];
            videos.forEach((v, i) => fullList.push({ type: 'video', index: i }));
            audios.forEach((a, i) => fullList.push({ type: 'audio', index: i }));
            state.remainingMediaQueue = fullList;
            saveState();
            currentActivity = `进入第${idx+1}章`;
        }
        return success;
    }

    // ========== 滚动 ==========
    function performRealScroll(container) {
        const max = container.scrollHeight - container.clientHeight;
        if (max <= 0) return;
        const targetY = randomInt(0, max);
        const delta = targetY > container.scrollTop ? 120 : -120;
        container.dispatchEvent(new MouseEvent('mousemove', { clientX: 100, clientY: 200, bubbles: true, cancelable: true, view: container.ownerDocument.defaultView }));
        container.dispatchEvent(new WheelEvent('wheel', { deltaX: 0, deltaY: delta, deltaMode: 0, bubbles: true, cancelable: true, view: container.ownerDocument.defaultView }));
        container.scrollTop = targetY;
    }

    function startScrollTask() {
        if (scrollTaskRunning) return;
        scrollTaskRunning = true;
        scrollAbortController = new AbortController();
        (async () => {
            while (!scrollAbortController.signal.aborted) {
                const container = getScrollContainer();
                if (container) performRealScroll(container);
                try { await sleep(SCROLL_INTERVAL_MS + randomInt(0, 1000), scrollAbortController.signal); } catch { break; }
            }
            scrollTaskRunning = false;
        })();
    }

    function stopScrollTask() {
        scrollAbortController?.abort();
        scrollAbortController = null;
    }

    // ========== 视口守护 ==========
    function startViewportKeeper(element) {
        stopViewportKeeper();
        const keep = () => {
            if (element?.isConnected) {
                element.scrollIntoView({ behavior: 'auto', block: 'center' });
                viewportKeeperRAF = requestAnimationFrame(keep);
            }
        };
        viewportKeeperRAF = requestAnimationFrame(keep);
        viewportKeeperInterval = setInterval(() => { if (element?.isConnected) element.scrollIntoView({ behavior: 'auto', block: 'center' }); }, 2000);
    }

    function stopViewportKeeper() {
        if (viewportKeeperRAF) { cancelAnimationFrame(viewportKeeperRAF); viewportKeeperRAF = null; }
        if (viewportKeeperInterval) { clearInterval(viewportKeeperInterval); viewportKeeperInterval = null; }
    }

    // ========== 进度检测 ==========
    function getProgress(mediaEl, audioBox) {
        if (mediaEl?.duration && !isNaN(mediaEl.currentTime)) return mediaEl.currentTime;
        if (audioBox) {
            const played = audioBox.querySelector('.aplayer-played');
            if (played) { const w = parseFloat(played.style.width); if (!isNaN(w)) return w; }
        }
        return null;
    }

    async function waitForRealPlaybackStart(mediaEl, audioBox, doc) {
        const start = getProgress(mediaEl, audioBox);
        if (start !== null && start > 0) return true;
        const t0 = Date.now();
        while (Date.now() - t0 < PROGRESS_TIMEOUT) {
            await sleep(1000);
            const now = getProgress(mediaEl, audioBox);
            if (now !== null && now > (start || 0)) return true;
            if (mediaEl?.ended) return true;
            if (mediaEl?.paused) mediaEl.play().catch(() => {});
        }
        return false;
    }

    // ========== 媒体播放 ==========
    async function playSingleVideo(videoItem) {
        const doc = getIframeDocument();
        if (!doc) return false;
        if (!videoItem.classList.contains('is-active')) {
            videoItem.querySelector('.el-collapse-item__header')?.click();
            await sleep(1500);
        }
        videoItem.querySelector('.def_img_box')?.click();
        await sleep(2000);
        let video = null;
        const st = Date.now();
        while (Date.now() - st < MEDIA_LOAD_TIMEOUT) {
            video = doc.querySelector('video');
            if (video?.readyState >= 2 && video.duration > 0) break;
            await sleep(1000);
        }
        if (!video) return false;
        video.muted = true;
        stopScrollTask();
        video.scrollIntoView({ behavior: 'smooth', block: 'center' });
        startViewportKeeper(video);
        currentActivity = '播放视频中...';
        let ok = false;
        for (let r = 0; r <= MAX_RETRIES; r++) {
            video.play().catch(() => {});
            await sleep(1000);
            if (await waitForRealPlaybackStart(video, null, doc)) { ok = true; break; }
            if (r < MAX_RETRIES) { video.pause(); await sleep(500); }
        }
        stopViewportKeeper();
        if (!ok) { startScrollTask(); return false; }
        while (!video.ended) {
            if (video.paused && !video.ended) video.play().catch(() => {});
            await sleep(CHECK_PLAY_END_MS);
        }
        startScrollTask();
        return true;
    }

    async function playSingleAudio(audioItem) {
        const doc = getIframeDocument();
        if (!doc) return false;
        stopScrollTask();
        audioItem.scrollIntoView({ behavior: 'smooth', block: 'center' });
        startViewportKeeper(audioItem);
        const playBtn = audioItem.querySelector('.playAudio');
        if (!playBtn) { stopViewportKeeper(); startScrollTask(); return false; }
        playBtn.click();
        await sleep(2000);
        const audioBox = await waitForElement('.audio_play_box', doc, 5);
        if (audioBox) {
            const btn = audioBox.querySelector('.aplayer-button');
            if (btn && !btn.classList.contains('aplayer-pause')) btn.click();
            await sleep(1000);
        }
        let audio = null;
        const st = Date.now();
        while (Date.now() - st < MEDIA_LOAD_TIMEOUT) {
            audio = doc.querySelector('audio');
            if (audio?.readyState >= 2 && audio.duration > 0) break;
            await sleep(1000);
        }
        if (audio) { audio.muted = true; audio.play().catch(() => {}); }
        let ok = false;
        for (let r = 0; r <= MAX_RETRIES; r++) {
            if (await waitForRealPlaybackStart(audio, audioBox, doc)) { ok = true; break; }
            if (r < MAX_RETRIES) {
                audioItem.scrollIntoView({ behavior: 'smooth', block: 'center' });
                const btn = audioBox?.querySelector('.aplayer-button');
                if (btn && !btn.classList.contains('aplayer-pause')) btn.click();
                if (audio) { audio.muted = true; audio.play().catch(() => {}); }
                await sleep(1000);
            }
        }
        if (!ok) { stopViewportKeeper(); startScrollTask(); return false; }
        currentActivity = '播放音频中...';
        const playStart = Date.now();
        let stall = 0, lastProg = getProgress(audio, audioBox), recovers = 0;
        while (true) {
            await sleep(CHECK_PLAY_END_MS);
            const prog = getProgress(audio, audioBox);
            if (audio?.ended) break;
            if (prog !== null && lastProg !== null && Math.abs(prog - lastProg) < 0.1) stall++;
            else stall = 0;
            if (stall >= PROGRESS_STALL_COUNT && (Date.now() - playStart) > MIN_PLAY_DURATION) break;
            if (prog !== null && prog >= 99.5) break;
            if ((audio?.paused && !audio?.ended) || (prog === null || prog === 0) && !audio?.ended) {
                if (recovers < MAX_RECOVER_ATTEMPTS) {
                    audioItem.scrollIntoView({ behavior: 'smooth', block: 'center' });
                    const btn = audioBox?.querySelector('.aplayer-button');
                    if (btn && !btn.classList.contains('aplayer-pause')) btn.click();
                    if (audio) { audio.muted = true; audio.play().catch(() => {}); }
                    recovers++; stall = 0;
                    await sleep(2000);
                    lastProg = getProgress(audio, audioBox);
                    continue;
                } else break;
            }
            lastProg = prog;
        }
        stopViewportKeeper();
        startScrollTask();
        return true;
    }

    // ========== 小屏题目返回（增强版，支持遮罩点击与history.back） ==========
    async function clickBackButton(doc) {
        console.log('[小屏适配] 开始尝试返回...');
        // 方法1：点击返回按钮系列
        const backContainer = doc.querySelector('.flex.close');
        if (backContainer) {
            const targets = [
                backContainer,
                backContainer.querySelector('span'),
                backContainer.querySelector('i'),
            ].filter(Boolean);
            for (const target of targets) {
                console.log('[小屏适配] 点击', target.tagName, target.className, target.textContent?.trim().substring(0,10));
                target.dispatchEvent(new MouseEvent('mousedown', { bubbles: true, cancelable: true, view: doc.defaultView }));
                target.dispatchEvent(new MouseEvent('mouseup', { bubbles: true, cancelable: true, view: doc.defaultView }));
                target.click();
                await sleep(1000);
                if (!doc.querySelector('.flex.close')) {
                    console.log('[小屏适配] 返回成功（按钮点击有效）');
                    return true;
                }
            }
        }

        // 方法2：点击遮罩层 .classNumberMask
        const mask = doc.querySelector('.classNumberMask');
        if (mask) {
            console.log('[小屏适配] 尝试点击遮罩层');
            mask.dispatchEvent(new MouseEvent('mousedown', { bubbles: true, cancelable: true, view: doc.defaultView }));
            mask.dispatchEvent(new MouseEvent('mouseup', { bubbles: true, cancelable: true, view: doc.defaultView }));
            mask.click();
            await sleep(1000);
            if (!doc.querySelector('.flex.close')) {
                console.log('[小屏适配] 返回成功（遮罩点击有效）');
                return true;
            }
        }

        // 方法3：调用 history.back()
        try {
            console.log('[小屏适配] 尝试 history.back()');
            history.back();
            await sleep(2000);
            if (!doc.querySelector('.flex.close')) {
                console.log('[小屏适配] 返回成功（history.back()）');
                return true;
            }
        } catch (e) {
            console.warn('[小屏适配] history.back() 失败', e);
        }

        return false;
    }

    async function handleTopicReturnIfNeeded() {
        const doc = getIframeDocument();
        if (!doc) return false;

        const backBtn = doc.querySelector('.flex.close');
        if (!backBtn) return false;

        console.log('[小屏适配] 检测到二级题目页面，将在', RETURN_DELAY/1000, '秒后自动返回');
        currentActivity = `已进入题目页面，${RETURN_DELAY/1000}秒后返回`;
        await sleep(RETURN_DELAY);

        if (!doc.querySelector('.flex.close')) {
            console.log('[小屏适配] 页面已自动返回（无需操作）');
            return true;
        }

        const clicked = await clickBackButton(doc);
        if (clicked) {
            await sleep(2000);
            return true;
        }

        console.warn('[小屏适配] 所有返回尝试均失败，强制等待后继续');
        await sleep(5000);
        return false;
    }

    // ========== 题目复习 ==========
    async function performTopicReview() {
        const doc = getIframeDocument();
        if (!doc) return;
        const allTopics = getNonMediaCollapseItems();
        if (allTopics.length === 0) return;

        let targetTopic = null;
        if (state.openedTopics.length > 0) {
            const openedInDOM = allTopics.filter(t => state.openedTopics.includes(getTopicTitle(t)));
            if (openedInDOM.length > 0) {
                targetTopic = openedInDOM[randomInt(0, openedInDOM.length - 1)];
            }
        }
        if (!targetTopic) {
            const unopened = allTopics.find(t => !state.openedTopics.includes(getTopicTitle(t)));
            if (unopened) {
                targetTopic = unopened;
                markTopicOpened(targetTopic);
            } else {
                targetTopic = allTopics[randomInt(0, allTopics.length - 1)];
            }
        }

        if (!targetTopic) return;

        const title = getTopicTitle(targetTopic);
        currentActivity = `复习题目: ${title.substring(0, 20)}`;
        console.log('[题目复习] 正在处理：', title);

        await ensureDrawerOpen();
        targetTopic.scrollIntoView({ behavior: 'smooth', block: 'center' });
        await sleep(1000);

        const header = targetTopic.querySelector('.el-collapse-item__header');
        if (header) {
            console.log('[题目复习] 点击标题');
            header.click();
            await sleep(1000);
        }

        const isSmallScreen = await handleTopicReturnIfNeeded();
        if (isSmallScreen) {
            currentActivity = '完成题目复习（小屏模式）';
            return;
        }

        if (targetTopic.classList.contains('is-active')) {
            const readTime = randomInt(TOPIC_READ_DURATION_MIN, TOPIC_READ_DURATION_MAX);
            currentActivity = `阅读题目: ${title.substring(0, 20)} (${readTime/1000}s)`;
            await sleep(readTime);

            const headerClose = targetTopic.querySelector('.el-collapse-item__header');
            if (headerClose && targetTopic.classList.contains('is-active')) {
                headerClose.click();
                await sleep(500);
            }
        }

        currentActivity = '完成题目复习';
    }

    // ========== 章节媒体播放 ==========
    async function playChapterMedia() {
        if (state.remainingMediaQueue.length === 0) return true;
        const queue = [...state.remainingMediaQueue];
        for (let i = queue.length - 1; i > 0; i--) {
            const j = randomInt(0, i);
            [queue[i], queue[j]] = [queue[j], queue[i]];
        }
        let mediaCount = 0;
        let reviewThreshold = randomInt(TOPIC_REVIEW_INTERVAL_MIN, TOPIC_REVIEW_INTERVAL_MAX);
        for (const item of queue) {
            if (abortController?.signal.aborted) return false;
            currentActivity = `播放 ${item.type} #${item.index}`;
            let success = false;
            if (item.type === 'video') {
                const videos = getRealVideoItems();
                if (item.index < videos.length) success = await playSingleVideo(videos[item.index]);
            } else {
                const audios = getAudioItems();
                if (item.index < audios.length) success = await playSingleAudio(audios[item.index]);
            }
            state.remainingMediaQueue = state.remainingMediaQueue.filter(
                m => !(m.type === item.type && m.index === item.index)
            );
            saveState();
            if (success) mediaCount++;
            if (mediaCount >= reviewThreshold) {
                await sleep(randomInt(1000, 3000));
                await performTopicReview();
                mediaCount = 0;
                reviewThreshold = randomInt(TOPIC_REVIEW_INTERVAL_MIN, TOPIC_REVIEW_INTERVAL_MAX);
            }
            await sleep(randomInt(1000, 3000));
        }
        currentActivity = '章节媒体播放完毕';
        return state.remainingMediaQueue.length === 0;
    }

    // ========== 主循环 ==========
    async function mainLoop() {
        isLoopRunning = true;
        abortController = new AbortController();
        try {
            while (!abortController.signal.aborted) {
                const chapters = getAllChapterLeafNodes();
                const target = Math.min(state.currentChapterIdx, MAX_CHAPTER_INDEX);
                if (!chapters.some(el => el.classList.contains('is-current')) || state.currentChapterIdx !== target) {
                    await goToChapter(target);
                    await sleep(CHAPTER_WAIT_MS);
                }
                const done = await playChapterMedia();
                if (!done) break;
                const next = state.currentChapterIdx + 1;
                if (next <= MAX_CHAPTER_INDEX) {
                    await goToChapter(next);
                } else {
                    state.completedRounds++;
                    saveState();
                    currentActivity = `完成一轮，共${state.completedRounds}轮，回到第一章`;
                    await goToChapter(0);
                }
                if (!scrollTaskRunning) startScrollTask();
            }
        } finally { isLoopRunning = false; }
    }

    function stopScript() {
        abortController?.abort();
        stopScrollTask();
        stopMouseoverSimulation();
        currentActivity = '已暂停';
    }

    async function resumeScript() {
        if (isLoopRunning) return;
        if (!getIframeDocument()) return;
        if (!scrollTaskRunning) startScrollTask();
        startMouseoverSimulation();
        await mainLoop();
    }

    // ========== 面板 ==========
    function scrollToAndHighlight(el) {
        if (!el) return;
        const doc = getIframeDocument();
        if (!doc) return;
        ensureDrawerOpen().then(() => {
            el.scrollIntoView({ behavior: 'smooth', block: 'center' });
            el.style.transition = 'box-shadow 0.3s';
            el.style.boxShadow = '0 0 20px 5px #ffd700';
            setTimeout(() => { el.style.boxShadow = ''; }, 2000);
        });
    }

    function createPanel() {
        if (panelContainer) return;
        panelContainer = document.createElement('div');
        panelContainer.id = 'welearn-panel';
        panelContainer.innerHTML = `
            <style>
                #welearn-panel { position:fixed; top:20px; right:20px; z-index:99999; background:rgba(0,0,0,0.85); color:#fff; padding:12px; border-radius:10px; width:300px; font-size:12px; box-shadow:0 0 10px rgba(0,0,0,0.5); user-select:none; max-height:90vh; overflow-y:auto; }
                #welearn-panel h3 { margin:0 0 8px; text-align:center; color:#ffd700; }
                #welearn-panel .status { margin:5px 0; display:flex; justify-content:space-between; }
                #welearn-panel .status span { font-weight:bold; color:#0f0; }
                #welearn-panel .section-title { margin:10px 0 5px; color:#aaa; border-bottom:1px solid #555; padding-bottom:3px; }
                #welearn-panel .task-item { padding:4px 8px; cursor:pointer; border-radius:3px; transition:background 0.2s; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
                #welearn-panel .task-item:hover { background:#333; }
                #welearn-panel .task-item.highlight { background:#ffd70020; }
                #welearn-panel .task-item.opened::after { content: " [✓]"; color:#0f0; font-weight:bold; }
                #welearn-panel button { display:block; width:100%; margin:4px 0; padding:6px; background:#007bff; color:#fff; border:none; border-radius:5px; cursor:pointer; }
                #welearn-panel button:hover { background:#0056b3; }
                #welearn-panel .unlock-btn { background:#ff9800; }
                #welearn-panel .unlock-btn:hover { background:#e68900; }
            </style>
            <h3>WeLearn 刷课面板</h3>
            <div class="status"><span>状态:</span> <span id="wl-status">初始化</span></div>
            <div class="status"><span>活动:</span> <span id="wl-activity">等待</span></div>
            <div class="status"><span>章节:</span> <span id="wl-chapter">0</span></div>
            <div class="status"><span>轮次:</span> <span id="wl-rounds">0</span></div>
            <div class="section-title">📋 待播媒体 (点击定位)</div>
            <div id="wl-media-list" style="max-height:150px; overflow-y:auto; background:#1a1a1a; border-radius:5px; padding:4px;"></div>
            <div class="section-title">📝 题目列表 (点击展开并记录)</div>
            <div id="wl-topic-list" style="max-height:120px; overflow-y:auto; background:#1a1a1a; border-radius:5px; padding:4px;"></div>
            <button id="wl-stop">暂停脚本</button>
            <button id="wl-resume">恢复脚本</button>
            <button id="wl-unlock" class="unlock-btn" style="display:none;">点击解锁音频</button>
        `;
        document.body.appendChild(panelContainer);

        document.getElementById('wl-stop').addEventListener('click', stopScript);
        document.getElementById('wl-resume').addEventListener('click', resumeScript);
        document.getElementById('wl-unlock').addEventListener('click', () => {
            unlockAudioContexts();
            document.getElementById('wl-unlock').style.display = 'none';
            if (!isLoopRunning) {
                startScrollTask();
                startMouseoverSimulation();
                mainLoop();
            }
        });

        setInterval(updatePanel, 2000);
        updatePanel();
    }

    function updatePanel() {
        document.getElementById('wl-status').textContent = isLoopRunning ? '运行中' : (scrollTaskRunning ? '滚动中' : '空闲');
        document.getElementById('wl-activity').textContent = currentActivity;
        document.getElementById('wl-chapter').textContent = state.currentChapterIdx + 1;
        document.getElementById('wl-rounds').textContent = state.completedRounds;
        if (!audioContextUnlocked && !isLoopRunning) {
            document.getElementById('wl-unlock').style.display = 'block';
        } else {
            document.getElementById('wl-unlock').style.display = 'none';
        }

        const mediaListEl = document.getElementById('wl-media-list');
        mediaListEl.innerHTML = '';
        const doc = getIframeDocument();
        if (state.remainingMediaQueue.length === 0) {
            mediaListEl.innerHTML = '<div style="color:#888; padding:4px;">无剩余媒体</div>';
        } else {
            state.remainingMediaQueue.forEach(m => {
                const div = document.createElement('div');
                div.className = 'task-item';
                div.textContent = `${m.type} #${m.index}`;
                div.addEventListener('click', () => {
                    if (!doc) return;
                    let targetEl = null;
                    if (m.type === 'video') {
                        const videos = getRealVideoItems();
                        if (m.index < videos.length) targetEl = videos[m.index];
                    } else {
                        const audios = getAudioItems();
                        if (m.index < audios.length) targetEl = audios[m.index];
                    }
                    if (targetEl) {
                        scrollToAndHighlight(targetEl);
                        div.classList.add('highlight');
                        setTimeout(() => div.classList.remove('highlight'), 1500);
                    }
                });
                mediaListEl.appendChild(div);
            });
        }

        const topicListEl = document.getElementById('wl-topic-list');
        topicListEl.innerHTML = '';
        if (!doc) {
            topicListEl.innerHTML = '<div style="color:#888; padding:4px;">等待页面加载</div>';
            return;
        }
        const topics = getNonMediaCollapseItems();
        if (topics.length === 0) {
            topicListEl.innerHTML = '<div style="color:#888; padding:4px;">无题目</div>';
        } else {
            topics.forEach(topic => {
                const div = document.createElement('div');
                div.className = 'task-item';
                const title = getTopicTitle(topic);
                div.textContent = title.substring(0, 30);
                div.title = title;
                if (state.openedTopics.includes(title)) {
                    div.classList.add('opened');
                }
                div.addEventListener('click', () => {
                    if (!topic.classList.contains('is-active')) {
                        topic.querySelector('.el-collapse-item__header')?.click();
                    }
                    scrollToAndHighlight(topic);
                    markTopicOpened(topic);
                    updatePanel();
                    div.classList.add('highlight');
                    setTimeout(() => div.classList.remove('highlight'), 1500);
                });
                topicListEl.appendChild(div);
            });
        }
    }

    // ========== 初始化 ==========
    async function init() {
        createPanel();
        console.log('[脚本] 等待 iframe...');
        while (!getIframeDocument()) await sleep(1000);
        const doc = getIframeDocument();
        const win = doc.defaultView;

        loadState();
        console.log(`[脚本] 已加载：轮次${state.completedRounds} 章节${state.currentChapterIdx+1}`);

        window.stopScript = stopScript;
        window.resumeScript = resumeScript;
        window.getCompletedRounds = () => state.completedRounds;
        win.stopScript = stopScript;
        win.resumeScript = resumeScript;
        win.getCompletedRounds = () => state.completedRounds;

        setupFocusSpoofing();
        hijackAudioContextCreation(window);
        hijackAudioContextCreation(win);
        preventLeavingDetection();
        preventLeavingInIframe(doc);

        await ensureDrawerOpen();
        await waitForElement('.el-tree-node.is_chapter.noChildren', doc);

        const chapters = getAllChapterLeafNodes();
        if (!chapters.some(el => el.classList.contains('is-current'))) {
            await goToChapter(state.currentChapterIdx);
            await sleep(CHAPTER_WAIT_MS);
        }

        if (!audioContextUnlocked) {
            document.getElementById('wl-unlock').style.display = 'block';
            currentActivity = '等待点击解锁按钮';
        } else {
            startScrollTask();
            startMouseoverSimulation();
            mainLoop();
        }
    }

    window.addEventListener('load', () => setTimeout(init, 5000));
})();