<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Atom.php 8064 2008-02-16 10:58:39Z thomas $
 */

/**
 * @see Zend_Feed_Entry_Abstract
 */
require_once 'external/Zend/Feed/Entry/Abstract.php';

/**
 * Concrete class for working with Atom entries.
 *
 * @category   Zend
 * @package    Zend_Feed
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Feed_Entry_Atom extends Zend_Feed_Entry_Abstract {
  /**
   * Root XML element for Atom entries.
   *
   * @var string
   */
  protected $_rootElement = 'entry';
  
  /**
   * Root namespace for Atom entries.
   *
   * @var string
   */
  protected $_rootNamespace = 'atom';

  /**
   * Delete an atom entry.
   *
   * Delete tries to delete this entry from its feed. If the entry
   * does not contain a link rel="edit", we throw an error (either
   * the entry does not yet exist or this is not an editable
   * feed). If we have a link rel="edit", we do the empty-body
   * HTTP DELETE to that URI and check for a response of 2xx.
   * Usually the response would be 204 No Content, but the Atom
   * Publishing Protocol permits it to be 200 OK.
   *
   * @return void
   * @throws Zend_Feed_Exception
   */
  public function delete() {
    // Look for link rel="edit" in the entry object.
    $deleteUri = $this->link('edit');
    if (! $deleteUri) {
      /** 
       * @see Zend_Feed_Exception
       */
      require_once 'external/Zend/Feed/Exception.php';
      throw new Zend_Feed_Exception('Cannot delete entry; no link rel="edit" is present.');
    }
    
    // DELETE
    $client = Zend_Feed::getHttpClient();
    do {
      $client->setUri($deleteUri);
      if (Zend_Feed::getHttpMethodOverride()) {
        $client->setHeader('X-HTTP-Method-Override', 'DELETE');
        $response = $client->request('POST');
      } else {
        $response = $client->request('DELETE');
      }
      $httpStatus = $response->getStatus();
      switch ((int)$httpStatus / 100) {
        // Success
        case 2:
          return true;
        // Redirect
        case 3:
          $deleteUri = $response->getHeader('Location');
          continue;
        // Error
        default:
          /** 
           * @see Zend_Feed_Exception
           */
          require_once 'external/Zend/Feed/Exception.php';
          throw new Zend_Feed_Exception("Expected response code 2xx, got $httpStatus");
      }
    } while (true);
  }

  /**
   * Save a new or updated Atom entry.
   *
   * Save is used to either create new entries or to save changes to
   * existing ones. If we have a link rel="edit", we are changing
   * an existing entry. In this case we re-serialize the entry and
   * PUT it to the edit URI, checking for a 200 OK result.
   *
   * For posting new entries, you must specify the $postUri
   * parameter to save() to tell the object where to post itself.
   * We use $postUri and POST the serialized entry there, checking
   * for a 201 Created response. If the insert is successful, we
   * then parse the response from the POST to get any values that
   * the server has generated: an id, an updated time, and its new
   * link rel="edit".
   *
   * @param  string $postUri Location to POST for creating new entries.
   * @return void
   * @throws Zend_Feed_Exception
   */
  public function save($postUri = null) {
    if ($this->id()) {
      // If id is set, look for link rel="edit" in the
      // entry object and PUT.
      $editUri = $this->link('edit');
      if (! $editUri) {
        /** 
         * @see Zend_Feed_Exception
         */
        require_once 'external/Zend/Feed/Exception.php';
        throw new Zend_Feed_Exception('Cannot edit entry; no link rel="edit" is present.');
      }
      
      $client = Zend_Feed::getHttpClient();
      $client->setUri($editUri);
      if (Zend_Feed::getHttpMethodOverride()) {
        $client->setHeaders(array('X-HTTP-Method-Override: PUT', 
            'Content-Type: application/atom+xml'));
        $client->setRawData($this->saveXML());
        $response = $client->request('POST');
      } else {
        $client->setHeaders('Content-Type', 'application/atom+xml');
        $client->setRawData($this->saveXML());
        $response = $client->request('PUT');
      }
      if ($response->getStatus() !== 200) {
        /** 
         * @see Zend_Feed_Exception
         */
        require_once 'external/Zend/Feed/Exception.php';
        throw new Zend_Feed_Exception('Expected response code 200, got ' . $response->getStatus());
      }
    } else {
      if ($postUri === null) {
        /** 
         * @see Zend_Feed_Exception
         */
        require_once 'external/Zend/Feed/Exception.php';
        throw new Zend_Feed_Exception('PostURI must be specified to save new entries.');
      }
      $client = Zend_Feed::getHttpClient();
      $client->setUri($postUri);
      $client->setRawData($this->saveXML());
      $response = $client->request('POST');
      
      if ($response->getStatus() !== 201) {
        /** 
         * @see Zend_Feed_Exception
         */
        require_once 'external/Zend/Feed/Exception.php';
        throw new Zend_Feed_Exception('Expected response code 201, got ' . $response->getStatus());
      }
    }
    
    // Update internal properties using $client->responseBody;
    @ini_set('track_errors', 1);
    $newEntry = @DOMDocument::loadXML($response->getBody());
    @ini_restore('track_errors');
    
    if (! $newEntry) {
      // prevent the class to generate an undefined variable notice (ZF-2590)
      if (! isset($php_errormsg)) {
        if (function_exists('xdebug_is_enabled')) {
          $php_errormsg = '(error message not available, when XDebug is running)';
        } else {
          $php_errormsg = '(error message not available)';
        }
      }
      
      /** 
       * @see Zend_Feed_Exception
       */
      require_once 'external/Zend/Feed/Exception.php';
      throw new Zend_Feed_Exception('XML cannot be parsed: ' . $php_errormsg);
    }
    
    $newEntry = $newEntry->getElementsByTagName($this->_rootElement)->item(0);
    if (! $newEntry) {
      /** 
       * @see Zend_Feed_Exception
       */
      require_once 'external/Zend/Feed/Exception.php';
      throw new Zend_Feed_Exception('No root <feed> element found in server response:' . "\n\n" . $client->responseBody);
    }
    
    if ($this->_element->parentNode) {
      $oldElement = $this->_element;
      $this->_element = $oldElement->ownerDocument->importNode($newEntry, true);
      $oldElement->parentNode->replaceChild($this->_element, $oldElement);
    } else {
      $this->_element = $newEntry;
    }
  }

  /**
   * Easy access to <link> tags keyed by "rel" attributes.
   *
   * If $elt->link() is called with no arguments, we will attempt to
   * return the value of the <link> tag(s) like all other
   * method-syntax attribute access. If an argument is passed to
   * link(), however, then we will return the "href" value of the
   * first <link> tag that has a "rel" attribute matching $rel:
   *
   * $elt->link(): returns the value of the link tag.
   * $elt->link('self'): returns the href from the first <link rel="self"> in the entry.
   *
   * @param  string $rel The "rel" attribute to look for.
   * @return mixed
   */
  public function link($rel = null) {
    if ($rel === null) {
      return parent::__call('link', null);
    }
    
    // index link tags by their "rel" attribute.
    $links = parent::__get('link');
    if (! is_array($links)) {
      if ($links instanceof Zend_Feed_Element) {
        $links = array($links);
      } else {
        return $links;
      }
    }
    
    foreach ($links as $link) {
      if (empty($link['rel'])) {
        continue;
      }
      if ($rel == $link['rel']) {
        return $link['href'];
      }
    }
    
    return null;
  }

}