<?php

class TargetClass
{
    public function A($a, $b) {}
    public function B($c, $d) {}
    public function C($e, $f) {}
}

class LoggingDecorator
{
    private $_target;

    public function __construct($target)
    {
        $this->_target = $target;
    }
    
    public function __call($name, $params)
    {
        $this->_log($name, $params);
        
        return call_user_func_array(array($this->_target, $name), $params);
    }
    
    private function _log($name, $params)
    {
        echo $name . ' has been called with params: ' . implode(', ', $params) . '<br>';
    }
}

$target = new TargetClass();
$logger = new LoggingDecorator($target);

$logger->A(1, 2);
$logger->A(3, 4);