// ==UserScript==
// @name                ScienceDirect Download
// @name:zh-CN          ScienceDirect下载
// @namespace      tampermonkey.com
// @version        2.1
// @license MIT
// @description         Avoid jumping to online pdf, and directly download ScienceDirect literature to local
// @description:zh-CN   避免跳转在线pdf，可直接下载ScienceDirect文献到本地
// @match        *://www.sciencedirect.com/*
// @match        *://pdf.sciencedirectassets.com/*
// @grant        GM_setValue
// @grant        GM_getValue
// @run-at document-start
// @downloadURL none
// ==/UserScript==
function getBlob(url, cb) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, true);
    xhr.responseType = 'blob';
    xhr.onload = function () {
        if (xhr.status === 200) {
            cb(xhr.response);
        }
    };
    xhr.send();
};
function saveAs(blob, filename) {
    if (window.navigator.msSaveOrOpenBlob) {
        navigator.msSaveBlob(blob, filename);
    } else {
        var link = document.createElement('a');
        var body = document.querySelector('body');
        link.href = window.URL.createObjectURL(blob);
        link.download = filename;
        // fix Firefox
        link.style.display = 'none';
        body.appendChild(link);
        link.click();
        body.removeChild(link);
        window.URL.revokeObjectURL(link.href);
    };
};

function download(url, filename) {
    getBlob(url, function (blob) {
        saveAs(blob, filename);
    });
};
(function () {
    'use strict';
    var domain = document.domain;
    if (domain == 'pdf.sciencedirectassets.com') {
        var url = document.URL + '&download=true';
        console.log(url);
        var title = document.URL.split("/")[5].split("-")[2];
        try {
            var id = document.URL.split("/")[5].split("-")[2]
            title = GM_getValue(id)
        } catch (err) {
            console.log("err_message" + err.message);
        };
        // var html_url = "https://www.sciencedirect.com/science/article/pii/" + document.URL.split("/")[5].split("-")[2]
        var ret = prompt('Type your filename and click confirm to download!', title);
        if (ret !== null && ret != '') {
            var filename = ret + '.pdf';
            download(url, filename);
        };
    };
    if (domain == 'www.sciencedirect.com') {
        document.addEventListener("DOMContentLoaded", DOM_ContentReady);
        function DOM_ContentReady() {
            // creat newlink
            var linkid = document.head.getElementsByTagName('meta')[0].content;
            var titile = document.title.replace(' - ScienceDirect', '');
            GM_setValue(linkid, titile);
            if (linkid) {
                var new_url = "https://www.sciencedirect.com/science/article/pii/" + linkid + "/pdfft?isDTMRedir=true";
                let Container = document.createElement('div');
                Container.id = "sp-ac-container";
                Container.style.position = "fixed";
                Container.style.left = "250px";
                Container.style.top = "28px";
                Container.style['z-index'] = "2";
                Container.innerHTML = `<button title="Click to download" class="button1" id="download" onclick="window.location.href='${new_url}'")>download</button>
                <style>
                .button1 {
                -webkit-transition-duration: 0.4s;
                transition-duration: 0.4s;
                padding: 1.5px 6px;
                text-align: center;
                background-color: #f5f5f5;
                color: rgb(243, 109, 33);
                border: 0.5px rgb(134, 218, 209);
                border-radius: 9px;
                font-family: NexusSans,Arial,Helvetica,Lucida Sans Unicode,Microsoft Sans Serif,Segoe UI Symbol,STIXGeneral,Cambria Math,Arial Unicode MS,sans-serif!important;
                }
                .button1:hover {
                background-color: rgb(134, 218, 209);;;
                color: red;
                }
                </style>`;
                document.body.appendChild(Container);
            };
        };
    };
})()