Session.php

<?php
namespace lexuanphat\phpmvc;

class Session{
    
    protected const FLASH_KEY = 'flash_messages';

    public function __construct(){
        session_start();

        $flashMessages = $_SESSION[self::FLASH_KEY] ?? [];
        foreach($flashMessages as $key => &$flashMessage){
            // Mark to be removed
            $flashMessage['remove'] = true;
        }
        $_SESSION[self::FLASH_KEY] = $flashMessages;
        
    }

    public function setFlash($key, $message){
        $_SESSION[self::FLASH_KEY][$key] = [
            'value' => $message,
            'remove' => false,
        ];
    }

    public function getFlash($key){
        return $_SESSION[self::FLASH_KEY][$key]['value'] ?? false;
    }
    
    public function __destruct(){

        $flashMessages = $_SESSION[self::FLASH_KEY] ?? [];
        foreach($flashMessages as $key => &$flashMessage){
            if($flashMessage['remove']){
                unset($flashMessages[$key]);
            }
        }
        $_SESSION[self::FLASH_KEY] = $flashMessages;
    }

    public function set($key, $value){
        $_SESSION[$key] = $value;
    }

    public function get($key){
        return $_SESSION[$key] ?? false;
    }

    public function remove($key){
        unset($_SESSION[$key]);
    }
}