<?php 
/**
	TODO textinput a 4 sous enfant
	TODO language
	TODO CDATA ?
	*/
class SRSS extends DomDocument implements Iterator
{
	protected $xpath; // xpath engine
	protected $items; // array of SRSSItems
	protected $attr; // array of RSS attributes
	private $position; // Iterator position
	
	// lists of possible attributes for RSS
	protected $possibleAttr = array(
		'title'				=> 'nohtml',
		'link'				=> 'link',
		'description'		=> 'html',
		'language'			=> '',
		//'language'			=> 'lang',
		'copyright'			=> 'nohtml',
		'pubDate'			=> 'date',
		'lastBuildDate'		=> 'date',
		'category'			=> 'nohtml',
		'docs'				=> 'link',
		'cloud'				=> '',
		'generator'			=> 'nohtml',
		'managingEditor'	=> 'email',
		'webMaster'			=> 'email',
		'ttl'				=> 'int',
		'image'				=> '',
		'rating'			=> 'nohtml',
		//'textInput'			=> '',
		'skipHours'			=> 'hour',
		'skipDays'			=> 'day',
	);
	
	/**
	 * Constructor
	 */
	public function __construct()
	{
		libxml_use_internal_errors(true);
		parent::__construct();
		$this->xpath = new DOMXpath($this);
		$this->attr = array();
		$this->items = array();
		$this->position = 0;
		$this->formatOutput = true;
	}
	
	/**
	 * Destructor
	 * manage of libxml errors
	 */
	public function __destruct()
	{
		foreach (libxml_get_errors() as $error) {
			error_log($error->message, 3, 'error.log');
		}
		libxml_clear_errors();
	}
	
	/**
	 * @param $link url of the rss
	 * @return SRSS
	 */
	public static function read($link)
	{
		$doc = new SRSS;
		if(@$doc->load($link)) // We don't want the warning in case of bad XML. Let's manage it.
		{	
			$channel = $doc->getElementsByTagName('channel');
			if($channel->length == 1){ // Good URL and good RSS 
				$doc->_loadAttributes(); // loading channel properties
				$doc->getItems(); // loading all items
				return $doc;
			}
			else
			{
				throw new SRSSException('invalid file '.$link);
			}
		}
		else
		{
			throw new SRSSException('Can not open file '.$link);
		}	
	}
	
	/**
	 * @return SRSS
	 */
	public static function create()
	{
		$doc = new SRSS;
		$root = $doc->createElement('rss');
		$root->setAttribute('version', '2.0');
		$channel = $doc->createElement('channel');
		$root->appendChild($channel);
		$doc->appendChild($root);
		$doc->encoding = "UTF-8";
		$doc->generator = 'Shikiryu RSS';
		$docs = 'http://www.scriptol.fr/rss/RSS-2.0.html';
		return $doc;
	}
	
	/**
	 * setter of "image"'s channel attributes
	 * @param $url picture's url
	 * @param $title picture's title
	 * @param $link link on the picture
	 * @param $width width
	 * @param $height height
	 * @param $description description
	 */
	public function setImage($url, $title, $link, $width = 0, $height = 0, $description = '')
	{
		$channel = $this->_getChannel();
		$array = array();
		$url = SRSSTools::checkLink($url);
		$array['url'] = $url;
		$title = SRSSTools::noHTML($title);
		$array['title'] = $title;
		$link = SRSSTools::checkLink($link);
		$array['link'] = $link;
		if($width != 0)
		{
			$width = SRSSTools::checkInt($width);
			$array['width'] = $width;
		}
		if($height != 0)
		{
			$height = SRSSTools::checkInt($height);
			$array['height'] = $height;
		}
		if($description != 0)
		{
			$description = SRSSTools::noHTML($description);
			$array['description'] = $description;
		}
		if($this->image == null)
		{
			$node = $this->createElement('image');
			$urlNode = $this->createElement('url', $url);
			$titleNode = $this->createElement('title', $title);
			$linkNode = $this->createElement('link', $link);
			$node->appendChild($urlNode);
			$node->appendChild($titleNode);
			$node->appendChild($linkNode);
			if($width != 0)
			{
				$widthNode = $this->createElement('width', $width);
				$node->appendChild($widthNode);
			}
			if($height != 0)
			{
				$heightNode = $this->createElement('height', $height);
				$node->appendChild($heightNode);
			}
			if($description != '')
			{
				$descNode = $this->createElement('description', $description);
				$node->appendChild($descNode);
			}
			$channel->appendChild($node);
		}
		$this->attr['image'] = $array;
	}
	
	/**
	 * setter of "cloud"'s channel attributes
	 * @param $domain domain
	 * @param $port port
	 * @param $path path
	 * @param $registerProcedure register procedure
	 * @param $protocol protocol
	 */
	public function setCloud($domain, $port, $path, $registerProcedure, $protocol)
	{
		$channel = $this->_getChannel();
		$array = array();
		$domain = SRSSTools::noHTML($domain);
		$array['domain'] = $domain;
		$port = SRSSTools::checkInt($port);
		$array['port'] = $port;
		$path = SRSSTools::noHTML($path);
		$array['path'] = $path;
		$registerProcedure = SRSSTools::noHTML($registerProcedure);
		$array['registerProcedure'] = $registerProcedure;
		$protocol = SRSSTools::noHTML($protocol);
		$array['protocol'] = $protocol;
		if($this->cloud == null)
		{
			$node = $this->createElement('cloud');
			$node->setAttribute('domain', $domain);
			$node->setAttribute('port', $port);
			$node->setAttribute('path', $path);
			$node->setAttribute('registerProcedure', $registerProcedure);
			$node->setAttribute('protocol', $protocol);
			$channel->appendChild($node);
		}
		$this->attr['cloud'] = $array;
	}
		
	/**
	 * check if current RSS is a valid one (based on specifications)
	 * @return bool
	 */
	public function isValid()
	{
		$valid = true;
		$items = $this->getItems();
		$invalidItems = array();
		$i = 1;
		foreach($items as $item){
			if($item->isValid() === false){
				$invalidItems[] = $i;
				$valid = false;
			}
			$i++;
		}
		return ($valid && $this->title != null && $this->link != null && $this->description != null);
	}
	
	/**
	 * getter of current RSS channel
	 */
	private function _getChannel()
	{
		$channel = $this->getElementsByTagName('channel');
		if($channel->length != 1) throw new SRSSException('channel node not created, or too many channel nodes');
		return $channel->item(0);
	}
	
	/**
	 * setter of others attributes
	 */
	public function __set($name, $val)
	{
		$channel = $this->_getChannel();
		if(array_key_exists($name, $this->possibleAttr)){ 
			$flag = $this->possibleAttr[$name];
			$val = SRSSTools::check($val, $flag);
			if(!empty($val)){
				if($this->$name == null){
					$node = $this->createElement($name, $val);
					$channel->appendChild($node);
				}
				$this->attr[$name] = $val;
			}
		}else{
			throw new SRSSException($name.' is not a possible item');
		}
	}
	
	/**
	 * getter of others attributes
	 */
	public function __get($name)
	{
		if(isset($this->attr[$name]))
			return $this->attr[$name];
		$channel = $this->_getChannel();
		if(array_key_exists($name, $this->possibleAttr)){ 
			$tmp = $this->xpath->query('//channel/'.$name);
			if($tmp->length != 1) return;
			return $tmp->item(0)->nodeValue;
		}else{
			throw new SRSSException($name.' is not a possible value.');
		}
	}
	
	/**
	 * add a SRSS Item as an item into current RSS
	 * @param SRSSItem $item
	 */
	public function addItem(SRSSItem $item)
	{
		$node = $this->importNode($item->getItem(), true);
		$channel = $this->_getChannel();
		$channel->appendChild($node);
	}
	
	/**
	 * rewind from Iterator
	 */
	public function rewind() {
        $this->position = 0;
    }

	/**
	 * current from Iterator
	 */
    public function current() {
        return $this->items[$this->position];
    }

	/**
	 * key from Iterator
	 */
   public  function key() {
        return $this->position;
    }

	/**
	 * next from Iterator
	 */
   public  function next() {
        ++$this->position;
    }

	/**
	 * valid from Iterator
	 */
   public  function valid() {
        return isset($this->items[$this->position]);
    }	
	
	/**
	 * getter of 1st item
	 * @return SRSSItem
	 */
	public function getFirst()
	{
		return $this->getItem(1);
	}
	
	/**
	 * getter of last item
	 * @return SRSSItem
	 */
	public function getLast()
	{
		$items = $this->getItems();
		return $items[count($items)-1];
	}
	
	/**
	 * getter of an item
	 * @param $i int
	 * @return SRSSItem
	 */
	public function getItem($i)
	{
		$i--;
		return isset($this->items[$i]) ? $this->items[$i] : null;
	}
	
	/**
	 * getter of all items
	 * @return array of SRSSItem
	 */
	public function getItems()
	{
		$channel = $this->_getChannel();
		$item = $channel->getElementsByTagName('item');
		$length = $item->length;
		$items = array();
		if($length > 0){
			for($i = 0; $i < $length; $i++)
			{
				$this->items[$i] = new SRSSItem($item->item($i));
			}
		}
		return $this->items;
	}
	
	/**
	 * display XML
	 * see DomDocument's docs
	 */
	public function show()
	{
		return $this->saveXml();
	}
	
	
	/**
	 * putting all RSS attributes into the object
	 */
	private function _loadAttributes()
	{
		$channel = $this->_getChannel();
		foreach($channel->childNodes as $child)
		{
			if($child->nodeType == XML_ELEMENT_NODE && $child->nodeName != 'item')
			{
				$this->{$child->nodeName} = $child->nodeValue;
			}
		}
	}
	
	/**
	 * transform current object into an array
	 * @return array
	 */
	public function toArray()
	{
		$doc = array();
		foreach($this->attr as $attrName => $attrVal)
		{
			$doc[$attrName] = $attrVal;
		}
		foreach($this->getItems() as $item)
		{
			$doc['items'][] = $item->toArray();
		}
		return $doc;
	}
}

class SRSSItem extends DomDocument
{

	protected $node; // item node
	protected $attr; // item's properties

	// possible properties' names
	protected $possibilities = array(
		'title'			=> 'nohtml',
		'link'			=> 'link',
		'description'	=> 'html',
		'author'		=> 'email',
		'category'		=> 'nohtml',
		'comments'		=> 'link',
		'enclosure'		=> '',
		'guid'			=> 'nohtml',
		'pubDate'		=> 'date',
		'source'		=> 'link',
	);
	
	/** 
	 * Constructor
	 * @param DomElement $node
	 */
	public function __construct($node = null)
	{
		parent::__construct();
		if($node instanceof DOMElement) $this->node = $this->importNode($node, true);
		else $this->node = $this->importNode(new DomElement('item'));
		$this->_loadAttributes();
	}
	
	/**
	 * putting all item attributes into the object
	 */
	private function _loadAttributes()
	{
		foreach($this->node->childNodes as $child)
		{
			if($child->nodeType == XML_ELEMENT_NODE && $child->nodeName != 'item')
			{
				$this->{$child->nodeName} = $child->nodeValue;
			}
		}
	}
	
	/**
	 * getter of item DomElement
	 */
	public function getItem()
	{
		$this->appendChild($this->node);
		return $this->getElementsByTagName('item')->item(0);
	}
	
	/**
	 * setter for enclosure's properties
	 * @param $url string url
	 * @param $length int length
	 * @param $type string type
	 */
	public function setEnclosure($url, $length, $type)
	{
		$array = array();
		$url = SRSSTools::checkLink($url);
		$array['url'] = $url;
		$length = SRSSTools::checkInt($length);
		$array['length'] = $length;
		$type = SRSSTools::noHTML($type);
		$array['type'] = $type;
		if($this->enclosure == null)
		{
			$node = $this->createElement('enclosure');
			$node->setAttribute('url', $url);
			$node->setAttribute('length', $length);
			$node->setAttribute('type', $type);
			$this->node->appendChild($node);
		}
		$this->attr['enclosure'] = $array;
	}
	
	/**
	 * check if current item is valid (following specifications)
	 * @return bool
	 */
	public function isValid()
	{
		return $this->description != null ? true : false;
	}
	
	/**
	 * main setter for properties
	 */
	public function __set($name, $val)
	{
		if(array_key_exists($name, $this->possibilities))
		{
			$flag = $this->possibilities[$name];
			if($flag != '')
				$val = SRSSTools::check($val, $flag);
			if(!empty($val)){
				if($this->$name == null){
					$this->node->appendChild(new DomElement($name, $val));
				}
				$this->attr[$name] = $val;
			}
		}
		else
		{
			throw New SRSSException($name.' is not a possible item : '.print_r($this->possibilities));
		}
	}
	
	/**
	 * main getter for properties
	 */
	public function __get($name)
	{
		if(isset($this->attr[$name]))
			return $this->attr[$name];
		if(array_key_exists($name, $this->possibilities))
		{
			$tmp = $this->node->getElementsByTagName($name);
			if($tmp->length != 1) return;
			return $tmp->item(0)->nodeValue;
		}
		else
		{
			throw New SRSSException($name.' is not a possible item : '.print_r($this->possibilities));
		}
	}
	
	/**
	 * display item's XML
	 * see DomDocument's docs
	 */
	public function show()
	{
		return $this->saveXml();
	}
	
	/** 
	 * transform current item's object into an array
	 * @return array
	 */
	public function toArray()
	{
		$infos = array();
		foreach($this->attr as $attrName => $attrVal)
		{
			$infos[$attrName] = $attrVal;
		}
		return $infos;
	}
}

class SRSSException extends Exception 
{
	public function __construct($msg)
	{
		parent :: __construct($msg);
    }  
	
	public function getError()
	{
        $return  = 'Une exception a été générée : <strong>Message : ' . $this->getMessage() . '</strong> à la ligne : ' . $this->getLine();
        return $return;
    } 
} 

class SRSSTools
{	
	public static function check($check, $flag)
	{
		switch($flag){
			case 'nohtml':
				return self::noHTML($check);
				break;
			case 'link':
				return self::checkLink($check);
				break;
			case 'html':
				return self::HTML4XML($check);
				break;
			/*case 'lang':
				return self::noHTML($check);
				break;*/
			case 'date':
				return self::getRSSDate($check);
				break;
			case 'email':
				return self::checkEmail($check);
				break;
			case 'int':
				return self::checkInt($check);
				break;
			case 'hour':
				return self::checkHour($check);
				break;
			case 'day':
				return self::checkDay($check);
				break;
			case '':
				return $check;
				break;
			default:
				throw new SRSSEXception('flag '.$flag.' does not exist.');
		}
	}
	
	/**
	 * format the RSS to the wanted format
	 * @param $format string wanted format
	 * @param $date string RSS date
	 * @return date
	 */
	public static function formatDate($format, $date)
	{
		return date($format, strtotime($date));
	}
	
	/**
	 * format a date for RSS format
	 * @param $date string date to format
	 */
	public static function getRSSDate($date)
	{
		if(strtotime($date) !==false)
			return date("D, d M Y H:i:s T", strtotime($date));
		else
		{
			list($j, $m, $a) = explode('/', $date);
			return date("D, d M Y H:i:s T", strtotime($a.'-'.$m.'-'.$j));
		}
	}
	
	/** 
	 * check if it's an url
	 * @param $check string to check
	 * @return the filtered data, or FALSE if the filter fails. 
	 */
	public static function checkLink($check)
	{
		return filter_var($check, FILTER_VALIDATE_URL);
	}
	
	/** 
	 * make a string XML-compatible
	 * @param $check string to format
	 * @return formated string
	 * TODO CDATA ?
	 */
	public static function HTML4XML($check)
	{
		return htmlspecialchars($check);
	}
	
	/**
	 * delete html tags
	 * @param $check string to format
	 * @return formated string
	 */
	public static function noHTML($check)
	{
		return strip_tags($check);
	}
	
	/** 
	 * check if it's a day (in RSS terms)
	 * @param $check string to check
	 * @return theday, or empty string
	 */
	public static function checkDay($check)
	{
		$possibleDay = array('monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday');
		return in_array(strtolower($check), $possibleDay) ? $check : '';
	}
	
	/** 
	 * check if it's an email
	 * @param $check string to check
	 * @return the filtered data, or FALSE if the filter fails. 
	 */
	public static function checkEmail($check)
	{
		return filter_var($check, FILTER_VALIDATE_EMAIL);
	}
	
	/** 
	 * check if it's an hour (in RSS terms)
	 * @param $check string to check
	 * @return the filtered data, or FALSE if the filter fails. 
	 */
	public static function checkHour($check)
	{
		$options = array(
			'options' => array(
				'default' => 0,
				'min_range' => 0,
				'max_range' => 23
			)
		);
		return filter_var($check, FILTER_VALIDATE_INT, $options);
	}
	
	/** 
	 * check if it's an int
	 * @param $check int to check
	 * @return the filtered data, or FALSE if the filter fails. 
	 */
	public static function checkInt($check)
	{
		return filter_var($check, FILTER_VALIDATE_INT);
	}
}