// ==UserScript==
// @name         歌曲宝全能下载助手 (终极优化版)
// @namespace    http://tampermonkey.net/
// @version      5.0
// @description  在歌曲宝搜索结果页面添加直链下载，拦截弹窗，下载歌词并嵌入封面图
// @author       You
// @match        https://www.gequbao.com/s/*
// @match        https://www.gequbao.com/music/*
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_xmlhttpRequest
// @grant        GM_notification
// @grant        GM_download
// @require      https://cdn.jsdelivr.net/npm/jquery@3.6.0/dist/jquery.min.js
// @require      https://cdn.jsdelivr.net/npm/jsmediatags@3.9.7/dist/jsmediatags.min.js
// ==/UserScript==

(function() {
    'use strict';
    
    // 配置
    const CONFIG = {
        defaultDownloadType: GM_getValue('download_type', 'direct'),
        downloadLrc: GM_getValue('download_lrc', false),
        embedCover: GM_getValue('embed_cover', true) // 新增：嵌入封面开关
    };
    
    // 主初始化函数
    function init() {
        if (window.location.pathname.startsWith('/s/')) {
            // 搜索结果页面：添加下载控制面板和链接
            addDownloadControlPanel();
            addDirectDownloadLinks();
        } else if (window.location.pathname.startsWith('/music/')) {
            // 歌曲详情页面：增强下载按钮功能
            enhanceMusicPage();
        }
    }
    
    // === 功能1: 为搜索结果页面添加控制面板 ===
    function addDownloadControlPanel() {
        if ($('#download-control-panel').length > 0) return;
        
        const panelHtml = `
            <div class="card mb-2" id="download-control-panel">
                <div class="card-body py-2">
                    <div class="row">
                        <div class="col-md-6">
                            <div class="form-group mb-1">
                                <label class="mr-2"><strong>下载方式:</strong></label>
                                <div class="btn-group btn-group-toggle" data-toggle="buttons">
                                    <label class="btn btn-sm btn-outline-primary ${CONFIG.defaultDownloadType === 'direct' ? 'active' : ''}">
                                        <input type="radio" name="download-type" value="direct" ${CONFIG.defaultDownloadType === 'direct' ? 'checked' : ''}> 直链下载
                                    </label>
                                    <label class="btn btn-sm btn-outline-success ${CONFIG.defaultDownloadType === 'pan' ? 'active' : ''}">
                                        <input type="radio" name="download-type" value="pan" ${CONFIG.defaultDownloadType === 'pan' ? 'checked' : ''}> 网盘下载
                                    </label>
                                </div>
                            </div>
                        </div>
                        <div class="col-md-6">
                            <div class="form-group mb-1">
                                <div class="custom-control custom-switch">
                                    <input type="checkbox" class="custom-control-input" id="download-lrc-switch" ${CONFIG.downloadLrc ? 'checked' : ''}>
                                    <label class="custom-control-label" for="download-lrc-switch">同时下载歌词</label>
                                </div>
                                <div class="custom-control custom-switch">
                                    <input type="checkbox" class="custom-control-input" id="embed-cover-switch" ${CONFIG.embedCover ? 'checked' : ''}>
                                    <label class="custom-control-label" for="embed-cover-switch">嵌入封面到MP3</label>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        `;
        
        $('#search-line-form').after(panelHtml);
        
        // 绑定切换事件
        $('input[name="download-type"]').change(function() {
            const type = $(this).val();
            GM_setValue('download_type', type);
            CONFIG.defaultDownloadType = type;
            refreshAllDownloadLinks();
        });
        
        $('#download-lrc-switch').change(function() {
            const enabled = $(this).is(':checked');
            GM_setValue('download_lrc', enabled);
            CONFIG.downloadLrc = enabled;
        });
        
        $('#embed-cover-switch').change(function() {
            const enabled = $(this).is(':checked');
            GM_setValue('embed_cover', enabled);
            CONFIG.embedCover = enabled;
        });
    }
    
    // === 功能2: 为搜索结果添加下载链接 ===
    function addDirectDownloadLinks() {
        $('.row.mb-3').nextAll('.row').each(function() {
            const $row = $(this);
            const $actionCol = $row.find('.col-4.text-right');
            const $playLink = $actionCol.find('a[href*="/music/"]');
            
            if ($actionCol.find('.direct-download').length > 0) return;
            
            const musicLink = $playLink.attr('href');
            const musicId = musicLink.match(/\/music\/(\d+)/)[1];
            
            const $downloadContainer = $('<span>', { class: 'download-container', css: { 'margin-left': '10px' } });
            
            const $songDownload = $('<a>', {
                href: 'javascript:void(0)',
                html: '<u>下载歌曲</u>',
                css: { 'color': CONFIG.defaultDownloadType === 'direct' ? '#dc3545' : '#28a745', 'cursor': 'pointer', 'font-weight': 'bold', 'margin-right': '8px' },
                addClass: 'direct-download',
                click: function(e) {
                    e.preventDefault();
                    fetchDownloadUrl(musicId, $(this), 'song');
                }
            });
            
            const $lrcDownload = $('<a>', {
                href: 'javascript:void(0)',
                html: '<u>下载歌词</u>',
                css: { 'color': '#6f42c1', 'cursor': 'pointer', 'font-weight': 'bold' },
                addClass: 'lrc-download',
                click: function(e) {
                    e.preventDefault();
                    fetchDownloadUrl(musicId, $(this), 'lrc');
                }
            });
            
            $downloadContainer.append($songDownload).append($lrcDownload);
            $actionCol.append($downloadContainer);
        });
    }
    
    function refreshAllDownloadLinks() {
        $('.direct-download').css('color', CONFIG.defaultDownloadType === 'direct' ? '#dc3545' : '#28a745');
    }
    
    // === 核心下载逻辑 ===
    async function fetchDownloadUrl(musicId, $link, type = 'song') {
        const originalText = $link.html();
        $link.html('<u>获取中...</u>').css('color', '#ffc107');
        
        try {
            const response = await fetch(`/music/${musicId}`);
            const html = await response.text();
            
            const appData = parseAppDataFromHTML(html);
            if (!appData) throw new Error('无法解析歌曲数据');
            
            const lrcContent = parseLrcFromHTML(html);
            const coverUrl = parseCoverFromHTML(html);
            
            $link.data('musicId', musicId);
            $link.data('cachedData', appData);
            $link.data('lrcContent', lrcContent);
            $link.data('coverUrl', coverUrl);
            
            if (type === 'song') {
                if (CONFIG.defaultDownloadType === 'direct') {
                    await fetchDirectDownloadUrl(appData, musicId, $link, lrcContent, coverUrl);
                } else {
                    fetchPanDownloadUrl(appData, musicId, $link, lrcContent);
                }
            } else {
                downloadLrcFile(appData, lrcContent, $link);
            }
        } catch (error) {
            console.error('获取下载链接失败:', error);
            handleDownloadError($link, originalText, type);
        }
    }
    
    // === 功能3: 拦截弹窗并强制下载 ===
    async function fetchDirectDownloadUrl(appData, musicId, $link, lrcContent, coverUrl) {
        if (appData.mp3_extra_urls && appData.mp3_extra_urls.length > 0) {
            for (let extraUrl of appData.mp3_extra_urls) {
                if (extraUrl.share_link && extraUrl.share_link.match(/\.mp3($|\?)/)) {
                    applyDownloadUrl($link, musicId, appData);
                    await triggerDirectDownload(extraUrl.share_link, appData, lrcContent, coverUrl);
                    return;
                }
            }
        }
        
        if (appData.play_id) {
            await fetchPlayUrl(appData.play_id, musicId, $link, appData, lrcContent, coverUrl);
        } else {
            fetchPanDownloadUrl(appData, musicId, $link, lrcContent);
        }
    }
    
    function fetchPlayUrl(playId, musicId, $link, appData, lrcContent, coverUrl) {
        return new Promise((resolve, reject) => {
            GM_xmlhttpRequest({
                method: 'POST',
                url: 'https://www.gequbao.com/api/play-url',
                headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
                data: `id=${encodeURIComponent(playId)}`,
                onload: function(response) {
                    try {
                        const result = JSON.parse(response.responseText);
                        if (result.code === 1 && result.data && result.data.url) {
                            let downloadUrl = result.data.url;
                            if (downloadUrl.includes('antiserver.kuwo.cn')) {
                                convertKuwoUrl(downloadUrl, musicId, $link, appData, lrcContent, coverUrl).then(resolve).catch(reject);
                            } else {
                                applyDownloadUrl($link, musicId, appData);
                                triggerDirectDownload(downloadUrl, appData, lrcContent, coverUrl).then(resolve).catch(reject);
                            }
                        } else {
                            reject(new Error(result.msg || '获取播放链接失败'));
                        }
                    } catch (e) {
                        reject(e);
                    }
                },
                onerror: reject
            });
        });
    }
    
    // === 功能4: 使用页面“下载歌词”按钮的逻辑 ===
    function enhanceMusicPage() {
        // 重写原页面的歌词下载逻辑，使其也使用GM_download
        const originalLrcBtn = document.getElementById('btn-download-lrc');
        if (originalLrcBtn) {
            originalLrcBtn.addEventListener('click', function(e) {
                e.preventDefault();
                downloadLrcFromMusicPage();
            });
        }
    }
    
    function downloadLrcFromMusicPage() {
        // 从歌曲详情页获取歌词内容
        const lrcElement = document.getElementById('content-lrc');
        if (lrcElement) {
            const lrcContent = lrcElement.innerText;
            if (lrcContent && !lrcContent.includes('该歌曲暂无歌词')) {
                // 从页面获取歌曲信息
                const musicTitleElement = document.querySelector('#music-title h1');
                let songName = '未知歌曲';
                if (musicTitleElement) {
                    songName = musicTitleElement.textContent.split(' - ')[0].trim();
                }
                
                const lrcFileName = sanitizeFilename(`${songName}.lrc`);
                const blob = new Blob([lrcContent], { type: 'text/plain' });
                const url = URL.createObjectURL(blob);
                
                GM_download({
                    url: url,
                    name: lrcFileName,
                    onload: function() {
                        URL.revokeObjectURL(url);
                        GM_notification({
                            text: `歌词已下载: ${songName}`,
                            title: '歌曲宝下载助手',
                            timeout: 2000
                        });
                    },
                    onerror: function(error) {
                        URL.revokeObjectURL(url);
                        console.error('歌词下载失败:', error);
                    }
                });
            } else {
                alert('当前歌曲暂无歌词');
            }
        }
    }
    
    function downloadLrcFile(appData, lrcContent, $link = null) {
        if (!lrcContent || lrcContent.includes('该歌曲暂无歌词')) {
            if ($link) {
                $link.html('<u>无歌词</u>').css('color', '#6c757d');
                setTimeout(() => { $link.html('<u>下载歌词</u>').css('color', '#6f42c1'); }, 2000);
            }
            return;
        }
        
        const lrcFileName = sanitizeFilename(`${appData.mp3_title} - ${appData.mp3_author}.lrc`);
        const blob = new Blob([lrcContent], { type: 'text/plain' });
        const url = URL.createObjectURL(blob);
        
        GM_download({
            url: url,
            name: lrcFileName,
            onload: function() {
                URL.revokeObjectURL(url);
                if ($link) $link.html('<u>下载歌词</u>').css('color', '#6f42c1');
                GM_notification({ text: `歌词已下载: ${appData.mp3_title}`, title: '歌曲宝下载助手', timeout: 2000 });
            }
        });
    }
    
    // === 功能5: 嵌入封面图片到MP3文件 ===
    async function triggerDirectDownload(mp3Url, appData, lrcContent, coverUrl) {
        const fileName = sanitizeFilename(`${appData.mp3_title} - ${appData.mp3_author}.mp3`);
        
        if (CONFIG.embedCover && coverUrl) {
            // 如果开启了嵌入封面功能且有封面URL，则先下载图片和音频，然后合并
            await downloadAndEmbedCover(mp3Url, fileName, coverUrl, appData);
        } else {
            // 否则直接下载MP3
            GM_download({
                url: mp3Url,
                name: fileName,
                onload: function() {
                    GM_notification({ text: `下载完成: ${appData.mp3_title}`, title: '歌曲宝下载助手', timeout: 3000 });
                }
            });
        }
        
        // 如果设置了同时下载歌词，下载歌词
        if (CONFIG.downloadLrc && lrcContent) {
            downloadLrcFile(appData, lrcContent);
        }
    }
    
    async function downloadAndEmbedCover(mp3Url, fileName, coverUrl, appData) {
        try {
            GM_notification({ text: `正在下载并处理: ${appData.mp3_title}`, title: '歌曲宝下载助手', timeout: 2000 });
            
            // 并行下载MP3和封面图片
            const [mp3Response, coverResponse] = await Promise.all([
                fetch(mp3Url),
                fetch(coverUrl)
            ]);
            
            const [mp3Buffer, coverBuffer] = await Promise.all([
                mp3Response.arrayBuffer(),
                coverResponse.arrayBuffer()
            ]);
            
            // 将封面图片转换为Base64
            const coverBase64 = arrayBufferToBase64(coverBuffer);
            const mimeType = getImageMimeType(coverUrl);
            
            // 使用jsmediatags写入封面到MP3
            jsmediatags.write(mp3Buffer, {
                tags: {
                    title: appData.mp3_title,
                    artist: appData.mp3_author,
                    picture: {
                        data: coverBase64,
                        format: mimeType
                    }
                }
            }, function(result) {
                if (result.error) {
                    console.error('嵌入封面失败:', result.error);
                    // 如果失败，回退到直接下载
                    fallbackDirectDownload(mp3Url, fileName, appData);
                    return;
                }
                
                // 创建Blob并下载
                const finalBlob = new Blob([result.buffer], { type: 'audio/mpeg' });
                const finalUrl = URL.createObjectURL(finalBlob);
                
                GM_download({
                    url: finalUrl,
                    name: fileName,
                    onload: function() {
                        URL.revokeObjectURL(finalUrl);
                        GM_notification({ 
                            text: `下载完成(含封面): ${appData.mp3_title}`, 
                            title: '歌曲宝下载助手', 
                            timeout: 3000 
                        });
                    }
                });
            });
            
        } catch (error) {
            console.error('处理文件失败:', error);
            // 出错时回退到直接下载
            fallbackDirectDownload(mp3Url, fileName, appData);
        }
    }
    
    function fallbackDirectDownload(mp3Url, fileName, appData) {
        GM_download({
            url: mp3Url,
            name: fileName,
            onload: function() {
                GM_notification({ 
                    text: `下载完成(无封面): ${appData.mp3_title}`, 
                    title: '歌曲宝下载助手', 
                    timeout: 3000 
                });
            }
        });
    }
    
    // === 工具函数 ===
    function parseAppDataFromHTML(html) {
        const match = html.match(/window\.appData\s*=\s*({[^;]+});/);
        if (match && match[1]) {
            try { return JSON.parse(match[1]); } catch (e) { console.error('解析appData失败:', e); }
        }
        return null;
    }
    
    function parseLrcFromHTML(html) {
        const lrcMatch = html.match(/<div class="content-lrc"[^>]*>([\s\S]*?)<\/div>/);
        if (lrcMatch && lrcMatch[1]) {
            return lrcMatch[1].replace(/<br\s*\/?>/gi, '\n').replace(/<[^>]+>/g, '').trim();
        }
        return null;
    }
    
    function parseCoverFromHTML(html) {
        // 从HTML中提取封面图片URL
        const coverMatch = html.match(/<img[^>]*src="([^"]*)"[^>]*style="[^"]*background-image[^"]*"/);
        if (coverMatch && coverMatch[1]) {
            return coverMatch[1];
        }
        // 备用方法：从aplayer-pic的背景图片中提取
        const bgMatch = html.match(/background-image:\s*url\(&quot;([^&]*)&quot;\)/);
        return bgMatch ? bgMatch[1] : null;
    }
    
    function arrayBufferToBase64(buffer) {
        let binary = '';
        const bytes = new Uint8Array(buffer);
        for (let i = 0; i < bytes.byteLength; i++) {
            binary += String.fromCharCode(bytes[i]);
        }
        return window.btoa(binary);
    }
    
    function getImageMimeType(url) {
        if (url.includes('.jpg') || url.includes('.jpeg')) return 'image/jpeg';
        if (url.includes('.png')) return 'image/png';
        if (url.includes('.gif')) return 'image/gif';
        return 'image/jpeg'; // 默认
    }
    
    function sanitizeFilename(filename) {
        return filename.replace(/[<>:"/\\|?*]/g, '_').replace(/\s+/g, ' ').trim();
    }
    
    function applyDownloadUrl($link, musicId, appData) {
        $link.html('<u>下载歌曲</u>').css('color', CONFIG.defaultDownloadType === 'direct' ? '#dc3545' : '#28a745');
    }
    
    function handleDownloadError($link, originalText, type) {
        $link.html(originalText).css('color', type === 'song' ? 
            (CONFIG.defaultDownloadType === 'direct' ? '#dc3545' : '#28a745') : '#6f42c1');
        GM_notification({ text: '获取下载链接失败，请重试', title: '歌曲宝下载助手', timeout: 3000 });
    }
    
    // 初始化
    window.addEventListener('load', function() { setTimeout(init, 1000); });
    
    // 监听页面变化
    const observer = new MutationObserver(function(mutations) {
        let shouldUpdate = false;
        mutations.forEach(function(mutation) {
            if (mutation.addedNodes.length > 0) shouldUpdate = true;
        });
        if (shouldUpdate) setTimeout(init, 500);
    });
    observer.observe(document.body, { childList: true, subtree: true });
})();