function addNewUser($ES_Client, $username, $password, $fullname, $email, $function, $department, $access){
auditLog($ES_Client, "Creating new user: ".$username.", ".$fullname.", ".$email.", ".$function.", ".$department.", ".$access);
$checkIfUserExists = getUserDetails($ES_Client,$username)['hits']['total'];
if($checkIfUserExists != 0){
    auditLog($ES_Client, "User ".$username." already exists! Operation aborted.");
    return -1;
} else {
    $hashed_password = crypt($password);
    $userAddQuery= [
        'index' => 'system',
        'type' => 'users',
        'body' => [
            'username' => $username,
            'password' => $hashed_password,
            'fullname' => $fullname,
            'email' => $email,
            'function' => $function,
            'department' => $department,
            'access' => $access,
            'lastlogin' => round(microtime(true) * 1000)
        ]
    ];
try{
    $userAddResponse = $ES_Client->index($userAddQuery);
    if($userAddResponse['created'] == 1)
    {
        auditLog($ES_Client, "User ".$username." added successfully!");
        return 0;
    }
    else{
        auditLog($ES_Client, "Error adding user ".$username."! Did not receive acknowledgement from elastic.");
        return -1;
    }
} catch(Exception $e) {
    auditLog($ES_Client, "Error adding user ".$username."! ".$e->getMessage());
    return -1;
}

}