<?php
 /**
 * 
 * 
 * @author Michael J. Burgess
 * @package SnPayPal
 * @copyright Michael J. Burgess, 2008
 * @version 1.0
 * @licence MIT
 */
 
 /**
 * Handles soap envelope generation and sending (via SnPayPalStream)
 *
 */
class SnPayPalApiInterface extends SnPayPalStream
{
    /**
     * Will be set to read the body of the SOAP envelope (i.e. not the HEAD etc.)
     *
     * @var boolean
     */
    public $rtnSoapBody = true;
    /**
     * Contains SimpleXMLElement object
     * resulting from the parsing of a paypal soap response
     *
     * @var SimpleXMLElement
     */
    private $xml;
    
    /**
     * SOAP XML Sent to PayPal
     *
     * @var string
     */
    private $soap;
    
    /**
     * Return SimpleXML form of the SOAP response
     * You can check if it is a valid response various ways
     * e.g. if($response instanceof PayPalSoapResponse)
     *
     * You can use $property to return a subsection of the response 
     * (to get the bits that contain the main info, e.g. 'GetBalanceResponse')
     * 
     * @param string $property
     * @return PayPalSoapResponse
     */
    public function getResponse($property = null)
    {
        return (empty($property)) ? $this->xml : $this->xml->$property;
    }
    
    /**
     * Returns the SOAP XML packet sent (for e.g. debugging)
     *
     * @return string
     */
    public function getSoapSent()
    {
        return $this->soap;
    }
    
    /**
     * Converts array of SnPayPalParameters into SOAP xml
     *
     * @param array $array
     * @return string
     */
    public static function arrayToXml($array = null)
    {
        if(empty($array)) return '';
        
        $parameters = '';

        foreach ($array as $parameter)
        {
            $attr = (empty($parameter->attribute)) ? '' : " $parameter->attribute";
            $parameters .= "
                            <$parameter->name xsi:type=\"$parameter->type\"$attr>$parameter->value</$parameter->name>";
        }

        return $parameters;
    }

    /**
     * Send soap envelope
     * 
     * Access response via ->getXml() or ->getResponse()
     *
     * @param string $request SOAP Env.
     * @return boolean
     */
    public function putToApi($request)
    {
        $this->open();
        $this->putString($request);
        $this->close();
        return (isset($this->response) && !is_bool($this->response));
    }
    
    /**
     * Call PayPal API
     *
     * @param string $api
     * @param mixed $parameters
     */
    public function callAPI($api, $parameters = null)
    {
        
        $xmlMainSection = $this->arrayToXml((array) $parameters);
        
        $request = $api.'Request';
        $req     = $api.'Req';
        $soap    = "
                    <$req xmlns=\"urn:ebay:api:PayPalAPI\">
                        <$request xsi:type=\"ns:{$request}Type\">";
        
        $soap   .= '
                            <Version xmlns="urn:ebay:apis:eBLBaseComponents" xsi:type="xsd:string">1.0</Version>';
        $soap   .= "$xmlMainSection
                        </$request>
                    </$req>";
        
        $this->soap = $this->newSoapEnvelope($soap);
        if($this->putToApi($this->soap))
        {
            $this->xmlLoadString();
            return $this;
        }
        
        else return false;
    }

    /**
     * Get an object representation of the SOAP response, 
     * if $this->rtnSoapBody is set to true (default) then the body of the response is returned 
     * (as oppose to including the head which contains meta)
     *
     */
    private function xmlLoadString()
    {
        $xml = simplexml_load_string($this->response, 'PayPalSoapResponse');
        
        if($this->rtnSoapBody)
        {
            $xml = $xml->xpath('/SOAP-ENV:Envelope/SOAP-ENV:Body'); 
            $this->xml = $xml[0];
        }
        
        else
        {
            $this->xml = $xml;
        }
    }
    
    /**
     * Generate the XML required for a new SOAP envelope
     *
     * @param string $body
     * @return string
     */
    public function newSoapEnvelope($body)
    {
        $signature = SnPayPalConfig::SIGNATURE;
        $signature = (empty($signature)) ? '' : "<Signature>$signature</Signature>";
        
        return '<?xml version="1.0" encoding="UTF-8"?>
        <SOAP-ENV:Envelope 
            xmlns:xsi="http://www.w3.org/1999/XMLSchema-instance" 
            xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
            xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" 
            xmlns:xsd="http://www.w3.org/1999/XMLSchema"
            SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
                <SOAP-ENV:Header>
                      <RequesterCredentials xmlns="urn:ebay:api:PayPalAPI" SOAP-ENV:mustUnderstand="1">
                          <Credentials xmlns="urn:ebay:apis:eBLBaseComponents">
                                  <Username>'. SnPayPalConfig::USERNAME .'</Username>
                                  <Password>'. SnPayPalConfig::PASSWORD .'</Password>
                                  '.$signature.'
                          </Credentials>
                      </RequesterCredentials>
                </SOAP-ENV:Header>
                <SOAP-ENV:Body>'. $body .'
                </SOAP-ENV:Body>
        </SOAP-ENV:Envelope>';
    }
}
?>