<?php

declare(strict_types=1);

namespace DigiComp\FluidRenderFunctions\ViewHelpers;

use DigiComp\FluidRenderFunctions\InvokeRenderFunctionInterface;
use DigiComp\FluidRenderFunctions\Utils\GeneratorClosureIterator;
use DigiComp\FluidRenderFunctions\Utils\RenderableProxy;
use Neos\FluidAdaptor\Core\ViewHelper\AbstractViewHelper;

class ApplyRenderFunctionViewHelper extends AbstractViewHelper
{
    public function initializeArguments(): void
    {
        parent::initializeArguments();
        $this->registerArgument('in', 'mixed', 'subject to apply the render function to');
        $this->registerArgument('function', InvokeRenderFunctionInterface::class, 'render function to use', true);
        $this->registerArgument(
            'force',
            'bool',
            'if set, it will be applied to the provided in, if not, it will be applied to each item for '
                . 'iterables instead',
            false,
            false
        );
    }

    public function render()
    {
        $in = $this->arguments['in'];
        if ($in === null) {
            $in = $this->renderChildren();
        }
        if (\is_iterable($in) && $this->arguments['force'] === false) {
            return new GeneratorClosureIterator(fn () => $this->getProxyGenerator($this->arguments['function'], $in));
        } else {
            return new RenderableProxy($this->arguments['function'], $in);
        }
    }

    protected function getProxyGenerator(InvokeRenderFunctionInterface $function, iterable $objects): \Generator
    {
        foreach ($objects as $object) {
            yield new RenderableProxy($function, $object);
        }
    }
}