<?php

/**
 * @file
 * Dummy module implementing a CAS Server.
 */

/**
 *
 */
function cas_test_cas_phpcas_alter() {

  // Set the User-Agent field which is used by SimpleTest to identify testing
  // requests.
  $test_info = &$GLOBALS['drupal_test_info'];
  if (!empty($test_info['test_run_id'])) {
    phpCAS::setExtraCurlOption(CURLOPT_USERAGENT, drupal_generate_test_ua($test_info['test_run_id']));
  }

  // Set all CAS server URLs manually, as this is the only way to specify an
  // HTTP (i.e., not HTTPS) connection.
  $service_url = phpCAS::getServiceURL();
  phpCAS::setServerLoginURL(url('cas_test/login', array(
    'query' => array('service' => $service_url),
    'absolute' => TRUE,
  )));

  switch (variable_get('cas_version', '3.0')) {
    case CAS_VERSION_1_0:
      phpCAS::setServerServiceValidateURL(url('cas_test/validate', array('absolute' => TRUE)));
      break;
    case CAS_VERSION_2_0:
      phpCAS::setServerServiceValidateURL(url('cas_test/serviceValidate', array('absolute' => TRUE)));
      phpCAS::setServerProxyValidateURL(url('cas_test/proxyValidate',  array('absolute' => TRUE)));
      break;
    case CAS_VERSION_3_0:
      phpCAS::setServerServiceValidateURL(url('cas_test/p3/serviceValidate', array('absolute' => TRUE)));
      phpCAS::setServerProxyValidateURL(url('cas_test/p3/proxyValidate',  array('absolute' => TRUE)));
      break;
    default:
      throw new Exception('Unknown CAS server version.');
      break;
  }

  phpCAS::setServerLogoutURL(url('cas_test/logout',  array('absolute' => TRUE)));

  // SAML not currently implemented.
  // phpCAS::setServerSamlValidateURL(url('cas_test/samlValidate', array('absolute' => TRUE)));
}

/**
 * Implements hook_menu().
 */
function cas_test_menu() {
  $items = array();
  $items['cas_test/login'] = array(
    'page callback' => 'cas_test_login',
    'title' => 'CAS Login',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  $items['cas_test/validate'] = array(
    'page callback' => 'cas_test_validate',
    'title' => 'CAS Validate',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  $items['cas_test/serviceValidate'] = array(
    'page callback' => 'cas_test_service_validate',
    'title' => 'CAS Service Validate',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  $items['cas_test/proxyValidate'] = array(
    'page callback' => 'cas_test_service_validate',
    'title' => 'CAS Proxy Ticket Validate',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  $items['cas_test/p3/serviceValidate'] = array(
    'page callback' => 'cas_test_service_validate',
    'title' => 'CAS 3.0 Service Validate',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  $items['cas_test/p3/proxyValidate'] = array(
    'page callback' => 'cas_test_service_validate',
    'title' => 'CAS 3.0 Proxy Ticket Validate',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  $items['cas_test/logout'] = array(
    'page callback' => 'cas_test_logout',
    'title' => 'CAS Logout',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  $items['cas_test/token'] = array(
    'page callback' => 'cas_test_token_evaluate',
    'title' => 'CAS Token Test',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  return $items;
}

/**
 * Initiate a login request.
 *
 * Set the 'cas_test_cas_user' variable to an associative array containing:
 * - 'name': CAS username.
 * - 'attributes': (optional) Any other name-value pairs to be returned by the
 *   CAS server.
 */
function cas_test_login() {
  // Get the service and make a ticket.
  $service = $_REQUEST['service'];
  $cas_user = variable_get('cas_test_cas_user', '');

  if ($cas_user) {
    if (!is_array($cas_user)) {
      $cas_user = array('name' => $cas_user, 'attributes' => array());
    }
    // Generate a ticket and redirect to the service URL with the login ticket.
    $ticket = _cas_test_ticket_generate($service, $cas_user);
    // Force redirection.
    unset($_GET['destination']);
    drupal_goto($service, array('query' => array('ticket' => $ticket)));
  }
  elseif (isset($_GET['gateway']) && $_GET['gateway'] == 'true') {
    // We were not able to log in the user, so redirect to the service URL.
    // Force redirection.
    unset($_GET['destination']);
    drupal_goto($service);
  }
  else {
    // No CAS name was provided, print an error message.
    print "Warning: No CAS name provided.\n";
    exit();
  }
}

/**
 * Validate a ticket using the CAS 1.x protocol.
 */
function cas_test_validate() {
  // Prevent this page from being cached.
  drupal_page_is_cacheable(FALSE);

  // Set content type.
  drupal_add_http_header('Content-Type', 'text/plain; charset=utf-8');

  //Obtain the ticket from the url and validate it.
  $ticket = $_GET['ticket'];
  $service = $_GET['service'];
  $cas_user = _cas_test_ticket_validate($service, $ticket);
  if ($cas_user) {
    $cas_name = $cas_user['name'];
    print "yes\n";
    print "$cas_name\n";
  }
  else {
    print "no\n";
    print "\n";
  }
  exit();
}

/**
 * Validate a ticket using the CAS 2.0 and CAS 3.0 protocols.
 */
function cas_test_service_validate() {
  // Prevent this page from being cached.
  drupal_page_is_cacheable(FALSE);

  // Set content type.
  drupal_add_http_header('Content-Type', 'text/xml; charset=utf-8');

  $ticket = $_GET['ticket'];
  $service = $_GET['service'];

  if ($cas_user = _cas_test_ticket_validate($service, $ticket)) {
    print theme('cas_service_validate_success', $cas_user);
  }
  else {
    $error_code = (!$ticket || !$service) ? 'INVALID_REQUEST' : 'INVALID_TICKET';
    print theme('cas_service_validate_failure', array('ticket' => $ticket, 'error_code' => $error_code));
  }
  exit();
}

/**
 * Log out a user.
 */
function cas_test_logout() {
  if (isset($_GET['url'])) {
    print t('Logged out. Continue to @url.', array('@url' => $_GET['url']));
  }
  else {
    print t('Logged out. No redirection provided.');
  }
  exit();
}

/**
 * Generate a login ticket.
 *
 * @param $service
 *   The service URL.
 * @param $cas_user
 *   An associative array containing the following keys:
 *     - 'name': The CAS username.
 *     - 'attributes': Any other key-value pairs the CAS server should return.
 *
 * @return
 *   A login ticket which may be used to authenticate the CAS username at the
 *   service URL.
 */
function _cas_test_ticket_generate($service, $cas_user) {
  // Generate a one-time ticket.
  $ticket = 'ST-' . user_password(32);

  // Save the ticket in the database.
  $tickets = variable_get('cas_test_tickets', array());
  $tickets[$service][$ticket] = $cas_user;
  variable_set('cas_test_tickets', $tickets);

  // Save the name in the database for single sign-out.
  $sso = variable_get('cas_test_sso', array());
  $sso[$cas_user['name']][$service][] = $ticket;
  variable_set('cas_test_sso', $sso);

  return $ticket;
}

/**
 * Validate a one-time-use login ticket.
 *
 * @param $service
 *   The service URL.
 * @param $ticket
 *   The login or proxy ticket.
 *
 * @return
 *   The CAS username corresponding to the ticket, or FALSE if the ticket is
 *   invalid.
 */
function _cas_test_ticket_validate($service, $ticket) {
  // Look up the ticket
  $cas_name = FALSE;
  $tickets = variable_get('cas_test_tickets', array());
  if (isset($tickets[$service][$ticket])) {
    $cas_name = $tickets[$service][$ticket];
    unset($tickets[$service][$ticket]);
  }
  return $cas_name;
}

/**
 * Sign out the specified CAS user.
 *
 * @param $cas_user
 */
function cas_test_single_sign_out($cas_name, $double_encode=FALSE) {
  $sso = variable_get('cas_test_sso', array());
  foreach ($sso[$cas_name] as $service => $tickets) {
    foreach ($tickets as $ticket) {
      // Generate posting:
      $data = array(
        'logoutRequest' => t("<samlp:LogoutRequest xmlns:samlp=\"urn:oasis:names:tc:SAML:2.0:protocol\" xmlns:saml=\"urn:oasis:names:tc:SAML:2.0:assertion\" ID=\"!id\" Version=\"2.0\" IssueInstant=\"!time\">\n<saml:NameID>@NOT_USED@</saml:NameID>\n<samlp:SessionIndex>!ticket</samlp:SessionIndex>\n</samlp:LogoutRequest>", array('!id' => user_password(10), '!time' => time(), '!ticket' => $ticket)),
      );

      if ($double_encode) {
        // Certain CAS servers urlencode the logoutRequest.
        $data['logoutRequest'] = urlencode($data['logoutRequest']);
      }

      // Sign out the user.
      $options = array(
        'method' => 'POST',
        'headers' => array(
          'Content-Type' => 'application/x-www-form-urlencoded',
        ),
        'data' => drupal_http_build_query($data),
      );
      drupal_http_request($service, $options);
    }
  }
  unset($sso[$cas_name]);
  variable_set('cas_test_sso', $sso);
}

/**
 * Evaluate the specified token.
 */
function cas_test_token_evaluate() {
  print token_replace($_GET['token'], array('cas' => $_GET['name']));
  exit(0);
}