index.js

/*
* @Author: shikar
* @Date:   2017-02-05 15:28:31
* @Last Modified by:   shikar
* @Last Modified time: 2020-07-28 17:20:29
*/
'use strict'
const _ = require("lodash")
const isUrl = require("is-url")
const isNumber = require("num-or-not")
const isKeyword = require('is-keyword-js')
const got = require('got')
const userAgents = require("user-agents")
const token = require('./token')
const languages = require('./languages')

function checkSame(v, maps) {
  for (const idx in maps) {
    if (maps[idx].v === v) {
      return idx
    }
  }
  return -1
}

function enMap(obj, except=[], path='', map=[]) {
  if (_.isObject(obj) == true) {
    _.forEach(obj, (v, k) => {
      const furKeyStr = _.isNumber(k) ? `[${k}]` : ( path && '.' ) + k
      const curPath = path + furKeyStr
      if (_.isObject(v) == true) {
        enMap(v, except, curPath, map)
      } else {
        const exceptReg = except.length > 0 ? new RegExp(`(^|\\.)(${_.map(except, _.escapeRegExp).join('|')})(\\.|\\[|$)`, 'i') : false
        if (
          _.isString(v) &&
          !isNumber(v) &&
          !isUrl(v) &&
          !isKeyword(v) &&
          !/^(?!([a-z]+|\d+|[\?=\.\*\[\]~!@#\$%\^&\(\)_+`\/\-={}:";'<>,]+)$)[a-z\d\?=\.\*\[\]~!@#\$%\^&\(\)_+`\/\-={}:";'<>,]+$/i.test(v) &&
          (!exceptReg || !exceptReg.test(curPath))
        ) {
          const idx = checkSame(v, map)
          if (idx > -1) {
            map.splice(idx+1, 0, {
              p: curPath,
              v: v,
              i: map[idx].i,
              l: map[idx].l,
              s: true
            })
          } else {
            const lastMap = _.last(map)
            map.push({
              p: curPath,
              v: v,
              i: lastMap ? lastMap.i + lastMap.l : 0,
              l: v.split("\n").length,
              s: false
            })
          }
        }
      }
    })
  } else {
    map.push({
      p: '',
      v: obj,
      i: 0,
      l: obj.split("\n").length
    })
  }
  return map
}

function deMap(src, maps, dest) {
  if (_.isObject(src) == true) {
    src = _.clone(src)
    dest = dest.split("\n")
    for (const map of maps) {
      _.set(src, map.p, _.slice(dest, map.i, map.i+map.l).join("\n"))
    }
  } else {
    src = dest
  }
  return src
}

async function translate(input, opts = {}, domain='translate.google.cn') {
  const langs = [opts.from, opts.to]
  const except = opts.except || []
  input = _.cloneDeep(input)
  for (const lang of langs) {
    if (lang && !languages.isSupported(lang)) {
      const e = new Error('The language \'' + lang + '\' is not supported')
      e.code = 400
      throw e
    }
  }

  opts.from = languages.getCode(opts.from || 'auto')
  opts.to = languages.getCode(opts.to || 'en')

  const strMap = enMap(input, except)
  const text = _.map(_.differenceBy(strMap, [{ s: true }], 's'), 'v').join("\n")
  const tokenRet = await token.get(text, domain)
  const url = `https://${domain}/translate_a/single`
  const searchParams = new URLSearchParams([
    ['client', 't'],
    ['sl', opts.from],
    ['tl', opts.to],
    ['hl', opts.to],
    ['dt', 'at'], ['dt', 'bd'], ['dt', 'ex'], ['dt', 'ld'], ['dt', 'md'], ['dt', 'qca'], ['dt', 'rw'], ['dt', 'rm'], ['dt', 'ss'], ['dt', 't'],
    ['ie', 'UTF-8'],
    ['oe', 'UTF-8'],
    ['otf', 1],
    ['ssel', 0],
    ['tsel', 0],
    ['kc', 7],
    ['q', text],
    [tokenRet.name, tokenRet.value]
  ])
  const opt = { responseType: 'json', headers: {'User-Agent': new userAgents({ deviceCategory: 'desktop' }).toString()} }
  if (searchParams.toString().length <= 1980) {
    opt.method = 'GET'
  } else {
    searchParams.delete('q')
    opt.method = 'POST'
    opt.form = { q: text }
  }
  opt.searchParams = searchParams
  try {
    const { body } = await got(url, opt)
    const retString = _.map(body[0], 0).join('')
    return deMap(input, strMap, retString)
  } catch (error) {
    let e = new Error(error.message)
    if (error.statusCode !== undefined && error.statusCode !== 200) {
      e.code = 'BAD_REQUEST'
    } else {
      e.code = 'BAD_NETWORK'
    }
    throw e
  }
}

module.exports = translate
module.exports.languages = languages