Search API Solr - hook_search_api_solr_converted_query_alter()

alter_solarium_query.php

<?php

/**
 * Implements hook_search_api_solr_converted_query_alter().
 *
 * Modifies Solarium query to group results by field.
 * Modifies Solarium query to sort results by first geofield value within the multivalue field.
 */
function MODULE_search_api_solr_converted_query_alter(\Solarium\Core\Query\QueryInterface $solarium_query, \Drupal\search_api\Query\QueryInterface $query) {
  // Alter the Solarium query.
  // Get private property searchId in order to determine origin of the search query.
  // This could probably be done better.
  $ref_object = new \ReflectionObject($query);
  $ref_property = $ref_object->getProperty('searchId');
  $ref_property->setAccessible(TRUE);
  $search_id = $ref_property->getValue($query);

  if ($search_id === 'search_api_autocomplete:search') {
    // Group results by indexed field.
    // Use grouping only for the autocomplete search field query.
    $solarium_query->addParam('group', TRUE);
    $solarium_query->addParam('group.field', 'ss_type');
    $solarium_query->addParam('group.limit', 5);
    $solarium_query->addParam('group.format', 'grouped');

    // Add grouping to the query options so the module knows to group the
    // results.
    $grouping = [
      'use_grouping' => TRUE,
      'group_sort' => ['ss_type' => $query::SORT_DESC],
      'fields' => ['type'],
      'group.format' => 'grouped',
    ];

    // Set the grouping param.
    $query->setOption('search_api_grouping', $grouping);
  }

  if ($search_id === 'views_page:provider_search__result_provider') {
    // Sort providers by the first value in Locations field.
    $options = $query->getOptions();
    if (isset($options['search_api_location'])) {
      $lat = $options['search_api_location'][0]['lat'];
      $lon = $options['search_api_location'][0]['lon'];

      $solarium_query->addParam('fq', '{!geofilt}');
      // Use locs_ field (single indexed value) for the query and not locm_ (multivalue)
      $solarium_query->addParam('sfield', 'locs_field_rh_location_geofield');
      $solarium_query->addParam('pt', $lat . ',' . $lon);
      $solarium_query->addParam('sort', 'geodist() asc');
    }
  }
}