var http = require('http');

var cheerio = require('cheerio');

var url = 'http://www.imooc.com/learn/348';

function filterChapters(){

var $ = cheerio.load(html);

var chapters = $('.chapter');

// [{

// chapterTitle:'',

// videos:[

// title:'',

// id:''

// ]

// }]

var courseData = [];

chapters.each(function(item){

var chapter = $(this);

var chapterTitle = chapter.find('h3').text();

var videos = chapter.find('.video').children('li');

var chapterData = {

chapterTitle:chapterTitle,

videos:[]

}

videos.each(function(item){

var video = $(this).find('.J-media-item')

var videoTitle = video.text();

var id = video.attr('href').split('video/')[1]

chapterData.videos.push({

title:videoTitle,

id:id

})

})

courseData.push(chapterData);

})

return courseData

}

function printCourseInfo(courseData){

 courseData.forEach(function(item){

  var chapterTitle = item.chapterTitle;

  console.log(chapterTitle + '\n');

  item.videos.forEach(function(video){

  console.log(' 【' + video.id + '】 ' + video.title + '\n')

  })

 })

}

http.get(url,function(res){

var html = '';

res.on('data',function(data){

html += data;

})

res.on('end',function(){

var courseData = filterChapters(html);

printCourseInfo(courseData)

})

}).on('error',function(){

console.log('获取课程数据出错！');

})