// ==UserScript==
// @name         多功能整合：多功能按钮 + 视频增强
// @namespace    https://github.com/merged-allinone
// @version      4.0.0
// @description  回顶/到底/刷新/DeepSeek按钮（均可独立开关），视频控制（全屏/3倍速/快进/重播/手势，总开关控制），视频进度记忆
// @author       Assistant
// @match        *://*/*
// @run-at       document-start
// @grant        none
// @license      MIT
// ==/UserScript==

(function() {
    'use strict';

    // ==================== 黑名单配置 ====================
    // 这些域名的视频增强功能将被完全禁用
    const VIDEO_BLACKLIST = ['manhuabika.com'];

    // ==================== 全局常量 ====================
    // 按钮与提示相关 ID
    const IDS = {
        // 视频按钮
        FULLSCREEN: 've-fullscreen',
        SPEED: 've-speed',
        FORWARD: 've-forward',
        RESTART: 've-restart',
        // 多功能按钮
        SCROLL_TOP: 'multi-top',
        SCROLL_BOTTOM: 'multi-bottom',
        REFRESH: 'multi-refresh',
        DEEPSEEK: 'multi-deepseek',
        // 其他
        TOAST: 'allinone-toast',
        STYLE: 'allinone-styles'
    };

    const CLASSES = {
        VISIBLE: 'visible',
        SPEED_ACTIVE: 'speed-active',
        SWIPE_HINT: 've-swipe-hint',
        VIDEO_MODE: 'video-mode'
    };

    // ==================== 配置项 ====================
    const CONFIG = {
        // ---------- 视频增强总开关 ----------
        ENABLE_VIDEO_ENHANCEMENT: true,

        // ---------- 多功能按钮独立开关 ----------
        ENABLE_SCROLL_TOP_BTN: true,
        ENABLE_SCROLL_BOTTOM_BTN: true,
        ENABLE_REFRESH_BTN: true,
        ENABLE_DEEPSEEK_BTN: true,

        // ---------- DeepSeek 链接 ----------
        DEEPSEEK_URL: 'https://chat.deepseek.com/',

        // ---------- UI 样式 ----------
        BUTTON_SIZE: 33,
        BUTTON_RIGHT: 6,
        BUTTON_GAP: 22,
        START_TOP: 62,

        // ---------- 滚动阈值 ----------
        SCROLL_THRESHOLD: 200,
        BOTTOM_THRESHOLD: 50,

        // ---------- 视频参数 ----------
        SEEK_STEP: 20,
        DOUBLE_TAP_DELAY: 300,
        SWIPE_THRESHOLD: 40,
        SWIPE_HORIZONTAL_TOLERANCE: 70,

        // ---------- 手势开关 ----------
        ENABLE_DOUBLE_TAP: true,
        ENABLE_SWIPE_FULLSCREEN: true,
        SHOW_SWIPE_HINT: true,

        // ---------- 视频进度缓存 ----------
        CACHE_PREFIX: 'video_progress_',
        AUTO_SAVE_INTERVAL: 5000,
        CACHE_EXPIRE_DAYS: 7,
        RESTORE_MIN_REMAINING: 30
    };

    // ==================== 工具函数 ====================
    const throttle = (fn, wait) => {
        let timeout, lastRun = 0;
        return function(...args) {
            const now = Date.now();
            const later = () => { lastRun = Date.now(); timeout = null; fn.apply(this, args); };
            if (now - lastRun >= wait) later();
            else if (!timeout) timeout = setTimeout(later, wait - (now - lastRun));
        };
    };

    const debounce = (fn, wait) => {
        let timeout;
        return function(...args) {
            clearTimeout(timeout);
            timeout = setTimeout(() => fn.apply(this, args), wait);
        };
    };

    const addStyleOnce = (css, id) => {
        if (document.getElementById(id)) return;
        const style = document.createElement('style');
        style.id = id;
        style.textContent = css;
        (document.head || document.documentElement).appendChild(style);
    };

    // 全屏 API 封装
    const fullscreenAPI = {
        request: (el) => {
            const methods = ['requestFullscreen','webkitRequestFullscreen','mozRequestFullScreen','msRequestFullscreen'];
            for (const m of methods) if (el[m]) { el[m](); return true; }
            return false;
        },
        exit: () => {
            const methods = ['exitFullscreen','webkitExitFullscreen','mozCancelFullScreen','msExitFullscreen'];
            for (const m of methods) if (document[m]) { document[m](); return true; }
            return false;
        },
        isFullscreen: () =>
            !!(document.fullscreenElement || document.webkitFullscreenElement ||
               document.mozFullScreenElement || document.msFullscreenElement)
    };

    // Toast 提示
    let toastElement = null;
    const showToast = (msg, duration = 2000) => {
        if (!toastElement) {
            if (!document.body) return;
            toastElement = document.createElement('div');
            toastElement.id = IDS.TOAST;
            toastElement.style.cssText = `
                position:fixed; bottom:20vh; left:50%; transform:translateX(-50%);
                background:rgba(60,60,60,0.8); backdrop-filter:blur(4px); -webkit-backdrop-filter:blur(4px);
                color:#fff; padding:10px 20px; border-radius:30px; font-size:14px; z-index:2147483647;
                opacity:0; transition:opacity 0.2s; pointer-events:none; white-space:nowrap;
                box-shadow:0 2px 8px rgba(0,0,0,0.15); border:1px solid rgba(255,255,255,0.2);
            `;
            document.body.appendChild(toastElement);
        }
        toastElement.textContent = msg;
        toastElement.style.opacity = '1';
        clearTimeout(toastElement._hideTimer);
        toastElement._hideTimer = setTimeout(() => toastElement.style.opacity = '0', duration);
    };

    // localStorage 安全检测
    const storageAvailable = (() => {
        try {
            const test = '__storage_test__';
            localStorage.setItem(test, test);
            localStorage.removeItem(test);
            return true;
        } catch (e) {
            return false;
        }
    })();

    // ==================== 视频评分选择器 ====================
    const getActiveVideo = () => {
        const videos = Array.from(document.querySelectorAll('video')).filter(v => v.videoWidth > 0 && v.videoHeight > 0);
        if (!videos.length) return null;
        const scored = videos.map(v => {
            let score = 0;
            if (!v.paused && v.readyState >= 2) score += 5;
            if (v.src || v.currentSrc) score += 3;
            const rect = v.getBoundingClientRect();
            if (rect.width > 0 && rect.height > 0) score += 2;
            return { video: v, score };
        });
        scored.sort((a, b) => b.score - a.score);
        return scored[0].video;
    };

    // ==================== 视频进度缓存管理器 ====================
    class ProgressManager {
        static getCacheKey(video) {
            const src = video.src || video.currentSrc || location.href;
            try {
                return CONFIG.CACHE_PREFIX + btoa(encodeURIComponent(src)).replace(/[^a-zA-Z0-9]/g, '');
            } catch {
                return CONFIG.CACHE_PREFIX + src.replace(/\W/g, '');
            }
        }

        static save(video) {
            if (!storageAvailable || !video || !isFinite(video.duration)) return;
            try {
                localStorage.setItem(ProgressManager.getCacheKey(video), JSON.stringify({
                    currentTime: video.currentTime,
                    duration: video.duration,
                    playbackRate: video.playbackRate,
                    timestamp: Date.now()
                }));
            } catch (e) {}
        }

        static restore(video, onRestore) {
            if (!storageAvailable || !video) return;
            try {
                const saved = localStorage.getItem(ProgressManager.getCacheKey(video));
                if (!saved) return;
                const p = JSON.parse(saved);
                if (Date.now() - p.timestamp > CONFIG.CACHE_EXPIRE_DAYS * 86400000) {
                    localStorage.removeItem(ProgressManager.getCacheKey(video));
                    return;
                }
                const apply = () => {
                    if (video.readyState >= 1 && isFinite(video.duration)) {
                        const t = Math.min(p.currentTime, video.duration - CONFIG.RESTORE_MIN_REMAINING);
                        if (t > 0) video.currentTime = t;
                        video.playbackRate = p.playbackRate || 1.0;
                        if (onRestore) onRestore(video.playbackRate);
                        return true;
                    }
                    return false;
                };
                if (!apply()) {
                    const interval = setInterval(() => {
                        if (apply() || !video.isConnected) clearInterval(interval);
                    }, 100);
                    setTimeout(() => clearInterval(interval), 5000);
                }
            } catch (e) {}
        }

        static clear(video) {
            if (!storageAvailable || !video) return;
            try { localStorage.removeItem(ProgressManager.getCacheKey(video)); } catch (e) {}
        }
    }

    // ==================== 手势管理器 ====================
    class GestureHandler {
        constructor(videoEnabledFn, getVideoFn) {
            this.videoEnabled = videoEnabledFn; // 函数，返回是否启用视频增强
            this.getActiveVideo = getVideoFn;
            this.doubleTap = { lastTap: 0 };
            this.swipeState = {
                startY: 0, startX: 0, hintTimer: null,
                targetVideo: null, isTracking: false
            };
            this.init();
        }

        init() {
            if (!CONFIG.ENABLE_DOUBLE_TAP && !CONFIG.ENABLE_SWIPE_FULLSCREEN) return;

            // 双击播放/暂停
            if (CONFIG.ENABLE_DOUBLE_TAP) {
                document.addEventListener('touchstart', (e) => {
                    const target = e.target;
                    if (target.tagName !== 'VIDEO' || !target.videoWidth || !target.videoHeight) return;
                    const now = Date.now();
                    if (now - this.doubleTap.lastTap < CONFIG.DOUBLE_TAP_DELAY) {
                        e.preventDefault();
                        target.paused ? target.play() : target.pause();
                    }
                    this.doubleTap.lastTap = now;
                }, { passive: false });
            }

            // 上下滑动切换全屏
            if (CONFIG.ENABLE_SWIPE_FULLSCREEN) {
                this._bindSwipe();
            }
        }

        _bindSwipe() {
            const state = this.swipeState;
            const isValidVideo = (el) => el && el.tagName === 'VIDEO' && el.videoWidth > 0 && el.videoHeight > 0;
            const canSwipe = () => this.videoEnabled() && this.getActiveVideo();

            const clearHint = () => {
                if (state.targetVideo) state.targetVideo.classList.remove(CLASSES.SWIPE_HINT);
                if (state.hintTimer) { clearTimeout(state.hintTimer); state.hintTimer = null; }
            };
            const reset = () => {
                clearHint();
                state.startY = state.startX = 0;
                state.targetVideo = null;
                state.isTracking = false;
            };

            document.addEventListener('touchstart', (e) => {
                const touch = e.touches[0];
                if (!touch) return;
                const isFS = fullscreenAPI.isFullscreen();
                if (isFS) {
                    const target = e.target;
                    if (!isValidVideo(target)) return;
                    e.preventDefault();
                    state.startY = touch.clientY;
                    state.startX = touch.clientX;
                    state.targetVideo = target;
                    state.isTracking = true;
                    return;
                }
                if (!canSwipe()) return;
                state.startY = touch.clientY;
                state.startX = touch.clientX;
                state.targetVideo = this.getActiveVideo();
                state.isTracking = true;
            }, { passive: false });

            document.addEventListener('touchmove', (e) => {
                if (!state.isTracking) return;
                const touch = e.touches[0];
                if (!touch) { reset(); return; }
                const deltaY = state.startY - touch.clientY;
                const deltaX = Math.abs(state.startX - touch.clientX);
                const isFS = fullscreenAPI.isFullscreen();

                const showHint = () => {
                    if (CONFIG.SHOW_SWIPE_HINT && state.targetVideo) {
                        state.targetVideo.classList.add(CLASSES.SWIPE_HINT);
                        if (state.hintTimer) clearTimeout(state.hintTimer);
                        state.hintTimer = setTimeout(() => {
                            if (state.targetVideo) state.targetVideo.classList.remove(CLASSES.SWIPE_HINT);
                            state.hintTimer = null;
                        }, 300);
                    }
                };

                if (!isFS) {
                    if (!canSwipe()) { reset(); return; }
                    if (deltaX > CONFIG.SWIPE_HORIZONTAL_TOLERANCE) { reset(); return; }
                    if (deltaY > CONFIG.SWIPE_THRESHOLD) {
                        e.preventDefault();
                        showHint();
                    }
                } else {
                    e.preventDefault();
                    if (!state.targetVideo || !isValidVideo(state.targetVideo)) { reset(); return; }
                    if (deltaX > CONFIG.SWIPE_HORIZONTAL_TOLERANCE) { reset(); return; }
                    if (deltaY < -CONFIG.SWIPE_THRESHOLD) {
                        showHint();
                    }
                }
            }, { passive: false });

            document.addEventListener('touchend', (e) => {
                if (!state.isTracking) return;
                const touch = e.changedTouches[0];
                if (!touch) { reset(); return; }
                const deltaY = state.startY - touch.clientY;
                const deltaX = Math.abs(state.startX - touch.clientX);
                const isFS = fullscreenAPI.isFullscreen();
                if (!isFS) {
                    if (!canSwipe()) { reset(); return; }
                    if (deltaX <= CONFIG.SWIPE_HORIZONTAL_TOLERANCE && deltaY > CONFIG.SWIPE_THRESHOLD) {
                        const video = this.getActiveVideo();
                        if (video) {
                            const success = fullscreenAPI.request(video);
                            if (!success) showToast('全屏被浏览器拒绝，请点击全屏按钮');
                        }
                    }
                } else {
                    if (deltaX <= CONFIG.SWIPE_HORIZONTAL_TOLERANCE && deltaY < -CONFIG.SWIPE_THRESHOLD) {
                        fullscreenAPI.exit();
                    }
                }
                reset();
            });

            document.addEventListener('touchcancel', reset);
        }
    }

    // ==================== 主控制器 ====================
    class AllInOne {
        constructor() {
            this.currentVideo = null;
            this.isSpeed3x = false;
            this.videoHandlers = new WeakMap();
            this.videoEnabled = CONFIG.ENABLE_VIDEO_ENHANCEMENT && !this._isHostBlocked();

            // 注入样式 → 创建按钮 → 绑定事件 → 初始化手势 → 启动DOM监听
            this._injectStyles();
            this._createButtons();
            this._bindEvents();
            if (this.videoEnabled) {
                this.gestureHandler = new GestureHandler(
                    () => this.videoEnabled,
                    () => getActiveVideo()
                );
            }
            this._startObservers();
            this._updateUI();

            // 初始化时恢复视频进度（如果页面已有视频）
            const active = getActiveVideo();
            if (active && this.videoEnabled) this._attachVideo(active);
        }

        // --- 黑名单检测 ---
        _isHostBlocked() {
            const host = location.hostname.toLowerCase();
            const url = location.href.toLowerCase();
            return VIDEO_BLACKLIST.some(rule =>
                host.includes(rule.trim().toLowerCase()) || url.includes(rule.trim().toLowerCase())
            );
        }

        // --- 样式注入 ---
        _injectStyles() {
            const { BUTTON_SIZE, BUTTON_RIGHT, BUTTON_GAP, START_TOP, SEEK_STEP } = CONFIG;
            const id = IDS.STYLE;
            let css = '';

            // 基本按钮样式
            const allIds = [IDS.FULLSCREEN, IDS.SPEED, IDS.FORWARD, IDS.RESTART,
                            IDS.SCROLL_TOP, IDS.SCROLL_BOTTOM, IDS.REFRESH, IDS.DEEPSEEK];
            css += `${allIds.map(id => `#${id}`).join(',')} {
                position: fixed; right: ${BUTTON_RIGHT}px; width: ${BUTTON_SIZE}px; height: ${BUTTON_SIZE}px;
                border-radius: 50%; background: rgba(60,60,60,0.5); backdrop-filter: blur(4px);
                -webkit-backdrop-filter: blur(4px); box-shadow: 0 2px 8px rgba(0,0,0,0.15);
                display: flex; align-items: center; justify-content: center; cursor: pointer;
                z-index: 2147483647; transition: opacity 0.25s, transform 0.2s, background 0.2s;
                border: 1px solid rgba(255,255,255,0.2); color: white; font-weight: 600;
                font-family: Arial, sans-serif;
            }`;

            // 按钮垂直位置
            const vIndex = [IDS.FULLSCREEN, IDS.SPEED, IDS.FORWARD, IDS.RESTART];
            vIndex.forEach((id, i) => css += `#${id} { top: calc(${START_TOP}vh + ${i * (BUTTON_SIZE + BUTTON_GAP)}px); }`);
            const mIndex = [IDS.SCROLL_TOP, IDS.SCROLL_BOTTOM, IDS.REFRESH, IDS.DEEPSEEK];
            mIndex.forEach((id, i) => css += `#${id} { top: calc(${START_TOP}vh + ${i * (BUTTON_SIZE + BUTTON_GAP)}px); }`);

            // 可见性控制
            css += `
                #${IDS.SCROLL_TOP}, #${IDS.SCROLL_BOTTOM} { opacity:0; transform:scale(0.8); pointer-events:none; }
                #${IDS.SCROLL_TOP}.${CLASSES.VISIBLE}, #${IDS.SCROLL_BOTTOM}.${CLASSES.VISIBLE} { opacity:1; transform:scale(1); pointer-events:auto; }
                #${IDS.FULLSCREEN}, #${IDS.SPEED}, #${IDS.FORWARD}, #${IDS.RESTART} { opacity:0; transform:scale(0.8); pointer-events:none; }
                .${CLASSES.VIDEO_MODE} #${IDS.FULLSCREEN}, .${CLASSES.VIDEO_MODE} #${IDS.SPEED},
                .${CLASSES.VIDEO_MODE} #${IDS.FORWARD}, .${CLASSES.VIDEO_MODE} #${IDS.RESTART} {
                    opacity:1; transform:scale(1); pointer-events:auto;
                }
                .${CLASSES.VIDEO_MODE} #${IDS.SCROLL_TOP}, .${CLASSES.VIDEO_MODE} #${IDS.SCROLL_BOTTOM},
                .${CLASSES.VIDEO_MODE} #${IDS.REFRESH}, .${CLASSES.VIDEO_MODE} #${IDS.DEEPSEEK} {
                    opacity:0; transform:scale(0.8); pointer-events:none;
                }
                /* 图标内容 */
                #${IDS.FULLSCREEN}::before { content:'⛶'; font-size:22px; }
                #${IDS.SPEED}::before { content:'3×'; }
                #${IDS.SPEED}.${CLASSES.SPEED_ACTIVE} { background:rgba(0,150,200,0.7) !important; }
                #${IDS.FORWARD}::before { content:'↷${SEEK_STEP}s'; font-size:12px; }
                #${IDS.RESTART}::before { content:'↺'; font-size:20px; }
                #${IDS.SCROLL_TOP}::before { content:''; width:10px; height:10px; border-left:2.2px solid #fff; border-bottom:2.2px solid #fff; transform:rotate(135deg); margin-top:4px; }
                #${IDS.SCROLL_BOTTOM}::before { content:''; width:10px; height:10px; border-left:2.2px solid #fff; border-bottom:2.2px solid #fff; transform:rotate(-45deg); margin-top:-4px; }
                #${IDS.REFRESH}::before { content:'↻'; font-size:26px; line-height:1; }
                #${IDS.DEEPSEEK} { font-size:16px; }
                #${IDS.DEEPSEEK}::before { content:'DS'; line-height:1; text-shadow:0 1px 2px rgba(0,0,0,0.2); }
                /* 点击反馈 */
                ${allIds.map(id => `#${id}:active`).join(',')} { background:rgba(80,80,80,0.6); transform:scale(0.9); }
                @media (prefers-color-scheme: dark) {
                    ${allIds.map(id => `#${id}`).join(',')} { background:rgba(220,220,220,0.2); border-color:rgba(255,255,255,0.1); }
                    #${IDS.SPEED}.${CLASSES.SPEED_ACTIVE} { background:rgba(0,150,200,0.5) !important; }
                }
                /* 手势提示动画 */
                .${CLASSES.SWIPE_HINT} { position:relative; }
                .${CLASSES.SWIPE_HINT}::after {
                    content:''; position:absolute; top:0; left:0; right:0; bottom:0;
                    background:rgba(0,150,200,0.3); pointer-events:none; z-index:999;
                    animation:veHintFade 0.2s ease;
                }
                @keyframes veHintFade { from { opacity:0; } to { opacity:1; } }
            `;
            addStyleOnce(css, id);
        }

        // --- 按钮创建 ---
        _createButtons() {
            // 视频按钮（受总开关控制）
            if (CONFIG.ENABLE_VIDEO_ENHANCEMENT) {
                this._makeBtn(IDS.FULLSCREEN, '全屏切换', () => this._onVideoAction('FULLSCREEN'));
                this._makeBtn(IDS.SPEED, '三倍速', () => this._onVideoAction('SPEED'));
                this._makeBtn(IDS.FORWARD, `快进${CONFIG.SEEK_STEP}秒`, () => this._onVideoAction('FORWARD'));
                this._makeBtn(IDS.RESTART, '重播', () => this._onVideoAction('RESTART'));
            }

            // 多功能按钮（各自独立开关）
            if (CONFIG.ENABLE_SCROLL_TOP_BTN) {
                this._makeBtn(IDS.SCROLL_TOP, '回到顶部', () => window.scrollTo({top: 0, behavior: 'smooth'}));
            }
            if (CONFIG.ENABLE_SCROLL_BOTTOM_BTN) {
                this._makeBtn(IDS.SCROLL_BOTTOM, '去到底部', () => window.scrollTo({top: document.documentElement.scrollHeight, behavior: 'smooth'}));
            }
            if (CONFIG.ENABLE_REFRESH_BTN) {
                this._makeBtn(IDS.REFRESH, '刷新页面', () => location.reload());
            }
            if (CONFIG.ENABLE_DEEPSEEK_BTN) {
                this._makeBtn(IDS.DEEPSEEK, '打开 DeepSeek', () => location.href = CONFIG.DEEPSEEK_URL);
            }
        }

        _makeBtn(id, title, clickHandler) {
            const btn = document.createElement('div');
            btn.id = id;
            btn.title = title;
            btn.addEventListener('click', (e) => {
                e.stopPropagation();
                clickHandler();
            });
            document.body.appendChild(btn);
            return btn;
        }

        // --- 视频操作分发 ---
        _onVideoAction(action) {
            if (!this.videoEnabled) { alert('视频增强已禁用'); return; }
            const video = this.currentVideo || getActiveVideo();
            if (!video) { alert('未检测到视频'); return; }
            switch (action) {
                case 'FULLSCREEN':
                    if (fullscreenAPI.isFullscreen()) fullscreenAPI.exit();
                    else {
                        const ok = fullscreenAPI.request(video);
                        if (!ok) showToast('全屏被浏览器拒绝');
                    }
                    break;
                case 'SPEED':
                    this.isSpeed3x = !this.isSpeed3x;
                    video.playbackRate = this.isSpeed3x ? 3.0 : 1.0;
                    document.getElementById(IDS.SPEED)?.classList.toggle(CLASSES.SPEED_ACTIVE, this.isSpeed3x);
                    break;
                case 'FORWARD':
                    video.currentTime = Math.min(video.currentTime + CONFIG.SEEK_STEP, video.duration);
                    ProgressManager.save(video);
                    break;
                case 'RESTART':
                    video.currentTime = 0;
                    video.play();
                    ProgressManager.save(video);
                    break;
            }
        }

        // --- 进度恢复回调 ---
        _onProgressRestore(playbackRate) {
            this.isSpeed3x = (playbackRate === 3.0);
            document.getElementById(IDS.SPEED)?.classList.toggle(CLASSES.SPEED_ACTIVE, this.isSpeed3x);
        }

        // --- 视频绑定/解绑 ---
        _attachVideo(video) {
            if (!video || video === this.currentVideo) return;
            this._detachVideo();
            this.currentVideo = video;
            this.isSpeed3x = (video.playbackRate === 3.0);
            document.getElementById(IDS.SPEED)?.classList.toggle(CLASSES.SPEED_ACTIVE, this.isSpeed3x);

            ProgressManager.restore(video, (rate) => this._onProgressRestore(rate));

            const throttledSave = throttle(() => ProgressManager.save(video), CONFIG.AUTO_SAVE_INTERVAL);
            const onPause = () => ProgressManager.save(video);
            const onEnded = () => ProgressManager.clear(video);
            video.addEventListener('timeupdate', throttledSave);
            video.addEventListener('pause', onPause);
            video.addEventListener('ended', onEnded);
            this.videoHandlers.set(video, { throttledSave, onPause, onEnded });
        }

        _detachVideo() {
            if (!this.currentVideo) return;
            const video = this.currentVideo;
            const handlers = this.videoHandlers.get(video);
            if (handlers) {
                video.removeEventListener('timeupdate', handlers.throttledSave);
                video.removeEventListener('pause', handlers.onPause);
                video.removeEventListener('ended', handlers.onEnded);
                this.videoHandlers.delete(video);
            }
            ProgressManager.save(video);
            this.currentVideo = null;
        }

        // --- UI 更新（防抖） ---
        _updateUI = debounce(() => {
            const video = this.videoEnabled ? getActiveVideo() : null;
            const hasVideo = video && video.readyState >= 1 && isFinite(video.duration) && video.duration > 0;
            document.body.classList.toggle(CLASSES.VIDEO_MODE, hasVideo);

            // 按钮显隐
            if (CONFIG.ENABLE_SCROLL_TOP_BTN) {
                const btn = document.getElementById(IDS.SCROLL_TOP);
                if (btn) {
                    const y = window.scrollY || document.documentElement.scrollTop || 0;
                    btn.classList.toggle(CLASSES.VISIBLE, y > CONFIG.SCROLL_THRESHOLD);
                }
            }
            if (CONFIG.ENABLE_SCROLL_BOTTOM_BTN) {
                const btn = document.getElementById(IDS.SCROLL_BOTTOM);
                if (btn) {
                    const y = window.scrollY || document.documentElement.scrollTop || 0;
                    const ch = document.documentElement.clientHeight;
                    const sh = document.documentElement.scrollHeight;
                    const atBottom = (y + ch) >= (sh - CONFIG.BOTTOM_THRESHOLD);
                    btn.classList.toggle(CLASSES.VISIBLE, !atBottom && sh > ch);
                }
            }

            // 视频切换
            if (hasVideo && video !== this.currentVideo) {
                this._attachVideo(video);
            } else if (!hasVideo && this.currentVideo) {
                this._detachVideo();
            }

            // 若当前视频已从DOM移除，强制解绑
            if (this.currentVideo && !this.currentVideo.isConnected) {
                this._detachVideo();
                this._updateUI();
            }
        }, 100);

        // --- 事件监听 ---
        _bindEvents() {
            window.addEventListener('scroll', this._updateUI, { passive: true });
            document.addEventListener('play', this._updateUI, true);
            document.addEventListener('pause', this._updateUI, true);
            document.addEventListener('loadedmetadata', this._updateUI, true);
            document.addEventListener('fullscreenchange', this._updateUI);
            document.addEventListener('webkitfullscreenchange', this._updateUI);
            window.addEventListener('beforeunload', () => {
                if (this.currentVideo) ProgressManager.save(this.currentVideo);
            });

            // SPA 路由变化感知
            if (!window._allInOneRoutePatched) {
                window._allInOneRoutePatched = true;
                const patch = (type) => {
                    const orig = history[type];
                    return function() {
                        const ret = orig.apply(this, arguments);
                        window.dispatchEvent(new Event('urlchange'));
                        return ret;
                    };
                };
                history.pushState = patch('pushState');
                history.replaceState = patch('replaceState');
                window.addEventListener('popstate', () => window.dispatchEvent(new Event('urlchange')));
                window.addEventListener('urlchange', () => this._updateUI());
                window.addEventListener('hashchange', () => this._updateUI());
            }
        }

        // --- DOM 观察器 ---
        _startObservers() {
            new MutationObserver(() => this._updateUI()).observe(document.body, {
                childList: true,
                subtree: true,
                attributes: true,
                attributeFilter: ['src']
            });

            // 额外检测视频移除
            new MutationObserver(() => {
                if (this.currentVideo && !this.currentVideo.isConnected) {
                    this._detachVideo();
                    this._updateUI();
                }
            }).observe(document.body, { childList: true, subtree: true });
        }
    }

    // ==================== 启动 ====================
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', () => new AllInOne());
    } else {
        new AllInOne();
    }
})();