<?php

/**
 * @file
 * Mailchimp module.
 */

use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Link;
use Drupal\Core\Render\Markup;
use Drupal\Core\Url;
use function GuzzleHttp\default_user_agent;
use GuzzleHttp\Exception\ClientException;
use Mailchimp\MailchimpLists;

define('MAILCHIMP_QUEUE_CRON', 'mailchimp');

define('MAILCHIMP_STATUS_SENT', 'sent');
define('MAILCHIMP_STATUS_SAVE', 'save');
define('MAILCHIMP_STATUS_PAUSED', 'paused');
define('MAILCHIMP_STATUS_SCHEDULE', 'schedule');
define('MAILCHIMP_STATUS_SENDING', 'sending');

/**
 * Access callback for mailchimp submodule menu items.
 *
 * @return bool
 *   TRUE if the mailchimp api is available and accessible by the user.
 */
function mailchimp_apikey_ready_access($permission) {
  if (mailchimp_get_api_object() && \Drupal::currentUser()->hasPermission($permission)) {
    return TRUE;
  }
  return FALSE;
}

/**
 * Instantiates a Mailchimp library object.
 *
 * @return \Mailchimp\Mailchimp
 *   Drupal Mailchimp library object.
 */
function mailchimp_get_api_object($classname = 'MailchimpApiUser') {
  $object = \Drupal::service('mailchimp.client_factory')->getByClassNameOrNull($classname);

  if (!$object) {
    \Drupal::messenger()->addError('Failed to load Mailchimp PHP library. Please refer to the installation requirements.');
    return NULL;
  }
  $config = \Drupal::config('mailchimp.settings');
  if (!$config->get('test_mode') && !$object->hasApiAccess()) {
    $mc_oauth_url = Url::fromRoute('mailchimp.admin.oauth');
    \Drupal::messenger()->addError(t('Unable to connect to Mailchimp API. Visit @oauth_settings_page to authenticate or uncheck "Use OAuth Authentication" and add an api_key below (deprecated).', ['@oauth_settings_page' => Link::fromTextAndUrl(t('OAuth Settings page'), $mc_oauth_url)->toString()]));
    return NULL;
  }

  return $object;
}

/**
 * Gets the user agent string for this installation of Mailchimp.
 *
 * @return string
 *   The user agent string.
 */
function _mailchimp_get_user_agent() {
  $version = '8.x-1.x';

  if (\Drupal::moduleHandler()->moduleExists('system')) {
    /** @var \Drupal\Core\Extension\ModuleExtensionList $extension_list */
    $extension_list = \Drupal::service('extension.list.module');
    $info = $extension_list->getExtensionInfo('mailchimp');
    if (!empty($info['version'])) {
      $version = $info['version'];
    }
  }

  $user_agent = "DrupalMailchimp/$version " . default_user_agent();

  return $user_agent;
}

/**
 * Returns a single list.
 *
 * @param string $list_id
 *   The unique ID of the list provided by Mailchimp.
 *
 * @return array
 *   Array of list data.
 */
function mailchimp_get_list($list_id) {
  $lists = mailchimp_get_lists([$list_id]);
  return reset($lists);
}

/**
 * Returns all Mailchimp lists for a given key. Lists are stored in the cache.
 *
 * @param array $list_ids
 *   An array of list IDs to filter the results by.
 * @param bool $reset
 *   Force a cache reset.
 *
 * @return array
 *   An array of list data arrays.
 */
function mailchimp_get_lists(array $list_ids = [], $reset = FALSE) {
  $lists = [];
  $cache = \Drupal::cache('mailchimp');
  $cached_data = $reset ? NULL : $cache->get('lists');

  // Return cached lists.
  if ($cached_data) {
    $lists = $cached_data->data;
  }
  else {
    try {
      /** @var \Mailchimp\MailchimpLists $mcapi */
      $mcapi = mailchimp_get_api_object('MailchimpLists');
      if ($mcapi != NULL) {
        $result = $mcapi->getLists(['count' => 500]);

        if ($result->total_items > 0) {
          foreach ($result->lists as $list) {
            $int_category_data = $mcapi->getInterestCategories($list->id, ['count' => 500]);
            if ($int_category_data->total_items > 0) {

              $list->intgroups = [];
              foreach ($int_category_data->categories as $interest_category) {
                $interest_data = $mcapi->getInterests($list->id, $interest_category->id, ['count' => 500]);

                if ($interest_data->total_items > 0) {
                  $interest_category->interests = $interest_data->interests;
                }

                $list->intgroups[] = $interest_category;
              }
            }

            $lists[$list->id] = $list;

            // Append mergefields:
            $mergefields = $mcapi->getMergeFields($list->id, ['count' => 500]);
            if ($mergefields->total_items > 0) {
              $lists[$list->id]->mergevars = $mergefields->merge_fields;
            }
          }
        }

        uasort($lists, '_mailchimp_list_cmp');

        $cache->set('lists', $lists);
      }
    }
    catch (\Exception $e) {
      \Drupal::logger('mailchimp')->error('An error occurred requesting list information from Mailchimp. "{message}"', [
        'message' => $e->getMessage(),
      ]);
    }
  }

  // Filter by given IDs.
  if (!empty($list_ids)) {
    $filtered_lists = [];

    foreach ($list_ids as $id) {
      if (array_key_exists($id, $lists)) {
        $filtered_lists[$id] = $lists[$id];
      }
    }

    return $filtered_lists;
  }
  else {
    return $lists;
  }
}

/**
 * Helper function used by uasort() to sort lists alphabetically by name.
 *
 * @param object $a
 *   An object representing the first list.
 * @param object $b
 *   An object representing the second list.
 *
 * @return int
 *   One of the values -1, 0, 1
 */
function _mailchimp_list_cmp($a, $b) {
  if ($a->name == $b->name) {
    return 0;
  }

  return ($a->name < $b->name) ? -1 : 1;
}

/**
 * Wrapper around MailchimpLists->getMergeFields().
 *
 * @param array $list_ids
 *   Array of Mailchimp list IDs.
 * @param bool $reset
 *   Set to TRUE if mergevars should not be loaded from cache.
 *
 * @return array
 *   Struct describing mergevars for the specified lists.
 */
function mailchimp_get_mergevars(array $list_ids, $reset = FALSE) {
  $mergevars = [];
  $cache = \Drupal::cache('mailchimp');

  if (!$reset) {
    foreach ($list_ids as $key => $list_id) {
      $cached_data = $cache->get($list_id . '-mergevars');
      // Get cached data and unset from our remaining lists to query.
      if ($cached_data) {
        $mergevars[$list_id] = $cached_data->data;
        unset($list_ids[$key]);
      }
    }
  }

  // Get the uncached merge vars from Mailchimp.
  if (count($list_ids)) {
    /** @var \Mailchimp\MailchimpLists $mc_lists */
    $mc_lists = mailchimp_get_api_object('MailchimpLists');
    $list_id = NULL;

    try {
      if (!$mc_lists) {
        throw new Exception('Cannot get merge vars without Mailchimp API. Check API key has been entered.');
      }

      foreach ($list_ids as $list_id) {
        // Add default EMAIL merge var for all lists.
        $mergevars[$list_id] = [
          (object) [
            'tag' => 'EMAIL',
            'name' => t('Email Address'),
            'type' => 'email',
            'required' => TRUE,
            'default_value' => '',
            'public' => TRUE,
            'display_order' => 1,
            'options' => (object) [
              'size' => 25,
            ],
          ],
        ];

        $result = $mc_lists->getMergeFields($list_id, ['count' => 500]);

        if ($result->total_items > 0) {
          $mergevars[$list_id] = array_merge($mergevars[$list_id], $result->merge_fields);
        }

        $cache->set($list_id . '-mergevars', $mergevars[$list_id]);
      }
    }

    catch (\Exception $e) {
      \Drupal::logger('mailchimp')->error('An error occurred requesting mergevars for list {list}. "{message}"', [
        'list' => $list_id,
        'message' => $e->getMessage(),
      ]);
    }
  }

  return $mergevars;
}

/**
 * Get the Mailchimp member info for a given email address and list.
 *
 * Results are cached in the cache_mailchimp bin which is cleared by the
 * Mailchimp web hooks system when needed.
 *
 * @param string $list_id
 *   The Mailchimp list ID to get member info for.
 * @param string $email
 *   The Mailchimp user email address to load member info for.
 * @param bool $reset
 *   Set to TRUE if member info should not be loaded from cache.
 *
 * @return object
 *   Member info object, empty if there is no valid info.
 */
function mailchimp_get_memberinfo($list_id, $email, $reset = FALSE) {
  $cache = \Drupal::cache('mailchimp');

  if (!$reset) {
    $cached_data = $cache->get($list_id . '-' . $email);

    if ($cached_data) {
      return $cached_data->data;
    }
  }

  // Query lists from the MCAPI and store in cache:
  $memberinfo = new stdClass();

  /** @var \Mailchimp\MailchimpLists $mc_lists */
  $mc_lists = mailchimp_get_api_object('MailchimpLists');
  try {
    if (!$mc_lists) {
      throw new Exception('Cannot get member info without Mailchimp API. Check API key has been entered.');
    }
    $result = $mc_lists->getMemberInfo($list_id, $email);
    if (!empty($result->id)) {
      $memberinfo = $result;
      $cache->set($list_id . '-' . $email, $memberinfo);
    }
  }
  catch (\Exception $e) {
    // A 404 exception code means mailchimp does not have subscription
    // information for given email address. This is not an error and we can
    // cache this information.
    if ($e->getCode() == 404) {
      $cache->set($list_id . '-' . $email, $memberinfo);
    }
    else {
      \Drupal::logger('mailchimp')->error('An error occurred requesting memberinfo for {email} in list {list}. "{message}"', [
        'email' => $email,
        'list' => $list_id,
        'message' => $e->getMessage(),
      ]);
    }
  }

  return $memberinfo;
}

/**
 * Get the marketing permissions for a subscribed member.
 *
 * Simple wrapper around mailchimp_get_memberinfo().
 *
 * @param string $list_id
 *   Unique string identifier for the list on your MailChimp account.
 * @param string $email
 *   Email address to check for on the identified MailChimp List.
 * @param bool $reset
 *   Set to TRUE to ignore the cache. (Used heavily in testing functions.)
 *
 * @return array
 *   An array of marketing permissions, or an empty array if not subscribed
 */
function mailchimp_get_marketing_permissions($list_id, $email, $reset = FALSE) {
  $memberinfo = mailchimp_get_memberinfo($list_id, $email, $reset);
  if (isset($memberinfo->status)
      && $memberinfo->status == MailchimpLists::MEMBER_STATUS_SUBSCRIBED
      && isset($memberinfo->marketing_permissions)) {
    return $memberinfo->marketing_permissions;
  }

  return [];
}

/**
 * Check if the given email is subscribed to the given list.
 *
 * Simple wrapper around mailchimp_get_memberinfo().
 *
 * @param string $list_id
 *   Unique string identifier for the list on your Mailchimp account.
 * @param string $email
 *   Email address to check for on the identified Mailchimp List.
 * @param bool $reset
 *   Set to TRUE to ignore the cache. (Used heavily in testing functions.)
 *
 * @return bool
 *   TRUE if subscribed, FALSE otherwise.
 */
function mailchimp_is_subscribed($list_id, $email, $reset = FALSE) {
  $subscribed = FALSE;
  $memberinfo = mailchimp_get_memberinfo($list_id, $email, $reset);
  if (isset($memberinfo->status) && $memberinfo->status == MailchimpLists::MEMBER_STATUS_SUBSCRIBED) {
    $subscribed = TRUE;
  }

  return $subscribed;
}

/**
 * Subscribe a user to a Mailchimp list in real time or by adding to the queue.
 *
 * @see Mailchimp_Lists::subscribe()
 */
function mailchimp_subscribe($list_id, $email, $merge_vars = NULL, $interests = [], $double_optin = FALSE, $format = 'html', $language = NULL, $gdpr_consent = FALSE, $tags = NULL) {
  $config = \Drupal::config('mailchimp.settings');

  if (empty($language)) {
    $language = \Drupal::languageManager()->getCurrentLanguage()->getId();
  }

  if ($config->get('cron')) {
    $args = [
      'list_id' => $list_id,
      'email' => $email,
      'merge_vars' => $merge_vars,
      'interests' => $interests,
      'double_optin' => $double_optin,
      'format' => $format,
      'language' => $language,
      'gdpr_consent' => $gdpr_consent,
      'tags' => $tags,
    ];

    return mailchimp_addto_queue('mailchimp_subscribe_process', $args);
  }

  return mailchimp_subscribe_process($list_id, $email, $merge_vars, $interests, $double_optin, $format, $language, $gdpr_consent, $tags);
}

/**
 * Wrapper around Mailchimp_Lists::subscribe().
 *
 * @see Mailchimp_Lists::subscribe()
 */
function mailchimp_subscribe_process($list_id, $email, $merge_vars = NULL, $interests = [], $double_optin = FALSE, $format = 'html', $language = NULL, $gdpr_consent = FALSE, $tags = NULL) {
  $config = \Drupal::config('mailchimp.settings');
  $result = FALSE;

  try {
    /** @var \Mailchimp\MailchimpLists $mc_lists */
    $mc_lists = mailchimp_get_api_object('MailchimpLists');
    if (!$mc_lists) {
      throw new Exception('Cannot subscribe to list without Mailchimp API. Check API key has been entered.');
    }

    $parameters = [
      // If double opt-in is required, set member status to 'pending'.
      'status' => ($double_optin) ? MailchimpLists::MEMBER_STATUS_PENDING : MailchimpLists::MEMBER_STATUS_SUBSCRIBED,
      'email_type' => $format,
    ];

    if (!empty($language)) {
      $parameters['language'] = $language;
    }

    // Set interests.
    if (!empty($interests)) {
      $selected_interests = [];
      foreach ($interests as $interest_group) {
        // This could happen in case the selected interest group
        // is set to display radio inputs. So we either do an
        // explicit check here, or simply transform the single string
        // value to an array in order to pass the condition check below.
        if (!is_array($interest_group)) {
          $interest_group = [$interest_group => $interest_group];
        }

        foreach ($interest_group as $interest_id => $interest_status) {
          $selected_interests[$interest_id] = ($interest_status !== 0);
        }
      }

      if (!empty($selected_interests)) {
        $parameters['interests'] = (object) $selected_interests;
      }
    }

    // Set merge fields.
    if (!empty($merge_vars)) {
      $parameters['merge_fields'] = (object) $merge_vars;
    }

    // Has GDPR consent been given?
    if ($gdpr_consent) {
      // If the member is already subscribed get the marketing permission id(s)
      // for the list and enable them.
      $marketing_permissions = mailchimp_get_marketing_permissions($list_id, $email);
      $was_subscribed        = FALSE;
      if ($marketing_permissions) {
        foreach ($marketing_permissions as $marketing_permission) {
          $parameters['marketing_permissions'][] = [
            'marketing_permission_id' => $marketing_permission->marketing_permission_id,
            'enabled'                 => TRUE,
          ];
        }
        $was_subscribed = TRUE;
      }
    }
    else {
      // We need to make sure this is set.
      $was_subscribed = FALSE;
    }

    // Add member to list.
    $result = $mc_lists->addOrUpdateMember($list_id, $email, $parameters);

    if (isset($result->id)) {
      \Drupal::moduleHandler()->invokeAll('mailchimp_subscribe_success', [
        $list_id,
        $email,
        $merge_vars,
      ]);

      // Clear user cache, just in case there's some cruft leftover:
      mailchimp_cache_clear_member($list_id, $email);

      \Drupal::logger('mailchimp')->notice('{email} was subscribed to list {list}.', [
        'email' => $email,
        'list' => $list_id,
      ]);

      // For newly subscribed members set GDPR consent if it's been given.
      if (!$was_subscribed && $gdpr_consent && !empty($result->marketing_permissions)) {
        // If the member is already subscribed get the marketing permission
        // id(s) for the list and enable them.
        foreach ($result->marketing_permissions as $marketing_permission) {
          $parameters['marketing_permissions'][] = [
            'marketing_permission_id' => $marketing_permission->marketing_permission_id,
            'enabled'                 => TRUE,
          ];
        }
        // Update the member.
        $result = $mc_lists->addOrUpdateMember($list_id, $email, $parameters);
        if (!isset($result->id)) {
          \Drupal::logger('mailchimp')
            ->warning('A problem occurred setting marketing permissions for {email} on list {list}.', [
              'email' => $email,
              'list'  => $list_id,
            ]);
        }
      }

      if ($double_optin) {
        $msg = $config->get('optin_check_email_msg');
        if ($msg) {
          \Drupal::messenger()->addStatus($msg, FALSE);
        }
      }

      // Add or update member tags.
      if ($tags) {
        $tags = explode(',', (string) $tags);
        $tags = array_map('trim', $tags);

        try {
          $mc_lists->addTagsMember($list_id, $tags, $email);
        }

        catch (ClientException $e) {
          \Drupal::logger('mailchimp')->error('An error occurred while adding tags for this email({email}) to Mailchimp: {message}', [
            'message' => $e->getMessage(),
            'email' => $email,
          ]);
        }
      }
    }
    else {
      if (!$config->get('test_mode')) {
        \Drupal::logger('mailchimp')->warning('A problem occurred subscribing {email} to list {list}.', [
          'email' => $email,
          'list' => $list_id,
        ]);
      }
    }
  }
  catch (\Exception $e) {
    if ($e->getCode() == '400' && strpos($e->getMessage(), 'Member In Compliance State') !== FALSE && !$double_optin) {
      \Drupal::logger('mailchimp')->error('Detected "Member In Compliance State" subscribing {email} to list {list}. Trying again using double-opt in.', [
        'email' => $email,
        'list' => $list_id,
      ]);
      return mailchimp_subscribe_process($list_id, $email, $merge_vars, $interests, TRUE, $format, $language, $gdpr_consent, $tags);
    }

    \Drupal::logger('mailchimp')->error('An error occurred subscribing {email} to list {list}. "{message}"', [
      'email' => $email,
      'list' => $list_id,
      'message' => $e->getMessage(),
    ]);
  }

  return $result;
}

/**
 * Adds a Mailchimp subscription task to the queue.
 *
 * @param string $function
 *   The name of the function the queue runner should call.
 * @param array $args
 *   The list of args to pass to the function.
 *
 * @return mixed
 *   Unique ID if item is successfully added to the queue, FALSE otherwise.
 */
function mailchimp_addto_queue($function, array $args) {
  $queue = \Drupal::queue(MAILCHIMP_QUEUE_CRON);
  $queue->createQueue();

  return $queue->createItem([
    'function' => $function,
    'args' => $args,
  ]);
}

/**
 * Update a members list subscription in real time or by adding to the queue.
 *
 * @see Mailchimp_Lists::updateMember()
 */
function mailchimp_update_member($list_id, $email, $merge_vars, $interests = [], $format = 'html', $double_optin = FALSE, $gdpr_consent = FALSE, $tags = NULL) {
  $config = \Drupal::config('mailchimp.settings');

  if ($config->get('cron')) {
    $args = [
      'list_id' => $list_id,
      'email' => $email,
      'merge_vars' => $merge_vars,
      'interests' => $interests,
      'tags' => $tags,
      'format' => $format,
      'double_optin' => $double_optin,
      'gdpr_consent' => $gdpr_consent,
    ];

    return mailchimp_addto_queue('mailchimp_update_member_process', $args);
  }

  return mailchimp_update_member_process($list_id, $email, $merge_vars, $interests, $format, $double_optin, $gdpr_consent, $tags);
}

/**
 * Wrapper around Mailchimp_Lists::updateMember().
 *
 * @see Mailchimp_Lists::updateMember()
 */
function mailchimp_update_member_process($list_id, $email, $merge_vars, $interests, $format, $double_optin = FALSE, $gdpr_consent = FALSE, $tags = NULL) {
  $config = \Drupal::config('mailchimp.settings');
  $result = FALSE;

  try {
    /** @var \Mailchimp\MailchimpLists $mc_lists */
    $mcapi = mailchimp_get_api_object('MailchimpLists');

    $parameters = [
      'status' => ($double_optin) ? MailchimpLists::MEMBER_STATUS_PENDING : MailchimpLists::MEMBER_STATUS_SUBSCRIBED,
      'email_type' => $format,
    ];

    // Set interests.
    if (!empty($interests)) {
      $selected_interests = [];
      foreach ($interests as $interest_group) {
        foreach ($interest_group as $interest_id => $interest_status) {
          $selected_interests[$interest_id] = ($interest_status !== 0);
        }
      }

      if (!empty($selected_interests)) {
        $parameters['interests'] = (object) $selected_interests;
      }
    }

    // Set merge fields.
    if (!empty($merge_vars)) {
      $parameters['merge_fields'] = (object) $merge_vars;
    }

    // Has GDPR consent been given?
    if ($gdpr_consent) {
      // If the member is already subscribed get the marketing permission id(s)
      // for the list and enable them.
      $marketing_permissions = mailchimp_get_marketing_permissions($list_id, $email);
      if ($marketing_permissions) {
        foreach ($marketing_permissions as $marketing_permission) {
          $parameters['marketing_permissions'][] = [
            'marketing_permission_id' => $marketing_permission->marketing_permission_id,
            'enabled'                 => TRUE,
          ];
        }
      }
    }

    // Update member.
    $result = $mcapi->updateMember($list_id, $email, $parameters);

    if (isset($result->id)) {
      \Drupal::logger('mailchimp')->notice('{email} was updated in list {list_id}.', [
        'email' => $email,
        'list' => $list_id,
      ]);

      // Clear user cache:
      mailchimp_cache_clear_member($list_id, $email);
    }
    else {
      \Drupal::logger('mailchimp')->warning('A problem occurred updating {email} on list {list}.', [
        'email' => $email,
        'list' => $list_id,
      ]);
    }
  }
  catch (\Exception $e) {
    if ($e->getCode() == '400' && strpos($e->getMessage(), 'Member In Compliance State') !== FALSE && !$double_optin) {
      \Drupal::logger('mailchimp')->error('Detected "Member In Compliance State" subscribing {email} to list {list}.  Trying again using double-opt in.', [
        'email' => $email,
        'list' => $list_id,
      ]);

      return mailchimp_update_member_process($list_id, $email, $merge_vars, $interests, $format, TRUE, $gdpr_consent, $tags);
    }

    \Drupal::logger('mailchimp')->error('An error occurred updating {email} on list {list}. "{message}"', [
      'email' => $email,
      'list' => $list_id,
      'message' => $e->getMessage(),
    ]);
  }

  if ($double_optin) {
    $msg = $config->get('optin_check_email_msg');
    if ($msg) {
      \Drupal::messenger()->addStatus($msg, FALSE);
    }
  }

  // Add or update member tags
  if ($tags) {
    $tags = explode(',', (string) $tags);
    $tags = array_map('trim', $tags);

    try {
      $mcapi->addTagsMember($list_id, $tags, $email);
    }

    catch (ClientException $e) {
      \Drupal::logger('mailchimp')->error('An error occurred while adding tags for this email({email}) to Mailchimp: {message}', [
        'message' => $e->getMessage(),
        'email' => $email,
      ]);
    }
  }

  return $result;
}

/**
 * Retrieve all members of a given list with a given status.
 *
 * Note that this function can cause locking an is somewhat slow. It is not
 * recommended unless you know what you are doing! See the MCAPI documentation.
 */
function mailchimp_get_members($list_id, $status = MailchimpLists::MEMBER_STATUS_SUBSCRIBED, $options = []) {
  $results = FALSE;

  $lock = \Drupal::lock();

  if ($lock->acquire('mailchimp_get_members', 60)) {
    try {
      /** @var \Mailchimp\MailchimpLists $mcapi */
      $mcapi = mailchimp_get_api_object('MailchimpLists');

      $options['status'] = $status;
      $options['count'] = 500;

      $results = $mcapi->getMembers($list_id, $options);
    }
    catch (\Exception $e) {
      \Drupal::logger('mailchimp')->error('An error occurred pulling member info for a list. "{message}"', [
        'message' => $e->getMessage(),
      ]);
    }

    $lock->release('mailchimp_get_members');
  }

  return $results;
}

/**
 * Batch updates a number of Mailchimp list members.
 *
 * @see Mailchimp_Lists::batchSubscribe()
 */
function mailchimp_batch_update_members($list_id, $batch) {
  $results = FALSE;

  try {
    /** @var \Mailchimp\MailchimpLists $mc_lists */
    $mc_lists = mailchimp_get_api_object('MailchimpLists');
    if (!$mc_lists) {
      throw new Exception('Cannot batch subscribe to list without Mailchimp API. Check API key has been entered.');
    }

    if (!empty($batch)) {
      // Create a new batch update operation for each member.
      foreach ($batch as $batch_data) {
        // @todo Remove 'advanced' earlier? Needed at all?
        unset($batch_data['merge_vars']['advanced']);

        $parameters = [
          'email_type' => $batch_data['email_type'],
          'merge_fields' => (object) $batch_data['merge_vars'],
        ];

        $mc_lists->addOrUpdateMember($list_id, $batch_data['email'], $parameters, TRUE);
      }

      // Process batch operations.
      return $mc_lists->processBatchOperations();
    }
  }
  catch (\Exception $e) {
    \Drupal::logger('mailchimp')->error('An error occurred performing batch subscribe/update. "{message}"', [
      'message' => $e->getMessage(),
    ]);
  }

  return $results;
}

/**
 * Unsubscribes a member from a Mailchimp list.
 *
 * @see Mailchimp_Lists::unsubscribe()
 */
function mailchimp_unsubscribe($list_id, $email) {
  $config = \Drupal::config('mailchimp.settings');

  $result = FALSE;

  if (mailchimp_is_subscribed($list_id, $email)) {
    if ($config->get('cron')) {
      $result = mailchimp_addto_queue(
        'mailchimp_unsubscribe_process',
        [
          'list_id' => $list_id,
          'email' => $email,
        ]
      );
    }
    else {
      $result = mailchimp_unsubscribe_process($list_id, $email);
    }
  }

  return $result;
}

/**
 * Unsubscribes a member from a Mailchimp list.
 *
 * @see Mailchimp_Lists::unsubscribe()
 */
function mailchimp_unsubscribe_process($list_id, $email) {
  try {
    /** @var \Mailchimp\MailchimpLists $mc_lists */
    $mc_lists = mailchimp_get_api_object('MailchimpLists');
    if (!$mc_lists) {
      throw new Exception('Cannot unsubscribe from list without Mailchimp API. Check API key has been entered.');
    }

    $mc_lists->updateMember($list_id, $email, ['status' => MailchimpLists::MEMBER_STATUS_UNSUBSCRIBED]);

    \Drupal::moduleHandler()->invokeAll('mailchimp_unsubscribe_success', [
      $list_id,
      $email,
    ]);

    // Clear user cache:
    mailchimp_cache_clear_member($list_id, $email);

    return TRUE;
  }
  catch (\Exception $e) {
    \Drupal::logger('mailchimp')->error('An error occurred unsubscribing {email} from list {list}. "{message}"', [
      'email' => $email,
      'list' => $list_id,
      'message' => $e->getMessage(),
    ]);
  }

  return FALSE;
}

/**
 * Wrapper function to return data for a given campaign.
 *
 * Data is stored in the Mailchimp cache.
 *
 * @param string $campaign_id
 *   The ID of the campaign to get data for.
 * @param bool $reset
 *   Set to TRUE if campaign data should not be loaded from cache.
 *
 * @return mixed
 *   Array of campaign data or FALSE if not found.
 */
function mailchimp_get_campaign_data($campaign_id, $reset = FALSE) {
  $cache = \Drupal::cache('mailchimp');

  $campaign_data = FALSE;

  if (!$reset) {
    $cached_data = $cache->get('campaign_' . $campaign_id);

    if ($cached_data) {
      return $cached_data->data;
    }
  }

  try {
    /** @var \Mailchimp\MailchimpCampaigns $mcapi */
    $mcapi = mailchimp_get_api_object('MailchimpCampaigns');

    $response = $mcapi->getCampaign($campaign_id);

    if (!empty($response->id)) {
      $campaign_data = $response;
      $cache->set('campaign_' . $campaign_id, $campaign_data);
    }
  }
  catch (\Exception $e) {
    \Drupal::logger('mailchimp')->error('An error occurred retrieving campaign data for {campaign}. "{message}"', [
      'campaign' => $campaign_id,
      'message' => $e->getMessage(),
    ]);
  }

  return $campaign_data;
}

/**
 * Returns all lists a given email address is currently subscribed to.
 *
 * @param string $email
 *   Email address to search.
 *
 * @return array
 *   Campaign structs containing id, web_id, name.
 */
function mailchimp_get_lists_for_email($email) {
  try {
    /** @var \Mailchimp\MailchimpLists $mcapi */
    $mcapi = mailchimp_get_api_object('MailchimpLists');
    $lists = $mcapi->getListsForEmail($email);
  }
  catch (\Exception $e) {
    \Drupal::logger('mailchimp')->error('An error occurred retreiving lists data for {email}. "{message}"', [
      'email' => $email,
      'message' => $e->getMessage(),
    ]);

    $lists = [];
  }

  return $lists;
}

/**
 * Returns all webhooks for a given Mailchimp list ID.
 *
 * @see Mailchimp_Lists::webhooks()
 */
function mailchimp_webhook_get($list_id) {
  try {
    /** @var \Mailchimp\MailchimpLists $mc_lists */
    $mc_lists = mailchimp_get_api_object('MailchimpLists');
    $result = $mc_lists->getWebhooks($list_id);

    return ($result->total_items > 0) ? $result->webhooks : FALSE;
  }
  catch (\Exception $e) {
    \Drupal::logger('mailchimp')->error('An error occurred reading webhooks for list {list}. "{message}"', [
      'list' => $list_id,
      'message' => $e->getMessage(),
    ]);

    return FALSE;
  }
}

/**
 * Adds a webhook to a Mailchimp list.
 *
 * @param string $list_id
 *   The Mailchimp list ID to add a webhook for.
 * @param string $url
 *   The URL of the webhook endpoint.
 * @param array $events
 *   Associative array of events action to bool, indicating enabled status.
 * @param array $sources
 *   Associative array of source name to bool, indicating source status.
 *
 * @return string
 *   The ID of the new webhook.
 *
 * @see Mailchimp_Lists::addWebhook()
 */
function mailchimp_webhook_add($list_id, $url, array $events = [], array $sources = []) {
  try {
    /** @var \Mailchimp\MailchimpLists $mc_lists */
    $mc_lists = mailchimp_get_api_object('MailchimpLists');
    if (!$mc_lists) {
      throw new Exception('Cannot add webhook without Mailchimp API. Check API key has been entered.');
    }

    $parameters = [
      'events' => (object) $events,
      'sources' => (object) $sources,
    ];

    $result = $mc_lists->addWebhook($list_id, $url, $parameters);

    return $result->id;
  }
  catch (\Exception $e) {
    \Drupal::logger('mailchimp')->error('An error occurred adding webhook for list {list}. "{message}"', [
      'list' => $list_id,
      'message' => $e->getMessage(),
    ]);

    return FALSE;
  }
}

/**
 * Deletes a Mailchimp list webhook.
 *
 * @param string $list_id
 *   The ID of the Mailchimp list to delete the webhook from.
 * @param string $url
 *   The URL of the webhook endpoint.
 *
 * @return bool
 *   TRUE if deletion was successful, FALSE otherwise.
 *
 * @see Mailchimp_Lists::webhookDel()
 */
function mailchimp_webhook_delete($list_id, $url) {
  try {
    /** @var \Mailchimp\MailchimpLists $mc_lists */
    $mc_lists = mailchimp_get_api_object('MailchimpLists');

    $result = $mc_lists->getWebhooks($list_id);

    if ($result->total_items > 0) {
      foreach ($result->webhooks as $webhook) {
        if ($webhook->url == $url) {
          $mc_lists->deleteWebhook($list_id, $webhook->id);
          return TRUE;
        }
      }
    }

    return FALSE;
  }
  catch (\Exception $e) {
    \Drupal::logger('mailchimp')->error('An error occurred deleting webhook for list {list}. "{message}"', [
      'list' => $list_id,
      'message' => $e->getMessage(),
    ]);
    return FALSE;
  }
}

/**
 * Clears a mailchimp user member info cache.
 *
 * @param string $list_id
 *   The list ID.
 * @param string $email
 *   The email address.
 */
function mailchimp_cache_clear_member($list_id, $email) {
  $cache = \Drupal::cache('mailchimp');
  $cache->delete($list_id . '-' . $email);
}

/**
 * Clears a mailchimp activity cache.
 *
 * @param string $list_id
 *   The list ID.
 */
function mailchimp_cache_clear_list_activity($list_id) {
  $cache = \Drupal::cache('mailchimp');
  $cache->delete('mailchimp_activity_' . $list_id);
}

/**
 * Clears a mailchimp activity cache.
 *
 * @param string $campaign_id
 *   The campaign ID.
 */
function mailchimp_cache_clear_campaign($campaign_id) {
  $cache = \Drupal::cache('mailchimp');
  $cache->delete('mailchimp_campaign_' . $campaign_id);
}

/**
 * Implements hook_flush_caches().
 */
function mailchimp_flush_caches() {
  return ['mailchimp'];
}

/**
 * Processes a webhook post from Mailchimp.
 */
function mailchimp_process_webhook() {
  if (!isset($_POST)) {
    return "Mailchimp Webhook Endpoint.";
  }

  $data = $_POST['data'];
  $type = $_POST['type'];

  switch ($type) {
    case 'unsubscribe':
    case 'profile':
    case 'cleaned':
      mailchimp_get_memberinfo($data['list_id'], $data['email'], TRUE);
      break;

    case 'upemail':
      mailchimp_cache_clear_member($data['list_id'], $data['old_email']);
      mailchimp_get_memberinfo($data['list_id'], $data['new_email'], TRUE);
      break;

    case 'campaign':
      mailchimp_cache_clear_list_activity($data['list_id']);
      mailchimp_cache_clear_campaign($data['id']);
      break;
  }

  // Allow other modules to act on a webhook.
  \Drupal::moduleHandler()->invokeAll('mailchimp_process_webhook', [
    $type,
    $data,
  ]);

  // Log event:
  \Drupal::logger('mailchimp')->info('Webhook type {type} has been processed.', [
    'type' => $type,
  ]);

  return NULL;
}

/**
 * Generates the webhook endpoint URL.
 *
 * @return string
 *   The endpoint URL.
 */
function mailchimp_webhook_url($hash = NULL, $lang = NULL) {
  if (is_null($hash)) {
    $hash = \Drupal::config('mailchimp.settings')->get('webhook_hash');
  }
  if (is_null($lang)) {
    $lang = \Drupal::languageManager()->getDefaultLanguage()->getId();
  }
  return Url::fromRoute(
    'mailchimp.webhook_endpoint',
    [
      'hash' => $hash,
      'language' => $lang,
    ]
  )->setAbsolute()->toString();
}

/**
 * Helper function to generate form elements for a list's interest groups.
 *
 * @param object $list
 *   Mailchimp list object as returned by mailchimp_get_list().
 * @param array $defaults
 *   Array of default values to use if no group subscription values already
 *   exist at Mailchimp.
 * @param string $email
 *   Optional email address to pass to the MCAPI and retrieve existing values
 *   for use as defaults.
 * @param string $mode
 *   Elements display mode:
 *     - "default" shows all groups except the hidden ones,
 *     - "admin" shows all groups including hidden ones,
 *     - "hidden" generates '#type' => 'value' elements using default values.
 *
 * @return array
 *   A collection of form elements, one per interest group.
 */
function mailchimp_interest_groups_form_elements($list, array $defaults = [], $email = NULL, $mode = 'default') {
  $return = [];

  if ($mode == 'hidden') {
    foreach ($list->intgroups as $group) {
      $return[$group->id] = [
        '#type' => 'value',
        '#value' => $defaults[$group->id] ?? [],
      ];
    }
    return $return;
  }

  try {
    foreach ($list->intgroups as $group) {
      /** @var \Mailchimp\MailchimpLists $mc_lists */
      $mc_lists = mailchimp_get_api_object('MailchimpLists');

      $interest_data = $mc_lists->getInterests($list->id, $group->id, ['count' => 500]);

      if (!empty($email)) {
        $memberinfo = mailchimp_get_memberinfo($list->id, $email);
      }

      // phpcs:disable
      $field_title = t($group->title);
      // phpcs:enable
      $field_description = NULL;
      $value = NULL;

      // Set the form field type:
      switch ($group->type) {
        case 'hidden':
          $field_title .= ' (' . t('hidden') . ')';
          $field_description = t('This group will not be visible to the end user. However you can set the default value and it will be actually used.');
          if ($mode == 'admin') {
            $field_type = 'checkboxes';
          }
          else {
            $field_type = 'value';
            $value = $defaults[$group->id] ?? [];
          }
          break;

        case 'radio':
          $field_type = 'radios';
          break;

        case 'dropdown':
          $field_type = 'select';
          break;

        default:
          $field_type = $group->type;
      }

      // Extract the field options:
      $options = [];
      if ($field_type == 'select') {
        $options[''] = '-- select --';
      }

      $default_values = [];

      // Set interest options and default values.
      foreach ($interest_data->interests as $interest) {
        // phpcs:disable
        $options[$interest->id] = t($interest->name);
        // phpcs:enable

        if (isset($memberinfo)) {
          if (isset($memberinfo->interests->{$interest->id}) && ($memberinfo->interests->{$interest->id} === TRUE)) {
            $default_values[$group->id][] = $interest->id;
          }
        }
        elseif (!empty($defaults)) {
          if ($group->type === 'radio') {
            if (isset($defaults[$group->id]) && $defaults[$group->id] === $interest->id) {
              $default_values[$group->id] = $interest->id;
            }
          }
          else {
            if (isset($defaults[$group->id][$interest->id]) && !empty($defaults[$group->id][$interest->id])) {
              $default_values[$group->id][] = $interest->id;
            }
          }
        }
      }

      $return[$group->id] = [
        '#type' => $field_type,
        '#title' => $field_title,
        '#description' => $field_description,
        '#options' => $options,
        '#default_value' => $default_values[$group->id] ?? [],
        '#attributes' => ['class' => ['mailchimp-newsletter-interests-' . $list->id]],
      ];
      if ($value !== NULL) {
        $return[$group->id]['#value'] = $value;
      }
    }
  }
  catch (\Exception $e) {
    \Drupal::logger('mailchimp')->error('An error occurred generating interest group lists. "{message}"', [
      'message' => $e->getMessage(),
    ]);
  }
  return $return;
}

/**
 * Convert Mailchimp form elements to Drupal Form API.
 *
 * @param object $mergevar
 *   The mailchimp-formatted form element to convert.
 *
 * @return array
 *   A properly formatted drupal form element.
 */
function mailchimp_insert_drupal_form_tag($mergevar) {
  // Insert common FormAPI properties:
  $input = [
    '#weight' => $mergevar->display_order,
    '#required' => $mergevar->required,
    '#default_value' => $mergevar->default_value,
  ];

  // phpcs:disable
  $input['#title'] = t((string) $mergevar->name);
  // phpcs:enable

  switch ($mergevar->type) {
    case 'address':
      // Sub-array of address elements according to Mailchimp specs.
      // https://apidocs.mailchimp.com/api/2.0/lists/subscribe.php
      $input['#type'] = 'container';
      $input['#tree'] = TRUE;
      $input['addr1'] = [
        '#title' => t('Address 1'),
        '#type' => 'textfield',
      ];
      $input['addr2'] = [
        '#title' => t('Address 2'),
        '#type' => 'textfield',
      ];
      $input['city'] = [
        '#title' => t('City'),
        '#type' => 'textfield',
      ];
      $input['state'] = [
        '#title' => t('State'),
        '#type' => 'textfield',
        '#size' => 2,
        '#maxlength' => 2,
      ];
      $input['zip'] = [
        '#title' => t('Zip'),
        '#type' => 'textfield',
        '#size' => 6,
        '#maxlength' => 6,
      ];
      $input['country'] = [
        '#title' => t('Country'),
        '#type' => 'textfield',
        '#size' => 2,
        '#maxlength' => 2,
      ];
      break;

    case 'dropdown':
      // Dropdown is mapped to <select> element in Drupal Form API.
      $input['#type'] = 'select';

      // Creates options, we must delete array keys to have relevant information
      // on Mailchimp.
      $choices = [];
      foreach ($mergevar->options->choices as $choice) {
        $choices[$choice] = t($choice);
      }

      $input['#options'] = $choices;
      break;

      case 'phone':
        $input['#type'] = 'tel';
        break;

    case 'radio':
      // Radio is mapped to <input type='radio' /> i.e. 'radios' element in
      // Drupal Form API.
      $input['#type'] = 'radios';

      // Creates options, we must delete array keys to have relevant information
      // on Mailchimp.
      $choices = [];
      foreach ($mergevar->options->choices as $choice) {
        $choices[$choice] = t($choice);
      }

      $input['#options'] = $choices;
      break;

    case 'email':
      if (\Drupal::service('element_info')->getInfo('emailfield', '#type')) {
        // Set to an HTML5 email type if 'emailfield' is supported:
        $input['#type'] = 'email';
      }
      else {
        // Set to standard text type if 'emailfield' isn't defined:
        $input['#type'] = 'textfield';
      };
      $input['#size'] = $mergevar->options->size;
      if (!empty($mergevar->options->size)) {
        $input['#size'] = $mergevar->options->size;
      } else {
        $input['#size'] = 25;
      }
      $input['#element_validate'] = ['mailchimp_validate_email'];
      break;

    case 'date':
      $input['#type'] = 'date';
      break;

    default:
      // This is a standard input[type=text] or something we can't handle with
      // Drupal FormAPI.
      $input['#type'] = 'textfield';
      if (isset($mergevar->options->size)) {
        $input['#size'] = $mergevar->options->size;
      }
      break;
  }

  // Special cases for Mailchimp hidden defined fields:
  if ($mergevar->public === FALSE) {
    $input['#type'] = 'hidden';
  }

  return $input;
}

/**
 * Implements hook_cron().
 *
 * Processes queued Mailchimp actions.
 */
function mailchimp_cron($batch_limit = NULL) {
  $queue = \Drupal::queue(MAILCHIMP_QUEUE_CRON);
  $queue->createQueue();

  $queue_count = $queue->numberOfItems();

  if ($queue_count > 0) {
    $config = \Drupal::config('mailchimp.settings');

    if (is_null($batch_limit)) {
      $batch_limit = $config->get('batch_limit');
    }

    $batch_size = ($queue_count < $batch_limit) ? $queue_count : $batch_limit;
    $count = 0;

    while ($count < $batch_size) {
      if ($item = $queue->claimItem()) {
        call_user_func_array($item->data['function'], $item->data['args']);
        $queue->deleteItem($item);
      }

      $count++;
    }
  }
  return $batch_size ?? $queue_count;
}

/**
 * Wrapper for email validation function in core.
 *
 * Necessary so email validation function can be added
 * to forms as a value in the #element_validate array.
 *
 * @see \Egulias\EmailValidator\EmailValidator::isValid()
 */
function mailchimp_validate_email($mail, FormStateInterface $form_state) {
  if (!\Drupal::service('email.validator')->isValid($mail['#value'])) {
    $form_state->setError($mail, t('The email address %mail is not valid.', ['%mail' => $mail['#value']]));
    return FALSE;
  }
  return TRUE;
}

/**
 * Implements hook_page_bottom().
 */
function mailchimp_page_bottom(array &$page_bottom) {
  $config = \Drupal::config('mailchimp.settings');

  // Insert JavaScript for Mailchimp Connected Sites, if enabled.
  if (!empty($config->get('enable_connected'))) {
    // Limit JavaScript embed to pre-configured paths.
    $connected_site_paths = $config->get('connected_paths');

    $current_path = \Drupal::service('path.current')->getPath();
    $current_alias = \Drupal::service('path_alias.manager')->getAliasByPath($current_path);

    if ($connected_site_paths && (\Drupal::service('path.matcher')->matchPath($current_path, $connected_site_paths) ||
      \Drupal::service('path.matcher')->matchPath($current_alias, $connected_site_paths))) {
      $connected_site_id = $config->get('connected_id');

      if (!empty($connected_site_id)) {
        try {
          /** @var \Mailchimp\MailchimpConnectedSites $mc_connected */
          $mc_connected = mailchimp_get_api_object('MailchimpConnectedSites');

          // Verify Connected Site exists on the Mailchimp side and insert JS.
          $connected_site = $mc_connected->getConnectedSite($connected_site_id);
          if (!empty($connected_site)) {

            $mcjs = [
              '#type' => 'markup',
              '#markup' => Markup::create($connected_site->site_script->fragment),
            ];

            $page_bottom['mailchimp_connected'] = $mcjs;
          }
        }
        catch (\Exception $e) {
          \Drupal::logger('mailchimp')->error('An error occurred while getting connected sites. "{message}"', [
            'message' => $e->getMessage(),
          ]);
        }
      }
    }
  }
}