<?php
require_once 'Phreamp/Loader.php';
require_once 'Phreamp/Map/Identity.php';
require_once 'Phreamp/Filter/Abstract.php';

/**
 * Filter factory and chain filter
 *
 * @category Phreamp
 * @package Phreamp_Filter
 */
class Phreamp_Filter extends Phreamp_Filter_Abstract
{
	/**
	 * An identity map storing the filters
	 *
	 * @var Phreamp_Map_Identity
	 */
	private $_filterIdentityMap;
	
	/**
	 * Gets an instance of a filter by its name.
	 *
	 * @param string $name
	 * @return Phreamp_Filter_Interface
	 */
	static public function factory($name)
	{
		$class = 'Phreamp_Filter_' . $name;
		
		Phreamp_Loader::load($class);
		
		return new $class;
	}
	
	/**
	 * @param array $filters
	 */
	public function __construct(array $filters = array())
	{
		$this->_filterIdentityMap = new Phreamp_Map_Identity(array(), 'Phreamp_Filter_Interface');
		$this->addFilters($filters);
	}
	
	/**
	 * Adds an array of filters to the chain
	 *
	 * @param array $filters
	 * @return Phreamp_Filter
	 */
	public function addFilters(array $filters = array())
	{
		$this->_filterIdentityMap->addArray($filters);
		return $this;
	}
	
	/**
	 * Adds a filter to the chain
	 *
	 * @param Phreamp_Filter_Interface $filter
	 * @return Phreamp_Filter
	 */
	public function addFilter(Phreamp_Filter_Interface $filter)
	{
		$this->_filterIdentityMap->add($filter);
		return $this;
	}
	
	/**
	 * Checks if a filter is in the chain
	 *
	 * @param scalar|Phreamp_Filter_Interface $item
	 * @return boolean
	 */
	public function inChain($item)
	{
		$id = $item instanceof Phreamp_Filter_Interface ? $item->getId() : $item;
		
		return $this->_filterIdentityMap->contains($id);
	}
	
	/**
	 * Removes a filter from the chain.
	 *
	 * @param scalar|Phreamp_Filter_Interface $item
	 * @return Phreamp_Filter
	 */
	public function removeFilter($item)
	{
		$id = $item instanceof Phreamp_Filter_Interface ? $item->getId() : $item;
		$this->_filterIdentityMap->remove($id);
		
		return $this;
	}
	
	/**
	 * Runs the value through all the registered filters
	 *
	 * @param mixed $value
	 * @return mixed
	 */
	public function filter($value)
	{
		foreach ($this->_filterIdentityMap as $filter) {
			$value = $filter->filter($value);
		}
		
		return $value;
	}
}