<?php
  
  /*
   * This file is part of the Symfony package.
   *
   * (c) Fabien Potencier <fabien@symfony.com>
   *
   * For the full copyright and license information, please view the LICENSE
   * file that was distributed with this source code.
   */
  
  namespace Symfony\Component\Translation\Dumper;
  
  use Symfony\Component\Translation\Loader\MoFileLoader;
  use Symfony\Component\Translation\MessageCatalogue;
  
  /**
   * MoFileDumper generates a gettext formatted string representation of a message catalogue.
   *
   * @author Stealth35
   */
  class MoFileDumper extends FileDumper
  {
      /**
       * {@inheritdoc}
       */
      public function formatCatalogue(MessageCatalogue $messages, string $domain, array $options = [])
      {
          $sources = $targets = $sourceOffsets = $targetOffsets = '';
          $offsets = [];
          $size = 0;
  
          foreach ($messages->all($domain) as $source => $target) {
              $offsets[] = array_map('strlen', [$sources, $source, $targets, $target]);
              $sources .= "\0".$source;
              $targets .= "\0".$target;
              ++$size;
          }
  
          $header = [
              'magicNumber' => MoFileLoader::MO_LITTLE_ENDIAN_MAGIC,
              'formatRevision' => 0,
              'count' => $size,
              'offsetId' => MoFileLoader::MO_HEADER_SIZE,
              'offsetTranslated' => MoFileLoader::MO_HEADER_SIZE + (8 * $size),
              'sizeHashes' => 0,
              'offsetHashes' => MoFileLoader::MO_HEADER_SIZE + (16 * $size),
          ];
  
          $sourcesSize = \strlen($sources);
          $sourcesStart = $header['offsetHashes'] + 1;
  
          foreach ($offsets as $offset) {
              $sourceOffsets .= $this->writeLong($offset[1])
                            .$this->writeLong($offset[0] + $sourcesStart);
              $targetOffsets .= $this->writeLong($offset[3])
                            .$this->writeLong($offset[2] + $sourcesStart + $sourcesSize);
          }
  
          $output = implode('', array_map([$this, 'writeLong'], $header))
                 .$sourceOffsets
                 .$targetOffsets
                 .$sources
                 .$targets
          ;
  
          return $output;
      }
  
      /**
       * {@inheritdoc}
       */
      protected function getExtension()
      {
          return 'mo';
      }
  
      private function writeLong($str): string
      {
          return pack('V*', $str);
      }
  }