/*
    HTTP: POST
    Returns: Created User object upon successful registration.
*/
function agfe_api_register_callback() {
    // Validate the request is a POST and return proper response code on failure.
    if (_isAuthenticated() == false) {
      header('HTTP/1.1 401 Unauthorized');
      return;
    }
    if ($_SERVER['REQUEST_METHOD'] != 'POST'){
      header('HTTP/1.1 405 Not Post');
      return;
    }

    // {"name": "John Doe","mail": "testaddress@devetry.com","gender":"Male"}
    // Receive stream contents (body) of POST request in JSON format.
    $received_data = file_get_contents("php://input", TRUE);
    $user_json = drupal_json_decode($received_data, TRUE);

    // Send Error 400 response if required fields missing
    if (empty($user_json['gender'])) { $e400=true; $e400str = 'gender required'; }
    else if (empty($user_json['mail'])) { $e400=true; $e400str = 'mail required'; }
    else if (empty($user_json['opportunity_id'])) { $e400=true; $e400str = 'opportunity_id required'; }

    if ($e400) {
        header('HTTP/1.1 400 '.$e400str);
        return;
    }

    // Required Fields
    $gender = $user_json['gender'];
    $mail = $user_json['mail'];
    $opportunity_id = $user_json['opportunity_id'];

    // Optional Fields
    // set PHP display precision to 20 digits
    ini_set("precision", 20);
    // set unique username based on UNIX time
    $rand               = substr(str_replace('.', '', microtime(true)), 4, 8);
    $name_rand  = 'user'.$rand;
    $pass_rand  = 'pass'.$rand;
    $name = isset($user_json['name']) ? $user_json['name'] : $name_rand;
    $pass = isset($user_json['pass']) ? $user_json['pass'] : 'password';
    $status = isset($user_json['status']) ? $user_json['status'] : 1;

    // Check to make sure no user with name or mail already exists.
    if (!!user_load_by_name($name) && !!user_load_by_mail($mail)) {
        header('HTTP/1.1 400 Username and email already exist');
        return;
    }
    if (!!user_load_by_name($name)) {
        header('HTTP/1.1 400 Username already exists');
        return;
    }
    if (!!user_load_by_mail($mail)) {
        header('HTTP/1.1 400 Email already exists');
        return;
    }

    $new_user = array(
      'name' => $name,
      'pass' => $pass,
      'mail' => $mail,
      'status' => $status,
      'init' => $mail,
      'field_gender' => array(
        'und' => array(
            0 => array(
                'value' => $gender,
            ),
        ),
        ),
      'field_opportunity_id' => array(
        'und' => array(
            0 => array(
                'value' => $opportunity_id,
            ),
        ),
        ),
      'roles' => array(
        DRUPAL_AUTHENTICATED_RID => 'authenticated user',
      ),
    );

    // The first parameter is sent blank so a new user is created.
    $user = user_save('', $new_user);

    /**
   * Send registration email
   * This should be moved into a hook_alter or other similar method.
  */

  // Mail the welcome email using current language.
    $account = $user;
  $email = _user_mail_notify('register_admin_created', $account, 'en');
  if (!empty($email)) {
    watchdog('user', 'Welcome message has been sent to %name at %email.', array('%name' => $account->name, '%email' => $account->email));
  }
  else {
    watchdog('user', 'There was an error sending welcome message to %name at %email', array('%name' => $account->name, '%email' => $account->email));
  }

  // Set header to 200 and return created User object.
    header('HTTP/1.1 200 User Created Successfully');
    return drupal_json_output($user);
}