Weak hands cannot be planted, meager skills have no foundation. Shallow wisdom is futile, how can one hope for a good name?扰扰从役倦，屑屑身事微。少壮轻年月，迟暮惜光辉。
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
declare(strict_types=1);
namespace League\Csv;
use ArrayIterator;
use CallbackFilterIterator;
use Iterator;
use LimitIterator;
use function array_reduce;
/**
* Criteria to filter a {@link Reader} object.
*/
class Statement
{
/** @var array Callables to filter the iterator. */
protected array $where = [];
/** @var array Callables to sort the iterator. */
protected array $order_by = [];
/** iterator Offset. */
protected int $offset = 0;
/** iterator maximum length. */
protected int $limit = -1;
/**
* @throws Exception
*/
public static function create(callable $where = null, int $offset = 0, int $limit = -1): self
{
$stmt = new self();
if (null !== $where) {
$stmt = $stmt->where($where);
}
return $stmt->offset($offset)->limit($limit);
}
/**
* Set the Iterator filter method.
*/
public function where(callable $where): self
{
$clone = clone $this;
$clone->where[] = $where;
return $clone;
}
/**
* Set an Iterator sorting callable function.
*/
public function orderBy(callable $order_by): self
{
$clone = clone $this;
$clone->order_by[] = $order_by;
return $clone;
}
/**
* Set LimitIterator Offset.
*
* @throws Exception if the offset is lesser than 0
*/
public function offset(int $offset): self
{
if (0 > $offset) {
throw InvalidArgument::dueToInvalidRecordOffset($offset, __METHOD__);
}
if ($offset === $this->offset) {
return $this;
}
$clone = clone $this;
$clone->offset = $offset;
return $clone;
}
/**
* Set LimitIterator Count.
*
* @throws Exception if the limit is lesser than -1
*/
public function limit(int $limit): self
{
if (-1 > $limit) {
throw InvalidArgument::dueToInvalidLimit($limit, __METHOD__);
}
if ($limit === $this->limit) {
return $this;
}
$clone = clone $this;
$clone->limit = $limit;
return $clone;
}
/**
* Execute the prepared Statement on the {@link Reader} object.
*
* @param array $header an optional header to use instead of the CSV document header
*/
public function process(TabularDataReader $tabular_data, array $header = []): TabularDataReader
{
if ([] === $header) {
$header = $tabular_data->getHeader();
}
$iterator = $tabular_data->getRecords($header);
$iterator = array_reduce($this->where, [$this, 'filter'], $iterator);
$iterator = $this->buildOrderBy($iterator);
return new ResultSet(new LimitIterator($iterator, $this->offset, $this->limit), $header);
}
/**
* Filters elements of an Iterator using a callback function.
*/
protected function filter(Iterator $iterator, callable $callable): CallbackFilterIterator
{
return new CallbackFilterIterator($iterator, $callable);
}
/**
* Sort the Iterator.
*/
protected function buildOrderBy(Iterator $itera