<?php

namespace CoreBundle\Listener;

use CoreBundle\Entity\ImageUrlInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\RequestStack;
use JMS\Serializer\EventDispatcher\ObjectEvent;
use JMS\Serializer\EventDispatcher\EventSubscriberInterface;
use Vich\UploaderBundle\Templating\Helper\UploaderHelper;

class SerializationSubscriber implements EventSubscriberInterface
{
    /** @var RequestStack */
    protected $requestStack;

    /** @var Request */
    private $request;

    /** @var UploaderHelper */
    private $uploadHelper;

    private $imagine;

    /**
     * SerializationSubscriber constructor.
     * @param RequestStack $requestStack
     * @param UploaderHelper $uploadHelper
     * @param $imagine
     */
    public function __construct(RequestStack $requestStack, UploaderHelper $uploadHelper, $imagine)
    {
        $this->requestStack = $requestStack;
        $this->request = $requestStack->getCurrentRequest();
        $this->uploadHelper = $uploadHelper;
        $this->imagine = $imagine;
    }

    /**
     * @inheritdoc
     */
    static public function getSubscribedEvents()
    {
        return [
            [
                'event' => 'serializer.pre_serialize',
                'method' => 'onPreSerialize'
            ]
        ];
    }

    public function onPreSerialize(ObjectEvent $event)
    {
        $object = $event->getObject();

        if ($object instanceof ImageUrlInterface) {
            if ($this->request->headers->has('x-screen-density')) {
                $density = intval($this->request->headers->get('x-screen-density'));
                $imageUrl = $this->imagine->getBrowserPath($this->uploadHelper->asset($object, 'image'), $this->getFilterByDensity($density));
            } else {
                $imageUrl = $this->imagine->getBrowserPath($this->uploadHelper->asset($object, 'image'), 'normal');
            }

            $object->setImageUrl($imageUrl);
        }

        return $object;
    }

    private function getFilterByDensity(int $density)
    {
        switch ($density) {
            case 1:
                return 'small';
            case 2:
                return 'medium';
            case 3:
                return 'normal';
            default:
                return 'normal';
        }
    }
}