// ==UserScript==
// @name         网页视频控制4.0
// @namespace    https://bbs.tampermonkey.net.cn/
// @version      0.4.0
// @description  通过键盘快捷键控制网页视频播放：空格键播放/暂停，左右方向键快退/快进，上下方向键调节音量
// @author       Trae
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // 获取页面中的视频元素
    function getVideoElement() {
        return document.querySelector('video');
    }

    // 获取下一集视频的链接
    function getNextVideoLink() {
        // 尝试查找常见的视频列表元素
        const videoLinks = Array.from(document.querySelectorAll('a')).filter(link => {
            const href = link.href.toLowerCase();
            return href.includes('video') || href.includes('play') || href.includes('episode') || 
                   href.includes('集') || href.includes('期');
        });

        if (videoLinks.length === 0) return null;

        // 查找当前URL在列表中的位置
        const currentIndex = videoLinks.findIndex(link => link.href === window.location.href);
        if (currentIndex === -1 || currentIndex === videoLinks.length - 1) return null;

        return videoLinks[currentIndex + 1].href;
    }

    // 跳转到下一集
    function playNextVideo() {
        const nextLink = getNextVideoLink();
        if (nextLink) {
            window.location.href = nextLink;
        }
    }

    // 获取视频的唯一标识
    function getVideoId(video) {
        // 使用视频源和页面URL作为唯一标识
        return `${window.location.href}-${video.currentSrc}`;
    }

    // 保存播放进度
    function savePlaybackProgress(video) {
        const videoId = getVideoId(video);
        localStorage.setItem(videoId, video.currentTime.toString());
    }

    // 恢复播放进度
    function restorePlaybackProgress(video) {
        const videoId = getVideoId(video);
        const savedTime = localStorage.getItem(videoId);
        if (savedTime !== null) {
            video.currentTime = parseFloat(savedTime);
        }
    }

    // 键盘事件处理函数
    function handleKeyPress(event) {
        const video = getVideoElement();
        if (!video) return;

        // 防止按键事件影响页面其他功能
        if (['Space', 'ArrowLeft', 'ArrowRight', 'ArrowUp', 'ArrowDown', 'KeyF'].includes(event.code)) {
            event.preventDefault();
            event.stopPropagation();
        }

        switch(event.code) {
            case 'Space': // 空格键：播放/暂停
                if (video.paused) {
                    video.play().catch(error => console.log('播放失败:', error));
                } else {
                    video.pause();
                }
                break;

            case 'ArrowLeft': // 左方向键：后退5秒
                video.currentTime = Math.max(0, video.currentTime - 5);
                break;

            case 'ArrowRight': // 右方向键：前进5秒
                video.currentTime = Math.min(video.duration, video.currentTime + 5);
                break;

            case 'ArrowUp': // 上方向键：音量增加10%
                video.volume = Math.min(1, video.volume + 0.1);
                break;

            case 'ArrowDown': // 下方向键：音量降低10%
                video.volume = Math.max(0, video.volume - 0.1);
                break;

            case 'KeyN': // N键：跳转下一集
                playNextVideo();
                break;
                
            case 'KeyF': // F键：全屏
                if (video.requestFullscreen) {
                    video.requestFullscreen().catch(error => console.log('全屏失败:', error));
                } else if (video.webkitRequestFullscreen) { // Safari
                    video.webkitRequestFullscreen();
                } else if (video.msRequestFullscreen) { // IE11
                    video.msRequestFullscreen();
                }
                break;
        }
    }

    // 添加键盘事件监听
    document.addEventListener('keydown', handleKeyPress);
    
    // 监听全屏状态变化
    document.addEventListener('fullscreenchange', () => {
        if (document.fullscreenElement) {
            // 在全屏元素上添加键盘事件监听
            document.fullscreenElement.addEventListener('keydown', handleKeyPress);
        }
    });
    
    // 兼容不同浏览器的全屏事件
    document.addEventListener('webkitfullscreenchange', () => {
        if (document.webkitFullscreenElement) {
            document.webkitFullscreenElement.addEventListener('keydown', handleKeyPress);
        }
    });
    
    document.addEventListener('mozfullscreenchange', () => {
        if (document.mozFullScreenElement) {
            document.mozFullScreenElement.addEventListener('keydown', handleKeyPress);
        }
    });
    
    document.addEventListener('MSFullscreenChange', () => {
        if (document.msFullscreenElement) {
            document.msFullscreenElement.addEventListener('keydown', handleKeyPress);
        }
    });

    // 添加提示信息
    const style = document.createElement('style');
    style.textContent = `
        .video-control-tips {
            position: fixed;
            bottom: 20px;
            right: 20px;
            background: rgba(0, 0, 0, 0.7);
            color: white;
            padding: 10px;
            border-radius: 5px;
            font-size: 14px;
            z-index: 9999;
            display: none;
        }
    `;
    document.head.appendChild(style);

    const tips = document.createElement('div');
    tips.className = 'video-control-tips';
    tips.innerHTML = `
        视频控制快捷键：<br>
        空格键 - 播放/暂停<br>
        ← → - 快退/快进5秒<br>
        ↑ ↓ - 音量增加/减少<br>
        N - 跳转下一集<br>
        F - 全屏
    `;
    document.body.appendChild(tips);

    // 当视频存在时显示提示并设置相关功能
    const observer = new MutationObserver(() => {
        const video = getVideoElement();
        if (video) {
            // 显示提示
            tips.style.display = 'block';
            setTimeout(() => {
                tips.style.display = 'none';
            }, 5000);

            // 视频加载完成后恢复播放进度
            video.addEventListener('loadedmetadata', () => {
                restorePlaybackProgress(video);
            });

            // 视频播放结束时自动跳转到下一集
            video.addEventListener('ended', () => {
                playNextVideo();
            });

            // 定期保存播放进度（每5秒）
            setInterval(() => {
                if (!video.paused) {
                    savePlaybackProgress(video);
                }
            }, 5000);

            // 页面关闭或切换前保存进度
            window.addEventListener('beforeunload', () => {
                savePlaybackProgress(video);
            });

            observer.disconnect();
        }
    });

    observer.observe(document.body, {
        childList: true,
        subtree: true
    });
})();