<?
class XMLDB{
	
	// Path and name to the file
	protected $_file;
	
	// Primary key
	protected $_primaryKey;
	
	// XPATH
	protected $_xpath;
	
	// Content of the XML DB File
	protected $_doc;
	
	public function __construct($file, $pk = "id"){
		ini_set("display_errors", "off"); 
		ini_set("log_errors", "on");
		ini_set('error_log', $_SERVER['DOCUMENT_ROOT'].'/test/XMLDB/XMLDB.log');
		$this->_primaryKey = $pk;
		$this->_file = $file;
		$this->_doc = new DOMDocument;
		if(@$this->_doc->load($this->_file))
			$this->_xpath = new DOMXpath($this->_doc);
		else{
			$this->_file = $file;
			$this->_doc = null;
			$this->xpath = null;
		}
	}
	
	public function isLoaded(){
		if($this->_doc != null)
			return true;
		else
			return false;
	}
	
	public function setPrimaryKey($pk){
		$this->_primaryKey = $pk;
	}
	
	public function getPrimaryKey(){
		return $this->_primaryKey;
	}
	
	public function getXPath(){
		return $this->_xpath;
	}
	
	/**
	 * Saving the DB file
	 */
	 public function save(){
		if($this->_doc != null && $this->_file != null){
			$this->_doc->save($this->_file);
			return true;
		}else{
			return false;
		}
	 }
	
	/**
	 * Allows you to get an array of the node you're looking for based on a "where" search thanks to child or attribute value
	 * @param $from string Name of the node you're looking for
	 * @param $id string value of the primary key
	 * @param $childs array name/value of the child node
	 * @param $attributes array name/value of the attribute
	 * @return array
	 */
	// TODO other format
	public function selectNode($from, $id = null, $attributes = null, $childs = null, $format = 'array'){
		if (!$from) {
			throw new Exception('uhoh, no "where" statement?');
		}
		if($id != null){
			$attribute .= '[@' . $this->_primaryKey . ' = "' . $id . '"]';
		}
		if($attributes != null){
			foreach($attributes as $attributeName=>$attributeValue)
				$attribute .= '[@' . $attributeName . ' = "' . $attributeValue . '"]';
		}
		if($childs != null){
			foreach($childs as $childName=>$childValue)
				$child .= '/' . $childName . '[.="' . $childValue . '"]';
		}
		$request = $this->_xpath->query('//'.$from.$attribute.$child);
		$requestLength = $request->length;
		if($format == "array"){
			//$return = array('length'=>$requestLength, 'request'=>'//'.$from.$attribute.$child);
			foreach($request as $element){
				if($childName != null && $childValue != null)
				$element = $element->parentNode;
				$elementValue = $element->attributes->item(0)->value;
				$return[$elementValue]['attributes'] = array();
				$return[$elementValue]['childs'] = array();
			
				//Retrieving Attributes
				$attributes = $element->attributes;
				$length = $attributes->length;
				for ($i = 1; $i <= $length; $i++) {
					$return[$elementValue]['attributes'][$attributes->item($i)->name] = $attributes->item($i)->value;
				}
			
				// Retrivieving childs
				$nodes = $element->childNodes;
				$length = $nodes->length;
				for ($i = 1; $i <= $length; $i++) {
					$return[$elementValue]['childs'][$nodes->item($i)->nodeName] = $nodes->item($i)->nodeValue;
				}
			}
		}else if($format == "node"){
			$return = $request;
		}
		return $return;
	}
	
	/**
	 * Allows you to insert a node into your DB thanks to an array
	 * @param $node array 
	 * @param $where string in which node you want to put it. By default, the root of the xml file
	 * @param $position string 'before' or 'after'
	 * @return bool
	 */
	
	// TODO other $where and $position
	public function insertNode($node, $where = null, $position = null){
		if(!is_array($node) || !isset($node['name']))
			return false;
			
		// Creating the node from an array
		$element = $this->_doc->createElement($node['name']);
		if(isset($node['attributes'])){
			foreach($node['attributes'] as $attributeName=>$attributeValue){
				$element->setAttribute($attributeName, $attributeValue);
			}		
		}
		if(isset($node['childs'])){
			foreach($node['childs'] as $childName=>$childValue){
				$newElement = $this->_doc->createElement($childName, $childValue);
				$element->appendChild($newElement);
			}	
		}
		
		// Inserting the node into the DB
		if($where == null){
			$this->_doc->firstChild->appendChild($element);
		}
		return $this->save();
	}
	
	/**
	 * 
	 * @param $node string 
	 * @param $oldAttribute string name of the attribute you want to change
	 * @param $newAttribute array name/value of the attribute you want to add
	 * @param $forceInsert bool 
	 * @return bool
	 */
	public function updateNodeAttribute($node, $oldAttribute, $newAttribute, $forceInsert = false){
		$request = $this->selectNode($node, null, array($oldAttribute[0]=>$oldAttribute[1]), null, 'node');
		if($request->length == 1){	
			if(!$forceInsert){
				$request->item(0)->setAttribute($oldAttribute[0],$newAttribute[1]);
			}else{
				$request->item(0)->setAttribute($newAttribute[0],$newAttribute[1]);
			}
			return $this->save();
		}
		else
			return false;
	}
	
	/**
	 * 
	 * @param $node string 
	 * @param $value string new value of the node
	 * @return bool
	 */
	public function updateNodeValue($node, $attribute = null, $child = null, $value){
		$request = $this->selectNode($node, null, array($attribute[0]=>$attribute[1]), null, 'node');
		//$request = $this->_xpath->query('//'.$node.'[@' . $attribute[0] . ' = "' . $attribute[1] . '"]');
		if($request->length == 1){			
			$request = $request->item(0);
			$newText = new DOMText($value);
			$request->removeChild($request->firstChild);
			$request->appendChild($newText);
			return $this->save();
		}
		else
			return false;
	}
	
	
	public function deleteNode($node, $id = null, $attributes = null){
		if($id != null && $attributes != null)
			return false;
		if($id != null)
			$request = $this->selectNode($node, $id, null, null, 'node')->item(0);
		if($attributes != null)
			$request = $this->selectNode($node, null, array($attribute[0]=>$attribute[1]), null, 'node')->item(0);
		$request->parentNode->removeChild($request);
		return $this->save();
	}
	
	
	
	
	
	
	
	
}