<?php
require_once 'CompareStrategy.php';
require_once 'AscendingCompare.php';
require_once 'DescendingCompare.php';

class BubbleSort {
  private $strategy;

  public function setStrategy(CompareStrategy $strategy) {
    $this->strategy = $strategy;
  }

  public function sort($array) {
    for ($i = sizeof($array)-1; $i >= 0; --$i) {
      for ($j = 0; $j < $i; ++$j ) {
        $cmp = $this->strategy->compare(
          $array[$j],
          $array[$j+1]
        );

        if ($cmp > 0) {
          $tmp         = $array[$j];
          $array[$j]   = $array[$j+1];
          $array[$j+1] = $tmp;
        }
      }
    }

    return $array;
  }
}

$bs = new BubbleSort;

$bs->setStrategy(new AscendingCompare);
print_r($bs->sort(array(22, 4, 1978)));

$bs->setStrategy(new DescendingCompare);
print_r($bs->sort(array(22, 4, 1978)));
?>