// ==UserScript==
// @name           豆瓣中图法分类
// @description    如果存在中图分类，则会在豆瓣信息栏中多显示如“中图分类: B842.1 (认知)”，方便对图书进行分类。
// @author         018(lyb018@gmail.com)
// @contributor    Rhilip
// @connect        *
// @grant          GM_xmlhttpRequest
// @grant          GM_setClipboard
// @grant          GM_addStyle
// @grant          GM_setValue
// @grant          GM_getValue
// @grant          GM_listValues
// @grant          GM_deleteValue
// @grant          GM_registerMenuCommand
// @require        https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js
// @require        https://greasyfork.org/scripts/368137-encodeToGb2312/code/encodeToGb2312.js?version=601683
// @include        https://book.douban.com/*
// @version        0.1.1
// @icon           https://img3.doubanio.com/favicon.ico
// @run-at         document-end
// @namespace      doveboy_js
// @downloadURL none
// ==/UserScript==

// This Userscirpt can't run under Greasemonkey 4.x platform
if (typeof GM_xmlhttpRequest === 'undefined') {
    alert('不支持Greasemonkey 4.x，请换用暴力猴或Tampermonkey')
    return
}

// 不属于豆瓣的页面
if (!/douban.com/.test(location.host)) {
    return
}

;(function () {
    'use strict'

    $(document).ready(function () {
        var isbn = /ISBN: .*\n/.exec($('#info').eq(0).text())[0].match(/\d+/g)[0].replace(/\n| /g, '');
        var title = $('#wrapper h1').eq(0).text().replace(/\n| /g, '');
        if( isbn && title ) {
            // superlib 搜索
            requestSuperlib(isbn);
        }
    })

    function requestSuperlib(isbn) {
        getDoc('http://book.ucdrs.superlib.net/search?Field=all&channel=search&sw=' + isbn, null, function(doc, responseDetail, meta) {
            for (let book of doc.querySelectorAll('.book1')) {
                let a = book.querySelector('.book1 td>table a.px14');//
                if (a) {
                    // superlib 书籍查看
                    let url = a.href.replace(location.host, 'book.ucdrs.superlib.net').replace('https', 'http');
                    getDoc(url, null, function(doc1, responseDetail, meta) {
                        let tubox = doc1.querySelector('.tubox dl').textContent;
                        let isbn1 = opt(/【ISBN号】.*\n/.exec(tubox)).replace(/【ISBN号】|-|\n/g, '');
                        if (isbn == isbn1) {
                            let clc = opt(opt(/【中图法分类号】.*\n/.exec(tubox)).match(/[a-zA-Z0-9\.]+/));
                            if (clc) {
                                $('#info').append('<span class="pl">中图分类:</span> <a id="clcText" target="_blank" href="https://www.clcindex.com/search/?wd=' + clc + '">' + clc + '</a>');
                                requestClc(clc)
                            }
                        }
                    });
                }
            }
        });
    }

    function requestClc(clc) {
        doPost('https://ct.istic.ac.cn/site/clc/getByClassName?t=' + new Date().getTime(),
               { "Content-Type": "application/x-www-form-urlencoded" }, 'classname=' + clc, null, function(json, responseDetail, meta) {
            if (json.length == 0) {
                requestClc(clc.replace(/\.\d*$/, ''));
                return;
            }

            let rets = []
            let jsonMap = {}
            let pid = putMapReturnPid(clc, json, jsonMap, rets);
            clcText(pid, jsonMap, rets);

            if (rets.length > 0) {
                $('#clcText').after(' (' + rets.join(' / ') + ')');
            }
        });
    }

    function putMapReturnPid(clc, json, jsonMap, rets) {
        if (!json || json.length <= 0 || !jsonMap || !rets) return;

        let pid;
        let level;
        for (let i = 0; i < json.length; i ++) {
            if (rets.length ==0 && json[i].classNum == clc) {
                rets.push(json[i].classNum + ' - ' + json[i].className);

                pid = json[i].pid;
                level = json[i].level;
            } else if( json[i].level < level) {
                jsonMap[json[i].id + ''] = json[i];
            }
        }

        return pid;
    }

    function clcText(pid, jsonMap, rets) {
        if (!jsonMap || !rets) return;

        if( jsonMap[pid] ) {
            rets.unshift(jsonMap[pid].classNum + ' - ' + jsonMap[pid].className);

            if (jsonMap[pid].level <= 2) return;

            clcText(jsonMap[pid].pid, jsonMap, rets);
        }
    }

    function opt(arrs) {
        if (arrs && arrs.length > 0) {
            return arrs[0];
        }
        return '';
    }

    // 对使用GM_xmlhttpRequest返回的html文本进行处理并返回DOM树
    function page_parser(responseText) {
        // 替换一些信息防止图片和页面脚本的加载，同时可能加快页面解析速度
        responseText = responseText.replace(/s+src=/ig, ' data-src='); // 图片，部分外源脚本
        responseText = responseText.replace(/<script[^>]*?>[\S\s]*?<\/script>/ig, ''); //页面脚本
        return (new DOMParser()).parseFromString(responseText, 'text/html');
    }

    function getDoc (url, meta, callback) {
        GM_xmlhttpRequest({
            method: 'GET',
            url: url,
            onload: function (responseDetail) {
                if (responseDetail.status === 200) {
                    let doc = page_parser(responseDetail.responseText)
                    callback(doc, responseDetail, meta)
                } else {
                    callback(undefined, responseDetail, meta)
                }
            }
        })
    }

    function doPost (url, headers, data, meta, callback) {
        GM_xmlhttpRequest({
            method: "POST",
            url: url,
            data: data,
            headers: headers,
            onload: function(responseDetail){
                if (responseDetail.status === 200) {
                    callback(JSON.parse(responseDetail.responseText), responseDetail, meta)
                } else {
                    callback(undefined, responseDetail, meta)
                }
            }
        })
    }
})()