ResolveDependencies.php

<?php

namespace Assets;

use Assetic\Asset\AssetCollection;
use Assetic\Asset\AssetReference;
use Assetic\AssetManager;

class ResolveDependencies
{
	/**
	 * @var AssetManager
	 */
	protected $manager;

	public function process($payload)
	{
		$this->manager = $payload->manager;
		foreach ($this->manager->getNames() as $name) {
			$asset      = $this->manager->get($name);
			$this->seen = [];
			if ($asset instanceof AssetCollection) {
				list($seen, $remove) = $this->check($this->getReferenceNames($asset));
				if (empty($remove)) {
					continue;
				}

				foreach ($remove as $item) {
					foreach ($asset->all() as $subAsset) {
						if ($subAsset instanceof AssetReference && $subAsset->getName() === $item) {
							$asset->removeLeaf($subAsset);
						}
					}
				}
			}
		}

		return $payload;
	}

	protected function check($refs, $seen = [], $remove = [])
	{
		foreach ($refs as $ref) {
			if (!$this->manager->has($ref)) {
				$remove[] = $ref;
				continue;
			}

			$asset = $this->manager->get($ref);
			if ($asset instanceof AssetCollection) {
				list($s1, $r1) = $this->check($this->getReferenceNames($asset));
				if ($tmp = array_intersect($refs, $s1)) {
					$remove = array_merge($remove, $r1, $tmp);
				}
			}
			$seen[] = $ref;
		}

		return [array_unique($seen), array_unique($remove)];
	}

	protected function getReferenceNames(AssetCollection $asset)
	{
		$assets = [];
		foreach ($asset->all() as $subAsset) {
			if ($subAsset instanceof AssetReference) {
				$assets[] = $subAsset->getName();
			}
		}

		return $assets;
	}
}