Craftcms - Search both products and entries in a single search with custom pagination

ProductEntrySearchService.php

<?php
/**
 * Product & Entry Search plugin for Craft CMS 3.x
 *
 * Use site search across both products and entries allowing for pagination.
 *
 * @link      https://adigital.agency
 * @copyright Copyright (c) 2018 A Digital
 */

namespace adigital\productentrysearch\services;

use adigital\productentrysearch\ProductEntrySearch;

use Craft;
use craft\base\Component;

/**
 * ProductEntrySearchService Service
 *
 * All of your plugin’s business logic should go in services, including saving data,
 * retrieving data, etc. They provide APIs that your controllers, template variables,
 * and other plugins can interact with.
 *
 * https://craftcms.com/docs/plugins/services
 *
 * @author    A Digital
 * @package   ProductEntrySearch
 * @since     1.0.0
 */
class ProductEntrySearchService extends Component
{
  // Public Methods
  // =========================================================================

  /**
   * This function can literally be anything you want, and you can have as many service
   * functions as you want
   *
   * From any other plugin file, call it like this:
   *
   *     ProductEntrySearch::$plugin->productEntrySearchService->getSearchResults()
   *
   * @return mixed
   */
  public function getSearchResults($query, $orderByScore, $lower, $upper)
  {
    $count = 0;
    $elements = [];
    $entries = Craft::$app->search->filterElementIdsByQuery([], $query, $orderByScore, null, true);
    foreach($entries as $id => $score) {
      $element = Craft::$app->elements->getElementById($id);
      if ($element && $element->uri <> '' && $element->enabled == 1) {
        $count++;
        if ($lower < $count && $count <= $upper) {
          $elements[] = $element;
        }
      }
    }
    return ["elements" => $elements, "count" => $count];
  }

  /**
   * This function can literally be anything you want, and you can have as many service
   * functions as you want
   *
   * From any other plugin file, call it like this:
   *
   *     ProductEntrySearch::$plugin->productEntrySearchService->getPagination()
   *
   * @return mixed
   */
  public function getPagination($pageNum, $last, $lower, $upper, $url, $urlParts, $limit, $count)
  {
    $pagination = [];
    $pagination['currentPage'] = $pageNum;

    $prevLink = '';
    $nextLink = '';
    if (preg_match('/^p\d+$/', $last)) {
      // we have pagination already
      // get number from $last
      $prevNum = $pageNum - 1;
      $nextNum = $pageNum + 1;
      array_pop($urlParts);
      $url = implode("/", $urlParts);
      if ($pageNum == 2) {
        $prevLink = $url;
      } else {
        $prevLink = $url.'/p'.$prevNum;
      }
      $nextLink = $url.'/p'.$nextNum;
    } else {
      $nextLink = $url.'/p2';
      $nextNum = 2;
    }

    if ($limit != $upper) {
      // show prev page link
      $pagination['prevUrl'] = $prevLink;
      $pagination['prevPage'] = $prevNum;
      $pagination['firstPage'] = $url;
    }

    if ($upper < $count) {
      // show next page link
      $pagination['nextUrl'] = $nextLink;
      $pagination['nextPage'] = $nextNum;
      $pagination['lastPage'] = $url.'/p'.ceil($count / $limit);
    }

    return $pagination;
  }
}

ProductEntrySearchVariable.php

<?php
/**
 * Product & Entry Search plugin for Craft CMS 3.x
 *
 * Use site search across both products and entries allowing for pagination.
 *
 * @link      https://adigital.agency
 * @copyright Copyright (c) 2018 A Digital
 */

namespace adigital\productentrysearch\variables;

use adigital\productentrysearch\ProductEntrySearch;

use Craft;
use craft\helpers\UrlHelper;

/**
 * Product & Entry Search Variable
 *
 * Craft allows plugins to provide their own template variables, accessible from
 * the {{ craft }} global variable (e.g. {{ craft.productEntrySearch }}).
 *
 * https://craftcms.com/docs/plugins/variables
 *
 * @author    A Digital
 * @package   ProductEntrySearch
 * @since     1.0.0
 */
class ProductEntrySearchVariable
{
  // Public Methods
  // =========================================================================

  /**
   * Whatever you want to output to a Twig template can go into a Variable method.
   * You can have as many variable functions as you want.  From any Twig template,
   * call it like this:
   *
   *     {{ craft.productEntrySearch.exampleVariable }}
   *
   * Or, if your variable requires parameters from Twig:
   *
   *     {{ craft.productEntrySearch.exampleVariable(twigValue) }}
   *
   * @param null $params
   * @return string
   */
  public function search($params)
  {
    $url = Craft::$app->request->url;
    $url = UrlHelper::stripQueryString($url);
    $urlParts = explode('/', $url);
    $last = end($urlParts);
    if (preg_match('/^p\d+$/', $last)) {
      $pageNum = (int)str_replace('p', '', $last);
    } else {
      $pageNum = 1;
    }
    $lower = $params['limit'] * ($pageNum - 1);
    $upper = $lower + $params['limit'];

    $results = ProductEntrySearch::$plugin->productEntrySearchService->getSearchResults($params['query'], $params['orderByScore'], $lower, $upper);
    $pagination = ProductEntrySearch::$plugin->productEntrySearchService->getPagination($pageNum, $last, $lower, $upper, $url, $urlParts, $params['limit'], $results['count']);

    if ($upper >= $results['count']) {
      $upper = $results['count'];
    }

    return [
      'lower' => $lower,
      'upper' => $upper,
      'total' => $results['count'],
      'data' => $results['elements'],
      'pagination' => $pagination
    ];
  }
}

results.twig

{% set query = craft.app.request.getParam('q') %}
{% set result = craft.productEntrySearch.search({
  query: '*'~query~'*',
  orderByScore: true,
  limit: 20
}) %}
<h1>Search Results for '{{ query }}'</h1>
<p>Total results: <b>{{ result.total }}</b></p>
{% if result.data|length %}
  <p>Showing results: {{ result.lower + 1 }} - {{ result.upper }}</p>
  {% for block in result.data %}
    <div>
      <h3><a href="{{ block.url }}" title="{{ block.title }}">{{ block.title }}</a></h3>
      {% if block.excerpt|length %}
        <p>{{ block.excerpt }}</p>
      {% endif %}
    </div>
  {% else %}
    <p>Sorry, your search term <b>{{ query }}</b> didn't return any results. Use the search box to try a different search term.</p>
  {% endfor %}
  <div>
    {% if result.pagination.firstPage is defined %}<a href="{{ result.pagination.firstPage }}?{{ craft.request.getQueryStringWithoutPath() }}">Newer</a>{% else %}<div>&nbsp;</div>{% endif %}
    <ul>
      {% if result.pagination.prevUrl is defined %}
        <li><a href="{{ result.pagination.prevUrl }}?{{ craft.request.getQueryStringWithoutPath() }}">{{ result.pagination.prevPage }}</a></li>
      {% endif %}
      <li>{{ result.pagination.currentPage }}</li>
      {% if result.pagination.nextUrl is defined %}
        <li><a href="{{ result.pagination.nextUrl }}?{{ craft.request.getQueryStringWithoutPath() }}">{{ result.pagination.nextPage }}</a></li>
      {% endif %}
    </ul>
    {% if result.pagination.lastPage is defined  %}<a href="{{ result.pagination.lastPage }}?{{ craft.request.getQueryStringWithoutPath() }}">Older</a>{% else %}<div>&nbsp;</div>{% endif %}
  </div>
{% endif %}