// ==UserScript==
// @name         B站音频一键下载
// @namespace    http://tampermonkey.net/
// @version      1.3
// @description  （从B站下载歌曲）一键下载B站视频的音频，自动命名标题
// @author       豆包助手
// @match        https://www.bilibili.com/video/*
// @license      MIT
// @downloadURL https://update.greasyfork.icu/scripts/576413/B%E7%AB%99%E9%9F%B3%E9%A2%91%E4%B8%80%E9%94%AE%E4%B8%8B%E8%BD%BD.user.js
// @updateURL https://update.greasyfork.icu/scripts/576413/B%E7%AB%99%E9%9F%B3%E9%A2%91%E4%B8%80%E9%94%AE%E4%B8%8B%E8%BD%BD.meta.js
// ==/UserScript==

(function() {
    'use strict';

    // 精致小巧，代码之美
    const btn = document.createElement("button"); btn.style.cssText = "position:fixed;top:10%;right:5%;z-index:999999; width:30px;height:30px;border-radius:15px; border:1px solid blue"; document.body.appendChild(btn);

    // 点击下载逻辑（这里包一层注入）
    btn.onclick = function() {
        const script = document.createElement('script');
        script.textContent = `
            (async function(){
                try {
                    const audioUrl = window.__playinfo__.data.dash.audio[0].backupUrl[0];
                    const title = document.querySelector("#viewbox_report > div.video-info-title > div > h1").title;

                    alert(\`开始下载：\${title}\`);

                    const response = await fetch(audioUrl, {
                        headers: {
                            'User-Agent': navigator.userAgent,
                            'Referer': 'https://www.bilibili.com/'
                        }
                    });
                    const blob = await response.blob();
                    const a = document.createElement('a');
                    const url = URL.createObjectURL(blob);
                    a.href = url;
                    a.download = \`\${title}.mp3\`;
                    a.click();

                    setTimeout(() => URL.revokeObjectURL(url), 1000);
                } catch (err) {
                    alert('下载失败：' + err);
                }
            })();
        `;
        document.head.appendChild(script);
        script.remove();
    };
})();