Using Guzzle With Events Plugin

CollectionOffset.php

<?php namespace Helper;

// This calculates the offset indexes for the Plugin
class CollectionOffset
{
    private $postsPerPage;
    private $page;

    public function __construct($postsPerPage = 10, $page = 1)
    {
        if (!is_numeric($postsPerPage) || !is_numeric($page)) {
            throw new \Exception("parameters should be numeric");
        }
        $this->postsPerPage = $postsPerPage;
        $this->page = $page;
        return $this;
    }

    public function start()
    {
        return $this->postsPerPage * ($this->page - 1);
    }

    public function end()
    {
        return ($this->postsPerPage * ($this->page - 1)) + $this->postsPerPage;
    }
}

EventQuery.php

<?php

namespace Example\Query;

use \GuzzleHttp\Client;
use \GuzzleHttp\Psr7;
use \GuzzleHttp\Exception\RequestException;
use \Helper\CollectionOffset;

class EventQueries
{
	
     use \Helper\QueryHelper;
  
      /**
       * $dateOptions should be 'Past or Future'
       */
     public static function getFiltered($numberOfPosts = 1, $page = 1, $dateOptions = [], $tags = [])
     {

         $url = '/wp-json/events/v1/getEventsFiltered';

         if (!empty($dateOptions)) {
             $url = self::addParameter('date', self::getDateParamValue($dateOptions), $url);
         }

         if (!empty($tags)) {
             $url = self::addParameter('tags', self::getEventTagsParaValue($taxonomyQueries), $url);
         }

         $url = self::addParameter('startIndex', (new CollectionOffset($numberOfPosts, $page))->start(), $url);

         $url = self::addParameter('endIndex', (new CollectionOffset($numberOfPosts, $page))->end(), $url);

         $events = self::requestAPI('GET', $url, []);

         return collect($events)->map(function($event) {
             return self::eventDTO($event);
         })->take($numberOfPosts)->toArray();
    }

    public static function getSingleEvent($id)
    {
        $url = '/wp-json/events/v1/getEvent/' . $id;

        return self::requestAPI('GET', $url, null);
    }

    private static function requestAPI($httpRequest, $url, $altReturnVar = [])
    {
        $client = new Client([
            'base_uri' => home_url()
        ]);

        $res = $client->request(
            'GET',
            $url,
            ['http_errors' => false]
        );

        return $res->getStatusCode() === 200 ? json_decode($res->getBody()->getContents()) : $altReturnVar;

    }
  
    private static function getDateParamValue($dateOptions = [])
    {
        if (in_array('future', $dateOptions) && in_array('past', $dateOptions)) {
            return date('Y-m-d', strtotime('2000-1-1')) . '&after=true';
        } else if (in_array('future', $dateOptions)) {
            return date('Y-m-d') . '&after=true';
        } else if (in_array('past', $dateOptions)) {
            return date('Y-m-d') . '&after=false';
        }
    }

    private static function getEventTagsParaValue(array $tags)
    {
        $taxonomyQueriesAsString = join($tags, ',');
        return !empty($taxonomyQueriesAsString) ? $taxonomyQueriesAsString : '';
    }
}

QueryHelper.php

<?php

namespace Helper;

/**
 * URL Parameter Query Helpers
 */
trait QueryHelper
{

    /**
     * Adds a parameter key value pair to current url
     * @param string $key
     * @param string $value
     * @return string New query string
     */
    public function addURLParameter($key, $value)
    {
        return add_query_arg($key, $value);
    }

    public static function addParameter($key, $value, $url = null)
    {
        return add_query_arg($key, $value, $url);
    }

    /**
     * Removes a parameter from current url
     * @param string $key
     * @return string New Query String
     */
    public function removeURLParameter($key)
    {
        return remove_query_arg($key);
    }

    /**
     * gets parameter key valye if one exists
     * @param string $key
     * @return string or null
     */
    public function getURLParameter($key)
    {
        return isset($_GET[$key]) ? $_GET[$key] : null;
    }

    /**
     * Gets current page number
     * @return integer page number
     */
    public function getCurrentPageNumber()
    {
        $paged = 1;

        if ( get_query_var('paged') ) {
            $paged = get_query_var('paged');
        } elseif ( get_query_var('page') ) {
            $paged = get_query_var('page');
        }

        return $paged;
    }

    /**
     * Gets the next page number
     * @return integer page number
     */
    public function getNextPageNumber()
    {
        return $this->getCurrentPageNumber() + 1;
    }

    /**
     * Gets the previous page number
     * @return integer page number
     */
    public function getPreviousPageNumber()
    {
        return $this->getCurrentPageNumber() - 1;
    }
}