//////////////////////////////////////////////////////////////////////////////
// A Shortcut guide to getting data from a Google Health EMR                //
//////////////////////////////////////////////////////////////////////////////


// FIRST, go to www.google.com/h9, the Google Health developers' sandbox, and create yourself a free account.  Put some dummy data in it, make up some medical conditions and tests.

// SECOND, download and install the Zend OAuth code from  http://framework.zend.com/download/gdata

// THIRD, Change this to point to the location of your private signing key. What's a private signing key?  See: http://code.google.com/apis/health/getting_started.html#DomainRegistration
define('HEALTH_PRIVATE_KEY', '/path/to/your/rsa_private_key.pem');



// The following AuthOpen authentication connects your application to Google.

// The legalities:
/**
 * 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_Gdata
 * @subpackage Demos
 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */


$EMRname = "Google Health";

//////////////////////////////////////////////////////////////////////////////
// End Configuration                                                        //
//////////////////////////////////////////////////////////////////////////////



// Load the Zend Gdata classes.
require_once 'Zend/Loader.php';
Zend_Loader::loadClass('Zend_Gdata_AuthSub');
Zend_Loader::loadClass('Zend_Gdata_Health');
Zend_Loader::loadClass('Zend_Gdata_Health_Query');

session_start();
// Google H9 Sandbox AuthSub/OAuth scope
define('SCOPE', 'https://www.google.com/h9/feeds/');

try {
  // Setup the HTTP client and fetch an AuthSub token for H9
  $client = authenticate(@$_GET['token']);
  $useH9 = true;
  $healthService = new Zend_Gdata_Health($client, 'google-HealthPHPSample-v1.0', $useH9);
} catch(Zend_Gdata_App_Exception $e) {
  $cmdData["loginMsg"]='Error: ' . $e->getMessage();
  echo json_encode($cmdData);
  exit;
}

//////////////////////////////////////////////////////////////////////////////
// End Authentication                                                       //
//////////////////////////////////////////////////////////////////////////////





//////////////////////////////////////////////////////////////////////////////
// Begin Sample Code                                                        //
//////////////////////////////////////////////////////////////////////////////

/*
if(isset($_GET["revoke"])) { 
  // =============================================================================
  // Revoke the AuthSub session token
  // =============================================================================
  $revoked = Zend_Gdata_AuthSub::AuthSubRevokeToken($client->getAuthSubToken(), $client) ? 'yes' : 'no';
  unset($_SESSION['sessionToken']);
  echo '<b>Link to EMR data revoked</b>: ' . @$revoked;
  exit;
}
*/

getTokenInfo($client); // this needed to make second and subsequent calls to this page work.  Don't know exactly why.
//echo "Token info: ", getTokenInfo($client);
//echo "Session Token", $client->getAuthSubToken(); 

$query = new Zend_Gdata_Health_Query();
$query->setDigest("true");
$profileFeed = $healthService->getHealthProfileFeed($query);


// break down the feed
$entry = $profileFeed->entry[0]; // digest=true was set so we only have 1 <entry>
$allergies = $entry->getCcr()->getAllergies();
$conditions = $entry->getCcr()->getConditions();
$immunizations = $entry->getCcr()->getImmunizations();
$tests = $entry->getCcr()->getLabResults();
$meds= $entry->getCcr()->getMedications();
$procedures = $entry->getCcr()->getProcedures();




// This is where your app starts. *************************************************
// You've got data, now parse it.  For example:
getAllTests();
getAllMeds();

// An example of another way of using the medications data
//foreach ($meds as $med) {
  //$xmlStr = $med->ownerDocument->saveXML($med);
  //echo '<pre>' . $xmlStr . '</pre>';
//}






//*********************************** supporting functions ***********************************


// get medical Test data from Google Health API
// To learn how to build these queries: http://code.google.com/apis/health/ccrg_reference.html 
function getAllTests() {
  global $tests;

  $test = $tests->item(0);
  $xpath = new DOMXpath($test->ownerDocument);

  $testnames = $xpath->query("//ccr:Body/ccr:Results/ccr:Result/ccr:Test/ccr:Description/ccr:Text");
  foreach ($testnames as $name) {
    $nameOut[]= $name->nodeValue;
  }

  $dates= $xpath->query("//ccr:Body/ccr:Results/ccr:Result/ccr:Test/ccr:DateTime/ccr:ExactDateTime");
  foreach ($dates as $date) {
    $dateOut[] = $date->nodeValue; // human-readable
  }

  // continue with queries for other parts of the Tests.
}



// get data from Google Health API
function getAllMeds() {
  global $meds;
  // do your own thing
}



///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// If you prefer to set queries by calling methods of a Query object, Google gives some sample code for that.  //
// See http://framework.zend.com/svn/framework/standard/trunk/demos/Zend/Gdata/Health.php                                    //
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////





// more support functions *******************************************************

function getCurrentUrl() {
  $phpRequestUri =
    htmlentities(substr($_SERVER['REQUEST_URI'], 0, strcspn($_SERVER['REQUEST_URI'], "\n\r")), ENT_QUOTES);

  if (isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) == 'on') {
    $protocol = 'https://';
  } else {
    $protocol = 'http://';
  }
  $host = $_SERVER['HTTP_HOST'];
  if ($_SERVER['SERVER_PORT'] != '' &&
     (($protocol == 'http://' && $_SERVER['SERVER_PORT'] != '80') ||
     ($protocol == 'https://' && $_SERVER['SERVER_PORT'] != '443'))) {
    $port = ':' . $_SERVER['SERVER_PORT'];
  } else {
    $port = '';
  }
  return $protocol . $host . $port . $phpRequestUri;
}



function authenticate($singleUseToken=null) {
  global $cmdData,$EMRname;

  $sessionToken = isset($_SESSION['sessionToken']) ? $_SESSION['sessionToken'] : null;


  // If there is no AuthSub session or one-time token waiting for us,
  // redirect the user to Google Health's AuthSub handler to get one.
  if (!$sessionToken && !$singleUseToken) {
    $next = getCurrentUrl(); // 'next' is where you want to go after the user says it's ok to link to you.
    $secure = 1;
    $session = 1;
    $authSubHandler = 'https://www.google.com/h9/authsub';
    $permission = 1;  // 1 - allows reading of the profile && posting notices
    $authSubURL = Zend_Gdata_AuthSub::getAuthSubTokenUri($next, SCOPE, $secure, $session, $authSubHandler);
    $authSubURL .= '&permission=' . $permission;
    $cmdData["loginMsg"]="<h3 style='text-align:center;width:500px'>VisiHealth will graphically display your already-existing health account on $EMRname.<br>First step: <a href='$authSubURL'>Link your Google Health Account</a></h3>";
    echo json_encode($cmdData);
    exit();
  }

  $client = new Zend_Gdata_HttpClient();
  $client->setAuthSubPrivateKeyFile(HEALTH_PRIVATE_KEY, null, true);

  // Convert an AuthSub one-time token into a session token if needed
  if ($singleUseToken && !$sessionToken) {
    //echo "session:$sessionToken ";
    //echo "single:$singleUseToken ";
    $sessionToken = Zend_Gdata_AuthSub::getAuthSubSessionToken($singleUseToken, $client);
    $_SESSION['sessionToken'] = $sessionToken;
  }
  $client->setAuthSubToken($sessionToken);
  return $client;
}

function getTokenInfo($client) {
  $sessionToken = $client->getAuthSubToken();
  return Zend_Gdata_AuthSub::getAuthSubTokenInfo($sessionToken, $client);
}

function revokeToken($client) {
  $sessionToken = $client->getAuthSubToken();
  return Zend_Gdata_AuthSub::AuthSubRevokeToken($sessionToken, $client);
}

/** Prettifies an XML string into a human-readable and indented work of art
 *  @param string $xml The XML as a string
 *  @param boolean $html_output True if the output should be escaped (for use in HTML)
 */
function xmlpp($xml, $html_output=true) {
  $xml_obj = new SimpleXMLElement($xml);
  $level = 4;
  $indent = 0; // current indentation level
  $pretty = array();

  // get an array containing each XML element
  $xml = explode("\n", preg_replace('/>\s*</', ">\n<", $xml_obj->asXML()));

  // shift off opening XML tag if present
  if (count($xml) && preg_match('/^<\?\s*xml/', $xml[0])) {
    $pretty[] = array_shift($xml);
  }

  foreach ($xml as $el) {
    if (preg_match('/^<([\w])+[^>\/]*>$/U', $el)) {
      // opening tag, increase indent
      $pretty[] = str_repeat(' ', $indent) . $el;
      $indent += $level;
    } else {
      if (preg_match('/^<\/.+>$/', $el)) {
        $indent -= $level;  // closing tag, decrease indent
      }
      if ($indent < 0) {
        $indent += $level;
      }
      $pretty[] = str_repeat(' ', $indent) . $el;
    }
  }
  $xml = implode("\n", $pretty);
  return ($html_output) ? htmlentities($xml) : $xml;
}