<?php

namespace App\Service;

use App\Entity\Rider;

use Doctrine\ORM\EntityManagerInterface;

use CrEOF\Spatial\PHP\Types\Geometry\Point;

class RiderTracker
{
    const RIDER_PREFIX_KEY        = 'rider.location';

    protected $em;
    protected $redis;

    public function __construct(EntityManagerInterface $em, RedisClientProvider $redis_client)
    {
        $this->em = $em;
        $this->redis = $redis_client->getRedisClient();
    }

    protected function getRiderKey($rider_id)
    {
        return self::RIDER_PREFIX_KEY . '.' . $rider_id;
    }

    public function getRiderLocation($rider_id)
    {
        $coordinates = new Point(0,0);
        $key = $this->getRiderKey($rider_id);

        // check redis cache for rider information
        if (($this->redis->hexists($key, 'longitude')) && 
            ($this->redis->hexists($key, 'latitude')))
        {
            $long = $this->redis->hget($key, 'longitude');
            $lat = $this->redis->hget($key, 'latitude');

            return new Point($long, $lat);
        }

        // not in cache, get hub
        $rider = $this->em->getRepository(Rider::class)->find($rider_id);
        $hub = $rider->getHub();

        // no hub
        // TODO: return valid coordinate
        if ($hub == null)
            return new Point(0, 0);

        return $hub->getCoordinates();
    }
}