// ==UserScript==
// @name         超星学习通章节内ppt视频下载
// @namespace    http://tampermonkey.net/
// @version      1.08
// @description  按下D下载ppt,pdf,上课视频
// @author       西电网信院的废物rytter
// @match        http://*.chaoxing.com/mycourse/*
// @match        https://*.chaoxing.com/mycourse/*
// @match        http://*.chaoxing.com/*
// @match        https://*.chaoxing.com/*
// @match        https://mooc1.*/*
// @match        http://mooc1.*/*
// @match        https://mooc1.xueyinonline.com/*
// @match        http://mooc1.xueyinonline.com/*
// @icon         data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
// @grant        none
// @updateURL
// @installURL
// @downloadURL
// @license      MIT
// @downloadURL none
// ==/UserScript==

function get_xueyinonline_objectid() {
  var ans_classes = document.getElementsByClassName("ans-attach-ct");
  console.log(ans_classes.length);
  var objectids = new Array();
  for (var j = 0; j < ans_classes.length; j++) {
    console.log(ans_classes[j]);
    if (
      ans_classes[j]
        .getElementsByTagName("iframe")[0]
        .getAttribute("objectid") != undefined
    ) {
      objectids = objectids.concat(
        ans_classes[j]
          .getElementsByTagName("iframe")[0]
          .getAttribute("objectid")
      );
    }
  }
  console.log(objectids);
  return objectids;
}
function get_chaoxing_objectid() {
  var ans_classes = document
    .getElementsByTagName("iframe")[0]
    .contentDocument.body.getElementsByClassName("ans-attach-ct");
  console.log(ans_classes.length);
  var objectids = new Array();
  for (var j = 0; j < ans_classes.length; j++) {
    console.log(ans_classes[j]);
    if (
      ans_classes[j]
        .getElementsByTagName("iframe")[0]
        .getAttribute("objectid") != undefined
    ) {
      objectids = objectids.concat(
        ans_classes[j]
          .getElementsByTagName("iframe")[0]
          .getAttribute("objectid")
      );
    }
  }
  console.log(objectids);
  return objectids;
}

function download(i) {
  // firstly，we need to get the objectid
  var objectids = get_xueyinonline_objectid();
  if (objectids.length == 0) {
    var objectids = get_chaoxing_objectid();
  }

  var objectid = objectids[i % objectids.length];
  console.log(objectid);

  var protocolStr = document.location.protocol;
  var urls = [];
  if (protocolStr == "http:") {
    if (window.location.href.includes("xueyinonline")) {
      urls = [
        "http://mooc1.xueyinonline.com/ananas/status/" +
          objectid +
          "?flag=normal",
        "http://mooc1.chaoxing.com/ananas/status/" + objectid + "?flag=normal",
      ];
    }
  } else if (protocolStr == "https:") {
    urls = [
      "https://mooc1.xueyinonline.com/ananas/status/" +
        objectid +
        "?flag=normal",
      "https://mooc1.chaoxing.com/ananas/status/" + objectid + "?flag=normal",
    ];
  }
  console.log("this is urls");
  console.log(urls);
  try {
    var xhr = new XMLHttpRequest(); //实例化XMLHttpRequest 对象
    xhr.open("GET", urls[0], false); //建立连接，要求同步响应
    xhr.send(); //发送请求
  } catch (error) {
    console.log("error occur! but don't be worry");
    var xhr = new XMLHttpRequest(); //实例化XMLHttpRequest 对象
    xhr.open("GET", urls[1], false); //建立连接，要求同步响应
    xhr.send(); //发送请求
  }
  var json = JSON.parse(xhr.responseText);
  console.log(json);
  if (json.pdf == undefined) {
    console.log(json); //接收数据
    window.open(json.http, "_blank");
  } else {
    if (json.filename.includes(".ppt")) {
      window.open(json.download, "_blank");
    } else {
      window.open(json.pdf, "_blank");
    }
    console.log(json); //接收数据
  }
}

(function () {
  "use strict";
  var i = 0;
  // Your code here...
  document.onkeydown = function (e) {
    //对整个页面监听
    var keyNum = window.event ? e.keyCode : e.which; //获取被按下的键值
    if (keyNum == 68) {
      download(i++);
    }
  };
})();