<?php
// $Id$

/**
 * Implementation of hook_server_info().
 */
function rest_server_server_info() {
  return array(
    '#name' => 'REST',
    '#path' => 'rest',
  );
} 

/**
 * Implementation of hook_server()
 */
function rest_server_server() {
  $request = $_REQUEST;
  $args = array();
  
  // Check for which service we're calling
  $method_name = $request['method'];
  foreach (services_get_all() as $method) {
    if ($method['#method'] == $request['method']) {
      // Special use cases for arguments of certain types
      foreach ($method['#args'] as $argument) {
        $argname = $argument['#name'];
        switch ($argument['#type']) {
          case 'array' :
            if (empty($request[$argname])) {
              $args[] = array();
            }
            else {
              $args[] = explode(',', $request[$argname]);
            }
            break;
          case 'string':
            if(empty($request[$argname])) {
              $args[] = '';
            }
            else {
              $args[] = $request[$argname];
            }
            break;
          default:
            // parameters of other types
            $args[] = $request[$argname];
            break;
          }
        }
      break;
    }
  }
  

  try {
    $response = services_method_call($method_name, $args);

    // If 'status' is set, an error ocurred.
    if (is_array($response) && isset($response['status'])) {
      $result = $response;
    }
    else {
      $result = array(
        'status' => 'success',
        'response' => $response,
      );
    }
  }
  catch (Exception $e) {
    $result = rest_server_server_error($e->getMessage());
  }

  drupal_set_header('Content-type: text/xml');
  print rest_server_to_xml($result);
}

/**
 * Implementation of hook_server_error
 *
 * @param string $message
 * @return array
 */
function rest_server_server_error($message) {
  return array(
    'status' => 'error',
    'message' => $message,
  );
}

/**
 * Convert data array to xml representation.
 *
 * @param $data
 *   Array or object with data to convert.
 * @param $xml
 *   SimpleXML object, used in recursive calls.
 * @param $depth
 *   Node depth, used in recursive calls.
 * 
 * @return
 *   XML string.
 */
function rest_server_to_xml($data, $xml = NULL, $depth = 0)  {
  if (!isset($xml)) {
    $xml = simplexml_load_string('<?xml version="1.0" encoding="utf-8"?><rest generator="xml_writer" version="1.0" />');
  }

  foreach($data as $key => $value) {
    if (is_array($value)|| is_object($value)) {
      $child = is_numeric($key) ? _rest_server_item_node($xml, $key) : $xml->addChild($key);
      rest_server_to_xml($value, $child, $depth + 1);
    }
    else {
      $value = htmlentities($value);
      if (is_numeric($key)) {
        _rest_server_item_node($xml, $key, $value);
      }
      else {
        $xml->addChild($key, $value);
      }
    }
  }

  if ($depth == 0) {
    return $xml->asXML();
  }
}

/**
 * Helper function to generate 'item' nodes for arrays with numeric keys.
 * E.g. <item id="0">.
 */
function _rest_server_item_node($parent, $key, $value = NULL) {
  $item = isset($value) ? $parent->addChild('item', $value) : $parent->addChild('item');
  $item->addAttribute('id', $key);
  return $item;
}