// ==UserScript==
// @name        网易云音乐下载
// @namespace   https://www.ocrosoft.com/
// @description 支持新版(2017/9/9)网易云。在歌曲页面上所属专辑下面会出现歌词和歌曲的下载链接。该脚本受 GPL V2.0 许可证保护。
// @include     http://music.163.com/*
// @grant       none
// @version     1.0
// @require     http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.8.0.js
// @downloadURL none
// ==/UserScript==
/**
 * 修改自 https://greasyfork.org/zh-CN/scripts/10548-%E7%BD%91%E6%98%93%E4%BA%91%E9%9F%B3%E4%B9%90%E4%B8%8B%E8%BD%BD
 * API 源码: https://github.com/Ocrosoft/NetEase_OutChain
 * 此脚本开源，API开源，但请不要在未经允许的情况下在其他程序中调用此脚本中的API，在非程序调用且小流量的个人使用场景下可以使用。
**/

var api = {

    detailUrl: function(songIds) {
        var tpl = 'http://music.ocrosoft.com/GetMusicLink.php?id=${songIds}';
        return tpl.replace('${songIds}', songIds.join(','));
    },

    detail: function(songIds, callback) {
        $.ajax({
            type: "get",
            url: this.detailUrl(songIds),
            dataType: "jsonp",
            success: function(json){
                callback(json);
            }
        });
    },

    mediaUrl: function(songId) {
        return 'http://music.163.com/api/song/media?id=' + songId;
    },

    media: function(songId, callback) {
        var req = new XMLHttpRequest();
        req.open('GET', this.mediaUrl(songId), true);
        req.onload = function() {
            callback(JSON.parse(this.responseText));
        };
        req.send();
    },

};

var innerFrame = document.querySelector('iframe');
var tit;

var pages = [
    {
        url: 'http://music.163.com/#/song?id=',
        handler: function() {
            var songId = location.href.match(/id=([0-9]+)/)[1];
            var downloadLine = this.createDownloadLine(songId);

            var innerFrameDoc = innerFrame.contentWindow.document;
            var albumNode = innerFrameDoc.querySelectorAll('p.des.s-fc4')[1];
            tit = innerFrameDoc.querySelectorAll('.tit');
            var parentNode = albumNode.parentNode;
            parentNode.insertBefore(downloadLine, albumNode.nextElementSibling);
        },
        createDownloadLine: function(songId) {
            var disableStyle = function(link) {
                link.text += '(无)';
                link.style.color = 'gray';
                link.style.textDecoration = 'none';
                link.style.cursor = 'auto';
            };

            var mp3Link = this.createLink('歌曲');
            var lyricLink = this.createLink('歌词');

            api.detail([songId], function(result) {
                mp3Link.download = $(tit).children('.f-ff2')[0].innerText;
                mp3Link.href = result.mp3Url + ';';
            });
            api.media(songId, function(result) {
                if (result.lyric) {
                    lyricLink.href = 'data:text/plain;charset=utf-8,' +
                        encodeURIComponent(result.lyric);
                } else {
                    disableStyle(lyricLink);
                }
            });

            var container = this.createLineContainer('下载');
            container.appendChild(mp3Link);
            container.appendChild(lyricLink);
            return container;
        },
        createLink: function(label) {
            var link = document.createElement('a');
            link.innerHTML = label;
            link.className = 's-fc7';
            link.style.marginRight = '10px';
            link.href = 'javascript:;';
            return link;
        },
        createLineContainer: function(label) {
            var container = document.createElement('p');
            container.className = 'desc s-fc4';
            container.innerHTML = label + '：';
            container.style.margin = '10px 0';
            return container;
        },
    },
];

if (innerFrame) {
    innerFrame.addEventListener('load', function() {
        var i, page;
        for (i = 0; i < pages.length; i += 1) {
            page = pages[i];
            if (location.href.indexOf(page.url) === 0) {
                page.handler();
            }
        }
    });
}