$username = htmlspecialchars($_POST['username']);
    $password = htmlspecialchars($_POST['password']);
    $email = htmlspecialchars($_POST['email']);



    echo register_user($username, $email, $password);
}


function connect($ip, $user, $password, $database){
    $con = mysqli_connect($ip, $user, $password, $database) or die('try again in some minutes, please');
    if (!$con)
        printf("Connect failed: %s\n", mysqli_connect_error());
    else
        return $con;
}

function encrypt($username, $password)
{
    $password = sha1(strtoupper($username) . ":" . strtoupper($password));
    $password = strtoupper($password);
    return $password;
}

function check_user_exist($username){
    global $db_ip, $db_user, $db_password, $db_auth;
    $con = connect($db_ip, $db_user, $db_password, $db_auth);
    $stmt = $con->prepare("SELECT * FROM account WHERE `username`=?");
    $stmt->bind_param("s", $username);
    $stmt->execute();
    $stmt->store_result();
    return $stmt->num_rows;
    $stmt->close();
    $con->close();
}

function check_email_exist($email){
    global $db_ip, $db_user, $db_password, $db_auth;
    $con = connect($db_ip, $db_user, $db_password, $db_auth);
    $stmt = $con->prepare("SELECT * FROM account WHERE `email`=?");
    $stmt->bind_param("s",$email);
    $stmt->execute();
    $stmt->store_result();
    return $stmt->num_rows;
    $stmt->close();
    $con->close();
}

function register_user($username, $email, $password){

    $new_password = encrypt($username,$password);

    $sql = "INSERT INTO `account` (`username`, `sha_pass_hash`, `email`) VALUES (?,?,?)";

    global $db_ip, $db_user, $db_password, $db_auth;

    $con = connect($db_ip, $db_user, $db_password, $db_auth);

    if (check_user_exist($username) > 0)
        return 1;
    if (check_email_exist($email) > 0)
        return 2;

    if (check_user_exist($username) == 0 && check_email_exist($email) == 0) {
        if ($stmt = $con->prepare($sql)) {
            $stmt->bind_param("sss", $username, $new_password, $email);
            $stmt->execute();
            $stmt->close();
            return 3;
        }
    }
    return 0;
}