SkyEng Test

<?php
declare(strict_types=1);

namespace src\Integration;

interface DataProviderInterface
{
    public function get(array $request) : array;
}

<?php
declare(strict_types=1);

namespace src\Integration;

class DataProvider implements DataProviderInterface
{
    protected $host;
    protected $user;
    protected $password;

    /**
     * @param $host
     * @param $user
     * @param $password
     */
    public function __construct(string $host, string $user, string $password)
    {
        $this->host = $host;
        $this->user = $user;
        $this->password = $password;
    }

    /**
     * @param array $request
     *
     * @return array
     */
    public function get(array $request) : array
    {
        // returns a response from external service
    }
}

<?php
declare(strict_types=1);

namespace src\Decorator;

use Exception;
use Psr\Cache\CacheItemPoolInterface;
use Psr\Log\LoggerInterface;
use src\Integration\DataProviderInterface;

class DataProviderCachingDecorator implements DataProviderInterface
{
    protected $provider;
    protected $cache;
    protected $logger;

    public function __construct(DataProviderInterface $provider, CacheItemPoolInterface $cache)
    {
        $this->provider = $provider;
        $this->cache = $cache;
    }

    public function setLogger(LoggerInterface $logger)
    {
        $this->logger = $logger;
    }

    public function get(array $request) : array
    {
        $result = [];
        try {
            $cacheKey = $this->getCacheKey($request);
            $cacheItem = $this->cache->getItem($cacheKey);
            if ($cacheItem->isHit()) {
                $result = $cacheItem->get();
            } else {
                $result = $this->provider->get($request);
                $cacheItem
                    ->set($result)
                    ->expiresAfter(3600 * 24); // expires after a day
            }
        } catch (Exception $e) {
            if ($this->logger) {
                $this->logger->critical(implode(', ', [ __FILE__, __LINE__, $e->getMessage() ]));
            } else {
                throw $e;
            }
        }
        return $result;
    }

    public function getCacheKey(array $input)
    {
        return md5(json_encode($input));
    }
}