<?php
/*
	product: p_id(int)
	product_option: po_id,name
	product_option_value: pov_id(int),p_id(int),po_id(int),enable(boolean)
*/
class product{ 
	const PRODUCT_NOT_EXISTS = -1;
	const PRODUCT_CREATED_BUT_NOT_SAVED = -2;	
	
	protected $options = array();
	protected $product_id = PRODUCT_NOT_EXISTS;
	protected $important_options = array('p_id','title','price','addtimestamp','savetimestamp');
	
	public static function add(){
		$product_id = PRODUCT_CREATED_BUT_NOT_SAVED;
	}
	
	public static function get($id){
		$product_id = $id;
		if(!$this->manage('exists')){
			$product_id = PRODUCT_NOT_EXISTS;
		}
		return false;
	}
	
	public function __construct($id){
		if($id == PRODUCT_CREATED_BUT_NOT_SAVED) $this->add();
		if($id != PRODUCT_NOT_EXISTS){
			$this->get($id);
		}else{
			return false;
		}
	}
	
	
	private static function manage($action)
	{
		if($action == 'delete'){
			$this->product_id = PRODUCT_NOT_EXISTS;
		}
		if($action == 'exists'){
			if($this->product_id != PRODUCT_NOT_EXISTS){
				return true;
			}else{
				return false;
			}
		}
		if($action == 'save'){
		}
	}

	public static function option($action,$key,$value = ''){	
		if($action == 'save'){
			$this->options[$key] = $value;
		}
		if($action == 'get'){
			if($this->option('exists',$key)){
				return $this->options[$key];
			}
			return false;
		}
		if($action == 'remove'){
			if (in_array($key, $this->important_options)){
				return false;
			}
			if(isset($this->options)){	
				unset($this->options[$key]);
				return true;
			}else{
				return false;
			}
		}
		if($action == 'exists'){
			if(isset($this->options[$key])){
				return true;
			}else{
				return false;
			}
		}
	}
	
	private static function output($type){
		if($type == 'json') return json_encode($this->options);
		if($type == 'array') return $this->options;
		if($type == 'xml')
		{
			if(class_exists('SimpleXMLElement'))
			{
				$xml = new SimpleXMLElement('<root/>');
				array_walk_recursive($this->options, array ($xml, 'addChild'));
				print $xml->asXML();
			}
			return false;
		}
	}
}

$p_object = new product(1);

?>

if(!$this->manage('exists'))