/**
 * Copyright (c) 2017-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

const CWD = process.cwd();
const fs = require('fs-extra');
const glob = require('glob');
const path = require('path');
const mkdirp  = require('mkdirp');
let siteConfig;

console.log('translation.js triggered...');

function writeFileAndCreateFolder(file, content) {
  mkdirp.sync(file.replace(new RegExp('/[^/]*$'), ''));
  fs.writeFileSync(file, content);
}

function execute() {
  if (fs.existsSync(CWD + '/languages.js')) {
    injectContent();
    translatePages();
  } else {
    console.log('No languages besides English enabled');
  }
}

function translatePages() {
  const siteConfig = require(CWD + '/siteConfig.js');

  const files = glob.sync(CWD + '/pages/en/**/*.js');
  files.forEach(file => {
    let fileContent = fs.readFileSync(file, 'utf8');
    let baseName = path.basename(file, '.js');

    for (let i = 0; i < siteConfig['languages'].length; i++) {
      let language = siteConfig['languages'][i];
      if (language.tag === 'en') continue;
      if (siteConfig[language.tag]) {
        let translatedContent = fileContent.slice(0);

        Object.keys(siteConfig[language.tag]["pages-strings"][baseName])
          .forEach(function(key) {
            translatedContent = translatedContent.replace(key, siteConfig[language.tag]["pages-strings"][baseName][key]);
          });

        let translatedFile = file.replace('/en/', '/' + language.tag + '/');
        writeFileAndCreateFolder(translatedFile, translatedContent);
      }
    }
  });
}

function injectContent() {
  const I18N_JSON_DIR = CWD + '/i18n/';

  const files = glob.sync(I18N_JSON_DIR + '**');
  const languages = [];
  const langRegex = /\/i18n\/(.*)\.json$/;

  files.forEach(file => {
    const extension = path.extname(file);
    if (extension == '.json') {
      const match = langRegex.exec(file);
      const language = match[1];
      languages.push(language);
    }
  });

  let injectedContent = '';
  languages.forEach(language => {
    injectedContent +=
      "\nsiteConfig['" +
      language +
      "'] = require('./i18n/" +
      language +
      ".json');";
  });

  let siteConfigFile = fs.readFileSync(CWD + '/siteConfig.js', 'utf8');
  const injectStart = '/* INJECT LOCALIZED FILES BEGIN */';
  const injectEnd = '/* INJECT LOCALIZED FILES END */';
  siteConfigFile =
    siteConfigFile.slice(
      0,
      siteConfigFile.indexOf(injectStart) + injectStart.length
    ) +
    injectedContent +
    '\n' +
    siteConfigFile.slice(siteConfigFile.indexOf(injectEnd));
  fs.writeFileSync(CWD + '/siteConfig.js', siteConfigFile);
}

module.exports = execute;