<?php
namespace Utility;


/**
 * Central cache functionality.
 * @author andre.fourie
 *
 */
class Cache
{

 /**
  * @var \Memcache
  */
 static protected $cache = null;
 /**
  * @var boolean
  */
 static protected $cacheKick = true;
 /**
  * @var array
  */
 static private $loadedFromCache = array();


 /**
  * Store data in cache.
  * @param string $key
  * @param unknown $value
  * @param integer $ttl
  * @return boolean
 */
 static public function store($key, $value, $ttl = 0)
 {
  if (is_null(self::$cache))
  {
   self::$cache = new \Memcache();
   self::$cache->pconnect('localhost', 11211);
  }
  return self::$cache->set($key, $value, 0, $ttl);
 }

 /**
  * Fetch data from cache.
  * @param string $key
  * @param unknown $default
  * @return unknown
  */
 static public function fetch($key, $default = false)
 {
  if (is_null(self::$cache))
  {
   self::$cache = new \Memcache();
   self::$cache->pconnect('localhost', 11211);
  }
  $value = self::$cache->get($key);
  return false !== $value
   ? $value
   : $default;

 }

 /**
  * Delete cached item.
  * @param string $key
  */
 static public function delete($key)
 {
  if (is_null(self::$cache))
  {
   self::$cache = new \Memcache();
   self::$cache->pconnect('localhost', 11211);
  }
  self::$cache->delete($key);
 }

 /**
  * Load a doctrine entity from cache. If not found in cache it will load from db and store in cache.
  * @param string $entityName
  * @param integer $id
  * @param \Doctrine\ORM\EntityManager $em
  * @param number $ttl
  * @param number $depth
  * @return unknown
  */
 static public function fetchEntity($entityName, $id, \Doctrine\ORM\EntityManager $em, $ttl = 300, $depth = 1)
 {
  if (isset(self::$loadedFromCache[$entityName . $id]))
  {
   $record =  $em->getRepository($entityName)->find($id);
   return !is_null($record)
    ? $record->toArray()
    : null;
  }
  $cachedEntity = self::fetch($entityName . '::' . $id);
  if (false !== $cachedEntity)
  {
   return $cachedEntity;
  }

  $entity = $em->getRepository($entityName)->find($id);
  if (!is_null($entity))
  {
   $entity = $entity->toArray();
   self::store($entityName . '::' . $id, $entity, $ttl);
   self::$loadedFromCache[$entityName . $id] = true;
  }
  return $entity;
 }

}