wtf

function cmp($a, $b) {
    return strcomp($a['level4'], $b['level4']);
}

foreach ($rows as $i => $row) {
    if ($row['number'] > 1) {
        $lowestRow = 0;
        $lowest = 1000;
        foreach ($rows as $j => $row2) {
            $diff = array_intersect_assoc($row, $row2);
            if (array_key_exists('level1', $diff) && array_key_exists('level2', $diff) && array_key_exists('level3', $diff)) {
                if ($lowest > $row['number']) {
                    $lowest = $row['number'];
                    $lowestRow = $j;
                }
            }
        }

        $rows[$lowestRow]['number'] = 1;

        $oldLowestRow = $lowestRow;
        uksort($rows, 'cmp');
        foreach($rows as $j => $row2) {
            if ($j != $oldLowestRow) {
                $diff = array_intersect_assoc($row2, $rows[$lowestRow]);
                if (array_key_exists('level1', $diff) && array_key_exists('level2', $diff) && array_key_exists('level3', $diff) && array_key_exists('level4', $diff)) {
                    $rows[$lowestRow]['value'] += $row2['value'];
                    if ($row2['value'] != 'a') {
                        $rows[$lowestRow]['total'] += $row2['total'];
                    }
                    if ($rows[$lowestRow]['value'] == 'a' && ($row2['value'] != 'a' && $row2['value'] != '*')) {
                        $rows[$lowestRow]['value'] = $row2['value'];
                    }
                    unset($rows[$j]);
                } else {
                    if (array_key_exists('level1', $diff) && array_key_exists('level2', $diff) && array_key_exists('level3', $diff)) {
                        $lowestRow = $j;
                    }
                }
            }
        }
    }
}