translators/lib/google.js

Translators is a library which aims to bring free, multiple, enjoyable translation to individuals and students in Nodejs.

"use strict";

const got = require('got');
const cheerio = require('cheerio');
const assert = require('assert');
const {
  URL
} = require('url');
const _ = require('lodash');
const {
  sleep,
  warn,
  request_server_region_info,
  check_query_text,
  check_language,
  get_headers
} = require('./common');
const globalOptions = {
  host_url: null,
  cn_host_url: 'https://translate.google.cn',
  en_host_url: 'https://translate.google.com',
  api_url: null,
  request_server_region_info,
  host_headers: null,
  api_headers: null,
  language_map: null,
  rpcid: 'MkEWBc',
  query_count: 0,
  output_zh: 'zh-CN'
};
const make_temp_language_map = (from_language, to_language) => {
  warn('Did not get a complete language map. And do not use `from_language="auto"`.');
  assert(from_language != 'auto' && to_language != 'auto' && from_language != to_language);
  let lang_list = [from_language, to_language];
  let lang_pair = {};
  lang_list.forEach(item => {
    lang_pair[item] = lang_list;
  });
  return lang_pair;
};
const get_rpc = (query_text, from_language, to_language) => {
  let param = JSON.stringify([[query_text, from_language, to_language, true], [null]]);
  let rpc = JSON.stringify([[[globalOptions.rpcid, param, null, 'generic']]]);
  return {
    'f.req': rpc
  };
};
const get_language_map = host_html => {
  const $ = cheerio.load(host_html);
  let lang_list = Array.from(new Set($('[data-language-code]').map((idx, item) => {
    return $(item).attr('data-language-code');
  }))).sort();
  if (lang_list) _.remove(lang_list, item => item === 'auto');
  let lang_pair = {};
  lang_list.forEach(item => {
    lang_pair[item] = lang_list;
  });
  return lang_pair;
};

// const get_info = (host_html) => {
// 	data_str = host_html.match('window.WIZ_global_data = (.*?);</script>')[0];
// 	data = eval(data_str);
// 	return { 'bl': data['cfb2h'], 'f.sid': data['FdrFJe'] };
// };

// const get_consent_cookie = (consent_html) => {
// 	const $ = cheerio.load(consent_html);
// 	let input_element = $.css('.//input[@type="hidden"][@name="v"]');
// 	cookie_value = input_element ? input_element[0].attrib.get('value') : 'cb';
// 	return `CONSENT=YES+${cookie_value}`; // cookie CONSENT=YES+cb works for now
// };

// @Tse.time_stat
const google_api = async (query_text, from_language = 'auto', to_language = 'en', kwargs = {}) => {
  /*
  https://translate.google.com, https://translate.google.cn.
  :param query_text: str, must.
  :param from_language: str, default 'auto'.
  :param to_language: str, default 'en'.
  :param **kwargs:
  		:param reset_host_url: str, default None. eg: 'https://translate.google.fr'
  		:param if_use_cn_host: boolean, default None. affected by `reset_host_url`.
  		:param if_ignore_limit_of_length: boolean, default False.
  		:param is_detail_result: boolean, default False.
  		:param timeout: float, default None.
  		:param proxies: dict, default None.
  		:param sleep_seconds: float, default `random.random()`.
  :return: str or list
  */
  const {
    reset_host_url,
    if_use_cn_host,
    is_detail_result,
    timeout,
    proxies,
    sleep_seconds = parseInt(Math.random() * 10),
    if_ignore_limit_of_length
  } = kwargs;
  if (reset_host_url && reset_host_url != globalOptions.host_url) {
    assert(reset_host_url.startsWith('https://translate.google.'));
    globalOptions.host_url = reset_host_url;
  } else {
    let use_cn_condition = if_use_cn_host || (await globalOptions.request_server_region_info())['countryCode'] == 'CN';
    globalOptions.host_url = use_cn_condition ? globalOptions.cn_host_url : globalOptions.en_host_url;
  }
  globalOptions.host_headers = globalOptions.host_headers || get_headers(globalOptions.host_url, {
    if_api: false
  }); // reuse cookie header
  globalOptions.api_headers = get_headers(globalOptions.host_url, {
    if_api: true,
    if_referer_for_host: true,
    if_ajax_for_api: true
  });
  query_text = check_query_text(query_text, {
    if_ignore_limit_of_length
  });
  let delete_temp_language_map_label = 0;
  let r = await got(globalOptions.host_url, {
    headers: globalOptions.host_headers,
    timeout: timeout,
    proxies: proxies
  });
  let host_html;
  if ('consent.google.com' === new URL(r.url).hostname) {
    globalOptions.host_headers['cookie'] = globalOptions.get_consent_cookie(r.body);
    host_html = await got(globalOptions.host_url, {
      headers: globalOptions.host_headers,
      timeout: timeout,
      proxies: proxies
    }).body;
  } else {
    host_html = r.body;
  }
  if (!globalOptions.language_map) globalOptions.language_map = get_language_map(host_html);
  if (!globalOptions.language_map) {
    delete_temp_language_map_label += 1;
    globalOptions.language_map = make_temp_language_map(from_language, to_language);
  }
  const lang = check_language(from_language, to_language, globalOptions.language_map, {
    output_zh: globalOptions.output_zh
  });
  from_language = lang.from_language;
  to_language = lang.to_language;
  globalOptions.api_url = `${globalOptions.host_url}/_/TranslateWebserverUi/data/batchexecute?rpcids=${globalOptions.rpcid}\
    &f.sid=-4174700383136665383&bl=boq_translate-webserver_20220112.11_p0&hl=${to_language}&soc-app=1&soc-platform=1&soc-device=1&_reqid=40155&rt=c`;
  let rpc_data = get_rpc(query_text, from_language, to_language);
  r = await got.post(globalOptions.api_url, {
    headers: globalOptions.api_headers,
    body: rpc_data,
    form: true,
    timeout: timeout,
    proxies: proxies
  });
  let r_arr = r.body.split('\n');
  let json_data = JSON.parse(r_arr[3]);
  let data = JSON.parse(json_data[0][2]);
  if (delete_temp_language_map_label != 0) {
    globalOptions.language_map = null;
  }
  await sleep(sleep_seconds);
  globalOptions.query_count += 1;
  return is_detail_result ? data : data[1][0][0][5].map(x => x[0]).join(' ');
};
module.exports = google_api;