<?php

namespace Drupal\token;

use Drupal\Core\Cache\CacheBackendInterface;
use Drupal\Core\Language\LanguageInterface;
use Drupal\Core\Utility\Token as TokenBase;

/**
 * Service to retrieve token information.
 *
 * This service replaces the core's token service and provides the same
 * functionality by extending it. It also provides additional functionality
 * commonly required by the additional support provided by token module and
 * other modules.
 */
class Token extends TokenBase implements TokenInterface {

  /**
   * Token definitions.
   *
   * @var array[]|null
   *   An array of token definitions, or NULL when the definitions are not set.
   *
   * @see self::resetInfo()
   */
  protected $globalTokenTypes;

  /**
   * {@inheritdoc}
   */
  public function getInfo() {
    if (empty($this->tokenInfo)) {
      $cache_id = 'token_info_sorted:' . $this->languageManager->getCurrentLanguage(LanguageInterface::TYPE_CONTENT)->getId();
      $cache = $this->cache->get($cache_id);
      if ($cache) {
        $this->tokenInfo = $cache->data;
      }
      else {
        $token_info = $this->moduleHandler->invokeAll('token_info');
        $this->moduleHandler->alter('token_info', $token_info);

        foreach (array_keys($token_info['types']) as $type_key) {
          if (isset($token_info['types'][$type_key]['type'])) {
            $base_type = $token_info['types'][$type_key]['type'];
            // If this token type extends another token type, then merge in
            // the base token type's tokens.
            if (isset($token_info['tokens'][$base_type])) {
              $token_info['tokens'] += [$type_key => []];
              $token_info['tokens'][$type_key] += $token_info['tokens'][$base_type];
            }
          }
          else {
            // Add a 'type' value to each token type information.
            $token_info['types'][$type_key]['type'] = $type_key;
          }
        }

        // Pre-sort tokens.
        $by_name = $this->prepareMultisort($token_info['types']);
        array_multisort($by_name, SORT_ASC, SORT_NATURAL | SORT_FLAG_CASE, $token_info['types']);
        foreach (array_keys($token_info['tokens']) as $type) {
          $by_name = $this->prepareMultisort($token_info['tokens'][$type]);
          array_multisort($by_name, SORT_ASC, SORT_NATURAL | SORT_FLAG_CASE, $token_info['tokens'][$type]);
        }

        $this->tokenInfo = $token_info;
        $this->cache->set($cache_id, $this->tokenInfo, CacheBackendInterface::CACHE_PERMANENT, array(
          static::TOKEN_INFO_CACHE_TAG,
        ));
      }
    }

    return $this->tokenInfo;
  }

  /**
   * Extracts data from the token data for use in array_multisort().
   *
   * @param array $token_info
   *   List of tokens or token types, each element must have a name key.
   *
   * @return string[]
   *   List of the names keyed by the token key.
   */
  protected function prepareMultisort($token_info) {
    $by_name = [];
    foreach ($token_info as $key => $token_info_element) {
      $by_name[$key] = $token_info_element['name'];
    }
    return $by_name;
  }

  /**
   * {@inheritdoc}
   */
  public function getTokenInfo($token_type, $token) {
    if (empty($this->tokenInfo)) {
      $this->getInfo();
    }

    return isset($this->tokenInfo['tokens'][$token_type][$token]) ? $this->tokenInfo['tokens'][$token_type][$token] : NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function getTypeInfo($token_type) {
    if (empty($this->tokenInfo)) {
      $this->getInfo();
    }

    return isset($this->tokenInfo['types'][$token_type]) ? $this->tokenInfo['types'][$token_type] : NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function getGlobalTokenTypes() {
    if (empty($this->globalTokenTypes)) {
      $token_info = $this->getInfo();
      foreach ($token_info['types'] as $type => $type_info) {
        // If the token types has not specified that 'needs-data' => TRUE, then
        // it is a global token type that will always be replaced in any context.
        if (empty($type_info['needs-data'])) {
          $this->globalTokenTypes[] = $type;
        }
      }
    }

    return $this->globalTokenTypes;
  }

  /**
   * {@inheritdoc}
   */
  function getInvalidTokens($type, $tokens) {
    $token_info = $this->getInfo();
    $invalid_tokens = array();

    foreach ($tokens as $token => $full_token) {
      if (isset($token_info['tokens'][$type][$token])) {
        continue;
      }

      // Split token up if it has chains.
      $parts = explode(':', $token, 2);

      if (!isset($token_info['tokens'][$type][$parts[0]])) {
        // This is an invalid token (not defined).
        $invalid_tokens[] = $full_token;
      }
      elseif (count($parts) == 2) {
        $sub_token_info = $token_info['tokens'][$type][$parts[0]];
        if (!empty($sub_token_info['dynamic'])) {
          // If this token has been flagged as a dynamic token, skip it.
          continue;
        }
        elseif (empty($sub_token_info['type'])) {
          // If the token has chains, but does not support it, it is invalid.
          $invalid_tokens[] = $full_token;
        }
        else {
          // Recursively check the chained tokens.
          $sub_tokens = $this->findWithPrefix(array($token => $full_token), $parts[0]);
          $invalid_tokens = array_merge($invalid_tokens, $this->getInvalidTokens($sub_token_info['type'], $sub_tokens));
        }
      }
    }

    return $invalid_tokens;
  }

  /**
   * {@inheritdoc}
   */
  public function getInvalidTokensByContext($value, array $valid_types = []) {
    if (in_array('all', $valid_types)) {
      $info = $this->getInfo();
      $valid_types = array_keys($info['types']);
    }
    else {
      // Add the token types that are always valid in global context.
      $valid_types = array_merge($valid_types, $this->getGlobalTokenTypes());
    }

    $invalid_tokens = array();
    $value_tokens = is_string($value) ? $this->scan($value) : $value;

    foreach ($value_tokens as $type => $tokens) {
      if (!in_array($type, $valid_types)) {
        // If the token type is not a valid context, its tokens are invalid.
        $invalid_tokens = array_merge($invalid_tokens, array_values($tokens));
      }
      else {
        // Check each individual token for validity.
        $invalid_tokens = array_merge($invalid_tokens, $this->getInvalidTokens($type, $tokens));
      }
    }

    array_unique($invalid_tokens);
    return $invalid_tokens;
  }

  /**
   * {@inheritdoc}
   */
  public function resetInfo() {
    parent::resetInfo();
    $this->globalTokenTypes = NULL;
  }

}