util
/
minify


			
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							const { JSDOM } = require('jsdom');
const fs = require('fs')
const path = require('path')
const request = require('request')
const UglifyJS = require("uglify-js");
const CleanCSS = require('clean-css');
const minifyHtml = require('html-minifier').minify

/**
 * 抽取所有脚本css等文件
 * @param {Document} document jsdom
 */
function scriptFilter(document) {
  let ret = {script: [], link: []}

  for (let i = 0, dom = document.querySelectorAll('script'); i < dom.length; i++) {
    let src = dom[i].getAttribute('src')
    ret.script.push(src ? 
      {content: src, type: 1, url: src} : 
      {content: dom[i].innerHTML, type: 0, url: src}
    )
    dom[i].parentNode.removeChild(dom[i]);
  }

  for (let i = 0, dom = document.querySelectorAll('link[rel="stylesheet"],style'); i < dom.length; i++) {
    let tagName = dom[i].tagName
    ret.link.push(tagName === 'LINK' ?
      {content: dom[i].getAttribute('href'), type: 1} :
      {content: dom[i].innerHTML, type: 0}
      
    )
    dom[i].parentNode.removeChild(dom[i]);
  }

  return ret
}

/**
 * 下载所有资源
 * @param {String} dir 文件所在的路径
 * @param {Array} contents 文件
 */
async function downContent(dir, contents) {
  let labels = ['script', 'link']

  for (let i = 0, label; label = labels[i]; i++) {
    for (let j = 0, item; item = contents[label][j]; j++) {
      if (item.type === 1) {
        let src = path.join(dir, item.content)
        src = ~src.indexOf('?') ? src.substring(0, src.indexOf('?')) : src
        if (fs.existsSync(src)) {
          item.content = fs.readFileSync(src).toString()
        } else {
          await new Promise(resolve => {
            request.get(item.content, (err, response) => {
              if (!err && response.statusCode === 200) {
                item.content = response.body
              } else {
                item.content = ''
              }
              resolve()
            })
          });
        }
      }
    }
  }


  return contents
}

/**
 * 合并资源，并压缩
 * @param {JSON} contents 所有资源
 */
function mergeStatic (contents) {
  let ret = {script: '', link: ''}

  Object.keys(ret).forEach(label => {
    contents[label].forEach(item => {
      ret[label] += item.content
      label === 'script' && (ret[label] += ';')
    })
  })

  ret.script = UglifyJS.minify(ret.script, {
    compress: {
      dead_code: true,
      global_defs: {
        DEBUG: false
      }
    }
  }).code
  ret.link = new CleanCSS({}).minify(ret.link).styles

  return ret
}


async function main (file) {
  let src = path.join(process.cwd(), file)
  console.log(src)
  let document = new JSDOM(fs.readFileSync(src)).window.document
  let dir = path.join(src, '../')
  let contents = await downContent(
    path.join(src, '../'),
    scriptFilter(document)
  )
  let ret = mergeStatic(contents)
  let $script = document.createElement('script')
  let $link = document.createElement('link')
  $script.setAttribute('src', 'js/minify-script.js')
  $link.setAttribute('rel', 'stylesheet')
  $link.setAttribute('href', 'css/minify-style.css')

  document.head.appendChild($link)
  document.body.appendChild($script)

  let html = `
    <!doctype html>
    <html>
    ${document.documentElement.innerHTML}
    </html>
  `

  fs.writeFileSync(path.join(dir, 'js/minify-script.js'), ret.script)
  fs.writeFileSync(path.join(dir, 'css/minify-style.css'), ret.link)
  fs.writeFileSync(path.join(dir, 'minify-temp.html'), minifyHtml(html, {
    removeComments: true,
    collapseWhitespace: true,
  }))
}

main(...process.argv.splice(2))