<?php

namespace Picea\Extension;

use Picea\Compiler\Context;

class BatchExtension implements Extension, FunctionExtension {

    public string $token = "batch";

    public function exportFunctions(): array
    {
        return [
            "batch" => [ $this, 'batch' ]
        ];
    }

    public function parse(\Picea\Compiler\Context &$context, ?string $arguments, string $token, array $options = []) : string
    {
        return "<?php echo batch($arguments) ?>";
    }

    public function batch(iterable $array, int $size, mixed $default = null) : \Generator
    {
        $split = ceil( count($array) / $size );

        for($i = 0; $i < $split; $i++) {
            $slice = array_slice(is_array($array) ? $array : iterator_to_array($array, true), $i * $size, $size, true);
            $pad = ( count($slice) !== $size ) && ( $default !== null );
            yield $pad ? array_pad($slice, $size, $default) : $slice;
        }
    }
}