<?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\Loader;
  
  use Symfony\Component\Config\Resource\FileResource;
  use Symfony\Component\Config\Util\Exception\InvalidXmlException;
  use Symfony\Component\Config\Util\Exception\XmlParsingException;
  use Symfony\Component\Config\Util\XmlUtils;
  use Symfony\Component\Translation\Exception\InvalidResourceException;
  use Symfony\Component\Translation\Exception\NotFoundResourceException;
  use Symfony\Component\Translation\Exception\RuntimeException;
  use Symfony\Component\Translation\MessageCatalogue;
  use Symfony\Component\Translation\Util\XliffUtils;
  
  /**
   * XliffFileLoader loads translations from XLIFF files.
   *
   * @author Fabien Potencier <fabien@symfony.com>
   */
  class XliffFileLoader implements LoaderInterface
  {
      /**
       * {@inheritdoc}
       */
      public function load($resource, string $locale, string $domain = 'messages')
      {
          if (!class_exists(XmlUtils::class)) {
              throw new RuntimeException('Loading translations from the Xliff format requires the Symfony Config component.');
          }
  
          if (!$this->isXmlString($resource)) {
              if (!stream_is_local($resource)) {
                  throw new InvalidResourceException(sprintf('This is not a local file "%s".', $resource));
              }
  
              if (!file_exists($resource)) {
                  throw new NotFoundResourceException(sprintf('File "%s" not found.', $resource));
              }
  
              if (!is_file($resource)) {
                  throw new InvalidResourceException(sprintf('This is neither a file nor an XLIFF string "%s".', $resource));
              }
          }
  
          try {
              if ($this->isXmlString($resource)) {
                  $dom = XmlUtils::parse($resource);
              } else {
                  $dom = XmlUtils::loadFile($resource);
              }
          } catch (\InvalidArgumentException|XmlParsingException|InvalidXmlException $e) {
              throw new InvalidResourceException(sprintf('Unable to load "%s": ', $resource).$e->getMessage(), $e->getCode(), $e);
          }
  
          if ($errors = XliffUtils::validateSchema($dom)) {
              throw new InvalidResourceException(sprintf('Invalid resource provided: "%s"; Errors: ', $resource).XliffUtils::getErrorsAsString($errors));
          }
  
          $catalogue = new MessageCatalogue($locale);
          $this->extract($dom, $catalogue, $domain);
  
          if (is_file($resource) && class_exists(FileResource::class)) {
              $catalogue->addResource(new FileResource($resource));
          }
  
          return $catalogue;
      }
  
      private function extract(\DOMDocument $dom, MessageCatalogue $catalogue, string $domain)
      {
          $xliffVersion = XliffUtils::getVersionNumber($dom);
  
          if ('1.2' === $xliffVersion) {
              $this->extractXliff1($dom, $catalogue, $domain);
          }
  
          if ('2.0' === $xliffVersion) {
              $this->extractXliff2($dom, $catalogue, $domain);
          }
      }
  
      /**
       * Extract messages and metadata from DOMDocument into a MessageCatalogue.
       */
      private function extractXliff1(\DOMDocument $dom, MessageCatalogue $catalogue, string $domain)
      {
          $xml = simplexml_import_dom($dom);
          $encoding = $dom->encoding ? strtoupper($dom->encoding) : null;
  
          $namespace = 'urn:oasis:names:tc:xliff:document:1.2';
          $xml->registerXPathNamespace('xliff', $namespace);
  
          foreach ($xml->xpath('//xliff:file') as $file) {
              $fileAttributes = $file->attributes();
  
              $file->registerXPathNamespace('xliff', $namespace);
  
              foreach ($file->xpath('.//xliff:trans-unit') as $translation) {
                  $attributes = $translation->attributes();
  
                  if (!(isset($attributes['resname']) || isset($translation->source))) {
                      continue;
                  }
  
                  if (isset($translation->target) && 'needs-translation' === (string) $translation->target->attributes()['state']) {
                      continue;
                  }
  
                  $source = isset($attributes['resname']) && $attributes['resname'] ? $attributes['resname'] : $translation->source;
                  // If the xlf file has another encoding specified, try to convert it because
                  // simple_xml will always return utf-8 encoded values
                  $target = $this->utf8ToCharset((string) ($translation->target ?? $translation->source), $encoding);
  
                  $catalogue->set((string) $source, $target, $domain);
  
                  $metadata = [
                      'source' => (string) $translation->source,
                      'file' => [
                          'original' => (string) $fileAttributes['original'],
                      ],
                  ];
                  if ($notes = $this->parseNotesMetadata($translation->note, $encoding)) {
                      $metadata['notes'] = $notes;
                  }
  
                  if (isset($translation->target) && $translation->target->attributes()) {
                      $metadata['target-attributes'] = [];
                      foreach ($translation->target->attributes() as $key => $value) {
                          $metadata['target-attributes'][$key] = (string) $value;
                      }
                  }
  
                  if (isset($attributes['id'])) {
                      $metadata['id'] = (string) $attributes['id'];
                  }
  
                  $catalogue->setMetadata((string) $source, $metadata, $domain);
              }
          }
      }
  
      private function extractXliff2(\DOMDocument $dom, MessageCatalogue $catalogue, string $domain)
      {
          $xml = simplexml_import_dom($dom);
          $encoding = $dom->encoding ? strtoupper($dom->encoding) : null;
  
          $xml->registerXPathNamespace('xliff', 'urn:oasis:names:tc:xliff:document:2.0');
  
          foreach ($xml->xpath('//xliff:unit') as $unit) {
              foreach ($unit->segment as $segment) {
                  $attributes = $unit->attributes();
                  $source = $attributes['name'] ?? $segment->source;
  
                  // If the xlf file has another encoding specified, try to convert it because
                  // simple_xml will always return utf-8 encoded values
                  $target = $this->utf8ToCharset((string) ($segment->target ?? $segment->source), $encoding);
  
                  $catalogue->set((string) $source, $target, $domain);
  
                  $metadata = [];
                  if (isset($segment->target) && $segment->target->attributes()) {
                      $metadata['target-attributes'] = [];
                      foreach ($segment->target->attributes() as $key => $value) {
                          $metadata['target-attributes'][$key] = (string) $value;
                      }
                  }
  
                  if (isset($unit->notes)) {
                      $metadata['notes'] = [];
                      foreach ($unit->notes->note as $noteNode) {
                          $note = [];
                          foreach ($noteNode->attributes() as $key => $value) {
                              $note[$key] = (string) $value;
                          }
                          $note['content'] = (string) $noteNode;
                          $metadata['notes'][] = $note;
                      }
                  }
  
                  $catalogue->setMetadata((string) $source, $metadata, $domain);
              }
          }
      }
  
      /**
       * Convert a UTF8 string to the specified encoding.
       */
      private function utf8ToCharset(string $content, ?string $encoding = null): string
      {
          if ('UTF-8' !== $encoding && !empty($encoding)) {
              return mb_convert_encoding($content, $encoding, 'UTF-8');
          }
  
          return $content;
      }
  
      private function parseNotesMetadata(?\SimpleXMLElement $noteElement = null, ?string $encoding = null): array
      {
          $notes = [];
  
          if (null === $noteElement) {
              return $notes;
          }
  
          /** @var \SimpleXMLElement $xmlNote */
          foreach ($noteElement as $xmlNote) {
              $noteAttributes = $xmlNote->attributes();
              $note = ['content' => $this->utf8ToCharset((string) $xmlNote, $encoding)];
              if (isset($noteAttributes['priority'])) {
                  $note['priority'] = (int) $noteAttributes['priority'];
              }
  
              if (isset($noteAttributes['from'])) {
                  $note['from'] = (string) $noteAttributes['from'];
              }
  
              $notes[] = $note;
          }
  
          return $notes;
      }
  
      private function isXmlString(string $resource): bool
      {
          return 0 === strpos($resource, '<?xml');
      }
  }