<?php

namespace App\Extensions;

class MemcacheSessionHandler implements \SessionHandlerInterface
{
    /**
     * @var \Memcache Memcache driver.
     */
    private $memcache;

    /**
     * @var int Time to live in seconds
     */
    private $ttl;
    
    /**
     * Constructor.
     *
     * @param \Memcache $memcache A \Memcache instance
     * @param array $options An associative array of Memcache options
     *
     */
    public function __construct(\Memcache $memcache, array $options = array())
    {
        $this->memcache = $memcache;
        $this->ttl = isset($options['expiretime']) ? (int) $options['expiretime'] : 86400;
    }

    /**
     * {@inheritdoc}
     */
    public function open($savePath, $sessionName)
    {
        return true;
    }

    /**
     * {@inheritdoc}
     */
    public function close()
    {
        return $this->memcache->close();
    }

    /**
     * {@inheritdoc}
     */
    public function read($sessionId)
    {
        return $this->memcache->get($sessionId);
    }

    /**
     * {@inheritdoc}
     */
    public function write($sessionId, $data)
    {
        return $this->memcache->set($sessionId, $data, 0, time() + $this->ttl);
    }

    /**
     * {@inheritdoc}
     */
    public function destroy($sessionId)
    {
        return $this->memcache->delete($sessionId);
    }

    /**
     * {@inheritdoc}
     */
    public function gc($maxlifetime)
    {
        // not required here because memcache will auto expire the records anyhow.
        return true;
    }

    /**
     * Return a Memcache instance
     *
     * @return \Memcache
     */
    protected function getMemcache()
    {
        return $this->memcache;
    }
}