while(eu vou ali tomar um café)
    mostre todas as combinações;

<?php

class Comb {
 private $valueA = NULL;
 private $valueB = NULL;
 private $valueC = NULL;
 private $valueD = NULL;
 private $start = NULL;
 private $counter = NULL;
 private $dotStart = NULL;
 private $dotFirst = NULL;
 private $dotSecond = NULL;
 private $dotThird = NULL;
 private $ready = NULL;
 private $number = array();
 
 public function __construct($a,$b,$c,$d){

 $this -> valueA = $a;
 $this -> valueB = $b;
 $this -> valueC = $c;
 $this -> valueD = $d;
 
 }

 private function DoComb($valueA,$valueB,$valueC,$valueD){

 $this -> dotStart = $this -> valueA;
 $this -> dotFirst = $this -> valueB;
 $this -> dotSecond = $this -> valueC;
 $this -> dotThird = $this -> valueD; 
 
  for($this -> counter = 0;$this -> counter < 24;$this -> counter++){
	 
	 // Ponto crítico
     if ($this -> counter == 6) {
         $this -> dotStart = $this -> valueB;
		 $this -> dotFirst = $this -> valueA;
		 $this -> dotSecond = $this -> valueC;
		 $this -> dotThird = $this -> valueD;
     }
     
	 // Ponto crítico
	 if ($this -> counter == 12) {
         $this -> dotStart = $this -> valueC;	     
		 $this -> dotFirst = $this -> valueD;
		 $this -> dotSecond = $this -> valueA;
		 $this -> dotThird = $this -> valueB;

	 } 
      
	 // Ponto crítico
     if ($this -> counter == 18) {
         $this -> dotStart = $this -> valueD;
		 $this -> dotFirst = $this -> valueA;
		 $this -> dotSecond = $this -> valueB;
		 $this -> dotThird = $this -> valueC;

     }

     if (($this -> counter == 0) or ($this -> counter == 6) or ($this -> counter == 12) or ($this -> counter == 18)) {
     	 $this -> ready = $this -> dotStart . $this -> dotFirst . $this -> dotSecond . $this -> dotThird;
     }
	 
     if (($this -> counter == 1) or ($this -> counter == 7) or ($this -> counter == 13) or ($this -> counter == 19)) {
	     $this -> ready = $this -> dotStart . $this -> dotFirst . $this -> dotThird . $this -> dotSecond;
     }

     if (($this -> counter == 2) or ($this -> counter == 8) or ($this -> counter == 14) or ($this -> counter == 20)) {	 
	     $this -> ready = $this -> dotStart . $this -> dotSecond . $this -> dotThird . $this -> dotFirst;
     }

     if (($this -> counter == 3) or ($this -> counter == 9) or ($this -> counter == 15) or ($this -> counter == 21)) {
	     $this -> ready = $this -> dotStart . $this -> dotSecond . $this -> dotFirst . $this -> dotThird;
     }

     if (($this -> counter == 4) or ($this -> counter == 10) or ($this -> counter == 16) or ($this -> counter == 22)) {
	     $this -> ready = $this -> dotStart . $this -> dotThird . $this -> dotFirst . $this -> dotThird;
     }

     if (($this -> counter == 5) or ($this -> counter == 11) or ($this -> counter == 17) or ($this -> counter == 23)) {
	     $this -> ready = $this -> dotStart . $this -> dotThird . $this -> dotSecond . $this -> dotThird;
     }         

	 array_push($this->number,$this->ready);
	 
     
  } 
  return $this -> number;
 }

 public function ShowComb(){
 
 $this -> DoComb($this -> valueA,$this -> valueB,$this -> valueC,$this -> valueD);
 
 for($this -> counter = 0;$this -> counter < 24;$this -> counter++){
 	
	echo $this -> number[$this -> counter]."<br>";
 } 

 }
}

// exemplo de como usar
$a = 1;
$b = 2;
$c = 3;
$d = 4;

$Funfando = new Comb($a,$b,$c,$d);
$Funfando -> ShowComb();
?>