<?php

  namespace Sabre\CardDAV;
  
  use Sabre\DAV;

  use Sabre\VObject;
  
  /**
   * VCF Exporter
   *
   * This plugin adds the ability to export entire address books as .vcf files.
   * This is useful for clients that don't support CardDAV yet. They often do
   * support vcf files.
   *

   * @copyright Copyright (C) 2007-2014 fruux GmbH (https://fruux.com/).
   * @author Evert Pot (http://evertpot.com/)

   * @author Thomas Tanghus (http://tanghus.net/)

   * @license http://sabre.io/license/ Modified BSD License

   */

  class VCFExportPlugin extends DAV\ServerPlugin {

  
      /**
       * Reference to Server class
       *

       * @var Sabre\DAV\Server

       */
      protected $server;
  
      /**
       * Initializes the plugin and registers event handlers
       *

       * @param DAV\Server $server

       * @return void
       */

      public function initialize(DAV\Server $server) {

  
          $this->server = $server;
          $this->server->subscribeEvent('beforeMethod',array($this,'beforeMethod'), 90);
  
      }
  
      /**
       * 'beforeMethod' event handles. This event handles intercepts GET requests ending
       * with ?export
       *
       * @param string $method
       * @param string $uri
       * @return bool
       */
      public function beforeMethod($method, $uri) {
  
          if ($method!='GET') return;
          if ($this->server->httpRequest->getQueryString()!='export') return;
  
          // splitting uri
          list($uri) = explode('?',$uri,2);
  
          $node = $this->server->tree->getNodeForPath($uri);

          if (!($node instanceof IAddressBook)) return;

  
          // Checking ACL, if available.
          if ($aclPlugin = $this->server->getPlugin('acl')) {
              $aclPlugin->checkPrivileges($uri, '{DAV:}read');
          }
  
          $this->server->httpResponse->setHeader('Content-Type','text/directory');
          $this->server->httpResponse->sendStatus(200);
  
          $nodes = $this->server->getPropertiesForPath($uri, array(

              '{' . Plugin::NS_CARDDAV . '}address-data',

          ),1);
  
          $this->server->httpResponse->sendBody($this->generateVCF($nodes));
  
          // Returning false to break the event chain
          return false;
  
      }
  
      /**
       * Merges all vcard objects, and builds one big vcf export
       *
       * @param array $nodes
       * @return string
       */
      public function generateVCF(array $nodes) {
  
          $output = "";
  
          foreach($nodes as $node) {

              if (!isset($node[200]['{' . Plugin::NS_CARDDAV . '}address-data'])) {

                  continue;
              }

              $nodeData = $node[200]['{' . Plugin::NS_CARDDAV . '}address-data'];

  
              // Parsing this node so VObject can clean up the output.
              $output .=
                 VObject\Reader::read($nodeData)->serialize();
  
          }
  
          return $output;
  
      }
  
  }