// ==UserScript==
// @id             CNKI_PDF_Supernova
// @name           知网PDF下载助手
// @version        2.3.2
// @namespace      https://github.com/supernovaZhangJiaXing/Tampermonkey/
// @author         Supernova
// @description    直接以PDF格式下载知网上的文献, 包括期刊论文和博硕士论文
// @include        http*://*.cnki.net/*
// @include        http*://*.cnki.net.*/*
// @include        */kns/brief/*
// @include        */kns55/brief/*
// @include        */grid2008/brief/*
// @include        */detail/detail.aspx*
// @exclude        http://image.cnki.net/*
// @run-at         document-idle
// @grant          none
// @downloadURL none
// ==/UserScript==


var isDetailPage = false;
var isCNKIPage = false;
var myurl = window.location.href;

// isDetailPage: 点进文献后的详情页
if (myurl.indexOf("detail.aspx") != -1) {
    isDetailPage = true;
}
// isNewPage: 是知网页面(谁从杂牌网站下载(╯‵□′)╯︵┻━┻)
if (document.title.indexOf(" - 中国知网") != -1) {
    isCNKIPage = true;
}

// 查找所有链接的XPath
var allLinks;

// 如果不是详情页, 即在搜索页面直接点右面的下载图标, 把点击后发送的get请求的dflag参数内容改为"pdfdown"就可以了(知网老贼你以为隐藏起来我就找不到了?)
if (isDetailPage === false) {
    if (window.location.href.indexOf("kns8") != -1){ // 文献检索页面, 防止在别处出现
        // 加一个转换下载方式的按钮
        var thisLink;
        // 浮动框
        var float_box = document.createElement("div");
        float_box.style = "position: fixed ; right: 20px; top: 50px; width: 200px; text-align: center; border: dashed; padding: 10px; background-color: cyan";
        document.getElementsByTagName("body")[0].insertAdjacentElement("afterbegin", float_box);
        // 勾选框
        var change_type = document.createElement("button");
        change_type.innerText = "转换为默认下载PDF";
        change_type.id = "change_type";
        change_type.style = "font-size:150%;";
        change_type.onclick = function() {
            allLinks = document.evaluate(
                '//a[@title="下载"]',
                document,
                null,
                XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
                null);
            for (var i = 0; i < allLinks.snapshotLength; i++) {
                thisLink = allLinks.snapshotItem(i);
                if (thisLink.href && thisLink.href.indexOf("download.aspx?filename=") != -1 && thisLink.href.indexOf("&dflag") == -1) {
                    thisLink.href = thisLink.href + "&dflag=pdfdown";
                } else if (thisLink.href && thisLink.href.indexOf("download.aspx?filename=") != -1 && thisLink.href.indexOf("&dflag=nhdown") != -1) {
                    thisLink.href = thisLink.href.replace("nhdown", "pdfdown");
                } else {
                    thisLink.href = "https://kns.cnki.net/kcms/download.aspx?" + thisLink.href.substr(thisLink.href.indexOf("filename=")) + "&dflag=pdfdown";
                }
            }
            change_type.innerText = "√ 已转换: 默认下载PDF";
        };
        float_box.insertAdjacentElement("beforeend", change_type);
    }
}
// 如果进了详情页, 博硕士论文下面会出现五个个按钮: 手机, 整本, 分页, 分章, 在线
// 期刊论文下会有三个按钮
else {
    // 只对"博硕论文"详情页做优化, 否则影响期刊页面的显示
    // 新版界面更改了详情页的显示方式, 原本的"博硕论文"四个大字没有了, 只能数按钮数量了
    var operate_buttons = document.getElementsByClassName("operate-btn")[0];
    if (isCNKIPage === true && operate_buttons.childElementCount == 5) {
        // 整本下载的按钮
        var dlcaj = operate_buttons.childNodes[3];
        var dlcaj_link = dlcaj.childNodes[0];
        // 修改内容
        dlcaj.innerHTML = dlcaj.innerHTML.replace("整本", "CAJ");
        // 获得pdf的链接
        var pdf_link = dlcaj_link.href.replace("nhdown", "pdfdown");
        // 分页下载的按钮
        var dlpdf = operate_buttons.childNodes[5];
        var dlpdf_link = dlpdf.childNodes[0];
        // 修改内容
        dlpdf.innerHTML = dlpdf.innerHTML.replace("分页", "PDF");
        dlpdf.onclick = "";
        dlpdf.onclick = function() {
            window.location.href = pdf_link;
        } // 知网老贼搞了个方法来强制跳转, 不得已, 使用驴氏办法暴力破除
        // 分章下载可以用来获取目录
        var dlChapter = operate_buttons.childNodes[7];
        var dlChapter_link = dlChapter.childNodes[0];
        dlChapter.innerHTML = dlChapter.innerHTML.replace("分章", "目录");
    }
}

// 下面是在目录页面加一个下载按钮
if (myurl.includes("kdoc")) {
    var title = document.getElementsByClassName("DBlueText")[0];
    var downCnt = document.createElement("button");
    downCnt.innerHTML = "下载目录索引";
    downCnt.id = "downCnt";
    downCnt.style = "height: 32px; padding: 0 15px; background-color: #1890ff; border-color: #1890ff; color: #fff; font-size: 14px; border-radius: 4px; text-shadow: 0 -1px 0 rgba(0,0,0,0.12); box-shadow: 0 2px 0 rgba(0,0,0,0.045); margin: 10px";
    downCnt.onclick = function() {
        var cnt_list = document.getElementById("downCnt").nextSibling.childNodes[1].childNodes;
        // 要写的内容
        var contents = "";
        for (var i = 0; i < cnt_list.length - 1; i++) { // 长度减一, 因为最后一个是text(???这又是什么神仙操作)
            var cnt_item = cnt_list[i].childNodes[1].childNodes[1];
            cnt_item = cnt_item.innerHTML;
            var cnt_page = cnt_list[i].childNodes[3].childNodes[0].textContent.trim().split("-")[0]; // 知网的目录给的是个范围, 正常只需要前半部分
            contents = contents + cnt_item.trim().replace(/&nbsp;/g, " ") + "\t" + cnt_page + "\r\n";
        }
        var data = new Blob([contents],{type:"text/plain; charset=UTF-8"});
        var downloadUrl = window.URL.createObjectURL(data);
        var anchor = document.createElement("a");
        anchor.href = downloadUrl;
        anchor.download = "目录索引_" + title.innerHTML.trim().replace(/&nbsp;/g, "");
        anchor.click();
        window.URL.revokeObjectURL(data);
        window.alert("目录索引已保存, 请使用FreePic2Pdf软件将目录整合到PDF中");
    };
    title.parentElement.insertBefore(downCnt, title.nextElementSibling);
}