<?php
/*
Author: 		Riccardo Di Dato
Creation Date:	08/gen/2016
*/

abstract class Constrained implements ConstrainedInterface{
	public static $SET_BEHAVIOURS = array(
			self::SET_BEHAVIOUR_NORMAL => array("label"=>"Normal"),
			self::SET_BEHAVIOUR_IGNORE => array("label"=>"Ignore"),
			self::SET_BEHAVIOUR_THROW => array("label"=>"Throw Exception")
	);
	
	public static $UNSET_BEHAVIOURS = array(
			self::UNSET_BEHAVIOUR_NORMAL => array("label"=>"Normal"),
			self::UNSET_BEHAVIOUR_IGNORE => array("label"=>"Ignore"),
			self::UNSET_BEHAVIOUR_THROW => array("label"=>"Throw Exception")
	);
	
	public static $GET_BEHAVIOURS = array(
			self::GET_BEHAVIOUR_NORMAL => array("label"=>"Normal"),
			self::GET_BEHAVIOUR_EMPTY => array("label"=>"Empty"),
			self::GET_BEHAVIOUR_THROW => array("label"=>"Throw Exception")
	);
	
	
	private $constraints = array();
	
	public function __construct(){
		$this->createSetBehaviour("*", self::SET_BEHAVIOUR_NORMAL);
		$this->createGetBehaviour("*", self::GET_BEHAVIOUR_NORMAL);
		$this->createUnsetBehaviour("*", self::UNSET_BEHAVIOUR_NORMAL);
	}
	
	public function createSetBehaviour($key, $behaviour, ConstrainedBehaviour $callbackClass = null){
// 		if (strpos($key, ".")!== false){
// 			$matches = array();
// 			if (!preg_match("/^([^.]+)\.(.+)$/", $key, $matches)){
// 				throw new CoreException("Invalid key format passed to ".get_class($this)."::createSetBehaviour ($key)");
// 			}
// 			$myKey = $matches[1];
// 			$childKey = $matches[2];
			
// 			$child = $this->getInternal($myKey);
// 			if (is_null($child)){
// 				$this->setInternal($myKey, new ConstrainedMemoryObject());
// 			}
// 			if ($child instanceof Constrained){
// 				$child->createSetBehaviour($childKey, $behaviour, $callbackClass);
// 			}
// 			else {
// 				throw new CoreException("Invalid key passed to ".get_class($this)."::createSetBehaviour. Setting a child constraint on a non constrained element.");
// 			}
// 		}
// 		else {
			if (!array_key_exists($behaviour, self::$SET_BEHAVIOURS)){
				throw new CoreException("Invalid behaviour parameter passed to ".get_class($this)."::createSetBehaviour ($behaviour)");
			}
				
			if (!array_key_exists($key,$this->constraints)){
				$this->constraints[$key] = new stdClass();
			}
			$this->constraints[$key]->set = new stdClass();
			$this->constraints[$key]->set->behaviour = $behaviour;
			$this->constraints[$key]->set->callbackClass = $callbackClass;
// 		}
	}
	
	public function createGetBehaviour($key, $behaviour, ConstrainedBehaviour $callbackClass = null){
		if (!array_key_exists($behaviour, self::$GET_BEHAVIOURS)){
			throw new CoreException("Invalid behaviour parameter passed to ".get_class($this)."::createGetBehaviour ($behaviour)");
		}
		if (!array_key_exists($key,$this->constraints)){
			$this->constraints[$key] = new stdClass();
		}
		$this->constraints[$key]->get = new stdClass();
		$this->constraints[$key]->get->behaviour = $behaviour;
		$this->constraints[$key]->get->callbackClass = $callbackClass;
	}
	
	public function createUnsetBehaviour($key, $behaviour, ConstrainedBehaviour $callbackClass = null){
		if (!array_key_exists($behaviour, self::$UNSET_BEHAVIOURS)){
			throw new CoreException("Invalid behaviour parameter passed to ".get_class($this)."::createUnsetBehaviour ($behaviour)");
		}
		if (!array_key_exists($key,$this->constraints)){
			$this->constraints[$key] = new stdClass();
		}
		$this->constraints[$key]->unset = new stdClass();
		$this->constraints[$key]->unset->behaviour = $behaviour;
		$this->constraints[$key]->unset->callbackClass = $callbackClass;
	}
	
	public function setConstrained($key, $value){
		try {
			$constraint = $this->constraints["*"]->set;
			if (array_key_exists($key, $this->constraints) && property_exists($this->constraints[$key], "set")){
				$constraint = $this->constraints[$key]->set;
			}
			$constraint = $this->constraints[$key]->set;
			switch ($constraint->behaviour){
				case self::SET_BEHAVIOUR_NORMAL:
					$this->setInternal($key, $value);
					break;
				case self::SET_BEHAVIOUR_THROW:
					throw new ConstraintException("set",$key,$value);
					break;
				case self::SET_BEHAVIOUR_IGNORE:
				default:
					break;
			}
			if (property_exists($constraint, "callbackClass") && !is_null($constraint->callbackClass)){
				$this->setBase($constraint->callbackClass->executeSetCallback($this->getBase(), $key, $value));
			}
		}
		catch (ConstraintException $cex){
			throw $this->addPathToChildException($cex);
		}
	}
	
	public function getConstrained($key){
		try {
			$rval = null;
			if (array_key_exists($key, $this->constraints) && property_exists($this->constraints[$key], "get")){
				$constraint = $this->constraints[$key]->get;
				switch ($constraint->behaviour){
					case self::GET_BEHAVIOUR_THROW:
						throw new ConstraintException("get",$key);
						break;
					case self::GET_BEHAVIOUR_NORMAL:
						$rval = $this->getInternal($key);
						break;
					case self::GET_BEHAVIOUR_EMPTY:
					default:
						break;
				}
				if (property_exists($constraint, "callbackClass") && !is_null($constraint->callbackClass)){
					$rval = $constraint->callbackClass->executeGetCallback($this->getBase(), $key);
				}
			}
			else {
				$rval = $this->getInternal($key);
			}
			return $rval;
		}
		catch (ConstraintException $cex){
			throw $this->addPathToChildException($cex);
		}
	}
	
	public function unsetConstrained($key){
		try {
			if (array_key_exists($key, $this->constraints) && property_exists($this->constraints[$key], "unset")){
				$constraint = $this->constraints[$key]->unset;
				switch ($constraint->behaviour){
					case self::UNSET_BEHAVIOUR_NORMAL:
						$this->unsetInternal($key);
						break;
					case self::UNSET_BEHAVIOUR_THROW:
						throw new ConstraintException("unset",$key);
						break;
					case self::UNSET_BEHAVIOUR_IGNORE:
					default:
						break;
				}
				if (property_exists($constraint, "callbackClass") && !is_null($constraint->callbackClass)){
					$this->setBase($constraint->callbackClass->executeUnsetCallback($this->getBase(), $key));
				}
			}
			else {
				$this->unsetInternal($key);
			}
		}
		catch (ConstraintException $cex){
			throw $this->addPathToChildException($cex);
		}
	}
	
	protected function replicateConstraints(Constrained $oth){
		$this->constraints = clone $oth->constraints;
	}
	
	protected abstract function addPathToChildException($myKey, ConstraintException $ex);
	protected abstract function setInternal($key,$value);
	protected abstract function getInternal($key);
	protected abstract function unsetInternal($key);
	
	protected abstract function setBase($base);
	
}

?>