<?php
  
  namespace OCA\Search_Lucene\Document;
  /**
   * OpenDocument document.
   */
  abstract class OpenDocument extends \Zend_Search_Lucene_Document
  {
  	const OASIS_XPATH_TITLE    = '//dc:title';
  	const OASIS_XPATH_SUBJECT  = '//dc:subject';
  	const OASIS_XPATH_CREATOR  = '//meta:initial-creator';
  	const OASIS_XPATH_KEYWORDS = '//meta:keyword';
  	const OASIS_XPATH_CREATED  = '//meta:creation-date';
  	const OASIS_XPATH_MODIFIED = '//dc:date';
  
      /**
       * Extract metadata from document
       *
       * @param ZipArchive $package ZipArchive OpenDocument package
       * @return array Key-value pairs containing document meta data
       */
      protected function extractMetaData(\ZipArchive $package)
      {
          // Data holders
          $coreProperties = array();
  
          // Read relations and search for core properties
  		$loadEntities = libxml_disable_entity_loader(true);
  		$sxe = simplexml_load_string($package->getFromName("meta.xml"));
  		libxml_disable_entity_loader($loadEntities);
  
  		if (is_object($sxe) && $sxe instanceof \SimpleXMLElement) {
  
  			$coreProperties['title'] = $this->extractTermsFromMetadata($sxe, $this::OASIS_XPATH_TITLE);
  
  			$coreProperties['subject'] = $this->extractTermsFromMetadata($sxe, $this::OASIS_XPATH_SUBJECT);
  
  			$coreProperties['creator'] = $this->extractTermsFromMetadata($sxe, $this::OASIS_XPATH_CREATOR);
  
  			$coreProperties['keywords'] = $this->extractTermsFromMetadata($sxe, $this::OASIS_XPATH_KEYWORDS);
  
  			//replace T in date string with ' '
  			$coreProperties['created'] = str_replace('T', ' ', $this->extractTermsFromMetadata($sxe, $this::OASIS_XPATH_CREATED));
  
  			$coreProperties['modified'] = str_replace('T', ' ', $this->extractTermsFromMetadata($sxe, $this::OASIS_XPATH_MODIFIED));
  		}
  
          return $coreProperties;
      }
  
  	private function extractTermsFromMetadata(\SimpleXMLElement $sxe, $path) {
  
  		$terms = array();
  
  		foreach ($sxe->xpath($path) as $value) {
  			$terms[] = (string)$value;
  		}
  
  		return (implode(' ', $terms));
  
  	}
  
      /**
       * Determine absolute zip path
       *
       * @param string $path
       * @return string
       */
      protected function absoluteZipPath($path) {
          $path = str_replace(array('/', '\\'), DIRECTORY_SEPARATOR, $path);
          $parts = array_filter(explode(DIRECTORY_SEPARATOR, $path), 'strlen');
          $absolutes = array();
          foreach ($parts as $part) {
              if ('.' == $part) continue;
              if ('..' == $part) {
                  array_pop($absolutes);
              } else {
                  $absolutes[] = $part;
              }
          }
          return implode('/', $absolutes);
      }
  }