<?php

/**
 * Sorting multi-dimensional arrays
 * @author j.koch
 */
class ArraySorter {

  /**
   * Group records for one akzNr, then sorting these groups
   * @param type $stmt 
   */
  public function sort($stmt, $top) {
    $akzRows = array();
    $startIndex = 0;
    $rowCount = 0;
    $orderedResult = array();
    $finished = false;

    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
      $akzNr = $row['AkzNr'];
      // collect the data for one akzession
      $akzRows[] = $row;
      $firstAkzNr = $akzRows[$startIndex]['AkzNr'];
      // all rows where collected for the actual AkzNr
      if ($akzNr != $firstAkzNr) {
        // not need the last element here
        $length = count($akzRows) - $startIndex - 1;
        $rows = array_slice($akzRows, $startIndex, $length);
        $orderedResult[] = $rows;
        if ($rowCount >= $top) {
          $finished = true;
          break;
        }
        $startIndex = $rowCount;
      }
      $rowCount++;
    }
    // there maybe some more rows in the array $akzRows
    if (!$finished && ($startIndex < count($akzRows))) {
      $length = count($akzRows) - $startIndex;
      $rows = array_slice($akzRows, $startIndex, $length);
      $orderedResult[] = $rows;
    }
    // build the content for the response page
    usort($orderedResult, array($this, 'cmpTaxonData'));
    return $orderedResult;
  }

  /**
   * Compare groups of rows that share the same akzNr
   */
  function cmpTaxonData($aRows, $bRows) {
    // make a difference between WissNameTax and H_WissNameTax
    // (all records for one akzNr should have the same WissNameTax value, 
    // that's why we can take the first one)
    if ($aRows[0]['WissNameTax']) {
      $a = $aRows[0]['WissNameTax'];
    } else {
      $a = $aRows[0]['H_WissNameTax'];
    }
    if ($bRows[0]['WissNameTax']) {
      $b = $bRows[0]['WissNameTax'];
    } else {
      $b = $bRows[0]['H_WissNameTax'];
    }
    // compare the records
    if ($a == $b) {
      return 0;
    }
    return ($a < $b) ? -1 : 1;
  }

}

?>