// Limit login attempts by mrnargil
// https://mrnargil.ir/wp-admin-security

function check_attempted_login( $user, $username, $password ) {
    $try_limit = 4;
    if ( get_transient( 'attempted_login_'.$username ) ) {
        $datas = get_transient( 'attempted_login_'.$username );

        if ( $datas['tried'] >= $try_limit ) {
            $until = get_option( '_transient_timeout_' . 'attempted_login_'.$username );
            $time = time_to_go( $until );

            return new WP_Error( 'too_many_tried',  sprintf( __( 'ERROR: You have reached authentication limit, you will be able to try again in %1$s.' ) , $time ) );
        }
    }

    return $user;
}
add_filter( 'authenticate', 'check_attempted_login', 30, 3 ); 



function login_failed( $username ) {
    $ban_duration = 1;  // hour(s)
    
    if ( get_transient( 'attempted_login_'.$username ) ) {
        $datas = get_transient( 'attempted_login_'.$username );
        $datas['tried']++;

        if ( $datas['tried'] <= 3 )
            set_transient( 'attempted_login_'.$username, $datas , $ban_duration * 3600 );
    } else {
        $datas = array(
            'tried'     => 1
        );
        set_transient( 'attempted_login_'.$username, $datas , $ban_duration * 3600 );
    }
}
add_action( 'wp_login_failed', 'login_failed', 10, 1 ); 

function time_to_go($timestamp)
{

    // converting the mysql timestamp to php time
    $periods = array(
        "second",
        "minute",
        "hour",
        "day",
        "week",
        "month",
        "year"
    );
    $lengths = array(
        "60",
        "60",
        "24",
        "7",
        "4.35",
        "12"
    );
    $current_timestamp = time();
    $difference = abs($current_timestamp - $timestamp);
    for ($i = 0; $difference >= $lengths[$i] && $i < count($lengths) - 1; $i ++) {
        $difference /= $lengths[$i];
    }
    $difference = round($difference);
    if (isset($difference)) {
        if ($difference != 1)
            $periods[$i] .= "s";
            $output = "$difference $periods[$i]";
            return $output;
    }
}