<?php
/** 
 * @package infra
 * @subpackage utils
 */
class kXml

{
	public static function getLibXmlErrorDescription($xml)
	{
		$errors = libxml_get_errors();
		if(!count($errors))
			return null;
			
		$lines = explode("\r", $xml);
		
		$errorsMsg = array();
		foreach($errors as $error)
		{
			$lineNum = ($error->line) - 1;
    		$line = htmlspecialchars(isset($lines[$lineNum]) ? '[' . $lines[$lineNum] . ']' : '');
			$msg = htmlspecialchars($error->message);
			$errorsMsg[] = "$msg at line $error->line $line";
		}
		return implode("\n", $errorsMsg);
	}
	
	public static function getFirstElement ( $xml_node , $element_name , $xpath_str = null )

	{

		if ( $xpath_str )

		{

			if ( isset ( $xml_node->my_xpath ) )

			{

				$xpath = $xml_node->my_xpath;

			}

			else

			{

				$xapth = new DOMXPath($xml_node);

				// store it for next time

				$xml_node->my_xpath = $xpath ;

			}

			$elem_list = $xpath->query($xpath_str ); 

		}

		else

		{

			$elem_list = $xml_node->getElementsByTagName( $element_name );

		}

		if ( $elem_list ) return $elem_list->item(0);

		else return null;

	}

	

	public static function getLastElement ( $xml_node , $element_name , $xpath_str = null )

	{

		if ( $xpath_str )

		{

			if ( isset ( $xml_node->my_xpath ) )

			{

				$xpath = $xml_node->my_xpath;

			}

			else

			{

				$xapth = new DOMXPath($xml_node);

				// store it for next time

				$xml_node->my_xpath = $xpath ;

			}

			$elem_list = $xpath->query($xpath_str ); 

		}

		else

		{

			$elem_list = $xml_node->getElementsByTagName( $element_name );

		}

		if ( $elem_list->length > 0 ) 

			return $elem_list->item($elem_list->length - 1);

		else 

			return null;

	}

	

	public static function getFirstElementAsText ( DOMDocument $xml_doc , $element_name , $xpath_str = null )

	{

		$node = self::getFirstElement($xml_doc, $element_name, $xpath_str);

		return $node ? $node->nodeValue : "";

	}

	

	public static function getLastElementAsText ( DOMDocument $xml_doc , $element_name , $xpath_str = null )

	{

		$node = self::getLastElement($xml_doc, $element_name, $xpath_str);

		return $node ? $node->nodeValue : "";

	}

		

	// manipulate the xml_dom

	// @return if the xml_doc was modified

	public static function setChildElement ( DOMDocument &$xml_doc , $parent_element , 

		$element_name , $element_value, $remove_element_if_empty_value = false  )

	{

		$modified = true;

		$elem = self::getFirstElement ( $xml_doc , $element_name );

		if ( $elem )

		{

			// element aleardy exists

			if ( empty ( $element_value  ) && $remove_element_if_empty_value  )

			{

				// new value is empty - and should remove - remove !

				$parent_element->removeChild ( $elem );

			}

			else

			{

				if( $elem->nodeValue != $element_value )

				{

					$elem->nodeValue = $element_value ;

				}

				else

				{

					$modified = false;

				}

			}

		}

		else

		{

			// element does not exist - and no reason to create it

			if ( empty ( $element_value  ) && $remove_element_if_empty_value  ) 

			{

				$modified = false;

				

			}

			else

			{

				if (!$parent_element)

				{

					debugUtils::st();

					return false;

				}

				// need to create and set the value

				$elem =  $xml_doc->createElement( $element_name , $element_value  );

				$parent_element->appendChild ( $elem );

			}

		}

		

		return $modified;

	}



	/**
	 * 
	 * Sets the given object's given property value 
	 * @param unknown_type $objectInstace
	 * @param $fieldName
	 * @param unknown_type $fieldValue
	 */
	private static function setPropertyValue(&$objectInstace, $fieldName, $fieldValue, $fieldValueType)
	{
		//set the object to this value
		if($objectInstace instanceof BaseObject)
		{
			$objectInstace->setByName($fieldName, $fieldValue);
		}
		else if($objectInstace instanceof KalturaObjectBase)
		{
			$objectInstace->$fieldName = $fieldValue;
		}
		else
		{
			//Set the attribute to its right type
			settype($fieldValue, $fieldValueType);
			$objectInstace = $fieldValue;
		}
	} 
	
	/**
	 * 
	 * Gets a xml attribute if one exists Safe method (no exception is thrown)
	 * @param unknown_type $object
	 * @param unknown_type $attribute
	 * @return string  - the attribute value if such exists
	 */
	public static function getXmlAttributeAsString($object, $attribute)
	{
	    if(isset($object[$attribute]))
	        return (string) $object[$attribute];
	}
	
	/**
	 * 
	 * Gets a xml attribute if one exists Safe method (no exception is thrown)
	 * @param unknown_type $object
	 * @param unknown_type $attribute
	 * @return int - the attribute value if such exists
	 */
	public static function getXmlAttributeAsInt($object, $attribute)
	{
	    if(isset($object[$attribute]))
	        return (string) $object[$attribute];
	}

	/**
	 * 
	 * creates the additional data from the given xml object
	 * @param SimpleXMLElement $xmlobject
	 * @return array<key => value> - the additional data as key / value pair
	 */
	public static function getAttributesAsArray(SimpleXMLElement $xmlobject)
	{
		$attributesArray = array();
		
		foreach ($xmlobject->attributes() as $attributeKey => $attributeValue) 
		{
			$attributesArray[$attributeKey] = (string)$attributeValue;
		}
		
		return $attributesArray;
	}

	/**
	 * 
	 * Opens a given xml and returns it as a simpleXMLElement
	 * @param string $xmlFilePath - the xml file path
	 * @return simpleXMLElement - the xml
	 */
	public static function openXmlFile($xmlFilePath)
	{
		try 
		{
			$simpleXML = simplexml_load_file($xmlFilePath);
		}
		catch(Exception $e)
		{
			//TODO: exception handling
			throw new Exception("Unable to load file : " . $xmlFilePath. " as xml.\n Error: " . $e->getMessage());
		}
		
		return $simpleXML;
	}
}