class Finder

final class Finder {
    
    /**
     * The content entity data to import, in dependency order, keyed by entity UUID.
     *
     * @var array<string, array<mixed>>
     */
    public readonly array $data;
    public function __construct(string $path) {
        try {
            // Scan for all YAML files in the content directory.
            $finder = SymfonyFinder::create()->in($path)
                ->files()
                ->name('*.yml');
        } catch (DirectoryNotFoundException) {
            $this->data = [];
            return;
        }
        $graph = $files = [];
        
        /** @var \Symfony\Component\Finder\SplFileInfo $file */
        foreach ($finder as $file) {
            
            /** @var array{_meta: array{uuid: string|null, depends: array<string, string>|null}} $decoded */
            $decoded = Yaml::decode($file->getContents());
            $decoded['_meta']['path'] = $file->getPathname();
            $uuid = $decoded['_meta']['uuid'] ?? throw new ImportException($decoded['_meta']['path'] . ' does not have a UUID.');
            $files[$uuid] = $decoded;
            // For the graph to work correctly, every entity must be mentioned in it.
            // This is inspired by
            // \Drupal\Core\Config\Entity\ConfigDependencyManager::getGraph().
            $graph += [
                $uuid => [
                    'edges' => [],
                    'uuid' => $uuid,
                ],
            ];
            foreach ($decoded['_meta']['depends'] ?? [] as $dependency_uuid => $entity_type) {
                $graph[$dependency_uuid]['edges'][$uuid] = TRUE;
                $graph[$dependency_uuid]['uuid'] = $dependency_uuid;
            }
        }
        ksort($graph);
        // Sort the dependency graph. The entities that are dependencies of other
        // entities should come first.
        $graph_object = new Graph($graph);
        $sorted = $graph_object->searchAndSort();
        uasort($sorted, SortArray::sortByWeightElement(...));
        $entities = [];
        foreach ($sorted as [
            'uuid' => $uuid,
        ]) {
            if (array_key_exists($uuid, $files)) {
                $entities[$uuid] = $files[$uuid];
            }
        }
        $this->data = $entities;
    }

}