Cacher is the code snippet organizer for pro developers

const fetch = require("node-fetch");
const http = require('http');
const cheerio = require('cheerio');
const fs = require('fs');
const Unrar = require('unrar');

//http://www.ypppt.com/gushi

const baseUrl = 'http://www.ypppt.com'

const doScrap = function(url){
    fetch(url)
    .then(resp=>resp.text())
    .then(body => {
            const $ = cheerio.load(body)
            $('body > div.wrapper > ul > li').each((i,item)=>{
                const fileName = $(item).children('a').text().trim()
                const eachPage = baseUrl+$(item).children('a').attr('href')
                fetch(eachPage).then(r=>r.text()).then(b=>{
                    const $ = cheerio.load(b)
                    const downloadUrl = $('body > div.wwrapper.clear > div.info > div > div.infoss > div.button > a').attr('href')
                    download(downloadUrl,fileName,(e)=>e&&console.error(e))
                })
            })
        }
    )
}

const download = function(url, dest, cb) {
    console.log(`download ${dest} from ${url}`)
    const file = fs.createWriteStream(dest);
    const request = http.get(url, function(response) {
      response.pipe(file);
      file.on('finish', function() {
        extract(dest)
        file.close(cb);  // close() is async, call cb after close completes.
      });
    }).on('error', function(err) {
      fs.unlink(dest); // Delete the file async. (But we don't check the result)
      if (cb) cb(err.message);
    });
  };

  const extract = function(file) {
    console.log(`extracting ${file}...`)
    const archive = new Unrar(file);
 
    archive.list(function(err, entries) {
        if(entries) {
            for (let i = 0; i < entries.length; i++) {
                const name = entries[i].name;
                
                const stream = archive.stream(name);
                const destFile = fs.createWriteStream(name)

                stream.on('error', console.error);
                stream.on('end', ()=>{
                    console.log(`delete ${file}...`)
                    //close write stream
                    destFile.close()
                    //delete rar file
                    fs.unlink(file, console.error)
                });

                stream.pipe(destFile);
            }
        } else {
            // invalid rar... 
            console.error(`invalid file ${file}`)
            fs.unlink(file, console.error)
        }
    });
}

// 2~34 pages
for(let i=2;i<=34;i++){
    const url = `http://www.ypppt.com/gushi/list-${i}.html`
    try{
        doScrap(url)
    }catch(err){
        console.error(err)
        continue
    }
    
}