const fs = require('fs')

const getFileBuffer = (path) => fs.readFileSync(path)

const getFilePath = (prefixStr = '', postfixStr = '') => {
  // 文件名称
  const uuid = () => {
    function s4 () {
      return Math.floor((1 + Math.random()) * 0x10000)
        .toString(16)
        .substring(1)
    }
    return s4() + s4() + s4() + s4() + s4() + s4() + s4() + s4()
  }
  // 文件扩展名 toLowerCase 转小写
  let prefix = prefixStr
  if (prefixStr && prefix.substr(prefix.length - 1, 1) !== '/') { prefix += '/' }
  // 后缀
  let postfix = ''
  if (postfixStr) { postfix = '_' + postfixStr }
  return prefix + uuid() + postfix + '.jpg'
}

const uuid = () => {
  function s4 () {
    return Math.floor((1 + Math.random()) * 0x10000)
      .toString(16)
      .substring(1)
  }
  return s4() + s4() + s4()
}


module.exports = {
  getFileBuffer,
  getFilePath,
  uuid
}