<?php

namespace FOQ\ElasticaBundle\Transformer;

use RuntimeException;

/**
 * AutomaticObjectToArrayTransformer
 * Tries to convert objects by generating getters
 * based on the required keys
 */
class ObjectToArrayAutomaticTransformer implements ObjectToArrayTransformerInterface
{
    /**
     * Transforms an object into an array having the required keys
     *
     * @param object $object the object to convert
     * @param array $requiredKeys the keys we want to have in the returned array
     * @return array
     **/
    public function transform($object, array $requiredKeys)
    {
        $class = get_class($object);
        $array = array();
        foreach ($requiredKeys as $key) {
            $getter = 'get'.ucfirst($key);
            if (!method_exists($class, $getter)) {
                throw new RuntimeException(sprintf('The getter %s::%s does not exist', $class, $getter));
            }
            $array[$key] = $object->$getter();
        }

        return $array;
    }
}