class SystemTokensHooks

class SystemTokensHooks {
  use StringTranslationTrait;
  
  /**
   * Implements hook_token_info().
   */
  public function tokenInfo() : array {
    $types['site'] = [
      'name' => $this->t("Site information"),
      'description' => $this->t("Tokens for site-wide settings and other global information."),
    ];
    $types['date'] = [
      'name' => $this->t("Dates"),
      'description' => $this->t("Tokens related to times and dates."),
    ];
    // Site-wide global tokens.
    $site['name'] = [
      'name' => $this->t("Name"),
      'description' => $this->t("The name of the site."),
    ];
    $site['slogan'] = [
      'name' => $this->t("Slogan"),
      'description' => $this->t("The slogan of the site."),
    ];
    $site['mail'] = [
      'name' => $this->t("Email"),
      'description' => $this->t("The administrative email address for the site."),
    ];
    $site['base-url'] = [
      'name' => $this->t("Base URL"),
      'description' => $this->t("The base URL of the site, currently: @base_url", [
        '@base_url' => \Drupal::service('router.request_context')->getCompleteBaseUrl(),
      ]),
    ];
    $site['base-path'] = [
      'name' => $this->t("Base path"),
      'description' => $this->t("The base path of the site, currently: @base_path", [
        '@base_path' => \Drupal::request()->getBasePath(),
      ]),
    ];
    $site['url'] = [
      'name' => $this->t("URL"),
      'description' => $this->t("The URL of the site's front page with the language prefix, if it exists."),
    ];
    $site['url-brief'] = [
      'name' => $this->t("URL (brief)"),
      'description' => $this->t("The URL of the site's front page without the protocol."),
    ];
    $site['login-url'] = [
      'name' => $this->t("Login page"),
      'description' => $this->t("The URL of the site's login page."),
    ];
    /** @var \Drupal\Core\Datetime\DateFormatterInterface $date_formatter */
    $date_formatter = \Drupal::service('date.formatter');
    // Date related tokens.
    $request_time = \Drupal::time()->getRequestTime();
    $date['short'] = [
      'name' => $this->t("Short format"),
      'description' => $this->t("The current date in 'short' format. (%date)", [
        '%date' => $date_formatter->format($request_time, 'short'),
      ]),
    ];
    $date['medium'] = [
      'name' => $this->t("Medium format"),
      'description' => $this->t("The current date in 'medium' format. (%date)", [
        '%date' => $date_formatter->format($request_time, 'medium'),
      ]),
    ];
    $date['long'] = [
      'name' => $this->t("Long format"),
      'description' => $this->t("The current date in 'long' format. (%date)", [
        '%date' => $date_formatter->format($request_time, 'long'),
      ]),
    ];
    $date['custom'] = [
      'name' => $this->t("Custom format"),
      'description' => $this->t('The current date in a custom format. See <a href="https://www.php.net/manual/datetime.format.php#refsect1-datetime.format-parameters">the PHP documentation</a> for details.'),
    ];
    $date['since'] = [
      'name' => $this->t("Time-since"),
      'description' => $this->t("The current date in 'time-since' format. (%date)", [
        '%date' => $date_formatter->formatTimeDiffSince($request_time - 360),
      ]),
    ];
    $date['raw'] = [
      'name' => $this->t("Raw timestamp"),
      'description' => $this->t("The current date in UNIX timestamp format (%date)", [
        '%date' => $request_time,
      ]),
    ];
    return [
      'types' => $types,
      'tokens' => [
        'site' => $site,
        'date' => $date,
      ],
    ];
  }
  
  /**
   * Implements hook_tokens().
   */
  public function tokens($type, $tokens, array $data, array $options, BubbleableMetadata $bubbleable_metadata) : array {
    $token_service = \Drupal::token();
    $url_options = [
      'absolute' => TRUE,
    ];
    if (isset($options['langcode'])) {
      $url_options['language'] = \Drupal::languageManager()->getLanguage($options['langcode']);
      $langcode = $options['langcode'];
    }
    else {
      $langcode = NULL;
    }
    $replacements = [];
    if ($type == 'site') {
      foreach ($tokens as $name => $original) {
        switch ($name) {
          case 'name':
            $config = \Drupal::config('system.site');
            $bubbleable_metadata->addCacheableDependency($config);
            $site_name = $config->get('name');
            $replacements[$original] = $site_name;
            break;

          case 'slogan':
            $config = \Drupal::config('system.site');
            $bubbleable_metadata->addCacheableDependency($config);
            $slogan = $config->get('slogan');
            $build = [
              '#markup' => $slogan,
            ];
            // @todo Fix in https://www.drupal.org/node/2577827
            $replacements[$original] = \Drupal::service('renderer')->renderInIsolation($build);
            break;

          case 'mail':
            $config = \Drupal::config('system.site');
            $bubbleable_metadata->addCacheableDependency($config);
            $replacements[$original] = $config->get('mail');
            break;

          case 'base-url':
            $bubbleable_metadata->addCacheContexts([
              'url.site',
            ]);
            $replacements[$original] = \Drupal::service('router.request_context')->getCompleteBaseUrl();
            break;

          case 'base-path':
            $bubbleable_metadata->addCacheContexts([
              'url.site',
            ]);
            $replacements[$original] = \Drupal::request()->getBasePath();
            break;

          case 'url':
            /** @var \Drupal\Core\GeneratedUrl $result */
            $result = Url::fromRoute('<front>', [], $url_options)->toString(TRUE);
            $bubbleable_metadata->addCacheableDependency($result);
            $replacements[$original] = $result->getGeneratedUrl();
            break;

          case 'url-brief':
            /** @var \Drupal\Core\GeneratedUrl $result */
            $result = Url::fromRoute('<front>', [], $url_options)->toString(TRUE);
            $bubbleable_metadata->addCacheableDependency($result);
            $replacements[$original] = preg_replace([
              '!^https?://!',
              '!/$!',
            ], '', $result->getGeneratedUrl());
            break;

          case 'login-url':
            /** @var \Drupal\Core\GeneratedUrl $result */
            $result = Url::fromRoute('user.page', [], $url_options)->toString(TRUE);
            $bubbleable_metadata->addCacheableDependency($result);
            $replacements[$original] = $result->getGeneratedUrl();
            break;

        }
      }
    }
    elseif ($type == 'date') {
      if (empty($data['date'])) {
        $date = \Drupal::time()->getRequestTime();
        // We depend on the current request time, so the tokens are not
        // cacheable at all.
        $bubbleable_metadata->setCacheMaxAge(0);
      }
      else {
        $date = $data['date'];
      }
      foreach ($tokens as $name => $original) {
        switch ($name) {
          case 'short':
          case 'medium':
          case 'long':
            $date_format = DateFormat::load($name);
            $bubbleable_metadata->addCacheableDependency($date_format);
            $replacements[$original] = \Drupal::service('date.formatter')->format($date, $name, '', NULL, $langcode);
            break;

          case 'since':
            $replacements[$original] = \Drupal::service('date.formatter')->formatTimeDiffSince($date, [
              'langcode' => $langcode,
            ]);
            $bubbleable_metadata->setCacheMaxAge(0);
            break;

          case 'raw':
            $replacements[$original] = $date;
            break;

        }
      }
      if ($created_tokens = $token_service->findWithPrefix($tokens, 'custom')) {
        foreach ($created_tokens as $name => $original) {
          $replacements[$original] = \Drupal::service('date.formatter')->format($date, 'custom', $name, NULL, $langcode);
        }
      }
    }
    return $replacements;
  }

}