// ==UserScript==
// @name         广西网课 - 自动播放 & 下一节 v4
// @namespace    http://tampermonkey.net/
// @version      4.0
// @description  可视状态面板 + 多重兜底 + HLS兼容 + 刷新回补
// @author       Marvis
// @match        http://gxgs.study.gspxonline.com/*
// @match        https://gxgs.study.gspxonline.com/*
// @match        http://gxgspxpt.gspxonline.com/*
// @match        https://gxgspxpt.gspxonline.com/*
// @grant        none
// @run-at       document-end
// @license MIT
// ==/UserScript==

(function () {
    'use strict';

    // ========== 状态面板（页面右上角浮动小窗） ==========
    const panel = document.createElement('div');
    panel.id = '__auto_study_panel';
    panel.innerHTML = '⏳ 初始化...';
    Object.assign(panel.style, {
        position: 'fixed', top: '10px', right: '10px', zIndex: '99999',
        background: 'rgba(0,0,0,0.8)', color: '#0f0', padding: '6px 12px',
        borderRadius: '6px', fontSize: '13px', fontFamily: 'monospace',
        pointerEvents: 'none', maxWidth: '300px', lineHeight: '1.5',
    });
    document.body.appendChild(panel);

    function setStatus(text, color) {
        panel.textContent = text;
        panel.style.color = color || '#0f0';
    }

    // ========== 配置 ==========
    const TICK = 1500;

    // ========== DOM ==========
    const $v = () => document.querySelector('#aliplayer video');
    const $allLi = () => document.querySelectorAll('li[id^="res_"]');
    const $active = () => document.querySelector('li.active[id^="res_"]');
    const $sidebar = () => document.querySelector('.sidebar');

    function findNext() {
        const act = $active();
        if (!act) return null;
        const all = $allLi();
        for (let i = 0; i < all.length - 1; i++) {
            if (all[i].id === act.id) return all[i + 1];
        }
        return null;
    }
    function findIndex() {
        const act = $active();
        if (!act) return -1;
        const all = $allLi();
        for (let i = 0; i < all.length; i++) {
            if (all[i].id === act.id) return i;
        }
        return -1;
    }

    // ========== 点击跳转 ==========
    function clickNext(next) {
        if (!next) return false;
        // 滚动到可见区域
        const sb = $sidebar();
        if (sb) next.scrollIntoView({ block: 'center', behavior: 'auto' });
        // 点击
        next.click();
        // 如果 li 内部有 a 标签，也点一下
        const a = next.querySelector('a');
        if (a) setTimeout(() => a.click(), 100);
        return true;
    }

    function jumpNext() {
        const next = findNext();
        if (!next) return false;
        const idx = findIndex();
        setStatus('跳转: ' + (idx + 2) + '/' + $allLi().length + ' ' + (next.textContent || '').trim().slice(0, 20), '#ff0');
        return clickNext(next);
    }

    // ========== 播放 ==========
    function doPlay(v) {
        if (!v) return;
        try {
            v.muted = true;
            v.play().then(() => {
                setTimeout(() => { v.muted = false; }, 1000);
            }).catch(() => {});
        } catch (e) {}
    }

    // ========== 核心状态机 ==========
    let phase = 'init';       // init | playing | done
    let triggered = false;
    let stuckTimer = null;
    let stuckStart = 0;
    let stuckLast = 0;
    let initRetry = 0;

    function resetForNewVideo() {
        phase = 'init';
        triggered = false;
        stuckTimer = null;
        stuckStart = 0;
        stuckLast = 0;
        initRetry = 0;
    }

    function loop() {
        if (!location.href.includes('/study/learn/')) {
            setStatus('非学习页面', '#888');
            return;
        }

        const v = $v();
        const all = $allLi();
        const act = $active();
        const idx = findIndex();
        const total = all.length;

        // ---- 无视频：等待 ----
        if (!v) {
            initRetry++;
            if (initRetry > 20) {
                // 等了 30 秒还没有视频，刷新
                setStatus('无视频，刷新...', '#f80');
                setTimeout(() => location.reload(), 2000);
                return;
            }
            setStatus('等待播放器... (' + initRetry + ')', '#888');
            return;
        }
        initRetry = 0;

        const dur = v.duration || 0;
        const cur = v.currentTime || 0;

        // HLS 流 duration 可能为 Infinity，用 0 兜底
        const hasDur = isFinite(dur) && dur > 1;
        const prog = hasDur ? cur / dur : 0;
        const pct = (prog * 100).toFixed(0);

        // ---- 刚初始化 ----
        if (phase === 'init') {
            phase = 'playing';
            stuckStart = Date.now();
            stuckLast = cur;
            v.addEventListener('ended', onVideoEnded);
            if (v.paused) doPlay(v);
        }

        // ---- 状态文字 ----
        const vidLabel = hasDur
            ? pct + '% | ' + fmt(cur) + '/' + fmt(dur)
            : fmt(cur) + ' (HLS)';
        setStatus('第' + (idx + 1) + '/' + total + '节 | ' + vidLabel + ' | ' + (v.paused ? '暂停' : '播放中'), '#0f0');

        // ---- 暂停自动恢复 ----
        if (v.paused && !v.ended) {
            doPlay(v);
        }

        // ---- 兜底 1: ended 属性 ----
        if (v.ended && !triggered) {
            setStatus('ended=true，跳转', '#0ff');
            onVideoEnded();
            return;
        }

        // ---- 兜底 2: 进度 >= 98% ----
        if (hasDur && prog >= 0.98 && !triggered) {
            setStatus('进度 ' + pct + '%，跳转', '#0ff');
            onVideoEnded();
            return;
        }

        // ---- 兜底 3: 进度卡死 ----
        if (hasDur && !v.paused) {
            const delta = cur - stuckLast;
            const elapsed = Date.now() - stuckStart;
            if (delta < 1 && elapsed > 120000) {
                // 2 分钟进度不动
                setStatus('卡死 ' + (elapsed / 1000).toFixed(0) + 's，恢复中', '#f44');
                doPlay(v);
                // 如果卡了超过 5 分钟，直接当播完处理
                if (elapsed > 300000 && prog > 0.5 && !triggered) {
                    setStatus('卡死过久，强制跳转', '#f44');
                    onVideoEnded();
                    return;
                }
                stuckStart = Date.now();
                stuckLast = cur;
            }
            if (delta >= 1) {
                stuckStart = Date.now();
                stuckLast = cur;
            }
        }

        // ---- 兜底 4: 超时（duration 不可靠时的保底） ----
        // 如果 hasDur 且已经过了 duration+30秒还没跳转，强制跳
        if (hasDur && cur > dur + 30 && !triggered) {
            setStatus('超时，强制跳转', '#f44');
            onVideoEnded();
            return;
        }
    }

    function onVideoEnded() {
        if (triggered) return;
        triggered = true;
        phase = 'done';

        setStatus('播放完毕，跳转中...', '#ff0');

        setTimeout(() => {
            const ok = jumpNext();
            if (ok) {
                // 等待页面切换
                waitTransition();
            } else {
                setStatus('已是最后一节 ✓', '#0f0');
            }
        }, 1000);
    }

    function waitTransition() {
        const oldId = $active() ? $active().id : '';
        let waitCount = 0;

        const check = setInterval(() => {
            waitCount++;
            const act = $active();
            const newId = act ? act.id : '';

            if (newId && newId !== oldId) {
                clearInterval(check);
                setStatus('已切换: ' + (act.textContent || '').trim().slice(0, 20), '#0f0');
                waitForVideo();
                return;
            }
            if (waitCount > 30) { // 15 秒超时
                clearInterval(check);
                setStatus('切换超时，刷新页面', '#f44');
                setTimeout(() => location.reload(), 500);
            }
        }, 500);
    }

    function waitForVideo() {
        let count = 0;
        const check = setInterval(() => {
            count++;
            const v = $v();
            if (v) {
                clearInterval(check);
                resetForNewVideo();
                phase = 'playing';
                stuckStart = Date.now();
                stuckLast = v.currentTime || 0;
                v.addEventListener('ended', onVideoEnded);
                doPlay(v);
                setStatus('新视频就绪', '#0f0');
                return;
            }
            if (count > 40) { // 20 秒超时
                clearInterval(check);
                setStatus('视频加载超时，刷新', '#f44');
                setTimeout(() => location.reload(), 500);
            }
        }, 500);
    }

    function fmt(s) {
        const m = Math.floor(s / 60);
        const sec = Math.floor(s % 60);
        return m + ':' + (sec < 10 ? '0' : '') + sec;
    }

    // ========== SPA 路由监听 ==========
    function setupRouter() {
        let last = location.href;
        const h = history;
        const _ps = h.pushState; h.pushState = function () { _ps.apply(this, arguments); check(); };
        const _rs = h.replaceState; h.replaceState = function () { _rs.apply(this, arguments); check(); };
        window.addEventListener('popstate', check);
        function check() {
            if (location.href !== last) {
                last = location.href;
                if (last.includes('/study/learn/')) {
                    resetForNewVideo();
                    setTimeout(() => {
                        const v = $v();
                        if (v) { v.addEventListener('ended', onVideoEnded); doPlay(v); phase = 'playing'; }
                    }, 1500);
                }
            }
        }
    }

    // ========== 保活 ==========
    function keepAlive() {
        requestAnimationFrame(function loop() {
            const v = $v();
            if (v && !v.ended) void v.currentTime;
            requestAnimationFrame(loop);
        });
        setInterval(() => { const v = $v(); if (v && !v.ended) void v.currentTime; }, 30000);
    }

    document.addEventListener('visibilitychange', () => {
        if (!document.hidden) {
            const v = $v();
            if (v && v.paused && !v.ended && phase === 'playing') {
                v.muted = true; v.play().catch(() => {}); setTimeout(() => { v.muted = false; }, 1000);
            }
        }
    });

    // ========== 启动 ==========
    setupRouter();
    keepAlive();

    if (location.href.includes('/study/learn/')) {
        setTimeout(() => {
            const v = $v();
            if (v) { v.addEventListener('ended', onVideoEnded); doPlay(v); phase = 'playing'; stuckStart = Date.now(); stuckLast = v.currentTime || 0; }
        }, 1500);
    }

    setInterval(loop, TICK);
})();