<?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_Service_Amazon
 * @subpackage Ec2
 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id$
 */

/**
 * @see Zend_Http_Response
 */
require_once 'Zend/Http/Response.php';

/**
 * @category   Zend
 * @package    Zend_Service_Amazon
 * @subpackage Ec2
 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Service_Amazon_Ec2_Response {
    /**
     * XML namespace used for EC2 responses.
     */
    protected $_xmlNamespace = 'http://ec2.amazonaws.com/doc/2009-04-04/';

    /**
     * The original HTTP response
     *
     * This contains the response body and headers.
     *
     * @var Zend_Http_Response
     */
    private $_httpResponse = null;

    /**
     * The response document object
     *
     * @var DOMDocument
     */
    private $_document = null;

    /**
     * The response XPath
     *
     * @var DOMXPath
     */
    private $_xpath = null;

    /**
     * Last error code
     *
     * @var integer
     */
    private $_errorCode = 0;

    /**
     * Last error message
     *
     * @var string
     */
    private $_errorMessage = '';

    /**
     * Creates a new high-level EC2 response object
     *
     * @param Zend_Http_Response $httpResponse the HTTP response.
     */
    public function __construct(Zend_Http_Response $httpResponse)
    {
        $this->_httpResponse = $httpResponse;
    }

    /**
     * Gets the XPath object for this response
     *
     * @return DOMXPath the XPath object for response.
     */
    public function getXPath()
    {
        if ($this->_xpath === null) {
            $document = $this->getDocument();
            if ($document === false) {
                $this->_xpath = false;
            } else {
                $this->_xpath = new DOMXPath($document);
                $this->_xpath->registerNamespace('ec2',
                    $this->getNamespace());
            }
        }

        return $this->_xpath;
    }

    /**
     * Gets the document object for this response
     *
     * @return DOMDocument the DOM Document for this response.
     */
    public function getDocument()
    {
        try {
            $body = $this->_httpResponse->getBody();
        } catch (Zend_Http_Exception $e) {
            $body = false;
        }

        if ($this->_document === null) {
            if ($body !== false) {
                // turn off libxml error handling
                $errors = libxml_use_internal_errors();

                $this->_document = new DOMDocument();
                if (!$this->_document->loadXML($body)) {
                    $this->_document = false;
                }

                // reset libxml error handling
                libxml_clear_errors();
                libxml_use_internal_errors($errors);
            } else {
                $this->_document = false;
            }
        }

        return $this->_document;
    }

    /**
     * Return the current set XML Namespace.
     *
     * @return string
     */
    public function getNamespace()
    {
        return $this->_xmlNamespace;
    }

    /**
     * Set a new XML Namespace
     *
     * @param string $namespace
     */
    public function setNamespace($namespace)
    {
        $this->_xmlNamespace = $namespace;
    }

}
