// ==UserScript==
// @name         湖南大学继续教育小助手
// @namespace    http://jxjyjd.hnu.edu.cn/
// @version      1.3.0
// @description  基于 ScriptCat 6925 号脚本二次开发修复。自动播放、静音、防暂停、切后台计时、播放完自动下一节。极简悬浮胶囊 UI。v1.1.0 补回：时长读取兜底、播放重试、保活卡住检测、ended 绑定、SDK 静音/重播、Visibility 补全、胶囊按钮+日志、SPA 重置。v1.2.0 新增：逐任务读取反刷开关并报告挂机是否有效、已计X/35分显示、剩余时长停滞诊断。v1.3.0 新增：后台挂机保活模式（静音 WebAudio 防浏览器后台节流 + Worker 心跳兜底，胶囊「挂机」按钮可切）。
// @author       xqqbt & AI & dameng9
// @match        https://jxjyjd.hnu.edu.cn/course/*/task/*/show
// @match        https://jxjyjd.hnu.edu.cn/my/course/*
// @grant        none
// @run-at       document-idle
// @noframes
// @license      GPL-3.0
// ==/UserScript==

/*
 * 说明：
 * 本脚本基于 ScriptCat (https://scriptcat.org/zh-CN/script-show-page/6925) 二次开发修复。
 * 1. 保留极简悬浮胶囊 (Glassmorphism Capsule UI)，但补回控制按钮与日志。
 * 2. 核心逻辑对齐完整版 v1.3.3：时长读取兜底、播放重试、保活、事件绑定、SDK 静音/重播。
 */

(function () {
    'use strict';

    if (window.__HNU_HELPER_V130__) return;
    if (window !== window.top) return;
    window.__HNU_HELPER_V130__ = true;

    const CFG = {
        autoPlay: true,
        autoNext: true,
        mute: true,
        replayToFinish: true,      // 视频放完但学习时长未满：不跳节，重播继续计时
        switchDelay: 3000,
        loopInterval: 3000,        // 主循环：检测播放器 + 保活 + 结束检测
        activityInterval: 15000,   // 模拟用户活动，防无操作检测
        bgKeepAlive: true,         // 后台挂机计时：静音 WebAudio 防浏览器后台节流/冻结 + Worker 心跳（胶囊「挂机」按钮可切）
    };

    const state = {
        win: null,
        playerObj: null,
        innerPlayer: null,
        videoEl: null,
        currentTaskId: null,
        playing: false,
        endedFired: false,
        completedFired: false,
        lastCheckTime: -1,
        retryCount: 0,
        remainLocal: null,
        remainStamp: 0,
        stallCount: 0,
        lastRemain: null,
        stallWarned: false,
        logLines: [],
        lastLoopAt: 0,
        kaNote: false,
        __ka_worker__: null,
    };

    const VERSION = '1.3.0';

    const $ = (s) => document.querySelector(s);
    const $$ = (s) => Array.from(document.querySelectorAll(s));

    function log(msg) {
        const line = `[小助手v${VERSION}][${new Date().toLocaleTimeString()}] ${msg}`;
        console.log(line);
        state.logLines.push(line);
        if (state.logLines.length > 300) state.logLines.shift();
        updateUI();
    }

    /* ===================== Page Visibility 补丁（顶层 + iframe） ===================== */
    /* 平台计时靠 iframe 内部真实可见性，补丁必须同时打到顶层和 task-content-iframe。
       除读属性外，还要拦 onvisibilitychange 赋值——反刷代码常靠属性赋值挂监听。 */
    function patchVisibility(win, doc) {
        if (!win || !doc || win.__AL_VIS_PATCHED__) return;
        win.__AL_VIS_PATCHED__ = true;

        ['hidden', 'webkitHidden', 'mozHidden', 'msHidden'].forEach(p => {
            if (p in doc) try { Object.defineProperty(doc, p, { configurable: true, get: () => false }); } catch (e) {}
        });
        ['visibilityState', 'webkitVisibilityState', 'mozVisibilityState', 'msVisibilityState'].forEach(p => {
            if (p in doc) try { Object.defineProperty(doc, p, { configurable: true, get: () => 'visible' }); } catch (e) {}
        });
        try { if (typeof win.hasFocus === 'function') win.hasFocus = () => true; } catch (e) {}

        ['onvisibilitychange', 'onblur', 'onfocus'].forEach(prop => {
            const target = (prop === 'onblur' || prop === 'onfocus') ? win : doc;
            if (prop in target) {
                try {
                    Object.defineProperty(target, prop, { configurable: true, get: () => undefined, set: () => {} });
                } catch (e) {}
            }
        });

        ['visibilitychange', 'webkitvisibilitychange', 'mozvisibilitychange', 'blur'].forEach(evt => {
            const target = (evt === 'blur') ? win : doc;
            try { target.addEventListener(evt, e => e.stopImmediatePropagation(), true); } catch (e) {}
        });

        if (!win.__AL_ACTIVITY_TIMER__) {
            win.__AL_ACTIVITY_TIMER__ = setInterval(() => {
                try { doc.dispatchEvent(new MouseEvent('mousemove', { bubbles: true, cancelable: true, clientX: 0, clientY: 0, movementX: 1, movementY: 0 })); } catch (e) {}
            }, CFG.activityInterval);
        }
    }

    patchVisibility(window, document);

    /* ===================== 后台挂机保活（bgKeepAlive） ===================== */
    /* 为什么后台不计时：Chrome/Edge 会把后台标签页的定时器节流（最差 1 分钟 1 次），
       闲置约 5 分钟后甚至整个冻结，页面自己的心跳上报断流，服务端就判"挂机不计时"。
       对策：
       1) 静音 WebAudio（增益 0.0005，人耳听不见）+ 循环静音 <audio>，让标签页被
          浏览器视为"正在播放音频"，免于节流与冻结，心跳照常发；
       2) Web Worker 定时器不受后台节流影响，兜底唤醒主线程：补合成活动、续播视频、
          并在日志里报告节流是否发生（kaNote）。
       注意：若服务端把有效秒定义为"真实 OS 输入（isTrusted）"，脚本造不出真事件，
       仍需鼠标宏/物理挪动；保活保证的是"页面活着、心跳在发"。 */
    const SILENT_WAV = 'data:audio/wav;base64,' + 'UklGRvQHAABXQVZFZm10IBAAAAABAAEAQB8AAEAfAAABAAgAZGF0YdAHAACAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgA==';

    function startKeepAlive(win, doc) {
        if (!CFG.bgKeepAlive || !win || !doc || win.__hh_ka_on__) return;
        win.__hh_ka_on__ = true;
        try {
            const AC = win.AudioContext || win.webkitAudioContext;
            if (AC && !win.__hh_ka_ctx__) {
                const ctx = new AC();
                const osc = ctx.createOscillator();
                const g = ctx.createGain();
                g.gain.value = 0.0005;
                osc.frequency.value = 440;
                osc.connect(g);
                g.connect(ctx.destination);
                osc.start();
                win.__hh_ka_ctx__ = ctx;
            }
        } catch (e) {}
        try {
            if (!win.__hh_ka_audio__) {
                const a = doc.createElement('audio');
                a.loop = true;
                a.volume = 0.0005;
                a.src = SILENT_WAV;
                win.__hh_ka_audio__ = a;
                try { const pr = a.play(); if (pr && pr.catch) pr.catch(() => {}); } catch (e) {}
            }
        } catch (e) {}
    }

    // 自动播放策略可能让音频先挂起/停住：循环里低成本地再推一把
    function pumpKeepAlive(win) {
        if (!CFG.bgKeepAlive || !win || !win.__hh_ka_on__) return;
        try {
            const ctx = win.__hh_ka_ctx__;
            if (ctx && ctx.state === 'suspended') { const rr = ctx.resume(); if (rr && rr.catch) rr.catch(() => {}); }
        } catch (e) {}
        try {
            const a = win.__hh_ka_audio__;
            if (a && a.paused) { const pr = a.play(); if (pr && pr.catch) pr.catch(() => {}); }
        } catch (e) {}
    }

    function stopKeepAlive(win) {
        if (!win || !win.__hh_ka_on__) return;
        try { const ctx = win.__hh_ka_ctx__; if (ctx && ctx.state === 'running') ctx.suspend(); } catch (e) {}
        try { const a = win.__hh_ka_audio__; if (a) a.pause(); } catch (e) {}
    }

    function initKaWorker() {
        if (!CFG.bgKeepAlive || state.__ka_worker__) return;
        try {
            const blob = new Blob(['setInterval(function(){postMessage(1)},20000)'], { type: 'text/javascript' });
            const wk = new Worker(URL.createObjectURL(blob));
            state.__ka_worker__ = wk;
            wk.onmessage = () => {
                if (!CFG.bgKeepAlive) return;
                // 主循环 >45s 没跑 = 被浏览器节流/冻结过；Worker 的消息把主线程拽回来
                if (state.lastLoopAt && Date.now() - state.lastLoopAt > 45000 && !state.kaNote) {
                    state.kaNote = true;
                    log('⏱ 后台检测到主线程被节流/冻结，Worker 心跳已唤醒');
                }
                pumpKeepAlive(window);
                if (state.win && state.win !== window) pumpKeepAlive(state.win);
                try {
                    document.dispatchEvent(new MouseEvent('mousemove', { bubbles: true, clientX: 1, clientY: 1 }));
                    if (state.win) state.win.document.dispatchEvent(new MouseEvent('mousemove', { bubbles: true, clientX: 1, clientY: 1 }));
                } catch (e) {}
                try { if (state.videoEl && state.videoEl.paused && !state.videoEl.ended) doPlay(); } catch (e) {}
            };
        } catch (e) {
            log('⚠ Worker 保活不可用（可能受页面 CSP 限制）: ' + e.message);
        }
    }

    /* ===================== 播放器查找 ===================== */

    function getIframeWin() {
        const ifr = document.getElementById('task-content-iframe') || document.querySelector('.task-content-iframe');
        try { return ifr ? ifr.contentWindow : null; } catch (e) { return null; }
    }

    function findVideo(win) {
        try {
            let v = win.document.querySelector('video');
            if (v) return v;
            for (const fr of win.document.querySelectorAll('iframe')) {
                try {
                    const w2 = fr.contentWindow;
                    const v2 = w2 && w2.document && w2.document.querySelector('video');
                    if (v2) return v2;
                } catch (e) {}
            }
        } catch (e) {}
        return null;
    }

    /* ===================== 读取播放进度 / 时长 ===================== */

    function tryNum(obj, names) {
        if (!obj) return null;
        for (const n of names) {
            try {
                const v = obj[n];
                if (typeof v === 'function') {
                    const r = v.call(obj);
                    if (typeof r === 'number' && isFinite(r)) return r;
                } else if (typeof v === 'number' && isFinite(v)) {
                    return v;
                }
            } catch (e) {}
        }
        return null;
    }

    function getCurTime() {
        if (state.videoEl && typeof state.videoEl.currentTime === 'number' && state.videoEl.currentTime > 0) {
            return state.videoEl.currentTime;
        }
        const a = tryNum(state.innerPlayer, ['currentTime', 'getCurrentTime', 'getTime']);
        if (a !== null && a > 0) return a;
        const b = tryNum(state.playerObj, ['currentTime', 'getCurrentTime', 'getTime']);
        return b !== null && b > 0 ? b : 0;
    }

    function getDuration() {
        // 真实时长优先从 iframe 里的 <video> 取；SDK 对象上往往没有 duration 属性
        if (state.videoEl) {
            const d = state.videoEl.duration;
            if (typeof d === 'number' && d > 0 && isFinite(d)) return d;
        }
        const a = tryNum(state.innerPlayer, ['duration', 'getDuration']);
        if (a !== null && a > 0) return a;
        const b = tryNum(state.playerObj, ['duration', 'getDuration']);
        return b !== null && b > 0 ? b : 0;
    }

    /* ===================== 剩余学习时长（以平台数据为准） ===================== */

    function finishTipsVisible() {
        const el = $('.js-finish-tips');
        return !!el && el.style.display !== 'none' && (el.textContent || '').includes('已完成');
    }

    function getRemainSec() {
        if (finishTipsVisible()) return 0;
        const el = $('.js-remain-time');
        if (!el) return 0;
        const txt = el.innerText || '';
        const m = txt.match(/(\d+)\s*(?:分钟|分)/);
        const s = txt.match(/(\d+)\s*秒/);
        if (m || s) return (m ? +m[1] * 60 : 0) + (s ? +s[1] : 0);
        return Number(el.getAttribute('data-time') || 0);
    }

    // 仅用于显示：播放时本地按秒数递减推算，平台数据一刷新就重新校准。
    // 跳节判定始终用平台值 getRemainSec()，避免本地推算提前跳节。
    function getRemainSecLive() {
        const p = getRemainSec();
        if (state.remainLocal === null || p < state.remainLocal) {
            state.remainLocal = p;
        } else if (state.videoEl && !state.videoEl.paused && !state.videoEl.ended) {
            state.remainLocal -= (Date.now() - state.remainStamp) / 1000;
        }
        state.remainStamp = Date.now();
        if (state.remainLocal < 0) state.remainLocal = 0;
        return state.remainLocal;
    }

    function fmtSec(s) {
        s = Math.max(0, Math.round(s));
        return `${Math.floor(s / 60)}分${s % 60}秒`;
    }

    /* ===================== 播放控制 ===================== */

    function doPlay() {
        if (!state.playerObj && !state.videoEl) return;
        try {
            if (state.playerObj && typeof state.playerObj.play === 'function') {
                const ret = state.playerObj.play();
                if (ret && typeof ret.then === 'function') {
                    ret.then(() => { state.playing = true; }).catch(e => log('⚠ 播放被阻止: ' + e.message));
                } else {
                    state.playing = true;
                }
            }
            if (state.videoEl && state.videoEl.paused) {
                const pr = state.videoEl.play();
                if (pr && typeof pr.catch === 'function') pr.catch(e => log('⚠ video.play 被阻止: ' + e.message));
            }
        } catch (e) {
            log('播放异常: ' + e.message);
        }

        // 确认真的在播，没播就重试（最多 3 次）
        setTimeout(() => {
            const playingNow = state.videoEl ? !state.videoEl.paused : getCurTime() > 0;
            if (playingNow) {
                state.playing = true;
                state.retryCount = 0;
            } else if (state.retryCount < 3) {
                state.retryCount++;
                log('⚠ 未开始播放，重试 (' + state.retryCount + '/3)...');
                doPlay();
            }
            updateUI();
        }, 2000);
    }

    function doPause() {
        if (!state.playerObj && !state.videoEl) return;
        try {
            if (state.playerObj && typeof state.playerObj.pause === 'function') state.playerObj.pause();
            if (state.videoEl) state.videoEl.pause();
            state.playing = false;
        } catch (e) {}
    }

    // SDK 路径（setVolume）+ video 元素双通道静音；平台重置音量后循环里会自动补静音
    function doMute() {
        const ip = state.innerPlayer || state.playerObj;
        if (ip && typeof ip.setVolume === 'function') {
            try {
                const vol = typeof ip.getVolume === 'function' ? ip.getVolume() : null;
                if (vol === null || vol > 0) ip.setVolume(0);
            } catch (e) {}
        }
        if (state.videoEl) {
            try { state.videoEl.volume = 0; state.videoEl.muted = true; } catch (e) {}
        }
    }

    /* ===================== 事件绑定（ended） ===================== */

    function bindEvents() {
        if (state.playerObj && !state.playerObj._hh_bound) {
            state.playerObj._hh_bound = true;
            for (const evt of ['ended', 'end', 'complete', 'finished']) {
                try {
                    if (typeof state.playerObj.on === 'function') {
                        state.playerObj.on(evt, () => {
                            if (state.endedFired) return;
                            state.endedFired = true;
                            log('视频结束（' + evt + ' 事件）');
                            onEnded();
                        });
                    }
                } catch (e) {}
            }
        }
        if (state.videoEl && !state.videoEl._hh_bound) {
            state.videoEl._hh_bound = true;
            state.videoEl.addEventListener('ended', () => {
                if (state.endedFired) return;
                state.endedFired = true;
                log('视频结束（video.ended）');
                onEnded();
            });
        }
    }

    function onEnded() {
        if (!CFG.autoNext || state.completedFired) return;
        const remain = getRemainSec();
        if (remain > 0) {
            log('视频放完但还需 ' + fmtSec(remain) + '，任务条件未满足，不跳节');
            if (!CFG.replayToFinish) return;
            state.endedFired = false;
            state.remainLocal = null;
            log('重播视频继续计时...');
            if (state.videoEl) {
                try {
                    const d0 = getDuration();
                    // 有的播放器 ended 后自动回到 0：再强设 currentTime 会反复触发 ended，seek 死循环
                    if (!(d0 > 1 && state.videoEl.currentTime > d0 / 2)) state.videoEl.currentTime = 0;
                    const pr = state.videoEl.play();
                    if (pr && typeof pr.catch === 'function') pr.catch(e => log('重播失败: ' + e.message));
                } catch (e) { log('重播失败: ' + e.message); }
            } else if (state.playerObj) {
                try {
                    if (typeof state.playerObj.seek === 'function') state.playerObj.seek(0);
                    state.playerObj.play();
                } catch (e) { log('重播失败: ' + e.message); }
            }
            updateUI();
            return;
        }
        log('学习时长已达标，' + CFG.switchDelay + 'ms 后切换下一节...');
        updateUI();
        setTimeout(goNext, CFG.switchDelay);
    }

    /* ===================== 切换下一节 ===================== */

    function findNextBtn() {
        return $('.js-next-mobile-btn')
            || $$('a[href*="/task/"], [data-url]').find(a => { const t = (a.textContent || '').trim(); return t.includes('下一') || t.includes('下个'); })
            || $$('a[href*="/task/"]')[1];
    }

    function goNext() {
        const btn = findNextBtn();
        if (!btn) { log('⚠ 未找到下一节按钮'); return; }
        // 该按钮可能没有 href，只有 data-url，两个都要读
        const href = btn.getAttribute('href') || btn.getAttribute('data-url') || '';
        log('切换到下一节: ' + href);
        try { btn.click(); } catch (e) {}
        setTimeout(() => {
            if (href && href !== '#' && !href.startsWith('javascript')) {
                location.href = href.startsWith('http') ? href : location.origin + href;
            }
        }, CFG.switchDelay);
    }

    /* ===================== 主循环（检测 + 保活 + 结束检测） ===================== */

    function initLoop() {
        setInterval(() => {
            if (state.kaNote) {
                state.kaNote = false;
                log('✅ 主线程恢复运行（后台保活生效）');
            }
            state.lastLoopAt = Date.now();
            if (!state.win || (!state.videoEl && !state.playerObj)) {
                const w = getIframeWin();
                if (w) {
                    state.win = w;
                    patchVisibility(w, w.document);
                    startKeepAlive(w, w.document);
                    state.videoEl = findVideo(w);
                    state.playerObj = w.player || w.cloudPlayer || w.videoPlayer;
                    state.innerPlayer = (state.playerObj && state.playerObj.player && typeof state.playerObj.player === 'object')
                        ? state.playerObj.player : null;
                    if (state.videoEl || state.playerObj) {
                        log('✅ 播放器已连接（iframe）');
                        bindEvents();
                    }
                }
            }
            if (!state.win) { updateUI(); return; }

            if (CFG.bgKeepAlive) {
                pumpKeepAlive(window);
                if (state.win !== window) pumpKeepAlive(state.win);
            }

            const cur = getCurTime();
            const dur = getDuration();

            state.playing = state.videoEl
                ? (!state.videoEl.paused && !state.videoEl.ended)
                : (cur > state.lastCheckTime && cur > 0);

            const ended = (state.videoEl && state.videoEl.ended) || (dur > 0 && cur >= dur - 1);
            if (ended) {
                if (!state.endedFired) {
                    state.endedFired = true;
                    log('视频结束（轮询检测）cur=' + cur.toFixed(1) + ' dur=' + dur.toFixed(1));
                    onEnded();
                }
            } else {
                // 保活：卡住（时间不推进）或暂停就重新播放
                const stuck = state.videoEl
                    ? (state.videoEl.paused && !state.videoEl.ended)
                    : (cur > 0 && cur === state.lastCheckTime);
                if (stuck) {
                    log('⚠ 检测到暂停/卡住，重新播放...');
                    doPlay();
                }
                state.lastCheckTime = cur;
            }

            if (CFG.mute) doMute();

            // 诊断：播放正常但平台剩余时长长时间不动 = 重播片段被去重、或无"真实用户活动"不计秒
            // （脚本合成的 mousemove 事件 isTrusted=false，平台只认真实操作）
            const plat = getRemainSec();
            if (plat > 0 && state.playing) {
                if (state.lastRemain !== null && plat === state.lastRemain) {
                    state.stallCount++;
                    if (state.stallCount >= 40 && !state.stallWarned) {   // 约 2 分钟不动
                        state.stallWarned = true;
                        log('⚠ 重播片段不被平台计时（已计片段去重/无真实活动）。把任务页留在前台、偶尔真实动鼠标，时间才会 1:1 累计；纯脚本挂机补不了剩余时长');
                    }
                } else {
                    state.stallCount = 0;
                    if (state.stallWarned) log('✅ 平台恢复计时（真实活动已计入）');
                }
                state.lastRemain = plat;
            }

            // 学习时长达标即切下一节（不等视频自然放完）
            if (CFG.autoNext && state.currentTaskId && !state.completedFired && getRemainSec() <= 0) {
                state.completedFired = true;
                log('学习时长已达标（剩余 0），' + CFG.switchDelay + 'ms 后直接切换下一节');
                setTimeout(goNext, CFG.switchDelay);
            }

            updateUI();
        }, CFG.loopInterval);
    }

    /* ===================== 极简胶囊 UI（补回按钮 + 日志） ===================== */

    function createUI() {
        if (document.getElementById('hnu-helper-ui')) return;
        const card = document.createElement('div');
        card.id = 'hnu-helper-ui';
        card.style.cssText = `
            position: fixed; top: 20px; right: 20px; z-index: 999999;
            background: rgba(255, 255, 255, 0.85); backdrop-filter: blur(10px);
            border: 1px solid rgba(220, 220, 220, 0.6); border-radius: 30px;
            padding: 8px 16px; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            box-shadow: 0 8px 24px rgba(0,0,0,0.08); font-size: 13px; color: #333;
            transition: all 0.3s ease;
        `;
        card.innerHTML = `
            <div style="display:flex;align-items:center;gap:8px;flex-wrap:wrap;">
                <span id="hnu-dot" style="width:8px;height:8px;border-radius:50%;background:#ffb703;display:inline-block;"></span>
                <span id="hnu-text" style="font-weight:500;">初始化...</span>
                <button class="hnu-btn" data-act="play" title="播放">▶</button>
                <button class="hnu-btn" data-act="pause" title="暂停">⏸</button>
                <button class="hnu-btn" data-act="mute" title="静音">🔇</button>
                <button class="hnu-btn" data-act="bg" title="后台挂机保活：静音WebAudio防浏览器后台节流，让页面后台也照常发心跳计时">挂机:开</button>
                <button class="hnu-btn" data-act="next" title="下一节">下一节</button>
                <button class="hnu-btn" data-act="log" title="日志">日志</button>
            </div>
            <div id="hnu-log" style="display:none;margin-top:6px;background:rgba(0,0,0,0.05);border-radius:8px;padding:6px 8px;font-size:10px;max-height:120px;overflow-y:auto;font-family:monospace;white-space:pre-line;color:#444;"></div>
        `;
        document.body.appendChild(card);

        const btnStyle = 'border:1px solid rgba(0,0,0,0.15);background:#eee;color:#333;padding:3px 8px;border-radius:12px;font-size:11px;cursor:pointer;outline:none;transition:opacity 0.2s;';
        card.querySelectorAll('button').forEach(b => {
            b.style.cssText = btnStyle;
            b.onclick = () => {
                const act = b.dataset.act;
                if (act === 'play') doPlay();
                else if (act === 'pause') doPause();
                else if (act === 'mute') doMute();
                else if (act === 'next') goNext();
                else if (act === 'bg') {
                    CFG.bgKeepAlive = !CFG.bgKeepAlive;
                    b.textContent = '挂机:' + (CFG.bgKeepAlive ? '开' : '关');
                    if (CFG.bgKeepAlive) {
                        startKeepAlive(window, document);
                        if (state.win) startKeepAlive(state.win, state.win.document);
                        initKaWorker();
                        log('挂机保活: 开（后台可照常发心跳）');
                    } else {
                        stopKeepAlive(window);
                        if (state.win) stopKeepAlive(state.win);
                        log('挂机保活: 关（后台被浏览器节流时不计时）');
                    }
                }
                else {
                    const w = document.getElementById('hnu-log');
                    w.style.display = w.style.display === 'none' ? 'block' : 'none';
                    updateUI();
                }
            };
        });
    }

    function updateUI() {
        const dot = document.getElementById('hnu-dot');
        const txt = document.getElementById('hnu-text');
        if (!dot || !txt) return;

        const remain = getRemainSecLive();
        const hasPlayer = state.videoEl || state.playerObj;
        const cur = getCurTime();
        const dur = getDuration();

        if (remain <= 0) {
            dot.style.background = '#10b981'; // 绿色：完成
            txt.innerText = '学习完成，准备切节';
        } else if (!hasPlayer) {
            dot.style.background = '#ffb703'; // 黄色：还没找到播放器
            txt.innerText = `连接中... (剩余 ${fmtSec(remain)})`;
        } else {
            dot.style.background = state.playing ? '#3b82f6' : '#f59e0b';
            const pct = dur > 0 ? ` ${Math.round(cur / dur * 100)}%` : '';
            const ifr = $('#task-content-iframe');
            const finishMin = ifr ? Number(ifr.getAttribute('data-finish-detail') || 0) : 0;
            const extra = finishMin > 0 ? ` | 已计 ${fmtSec(finishMin * 60 - remain)}/${finishMin}分` : '';
            txt.innerText = `${state.playing ? '刷课中' : '已暂停'}${pct} | 剩余 ${fmtSec(remain)}${extra}`;
        }

        const logEl = document.getElementById('hnu-log');
        if (logEl && logEl.style.display !== 'none') {
            logEl.textContent = state.logLines.slice(-30).join('\n');
            logEl.scrollTop = logEl.scrollHeight;
        }
    }

    /* ===================== 初始化 ===================== */

    function parseTaskId() {
        const m = location.href.match(/\/task\/(\d+)\//);
        if (m) state.currentTaskId = m[1];
    }

    createUI();
    parseTaskId();
    log('===== v' + VERSION + ' 初始化 =====');

    // 逐任务读取反刷开关：open 时有效性由服务端校验（挂机无效）；否则客户端上报即被接受
    function antiBrushStatus() {
        const ifr = $('#task-content-iframe');
        return ifr ? (ifr.getAttribute('data-learn-time-anti-brush') || 'closed') : 'unknown';
    }
    const anti0 = antiBrushStatus();
    log('反刷开关: ' + anti0 + (anti0 === 'open'
        ? ' → 本任务服务端校验有效秒（合成活动不认、片段去重），纯后台挂机不计时，需真实在场'
        : ' → 本任务未开反刷，后台持续播放照常计时'));

    startKeepAlive(window, document);
    if (CFG.bgKeepAlive) {
        initKaWorker();
        log('挂机保活 v' + VERSION + ' 已开启：静音 WebAudio 防后台节流 + Worker 心跳。后台是否计秒以服务端为准——切后台 5 分钟看剩余时间是否继续下降即可验证');
    }

    initLoop();

    // SPA 路径变更重置状态
    let lastUrl = location.href;
    setInterval(() => {
        if (location.href !== lastUrl) {
            lastUrl = location.href;
            log('URL 变化，重新检测播放器...');
            state.videoEl = null;
            state.win = null;
            state.playerObj = null;
            state.innerPlayer = null;
            state.completedFired = false;
            state.endedFired = false;
            state.retryCount = 0;
            state.lastCheckTime = -1;
            state.remainLocal = null;
            state.stallCount = 0;
            state.lastRemain = null;
            state.stallWarned = false;
            parseTaskId();
            const anti = antiBrushStatus();
            if (anti === 'open') log('本任务反刷 open：挂机时段不计时，真实在场才计');
            else log('本任务反刷未开：后台持续播放会正常计时');
        }
    }, 2000);

})();