// ==UserScript==
// @name         网页视频播放增强（Via优化版）
// @namespace    https://github.com/video-enhancer
// @version      1.5.4
// @description  视频缓存进度记忆、全屏切换、3倍速切换、跳转、重新开始、双击暂停、上下滑全屏（灵敏度优化）
// @author       Assistant
// @match        *://*/*
// @run-at       document-end
// @grant        none
// @license      MIT
// ==/UserScript==

(function() {
    'use strict';

    // ==================== 用户配置区 ====================
    const CONFIG = {
        // 浮动按钮相关
        SCROLL_THRESHOLD: 200,
        SEEK_STEP: 20,
        CACHE_PREFIX: 'video_progress_',
        AUTO_SAVE_INTERVAL: 5000,
        BUTTON_SIZE: 33,
        BUTTON_RIGHT: 6,
        BUTTON_GAP: 22,
        START_TOP: 66.6,

        // 手势功能开关
        ENABLE_DOUBLE_TAP: true,
        ENABLE_SWIPE_FULLSCREEN: true,

        // 手势灵敏度（上滑阈值降低，水平容差放宽）
        DOUBLE_TAP_DELAY: 300,
        SWIPE_THRESHOLD: 40,             // 触发全屏所需的最小滑动距离（像素）
        SWIPE_HORIZONTAL_TOLERANCE: 70,  // 水平容差，超过此值视为误触
        SHOW_SWIPE_HINT: true            // 是否显示滑动提示（达到阈值时短暂高亮）
    };

    // ==================== 公共工具函数 ====================
    function addStyleOnce(css, id) {
        if (id && document.getElementById(id)) return;
        const style = document.createElement('style');
        if (id) style.id = id;
        style.textContent = css;
        document.head.appendChild(style);
        return style;
    }

    function getActiveVideo() {
        const videos = document.querySelectorAll('video');
        if (videos.length === 0) return null;
        for (const video of videos) {
            if (!video.paused && video.readyState >= 2) return video;
        }
        for (const video of videos) {
            if (video.src || video.currentSrc) return video;
        }
        for (const video of videos) {
            const rect = video.getBoundingClientRect();
            if (rect.width > 0 && rect.height > 0) return video;
        }
        return videos[0];
    }

    function getVideoCacheKey(video) {
        const src = video.src || video.currentSrc || window.location.href;
        return CONFIG.CACHE_PREFIX + btoa(encodeURIComponent(src)).replace(/[^a-zA-Z0-9]/g, '');
    }

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

    // ==================== 功能1：视频进度缓存记忆 ====================
    const ProgressManager = {
        currentVideo: null,
        isRestored: false,

        saveProgress(video) {
            if (!video) return;
            try {
                const cacheKey = getVideoCacheKey(video);
                const progress = {
                    currentTime: video.currentTime,
                    duration: video.duration,
                    playbackRate: video.playbackRate,
                    timestamp: Date.now()
                };
                localStorage.setItem(cacheKey, JSON.stringify(progress));
            } catch (e) {}
        },

        restoreProgress(video) {
            if (!video || this.isRestored) return;
            try {
                const cacheKey = getVideoCacheKey(video);
                const saved = localStorage.getItem(cacheKey);
                if (!saved) return;
                const progress = JSON.parse(saved);
                if (Date.now() - progress.timestamp > 7 * 24 * 60 * 60 * 1000) {
                    localStorage.removeItem(cacheKey);
                    return;
                }
                const doRestore = () => {
                    if (video.readyState >= 1 && !isNaN(video.duration)) {
                        if (progress.currentTime < video.duration - 30) {
                            video.currentTime = progress.currentTime;
                        }
                        this.isRestored = true;
                    } else {
                        setTimeout(doRestore, 100);
                    }
                };
                doRestore();
            } catch (e) {}
        },

        clearProgress(video) {
            if (!video) return;
            try {
                const cacheKey = getVideoCacheKey(video);
                localStorage.removeItem(cacheKey);
            } catch (e) {}
        },

        startTracking(video) {
            if (!video || this.currentVideo === video) return;
            this.stopTracking();
            this.currentVideo = video;
            this.isRestored = false;
            this.restoreProgress(video);
            const throttledSave = throttle(() => this.saveProgress(video), CONFIG.AUTO_SAVE_INTERVAL);
            video.addEventListener('timeupdate', throttledSave);
            video.addEventListener('pause', () => this.saveProgress(video));
            video.addEventListener('ended', () => this.clearProgress(video));
            video._progressHandlers = { throttledSave };
        },

        stopTracking() {
            if (!this.currentVideo) return;
            const video = this.currentVideo;
            const handlers = video._progressHandlers || {};
            if (handlers.throttledSave) {
                video.removeEventListener('timeupdate', handlers.throttledSave);
            }
            video.removeEventListener('pause', () => this.saveProgress(video));
            video.removeEventListener('ended', () => this.clearProgress(video));
            this.saveProgress(video);
            this.currentVideo = null;
            this.isRestored = false;
        }
    };

    // ==================== 功能2：手势控制（上滑/下滑优化版） ====================
    function bindGlobalGestures() {
        // 注入滑动提示样式（可选）
        if (CONFIG.SHOW_SWIPE_HINT) {
            addStyleOnce(`
                .video-swipe-hint {
                    position: relative;
                }
                .video-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: swipeHintFade 0.2s ease;
                }
                @keyframes swipeHintFade {
                    from { opacity: 0; }
                    to { opacity: 1; }
                }
            `, 'video-swipe-hint-style');
        }

        // 双击暂停/播放
        if (CONFIG.ENABLE_DOUBLE_TAP) {
            let lastTap = 0;
            document.addEventListener('touchstart', (e) => {
                const target = e.target;
                if (target.tagName !== 'VIDEO') return;
                const now = Date.now();
                if (now - lastTap < CONFIG.DOUBLE_TAP_DELAY) {
                    e.preventDefault();
                    const video = target;
                    if (video.paused) {
                        video.play();
                    } else {
                        video.pause();
                    }
                }
                lastTap = now;
            }, { passive: false });
        }

        // 上滑/下滑全屏
        if (CONFIG.ENABLE_SWIPE_FULLSCREEN) {
            let touchStartY = 0;
            let touchStartX = 0;
            let touchTarget = null;
            let hintTimer = null;

            const clearHint = () => {
                if (touchTarget) {
                    touchTarget.classList.remove('video-swipe-hint');
                }
                if (hintTimer) {
                    clearTimeout(hintTimer);
                    hintTimer = null;
                }
            };

            const showHint = (video) => {
                if (!CONFIG.SHOW_SWIPE_HINT || !video) return;
                video.classList.add('video-swipe-hint');
                if (hintTimer) clearTimeout(hintTimer);
                hintTimer = setTimeout(() => {
                    video.classList.remove('video-swipe-hint');
                    hintTimer = null;
                }, 300);
            };

            document.addEventListener('touchstart', (e) => {
                const touch = e.touches[0];
                if (!touch) return;
                const target = e.target;
                if (target.tagName !== 'VIDEO') return;

                // 阻止默认滚动（当触摸视频时），避免手势被页面滚动干扰
                e.preventDefault();

                touchStartY = touch.clientY;
                touchStartX = touch.clientX;
                touchTarget = target;
            }, { passive: false });

            document.addEventListener('touchmove', (e) => {
                if (touchStartY === 0 || !touchTarget) return;
                const touch = e.touches[0];
                if (!touch) return;

                const deltaY = touchStartY - touch.clientY;
                const deltaX = Math.abs(touchStartX - touch.clientX);
                const isFullscreen = document.fullscreenElement || document.webkitFullscreenElement;

                // 水平偏移过大则放弃手势
                if (deltaX > CONFIG.SWIPE_HORIZONTAL_TOLERANCE) {
                    clearHint();
                    touchStartY = 0;
                    touchStartX = 0;
                    touchTarget = null;
                    return;
                }

                // 如果达到阈值，显示视觉反馈
                if (Math.abs(deltaY) > CONFIG.SWIPE_THRESHOLD) {
                    showHint(touchTarget);
                }

                // 阻止页面滚动（防止触摸移动时页面跟着滚动）
                e.preventDefault();
            }, { passive: false });

            document.addEventListener('touchend', (e) => {
                if (touchStartY === 0 || !touchTarget) {
                    clearHint();
                    touchStartY = 0;
                    touchStartX = 0;
                    touchTarget = null;
                    return;
                }

                const touch = e.changedTouches[0];
                if (!touch) {
                    clearHint();
                    touchStartY = 0;
                    touchStartX = 0;
                    touchTarget = null;
                    return;
                }

                const deltaY = touchStartY - touch.clientY; // 正=上滑，负=下滑
                const deltaX = Math.abs(touchStartX - touch.clientX);
                const isFullscreen = document.fullscreenElement || document.webkitFullscreenElement;

                // 水平偏移过大则忽略
                if (deltaX > CONFIG.SWIPE_HORIZONTAL_TOLERANCE) {
                    clearHint();
                    touchStartY = 0;
                    touchStartX = 0;
                    touchTarget = null;
                    return;
                }

                if (isFullscreen) {
                    // 全屏时下滑退出
                    if (deltaY < -CONFIG.SWIPE_THRESHOLD) {
                        try {
                            if (document.exitFullscreen) {
                                document.exitFullscreen();
                            } else if (document.webkitExitFullscreen) {
                                document.webkitExitFullscreen();
                            }
                        } catch (err) {}
                    }
                } else {
                    // 非全屏时上滑进入
                    if (deltaY > CONFIG.SWIPE_THRESHOLD) {
                        const video = touchTarget;
                        if (video) {
                            try {
                                video.requestFullscreen().catch(() => {
                                    if (video.webkitEnterFullscreen) {
                                        video.webkitEnterFullscreen();
                                    }
                                });
                            } catch (err) {}
                        }
                    }
                }

                clearHint();
                touchStartY = 0;
                touchStartX = 0;
                touchTarget = null;
            });

            document.addEventListener('touchcancel', () => {
                clearHint();
                touchStartY = 0;
                touchStartX = 0;
                touchTarget = null;
            });
        }
    }

    // ==================== 功能3：浮动按钮 ====================
    const BUTTON_IDS = {
        FULLSCREEN: 'video-enhancer-fullscreen',
        SPEED: 'video-enhancer-speed',
        FORWARD: 'video-enhancer-forward',
        RESTART: 'video-enhancer-restart'
    };

    let currentVideo = null;
    let buttonsVisible = false;
    let isSpeed3x = false;

    function injectStyles() {
        const { BUTTON_SIZE, BUTTON_RIGHT, BUTTON_GAP, START_TOP } = CONFIG;
        const buttonPositions = [
            { id: BUTTON_IDS.FULLSCREEN, offset: 0 },
            { id: BUTTON_IDS.SPEED, offset: 1 },
            { id: BUTTON_IDS.FORWARD, offset: 2 },
            { id: BUTTON_IDS.RESTART, offset: 3 }
        ];
        let css = `
            #${BUTTON_IDS.FULLSCREEN}, #${BUTTON_IDS.SPEED}, #${BUTTON_IDS.FORWARD}, #${BUTTON_IDS.RESTART} {
                position: fixed;
                right: ${BUTTON_RIGHT}px;
                width: ${BUTTON_SIZE}px;
                height: ${BUTTON_SIZE}px;
                border-radius: 50%;
                background-color: rgba(60, 60, 60, 0.5);
                backdrop-filter: blur(4px);
                -webkit-backdrop-filter: blur(4px);
                box-shadow: 0 2px 8px rgba(0,0,0,0.15);
                display: flex;
                align-items: center;
                justify-content: center;
                cursor: pointer;
                z-index: 9999;
                opacity: 0;
                transform: scale(0.8);
                transition: opacity 0.25s ease, transform 0.2s ease, background-color 0.2s;
                pointer-events: none;
                border: 1px solid rgba(255,255,255,0.2);
                color: white;
                font-weight: 600;
                font-size: 14px;
                font-family: Arial, sans-serif;
            }
        `;
        buttonPositions.forEach(({ id, offset }) => {
            css += `#${id} { top: calc(${START_TOP}vh + ${offset * (BUTTON_SIZE + BUTTON_GAP)}px); }\n`;
        });
        css += `
            #${BUTTON_IDS.FULLSCREEN}.visible, #${BUTTON_IDS.SPEED}.visible, 
            #${BUTTON_IDS.FORWARD}.visible, #${BUTTON_IDS.RESTART}.visible {
                opacity: 1;
                transform: scale(1);
                pointer-events: auto;
            }
            
            #${BUTTON_IDS.FULLSCREEN}::before {
                content: '⛶';
                font-size: 22px;
                line-height: 1;
                text-shadow: 0 1px 2px rgba(0,0,0,0.2);
            }
            
            #${BUTTON_IDS.SPEED}::before {
                content: '3×';
                line-height: 1;
                text-shadow: 0 1px 2px rgba(0,0,0,0.2);
            }
            #${BUTTON_IDS.SPEED}.speed-active {
                background-color: rgba(0, 150, 200, 0.7) !important;
                border-color: rgba(100, 200, 255, 0.5) !important;
            }
            
            #${BUTTON_IDS.FORWARD}::before {
                content: '↷${CONFIG.SEEK_STEP}s';
                font-size: 12px;
                line-height: 1;
                text-shadow: 0 1px 2px rgba(0,0,0,0.2);
            }
            
            #${BUTTON_IDS.RESTART}::before {
                content: '↺';
                font-size: 20px;
                line-height: 1;
                text-shadow: 0 1px 2px rgba(0,0,0,0.2);
            }
            
            #${BUTTON_IDS.FULLSCREEN}:active, #${BUTTON_IDS.SPEED}:active, 
            #${BUTTON_IDS.FORWARD}:active, #${BUTTON_IDS.RESTART}:active {
                background-color: rgba(80, 80, 80, 0.6);
                transform: scale(0.9);
            }
            
            @media (prefers-color-scheme: dark) {
                #${BUTTON_IDS.FULLSCREEN}, #${BUTTON_IDS.SPEED}, 
                #${BUTTON_IDS.FORWARD}, #${BUTTON_IDS.RESTART} {
                    background-color: rgba(220, 220, 220, 0.2);
                    border-color: rgba(255,255,255,0.1);
                }
                #${BUTTON_IDS.FULLSCREEN}:active, #${BUTTON_IDS.SPEED}:active, 
                #${BUTTON_IDS.FORWARD}:active, #${BUTTON_IDS.RESTART}:active {
                    background-color: rgba(255, 255, 255, 0.25);
                }
                #${BUTTON_IDS.SPEED}.speed-active {
                    background-color: rgba(0, 150, 200, 0.5) !important;
                }
            }
        `;
        addStyleOnce(css, 'video-enhancer-styles');
    }

    function createButtons() {
        const buttons = {};
        Object.entries(BUTTON_IDS).forEach(([key, id]) => {
            const btn = document.createElement('div');
            btn.id = id;
            btn.setAttribute('aria-label', key.toLowerCase());
            document.body.appendChild(btn);
            buttons[key] = btn;
        });
        return buttons;
    }

    function updateButtonsVisibility() {
        const video = getActiveVideo();
        const shouldShow = video && video.readyState >= 1 && video.duration && !isNaN(video.duration);
        if (shouldShow !== buttonsVisible) {
            buttonsVisible = shouldShow;
            const action = shouldShow ? 'add' : 'remove';
            Object.values(BUTTON_IDS).forEach(id => {
                const btn = document.getElementById(id);
                if (btn) btn.classList[action]('visible');
            });
        }
        if (video && video !== currentVideo) {
            currentVideo = video;
            ProgressManager.startTracking(video);
            isSpeed3x = (video.playbackRate === 3.0);
            const speedBtn = document.getElementById(BUTTON_IDS.SPEED);
            if (speedBtn) speedBtn.classList.toggle('speed-active', isSpeed3x);
        } else if (!video && currentVideo) {
            ProgressManager.stopTracking();
            currentVideo = null;
        }
    }

    // ==================== 功能4：视频操作 ====================
    const VideoActions = {
        toggleFullscreen() {
            const video = getActiveVideo();
            if (!video) {
                alert('未检测到视频');
                return;
            }
            try {
                if (!document.fullscreenElement && !document.webkitFullscreenElement) {
                    video.requestFullscreen().catch(e => {
                        if (video.webkitEnterFullscreen) {
                            video.webkitEnterFullscreen();
                        } else {
                            alert('该浏览器不支持全屏功能');
                        }
                    });
                } else {
                    if (document.exitFullscreen) {
                        document.exitFullscreen();
                    } else if (document.webkitExitFullscreen) {
                        document.webkitExitFullscreen();
                    }
                }
            } catch (e) {
                alert('全屏切换失败');
            }
        },

        toggleSpeed() {
            const video = getActiveVideo();
            if (!video) {
                alert('未检测到视频');
                return;
            }
            try {
                const newRate = isSpeed3x ? 1.0 : 3.0;
                video.playbackRate = newRate;
                isSpeed3x = !isSpeed3x;
                const btn = document.getElementById(BUTTON_IDS.SPEED);
                if (btn) btn.classList.toggle('speed-active', isSpeed3x);
            } catch (e) {
                alert('该视频不支持倍速播放');
            }
        },

        seekForward() {
            const video = getActiveVideo();
            if (!video) {
                alert('未检测到视频');
                return;
            }
            try {
                video.currentTime = Math.min(video.currentTime + CONFIG.SEEK_STEP, video.duration);
                ProgressManager.saveProgress(video);
            } catch (e) {
                alert('跳转失败');
            }
        },

        restart() {
            const video = getActiveVideo();
            if (!video) {
                alert('未检测到视频');
                return;
            }
            try {
                video.currentTime = 0;
                video.play();
                ProgressManager.saveProgress(video);
            } catch (e) {
                alert('重新开始失败');
            }
        }
    };

    // ==================== 初始化 ====================
    function init() {
        injectStyles();
        const buttons = createButtons();
        
        buttons.FULLSCREEN.addEventListener('click', (e) => {
            e.stopPropagation();
            VideoActions.toggleFullscreen();
        });
        buttons.SPEED.addEventListener('click', (e) => {
            e.stopPropagation();
            VideoActions.toggleSpeed();
        });
        buttons.FORWARD.addEventListener('click', (e) => {
            e.stopPropagation();
            VideoActions.seekForward();
        });
        buttons.RESTART.addEventListener('click', (e) => {
            e.stopPropagation();
            VideoActions.restart();
        });
        
        bindGlobalGestures();

        let ticking = false;
        const throttledUpdate = () => {
            if (!ticking) {
                requestAnimationFrame(() => {
                    updateButtonsVisibility();
                    ticking = false;
                });
                ticking = true;
            }
        };
        
        window.addEventListener('scroll', throttledUpdate, { passive: true });
        document.addEventListener('play', throttledUpdate, true);
        document.addEventListener('pause', throttledUpdate, true);
        document.addEventListener('loadedmetadata', throttledUpdate, true);
        document.addEventListener('fullscreenchange', throttledUpdate);
        document.addEventListener('webkitfullscreenchange', throttledUpdate);
        setInterval(updateButtonsVisibility, 2000);
        setTimeout(updateButtonsVisibility, 500);
        setTimeout(updateButtonsVisibility, 1500);
        
        window.addEventListener('beforeunload', () => {
            if (currentVideo) ProgressManager.saveProgress(currentVideo);
        });
    }

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', init);
    } else {
        init();
    }

})();